The Head and Neck Lecture Presentation

The Head and Neck
Upper Respiratory Tract

• Nose
• Nostril
• Nasal Cavity
• Oral Cavity
• Pharynx

Nose

• Nose is the only portion of the RT that is externally visible
• CT, bone, hyaline cartilage
• Air enters here during breathing
• Passes through the external nares (nostrils)

Vestibule

• Superior to nostrils
• Skin lined with:
•  Sebaceous glands
• Greasy secretion
• Collect dirt
• Lubricate
• Kill bacteria
• Sweat glands
• Acidic
• Slows growth of bacteria
• Hair follicles
• Trap small particles of dirt
• Vibrissae
• Nose hairs
• Filter large particles (insects)

Nasal Cavity
Functions:
Provides airway for respiration
Moistens and warms air
Filters inhaled air
Resonating chamber for speech
Houses olfactory receptors
2 divisions:
External nose
Internal nasal cavity
Nasal Cavity

• Divided into R and L by nasal septum
• Continuous with the nasopharynx through the internal nares (choanae)

Nasal Cavity

• Boundries:
• Roof – ethmoid bone (cribiform plate)
• Floor – maxilla (palatine process)

                    palatine (horizontal plate)

• Lateral walls – nasal bones, superior and middle nasal conchae of ethmoid bone, inferior nasal conchae, maxilla, palatine bone
• Hard palate
• Palatine bones and maxillary bone
• Soft palate
• Skeletal muscle posterior portion
• End in uvula

Lining of the Nasal Cavity

• Respiratory Mucosa    
• Pseudostratified ciliated columnar epithelium
• Goblet cells
• Lamina propria
• Mucous and serous cells
• Venous plexus
• Function is to filter and warm inhaled air
• Highly innervated
• Sneeze!
• Olfactory Mucosa
• Roof of nasal cavity
• Houses smell receptors
• No goblet cells
• Cilia modified for olfaction

Nasal Conchae

• Project medially from each lateral wall
• 3 structures:
• Superior of ethmoid bone
• Middle of ethmoid bone
• Inferior
• Functions:
• Create turbulence to increase:
• Filters air
• Heats air
• Moistens air
• Reclaim heat and moisture during exhalation

Paranasal Sinuses

• Air filled cavities that surround the nasal cavity
• Lined by mucosa
• Perform same function as nasal cavity and lightens skull
• Located in Frontal, Ethmoid, Sphenoid, Maxilla bones

Pharynx

• Connects the nasal cavity and mouth to larynx and esophagus
• Extends from base of skull to level of C6 vertebra
• Common passage for food and air
• Lined with skeletal muscle
• Divided into:
• Nasopharynx
• Oropharynx
• Laryngopharynx

Tonsils

• Lymphoid organ
• MALT
• Swellings of the mucosa lining the pharynx
• Form ring around the entrance to the pharynx
• 4 groups:
• Palatine
• Lingual
• Pharyngeal
• Tubal
• Remove pathogens

Nasopharynx

• Location:
• Posterior to nasal cavity
• Inferior to sphenoid bone
• Superior to level of soft palate
• ONLY an air passageway
• Closed off during swallowing by the soft palates’ uvula
• Giggling!
• Ciliated pseudostratified epithelium
• Contain:
• Pharyngeal tonsils (adenoids)
• Tubal tonsils

Oropharynx

• Location:
• Posterior to the oral cavity
• Extends inferiorly from level of the soft palate to level of the esophagus
• Swallowed food and inhaled air pass through here
• Stratified squamous epithelium
• Contain:
• Palatine tonsils
• Lingual tonsils

Laryngopharynx

• Location:
• Lies posterior to larynx
• Continuous with the esophagus and larynx
• Common passageway for food and air
• Food – esophagus
• Air - larynx
• Stratified squamous epithelium

Larynx

• “Voice box”
• Extends from C4 to C6
• Attachments:
• Hyoid bone superiorly
• Continuous with trachea inferiorly
• Functions:
• Vocalization
• Provides open airway
• Switches to route air and food into proper channels
• Innervation: Vagus
• Superior part = stratified squamous epithelium
• Below vocal cords= ciliated pseudostratified columnar

Larynx

• All hyaline cartilage except epiglottis
• Composed of 9 cartilages connected by membranes and ligaments:
• 1 Thyroid
• 1 Cricoid
• 1 Epiglottis
• 2 Arytenoid
• 2 Corniculate
• 2 Cuneiform

Laryngeal Cartilages

• Thyroid Cartilage
• Large
• Shield shaped
• Formed by 2 plates
• Contains laryngeal prominence
• Adam’s Apple!!

Laryngeal Cartilages

• Cricoid
• Inferior to thyroid cartilage
• Forms a complete ring
• Directly superior to trachea

Laryngeal Cartilages

• Epiglottis
• Composed of elastic cartilage
• Covered by mucosa
• Projects upward from anterior wall of laryngeal inlet to level of base of tongue
• Close off larynx during swallowing

Vocal Cords

• Located in the larynx
• Mucosal folds formed by vocal ligaments
• Composed of elastic fibers
• Run from arytenoid cartilages (posterior) to the thyroid cartilages (anterior)
• Exhaled air passes over them and causes vibration
• Force of air = volume
• Length & tension of folds = pitch
• False vocal cords
• Vestibular folds (superior to true)

Thyroid Gland

• Location:
• In anterior neck
• On trachea, inferior to larynx
• 2 lateral lobes
• Connected by the isthmus
• Butterfly shape
• Largest endocrine gland in body
• Produces Thyroid hormone (TH)
• Increases metabolic rate
• Calcitonin
• Depresses excess levels of Ca+ in blood

Thyroid Gland

• Internally, composed of follicles
• Follicular cells
• TH
• Parafollicular cells
• Calcitonin
• Blood supply
• Superior thyroid arteries
• Branches of external carotids
• Inferior thyroid arteries
• Branches of subclavians

Parathyroid Gland

• Two pairs
• Located on the deep surface of the lateral lobes of the thyroid gland
• Produce parathyroid hormone
• Increases blood calcium levels

Hyoid Bone

• Location:
• Inferior to mandible
• In anterior neck
• Associated with the skull
• Only bone in skeleton that does not articulate directly to another bone!!!
• Attaches via ligaments to temporal bone, larynx
• Composed of:
• Body
• 2 pairs of horns
• Functions:
• Moveable base for tongue
• Points of attachment for larynx and neck muscles
• Sternohyoid, thyrohyoid,

Oral Cavity and Associated Organs

• Mouth
• Tongue
• Teeth
• External Salivary glands

Mouth - Oral Cavity

• Food enters alimentary canal through here
• Mucosa-lined
• Thick stratified squamous epithelium, with keratinization in some areas
• Boundaries:
• Lips anteriorly
• Cheeks laterally
• Palate superiorly
• Tongue inferiorly
• Oropharynx posteriorly
• Mouth divided into 2 parts:
• Vestibule
• Oral cavity proper

Mouth

• Lips (labia) and Cheeks
• Keep food inside mouth during chewing
• Composed of skeletal muscle surrounded by skin
• Lips formed by orbicularis oris muscle
• Cheeks; Muscles of Mastication
•  Temporalis & Masseter (elevate mandible, close mouth)
•  Buccinator (chewing)
•  Digastric (lower mandible against resistance, opens mouth)
•  Pterygoids (lateral movements)
• Palate: forms the roof of the mouth
• Soft palate (posterior) rises to close off nasopharynx during swallowing; made of skeletal muscle
• Hard palate (anterior) provides surface for tongue to force food against during chewing

Tongue

• Functions
• Grips and moves food between teeth

          during chewing

• Mixes food with saliva = BOLUS
• Moves bolus down pharynx
• Speech production
• Houses taste buds (= gustation)
• Creates floor of mouth
• Attachments: hyoid, mandible, styloid process, soft palate
• Made of Skeletal muscle with a CT septum
• Intrinsic muscles (change shape; rolling)
• Extrinsic muscles (movement; protrude, retract)
• Motor = Hypoglossal (CN XII)
• Sensory = Mandibular (CN V3), Facial (CN VII), Glossopharyngeal (CN IX)

Moving Bolus

• Swallowing voluntarily initiated (pharynx)
• Peristalsis = propulsion
• Involuntary
• Alternate waves of contraction and relaxation of muscles in organ walls (e.g. esophagus)
• Squeezes food from one organ to next
• Some mixing

Salivary Glands

• Compound tubuloalveolar glands
• Intrinsic salivary glands
• In mucosa of tongue, palate, lips and cheeks
• Keeps mouth moist at all times
• Extrinsic salivary glands
• Lie external to mouth
• Connected by ducts
• Secrete only during eating or prior to (“mouth watering”)
• 3 paired glands:
• Parotid
• Submandibular
• sublingual

Salivary Glands

• Produce saliva
• Mixture of water, ions, mucus and enzymes
• Moistens mouth
• Dissolves food for taste
• Binds food into a bolus
• Enzymes digest starch
• Bicarbonate buffer neutralizes acids
• Kill microorganisms
• Contains proteins to promote growth of beneficial bacteria

Teeth – From Eruption to Edentate

• Function:
• Ingestion and mechanical breakdown of food
• Have 2 sets of teeth (dentitions)
• Primary dentition / deciduous (milk) teeth
• Permanent dentition
• Incisors: rip, cut
• Canines: tear and pierce
• Premolars: grinding
• Molars: grinding

Teeth

• Gomphosis
• Synarthrosis
• Peg in socket with ligament
• The sockets (alveoli) are in gum-covered margins in mandible and maxilla
• Periodontal ligaments (collagen fibers) anchor tooth in bony socket
• Continous with gingiva (gum)

Teeth Substances

• Enamel
• Made of calcium salts
• Avascular, acellular
• Not renewed or replaced
• HARDEST substance in body!!!!
• Dentin
• Underlines enamel
• Forms bulk of tooth
• Made of minerals and collagen
• Maintained during life
• Harder than bone
• Cementum
• Calcified external surface
• Attaches tooth to periodontal ligament

Teeth

• Regions:
• Crown
• Covered with enamel
• Projecting into oral cavity
• Neck (gumline)
• Root
• Area beyond neck in alveolus
• Pulp cavity
• Center of tooth
• Loose CT with vessels and nerves
• Supplies nutrients to hard tissues

Teeth

• Root Canal
• Portion of the pulp cavity in the root
• Apical foramen
• Opening into the root canal at the tip of each root
• Blood supply
• Superior/Inferior Alveolar artery, branches of External Carotid artery
• Innervation
• Maxilla = Superior Alveolar Nerves
• Mandible = Inferior Alveolar Nerves

Teeth at Birth

• Number of erupted teeth = 0
• Jaws covered by gingiva (gums)
• Lots of drooling!!!

First Teeth – 6 Months

• Lower central incisors first to appear
• 8 Incisors = 6-10 months
• 4 Canines = 16-20 months
• 4 1st Molars = 12-16 months
• 4 2nd Molars = 20-24 months
• 20 deciduous teeth emerge by age 2
• Dental formula
• Describes the number and position of classes of teeth (half of the mouth)

2I, 1C, 2M   
2I, 1C, 2M
Adolescence – Adult

• Permanent teeth enlarge and develop
• Roots of deciduous teeth reabsorbed
• Teeth loosen and fall out
•  Begin to erupt from 7-13 years of age
• Third molars (wisdom teeth) emerge from 17-25 years
• May be absent!!

• Adult dental formula:

2I, 1C, 2P, 3M
2I, 1C, 2P, 3M
Tooth Troubles

• Cavities (caries)
• Demineralization of enamel by bacteria
• In severe cases, erodes the dentin of tooth
• Most severe cases erosion penetrates pulp cavity

Tooth Troubles

• Gingivitis
• Inflammation of the gingiva caused by plaque accumulation
• Leads to…….
• Periodontitis
• Infection of periodontal ligament leading to its destruction along with the bone around the teeth
• Leads to toothlessness!

Triangles of the Neck

• Neck subdivided into two triangles
• Separated by the sternocleidomastoid muscle
• Anterior triangle
• Posterior triangle

Triangles of the Neck: Posterior

• Boundries:
• Anterior - sternocleidomastoid
• Posterior - trapezius
• Inferior – clavicle
• Contents:
• Nerves: accessory nerve, phrenic nerve, brachial plexus
• Artery: Subclavian
• Vein: External jugular

Triangles of the Neck: Anterior

• Boundries:
• Anterior - midline
• Posterior - sternocleidomastoid
• Superior – inferior margin of the mandible
• Contents:
• Glands: Submandibular
• Muscles: Suprahyoid and infrahyoid muscles
• Artery: Common carotid
• Vein: Internal jugular, External jugular
• Nerve: Accessory

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Brain and Cranial N lecture presentation

Skull, Brain and Cranial Nerves

Skull

• Part of Axial Skeleton
• Cranial bones = cranium
• Enclose and protect brain
• Attachment for head + neck muscles
• Facial bones =framework of face
• Form cavities for sense organs
• Opening for air + food passage
• Hold teeth
• Anchor face muscles

Cranial and Facial Bones

• Cranial - 8
• Frontal
• Occipital
• Sphenoid
• Ethmoid
• Parietal (2)
• Temporal (2)
• Facial – 14
• Mandible
• Maxilla (2)
• Zygomatic (2)
• Nasal (2)
• Lacrimal (2)
• Palatine (2)
• Vomer
• Inf. Nasal Conchae(2)

Bones of Skull

• Flat bones: thin, flattened, some curve
• Sutures: immovable joints joining bones
• Calvaria = Skullcap =Vault
• Superior, Lateral, Posterior part of skull
• Floor = Base
• Inferior part of skull
• 85 openings in skull
• Spinal cord, blood vessels, nerves
• Foramina, meatus, canal, fissure, notch

Cranial Fossae

• Created by bony ridges
• Supports, encircles brain
• 3 Fossae
• Anterior
• Middle
• Posterior
• All the bones visible from this view are the cranial bones!!

Other Cavities of Skul

Orbits
Nasal Cavity
Middle Ear
Inner Ear
Skull through Life

• Ossifies late in 2 nd month of development
• Frontal + Mandible start as 2 halves-then fuse
• Growth of Skull
• ½ adult size by age 9 months
• ¾ adult size by 2 years
• 100% adult size by 8-9 years
• Face enlarges between ages 6-13 years

Fetal Skull

• Skull bones separated by unossified membranes = Fontanels
• Allow compression of skull during delivery
• Allows rapid growth of brain
• Mostly replaced w/bone after 1 st year

The Brain

• 4 Parts
• Cerebrum
• *Diencephalon
• Brain Stem
• Midbrain
• Pons
• Medulla
• Cerebellum
• Gray matter surrounded by White matter w/outer cortex of gray matter

*some texts consider this part of brain stem

Meninges: 3 membranes around brain and spinal cord

Meninges (continued)

• Dura mater
• Strongest, 2 Layers, Fibrous Connective Tissue
• Periosteal layer (Periosteum): External/superficial layer
• Meningeal layer: Internal/deep layer
• Layers fused except around dural sinuses (venous blood filled à internal jugular vein)

Extensions of Dura Mater

• Partitions: limit movement of brain
• Falx Cerebri –vertical, between cerebral hemispheres
• Falx Cerebelli -vertical, between cerebellar hemispheres
• Tentorium Cerebelli –horizontal, between cerebrum and cerebellum

Meninges

• Arachnoid Mater
• Middle layer
• Subarachnoid Space-between arachnoid mater and pia mater (contains most of CSF, blood vessels)
• Arachnoid Villi (Granulations)- projections of arachnoid mater through dura into superior sagittal sinus, act as valves to help CSF pass into dural sinuses

Meninges (continued)

• Pia Mater
• Innermost layer
• Delicate, highly vascular
• Clings directly to brain tissue, dips into convolutions

Ventricles

• Expansions of brain’s central cavity
• Lined with Ependymal Cells
• Filled with CSF (cerebrospinal fluid)
• Ventricles continuous w/each other + central canal of spinal cord

Ventricles (continued)

• Lateral Ventricles (#1+2)
• Cerebral Hemisphere
• Separated by Septum Pellucidum
• Third Ventricle
• Diencephalon
• Interventricular Foramen: connects to lateral ventricle
• Fourth Ventricle
• Hindbrain
• Cerebral Aqueduct: connects 3 rd and 4 th ventricles
• Connects to central canal of spinal cord & medulla
• 3 openings connect 4 th to subarachnoid space
• 2 lateral apertures
• 1 median aperture

Cerebrospinal Fluid

• Liquid cushion for brain and spinal cord
• Nourishes brain
• Removes waste
• Conducts chemical signals between parts of CNS (e.g. hormones)
• Forms as a filtrate of blood in choroid plexuses

Choroid Plexuses

• Choroid Plexuses: groups of capillaries surrounded by ependymal cells
• Made of sodium, chloride ions, proteins, glucose, O 2

Flow of CSF

• Formed in Choroid plexuses
• Through Ventricles
• Into Subarachnoid space & central canal from 4 th ventricle
• Through Arachnoid Villi into Superior Sagittal Sinus
• Into Internal Jugular Vein

Organization of the Brain

• Composed of gray and white matter
• Different organization than in the spinal cord
• Centrally located gray matter surrounded by white matter
• Cortex: external sheets of gray matter in cerebrum & cerebellum (some parts of brain)
• Nuclei: deep masses of gray matter surrounded by white matter

(some parts of brain)

Cerebrum

• “Executive Suite” of nervous system
• Self-awareness, initiate + control voluntary movements, communicate, remember, understanding, language
• Most superior region
• Covers diencephalon + top of brain stem like mushroom cap
• Cerebral cortex

Cerebral Hemispheres

• Fissures and Grooves
• Fissures – deepest
• Transverse cerebral fissure
• Separates cerebral hemispheres from cerebellum
• Longitudinal fissure
• Separates R and L cerebral hemispheres
• Sulci
• Grooves on surface
• Gyri
• Ridges of brain tissue among the sulci

Cerebral Hemispheres:

• Each hemisphere divided into 5 lobes
• Frontal
• Parietal
• Occipital
• Temporal
• Insula
• Created by deep sulci
• Functional areas: motor, sensory
• Associative areas: integrate

Cerebral Hemispheres

• The 2 hemispheres control opposite sides of body
• Corpus callosum
• The largest commissure between the hemispheres
• Hemispheres specialized for different cognitive functions
• Left Cerebral hemisphere
• Language, mathematics and logic
• Right Cerebral hemisphere
• Visual-spatial, interpreting facial expressions, intuition, emotion, artistic/musical skills

Diencephalon

• Surrounded by cerebral hemispheres
• Made of 3 Paired Structures
• Thalamus “gateway”
• Communicates sensory info of cerebral cortex
• Hypothalamus
• Regulates many body activities
• Emotion, sleep, memory, etc.
• Pituitary Gland
• Growth Hormone
• Thyroid Stimulating Hormone
• Epithalamus
• Pineal Gland
• Melatonin

Brainstem

• Midbrain, Pons, Medulla Oblongata
• Passage of all signals between spinal cord and brain
• Regulates basic physiological functions
• Innervation of head and neck

Brainstem

• Midbrain
• Visual and Auditory reflex centers
• Attachment for CN III, IV
• Pons
• Attachment for CN V, VI, VII, VIII
• Medulla oblongata
• Regulates several basic physiological functions
• Attachment of CN IX, X, XI, XII
• Smooths + coordinates body movements directed by other parts of brain
• 2 Cerebellar Hemispheres
• Cerebellar cortex surrounds Arbor vitae
• Functions
• Information on equilibrium
• Movement of neck, trunk, limbs
• Information from cerebral cortex on voluntary movement

Blood Brain Barrier

• Protects brain from blood-borne toxins (e.g. urea, food toxins, bacteria)
• Endothelium of brain capillaries are loaded with tight junction to decrease permeability
• Not complete protection, some things still have to get through (e.g. fat-soluble molecules can pass through)

Blood Supply to Brain

• Arteries
• External carotid arteries and branches
• Tissues of head & face, skin, muscles
• Middle meningeal a. = brain
• Boxers!
• Internal carotid arteries and branches
• Opthalmic a. = Eye & Orbits
• Ant & Middle Cerebral arts = Cerebrum
• Branches form Cerebral Arterial Circle = Anastomosis
• Vertebral arteries
• Posterior brain
• Vertebrae & Cervical Spinal Cord
• Branches form Cerebral Arterial Circle = Anastomosis

Blood Supply to the Brain

• Veins
• Dural sinuses
• Superior & Inferior Sagittal, transverse, sigmoid, straight, etc
• Internal jugular
• Receives from dural sinuses
• External jugular
• Drains scalp and face (superficial)
• Vertebral
• Drains cervical vertebrae, cervical spinal cord, small neck muscles

Cranial Nerves

• 12 Pairs: I-XII
• Numbered Anterior to Posterior
• Attach to inferior surface of brain
• Exit brain through foramina in skull
• I + II attach to Forebrain (cerebrum + diencephalon)
• III-XII attach to Brainstem (midbrain, pons, medulla)
• Only X goes beyond the head-neck

Foramina serving Cranial Nerves

• You must know what foramina each CN leaves the skull through
• (refer to lab manual)

How to Remember CN I-XII

Oh! Oh! Oh! To Touch And Feel Very Good Velvet! Ah Heaven!
I Olfactory (oh)
II Optic (oh)
III Oculomotor (oh)
IV Trochlear (to)
V Trigeminal (1-3) (touch)
VI Abducens (and)
VII Facial (feel)
VIII Vestibulocochlear (very)
IX Glossopharyngeal (good)
X Vagus (velvet)
XI Accessory (ah)
XII Hypoglossal (heaven)

Motor vs. Sensory Nerves

• Sensory = Afferent
• Send nervous impulse from sensory receptors to brain to bring in information
• e.g. pressure, temperature, pain
• Motor = Efferent
• Send nervous impulses from brain to body to accomplish an action
• e.g. movement of a muscle, activation of a gland

Sensory Nerves

• Sensory = Afferent
• Visceral Sensory (sensory innervation of viscera)
• stretch, pain, temp., chemical changes, irritation in viscera
• Special: taste
• Somatic Sensory (sensory innervation of outer part body)
• touch, pain, pressure, vibration, temp. in skin, body wall, limbs
• Special: hearing, equilibrium, vision, smell

Motor Nerves

• Motor Nerves
• Visceral Motor (motor innervation muscle in viscera + glands)
• innervation smooth + cardiac muscle, glands
• Somatic Motor (motor innervation of skeletal muscle)
• innervation of skeletal muscles (except pharyngeal arch m.)

Mnemonic for CN Function

• Some (CN I)
• Say (CN II)
• Marry (CN III)
• Money (CN IV)
• But (CN V)
• My (CN VI)
• Brother (CN VII)
• Says (CN VIII)
• Big (CN IX)
• Brains (CN X)
• Matter (CN XI)
• Most! (CN XII)
• S = Sensory function M = Motor function
• B = BOTH (Sensory and Motor function)
• Cranial Nerve Function
• I Olfactory--------Sensory--smell
• II Optic-------------Sensory--vision
• III Oculomotor----Motor----extrinsic eye muscles
• IV Trochlear-------Motor----extrinsic eye muscles
• V Trigeminal
• V 1 Opthalmic-----Sensory-cornea, nasal mucosa, face skin
• V 2 Maxillary------Sensory-skin of face, oral cavity, teeth
• V 3 Mandibular---Motor-muscles of mastication
• ---Sensory-face skin, teeth, tongue (general)

Cranial Nerves (continued)

• VI Abducens--------------Motor-----eye abduction muscles
• VII Facial-------------------Sensory---part of tongue (taste)
• -------------------Motor------muscles of facial expression
• VIII Vestibulocochlear---Sensory----hearing, equilibrium
• IX Glossopharyngeal----Motor------stylopharyngeus muscle
• ----Sensory----tongue (gen & taste), pharynx
• X Vagus------------------Motor-------pharynx, larynx
• -------------------Sensory----pharynx, larynx, abd. organs
• XI Accessory-------------Motor------trapezius, sternocleidomastoid
• XII Hypoglossal----------Motor-------tongue muscles

CN I: Olfactory Nerve

• Attaches to cerebrum
• Many nerve endings from olfactory bulbs
• Pass through olfactory foramina in cribriform plate of ethmoid bone to receptors in roof of nasal cavity
• Sensory for smell
• Attaches to Diencephalon
• Enters orbit through optic canal
• Sensory for vision

CN III: Oculomotor Nerve

• Attaches to Midbrain
• Enters orbit through superior orbital fissure
• Motor to 3 of 4 extrinsic muscles of eye
• Superior, inferior and medial rectus muscles & inferior oblique muscle
• Parasympathetic to muscles controlling pupil & lens of eye

CN IV: Trochlear Nerve

• Attaches to Midbrain
• Enters orbit through superior orbital fissure
• Motor to superior oblique muscle of eye

CN V 1: Ophthalmic Nerve

• First branch of Trigeminal nerve (CN V)
• Attaches to Pons
• Enters orbit through superior orbital fissure, then exits orbit through supraorbital foramen/notch
• Sensory-cornea, nasal mucosa, face skin

CN V 2 : Maxillary Nerve

• Second branch of Trigeminal nerve (CN V)
• Attaches to the pons
• Passes through the foramen rotundum, inferior orbital fissure and out the infraorbital foramen
• Sensory-skin of face, oral cavity, teeth

CN V 3: Mandibular Nerve

• Third branch of Trigeminal nerve (CN V)
• Attaches to Pons
• Exits cranial cavity through foramen ovale, into the mandibular foramen and out the mental foramen
• Motor-muscles of mastication
• Sensory-face skin, teeth, anterior 2/3 tongue (general)

Distribution of sensory innervation to skin of face from CN V

CN VI: Abducens Nerve

• Attaches to Pons
• Enters orbit through superior orbital fissure
• Motor to lateral rectus muscle of eye

CN VII: Facial Nerve

• Attaches to Pons
• Exits cranial cavity through internal acoustic meatus, then exits skull through stylomastoid foramen
• Sensory to anterior 2/3 tongue for taste
• Motor to muscles of facial expression
• Parasympathetic to Mandibular & Sublingual glands, Lacrimal gland

CN VIII: Vestibulocochlear Nerve

• Attaches to Pons
• Enters inner ear through internal acoustic meatus
• Sensory to organs of hearing and equilibrium

CN IX: Glossopharyngeal nerve

• Attaches to medulla oblongata
• Exits cranial cavity through jugular foramen
• Motor to stylopharyngeus muscle
• Sensory to posterior 1/3 tongue (general & taste), pharynx
• Parasympathetic to parotid gland
• Figs 8.162, 8.247

CN X: Vagus Nerve

• Attaches to Medulla oblongata
• Exits cranial cavity through jugular foramen
• Nicknamed the “wanderer”
• Motor to pharynx, larynx
• Sensory to pharynx, larynx, abdominal organs
• Parasympathetic to thoracic and abdominal organs

CN X: Vagus Nerve

• Attaches to Medulla oblongata
• Exits cranial cavity through jugular foramen
• Nicknamed the “wanderer”
• Motor to pharynx, larynx
• Sensory to pharynx, larynx, abdominal organs
• Parasympathetic to thoracic and abdominal organs

CN XI: Accessory Nerve

• Attaches to Medulla oblongata
• Exits cranial cavity through jugular foramen
• Joined by a spinal segment passing through foramen magnum
• Motor to trapezius & sternocleidomastoid muscles

CN XII: Hypoglossal Nerve

• Attaches to Medulla oblongata
• Exits cranial cavity through hypoglossal canal
• Motor to tongue muscles

Summary of Functional Groups

• Purely Sensory = I, II, VIII
• Primarily Motor = III, IV, VI, XI, XII
• Mixed = V, VII, IX, X
• Parasympathetic Fibers = III, VII, IX, X (Division of Autonomic NS = Visceral Motor)

Parasympathetic Fibers

• CN III = Oculomotor
• Contracts Iris (controls pupil)
• Contracts Ciliary Muscle (controls lens)
• CN VII = Facial
• Innervates Salivary glands (mandibular & sublingual)
• Innervates Lacrimal gland
• CN IX = Glossopharyngeal
• Innervates Parotid Salivary gland
• CN X = Vagus
• Innervates thoracic & abdominal viscera

    download lecture presentation  Brain and Cranial N

Spinal Cord and Nerves lecture presentation

Spinal Cord and Nerves
The Nervous System

• Coordinates the activity of muscles, organs, senses, and actions
• Made up of nervous tissue
• Has 3 main functions:
• 1. Receives sensory Input
• 2. Integration
• 3. Dictates motor output

Structural Divisions of the
Nervous System

• Central Nervous System (CNS)
• Brain and spinal cord
• Interprets incoming sensory signals
• Dictates motor responses
• Peripheral Nervous System (PNS)
• Nerves
• Cranial nerves and spinal nerves
• Nerve plexuses
• Enteric system
• Communication between regions of body and CNS

Review of Nervous Tissue

• Features of Nervous Tissue
• Neuron
• Cell body
• Dendrite
• Axon
• Myelin Sheath
• Surrounds thicker axons
• Forms insulating layer
• Prevents leakage of electrical current
• Speeds up the impulse conduction

Review of Nervous Tissue

• Neuroglia
• Reflex Arc
• Interneurons
• Rapid, automatic motor response
• Synapse
• Action potential

Organization of a Nerve

• Endoneurium
• Surrounds each axon (nerve fiber)
• Myelinated and Unmyelinated axons
• Motor and Sensory nerve fibers
• Loose CT
• Perineurium
• Bundles axons into fascicles
• CT
• Epineurium
• Bundles fascicles into a nerve
• Fibrous CT
• CT layers contain blood vessels

Types of Nerve Signals/Fibers

• Sensory (afferent)
• Picked up by sensory receptors thru body
• Carried by nerve fibers of PNS into CNS
• Motor (efferent)
• Carried away from the CNS by nerve fibers into PNS
• Innervate muscles and glands
• Causes these organs to contract or secrete
• Remember: SAME

Sensory and Motor Signals/Fibers

• Somatic sensory
• Body senses
• touch, pressure, temperature, vibration of body, muscles stretching, balance
• Visceral sensory
• Organ senses
• Stretch, pain, temperature in organs
• (eg) nausea, hunger, cramps
• Somatic motor
• Body movement
• Voluntary contraction of skeletal muscles
• Visceral motor
• Organ movement
• Contraction of smooth muscle, glands
• = Autonomic Nervous System (involuntary)

CNS – Spinal Cord

• Runs through vertebral canal of the vertebral column
• Protected by bone, meninges, and cerebrospinal fluid
• Spinal cord made of a core of gray matter surrounded by white matter
• 31 pairs of spinal nerves branch off spinal cord through intervertebral foramen
• Functions in many ways:
• Involved in sensory and motor innervation of body inferior to the head (through spinal nerves)
• Provides a 2-way conduction pathway for signals between body and brain
• Major center for reflexes

Meninges of Spinal Cord

• Membranes surrounding the spinal cord
• 3 Layers of connective tissue
• Functions
• Protect spinal cord
• Contains cerebrospinal fluid (CSF)
• Protect blood vessels serving spinal cord

Meninges of Spinal Cord 

• Dura mater (superficial)
• Spinal dural sheath
• Does not attach to bone
• Merges w/epineurium of spinal roots & nerves
• Epidural space
• Loose CT, fat and veins
• Between dura mater and vertebra
• Not present around brain
• Subdural space
• Between dura mater and arachnoid

Meninges of Spinal Cord 

• Arachnoid mater (middle)
• Impermeable layer = barrier
• Raised off pia mater by rootlets
• Subarachnoid space
• Between arachnoid and pia mater
• Contains cerebrospinal fluid
• Contains large blood vessels
• *Runs to level of S2
• Pia mater (deep)
• Highly vascular
• Adheres to brain/spinal cord tissue
• Creates denticulate ligaments

Regions of Spinal Cord

• Cervical
• Thoracic
• Lumbar
• Sacral
• Coccygeal
• Cervical + Lumbosacral enlargements
• Cauda equina
• Conus medullaris
• Filum terminale
• CT & pia mater
• Attaches to coccyx

Gray Matter

• Consists of neuron cell bodies, unmyelinated axons, dendrites, and neuroglia
• Shaped like an “H”
• Gray commissure (crossbar)
• Central canal
• Posterior horns
• Anterior horns

Gray Matter

• Posterior horns
• Consist of interneurons that transmit in from outside spinal cord into it
• Dorsal root contain sensory fibers
• Somatic Sensory (SS)
• Visceral Sensory (VS)
• Dorsal root ganglia –clusters of cell bodies outside of CNS
• Anterior horns
• Cell bodies of motor neurons send info out of spinal cord to muscles and glands
• Ventral Root contains Motor Fibers
• Visceral Motor
• Somatic Motor

White Matter

• Surrounds gray matter
• Composed of myelinated and unmyelinated axons
• Divided into white columns (funiculi) that create tracts
• Tracts = bundles of axons traveling to similar destination
• Posterior funiculus
• Anterior funiculus
• Lateral funiculus
• Allow for communication between
• Parts of the spinal cord
• Spinal cord and brain

White Matter

• 3 types of nerve fibers:
• Ascending
• Carry sensory info from sensory neurons of body to brain
• touch, pressure, pain, temperature
• Descending
• Carry motor instructions from brain to spinal cord
• Contraction of muscles and secretion of glands
• controlling precise, skilled movement  (e.g. writing, maintain balance, create movement)
• Commissural
• Cross from one side of cord to the other

Spinal Nerves (31 Pairs)

• Part of the PNS
• Lie in intervertebral foramina
• Send lateral branches to body
• Named according to their point of attachment to spinal cord segment
• 8 pairs of cervical spinal nerves; C1-C8
• 12 pairs of thoracic spinal nerves; T1-T12
• 5 pairs of lumbar spinal nerves; L1-L5
• 5 pairs of sacral spinal nerves; S1-S5
• 1 pair of coccygeal spinal nerves; C01

Spinal Nerves

• Each spinal nerve connects to spinal cord via posterior root (sensory) and anterior root (motor)
• Each spinal nerve branches into a posterior ramus and an anterior ramus
• Anterior rami
• Supply anterior and lateral regions of the neck, trunk, and limbs
• Posterior rami
• Supply the dorsum of the neck and trunk (back)

Recurrent Meningeal Nerves
Recurrent meningeal nerves branch from spinal nerves to supply intervertebral discs, dura mater, ligaments and blood vessels.
They access the vertebral canal via intervertebral foramina.
The Big Picture

• Just lateral to the intervertebral foramen, each spinal nerve then splits in 2
• Dorsal Ramus
• Ventral Ramus

• RAMI contain BOTH Sensory and Motor fibers!!

• Remember: Roots have sensory OR motor fibers, not both

Dermatomes

• Area of skin innervated by cutaneous branches of single spinal nerve
• Clinical application for testing neurological function

Autonomic Nervous System

• Visceral Motor Function
• Not controlled voluntarily
• e.g. get nervous and sweat
• Innervates smooth muscle, cardiac muscle, glands
• Regulates visceral function
• Heart rate, blood pressure, digestion, urination
• Has 2 divisions:
• Parasympathetic
• Sympathetic

Autonomic Nervous System

• Sympathetic
• “fight or flight”
• Mobilizes the body during extreme situations
• Becomes active when extra metabolic effort needed
• Most release norepinephrine
• Axons branch widely
• Thoracolumbar division
• Fibers arise from thoracic and lumbar parts of spinal cord

• Parasympathetic
• “rest and digest”
• Enables body to unwind and calm down
• Most active when body at rest, normal activities
• Routine maintenance functions
• Most release acetylcholine
• Axons branch less
• Craniosacral division
• Fibers arise from brain and sacral spinal cord

Sympathetic Innervation

• Comes from thoracolumbar regions (T1-L2)
• Travels through anterior root and rami
• Communicates with the sympathetic trunk          (via a connection called a ramus communicans)
• Back to anterior rami (via another ramus communicans) to spinal nerve to reach target structures
• Can operate at same level of spinal cord (T1-L2) or above a different level

Parasympathetic Innvervation

• Parasympathetic innervation comes from cranio-sacral region of central nervous system
• Cranial nerves III, VII and IX provide parasympathetic innervation to structures of head and neck
• CN X (Vagus) provides parasympathetic innervation below neck to organs of thoracic & abdominal cavities
• Spinal nerves S2-S4 provide parasympathetic innervation to inferior abdominal organs, pelvic organs and tissue of perineum
•  Nerve fibers exit spinal cord through anterior roots and then anterior rami into plexuses to serve organs

Nervous System Overview

• Sensory information (visceral and somatic) travels along sensory nerves to the posterior root into the spinal cord
• The information is then processed by brain or a response is determined within the spinal cord (e.g. in a reflex arc)
• Motor information (visceral and somatic) goes out of the spinal cord through the anterior root along motor nerves to the body to make muscles contract or glands secrete

Sympathetic Innervation at Same Level of Spinal Cord

• Sympathetic fibers providing innervation through spinal nerves at same level of spinal cord (T1-L2)
• Sympathetic fibers runs through anterior root into anterior ramus
• It then connects to a white ramus communicans, which leads to the sympathetic chain ganglia and sympathetic trunk
• Fibers then pass through the gray ramus communicans back out the anterior ramus into a spinal nerve to body

Sympathetic Innervation at Different Level of Spinal Cord
Only from level T1-L2, so

• Fibers may travel out anterior root and anterior ramus
• Through white ramus communicans up or down sympathetic trunk to different level of cord
• Then through gray ramus communicans out anterior root along spinal nerve to the body

Heart and Circulation lecture presentation

CirculationCirculation

Cardiovascular System = Heart, Blood and Vessels
Lymphatic System = Lymph nodes, Organs and Vessels

The Lymphatic Vessels

• Function: to collect excess tissue fluid collecting at arteriole end of capillary beds, and return leaked blood proteins to blood (maintain osmotic pressure needed to take up water into bloodstream)
• Lymph is moved through vessels
• Pulse of nearby arteries
• Contraction of surrounding skeletal muscle
• Regular movement of body (wiggling legs)
• Muscle in Tunica Media

Lymphatic System…The Players:

• Lymph- clear fluid from loose CT at capillaries
• Contains small molecules of blood plasma, water, various ions, nutrient molecules, respiratory gases
• Lymphatic capillaries (near blood capillaries) à
• Lymph collecting vessels (small, 3 tunicas, # valves) à
• Lymph nodes (sit along collecting vessels)-clean lymph of pathogens, they are NOT glands
• Lymphatic trunks à(convergence large collecting vessels)
• Lymphatic ducts à empty into veins of neck

Lymphatic Ducts

• Thoracic Duct
• Receives lymph from large trunks in abdomen and thorax
• Receives lymph from ducts of thoracic lymph nodes
• Along vertebral bodies
• Contain valves to ensure 1-way flow of lymph to lymph nodes
• Drains into left Brachiocephalic Vein (or subclavian or int. jugular veins)

Functions of Heart and Cardiovascular System

• Cardiovascular System
• Bulk flow of blood
• Exchange with tissue
• Heart
• Right side receives oxygen-poor blood from body tissues and pumps the blood to the lungs
• Left side receives the oxygenated blood from the lungs and pumps the blood throughout the body

Location of Heart in Chest

• Oblique Position
• Apex = Left of Midline (5th ICS), Anterior to rest of heart
• Base (posterior surface) sits on vertebral column
• Superior Right = 3rd Costal Cartilage, 1” right midsternum
• Superior Left = 2nd Costal Cartilage, 1” left midsternum
• Inferior Right = 6th Costal Cartilage, 1” right midsternum
• Inferior Left = 5th Intercostal Space at Midclavicular line

Cardiac Conduction

• Intrinsic system initiating and coordinating contraction of heart muscle
• Sinoatrial node (where SVC enters RA)
• Atrioventricular node (in atrioventricular septum)
• AV Bundle (in IV septum then splits)
• Purkinje fibers (throughout LV)
• Cardiac Plexus (external innervation)
• Vagus (parasympathetic)
• Sympathetic trunk

Blood Flow to Supply the Heart Muscle

• Heart wall too thick for diffusion of nutrients
• Rt and Lft Coronary Arteries
• Branch from Ascending Aorta
• Have multiple branches along heart
• Sit in Coronary Sulcus
• Coronary Heart Disease
• Cardiac Veins
• Coronary Sinus (largest)
• Many branches feed into sinus
• Sits in Coronary Sulcus

Pericardium

• Pericardium (3 layers)
• 1) Outer-fibrous pericardium
• Serous pericardium
• 2) parietal
• 3) visceral (epicardium)
• Pericardial Cavity
• between layers of serous pericardium
• serous fluid
• lubricate heart while beating

External Features of Heart

• Interventricular sulcus
• Coronal/Coronary sulcus
• Auricles of atria
• Apex
• Base
• Coronary vessels
• Ligamentum Arteriosum

The Great Vessels and major branches

Aorta (from Left Ventricle)

• Ascending
• Coronary arteries
• Aortic Arch
• Brachiocephalic trunk
• Left Common Carotid
• Left Subclavian
• Descending (Thoracic/Abdominal)
• Many small branches to organs

Pulmonary Trunk (from Rt Ventricle)

• -2 Pulmonary Arteries into lungs

Inferior/Superior Vena Cava

- Coronary sinus

Layers of Heart

• Epicardium (most superficial)

– Visceral serosa

• Myocardium (middle layer)
• Cardiac muscle
• Contracts
• Endocardium (inner layer = lining)
• Endothelium on CT
• Lines the heart
• Creates the valves

Fibrous Skeleton of Heart

• Insertion for cardiac muscle
• Anchors valve cusps
• Prevents valves from opening too much
• Block electrical impulses from atria to ventricles
• Contains AV node

Heart Chambers

• 2 receiving chambers:
• Right atria
• Left atria
• 2 pumping chambers:
• Right ventricle
• Left ventricle
• Atria are superior to ventricles
• Arrangement is not linear…it’s twisted!

Right Heart Chambers: Pulmonary Pump

• Right Atrium (forms most of base of heart)
• Receives O 2-poor blood from body via IVC, SVC, Coronary sinus
• Ventral wall (w/Pectinate muscles) and dorsal wall (no pectinate muscles) separated by crista terminalis
• Fossa Ovalis- on interatrial septum, remnant of Foramen Ovale
• Right Ventricle
• Receives O 2-poor blood from right atrium through tricuspid valve
• Trabeculae Carnae- muscle ridgesalong ventral surface
• Chordae Tendinae-fibrous cords running between AV valve cusps and papillary muscles
• Papillary Muscles (3)-cone-shaped muscles within ventricles to which chordae tendinae are anchored
• Moderator Band (septomarginal trabecula)-muscular band connecting anterior papillary muscle to interventricular septum
• Pumps blood to lungs via Pulmonary Semilunar Valve in pulmonary trunk

Left Heart Chambers: Systemic Pump

• Left Atrium
• Receives O 2-rich blood from 4 Pulmonary Veins
• Pectinate Muscles line only auricle
• Left Ventricle (forms apex of heart)
• Receives blood from Left Atrium via bicuspid valve
• Same structures as Rt Ventricle: Trabeculae carnae, Papillary muscles (2), Chordae tendinae
• No Moderator band
• Pumps blood into aorta via Aortic Semilunar Valve to body

Heart Valves: Lub*-Dub**

• *Tricuspid Valve: Right AV valve
• 3 Cusps (flaps) made of endocardium and CT
• Cusps anchored in Rt. Ventricle by Chordae Tendinae
• Chordae Tendinae prevent inversion of cusps into atrium
• Flow of blood pushes cusps open
• When ventricle is in diastole (relaxed), cusps hang limp in ventricle
• Ventricular contraction increases pressure and forces cusps closed
• *Bicuspid (Mitral) Valve: Left AV valve
• 2 cusps anchored in Left Ventricle by chordae tendinae
• Functions same as Rt. AV valve
• They close together

Semilunar Valves (the dub)

• Semilunar valves: prevents backflow in large arteries
• Pulmonary Semilunar Valve
• Right Ventricle and Pulmonary Trunk
• Aortic Semilunar Valve
• Left Ventricle and Aorta
• Made of 3 Cusps
• As blood rushes past the cusps are flattened
• As it settles they’re pushed down (valve closed)

Flow of Blood

• O 2-poor blood (S+I VC, Coronary Sinus) enters Rt Atrium
• Travels through Tricuspid Valve into Rt Ventricle
• Pumped out through Pulmonary Semilunar Valve into Pulmonary trunk (branches into Pulmonary Arteries) and to lungs
• After circulating through lungs, O 2-rich blood returns to the heart through 4 Pulmonary veins
• The O 2-rich blood enters the Left Atrium
• Travels through Bicuspid/Mitral Valve into Left Ventricle
• Pumped out through Aortic Semilunar Valve into Aorta to be distributed to rest of body by descending aorta and branches of aortic arch

Cardiovascular Flow of Blood

• Heart àArteries à(conducting-distributing) àArterioles àCapillaries of tissues
• At Capillaries O 2 is delivered and CO 2 picked up
• Capillaries àVenules àVeins àHeart
• Heart àArteries à(conducting-distributing) àArterioles àCapillaries of tissues
• At Capillaries O 2 is delivered and CO 2 picked up
• Capillaries àVenules àVeins àHeart

Circuits

• Pulmonary Circuit
• Vessels carrying blood to and from lungs
• Pulmonary arteries and veins
• Systemic Circuit
• Vessels carrying blood to and from the rest of the body
• All other vessels

Blood Vessels

• Powered by the heart!
• Carry blood to and from the heart
• 3 main types:
• Arteries
• Carry blood away from heart
• arterioles
• Capillaries
• Veins
• Carry blood toward heart
• Venules

Anatomy of Arteries and Veins

• Tunica externa
• Outermost layer
• CT w/elastin and collagen
• Vaso Vasorum
• Tiny arteries, veins, capillaries on vessels to nourish them (outer half)
• Protects, Strengthens, Anchors
• Tunica media
• Middle layer
• Circular Smooth Muscle
• Collagen & Elastic Fibers
• Vaso-constriction/dilation
• Tunica intima
• Innermost layer
• Endothelium
• Minimize friction
• Lumen

Vessels of Cardiovascular System:
Arteries

• Carry blood AWAY from heart
• Systemic Circuit: carry O 2 blood
• Pulmonary Circuit: carry de-O 2 blood
• Walls thicker than Veins
• Tunica media > Tunica externa
• 3 Types
• Conducting (elastic)
• large, elastin, high pressure
• Distributing (muscular)
• medium size, to organs
• Arterioles
• smallest

Capillaries

• Smallest blood vessels
• Lumen is typically only 1 RBC thick
• Only 1 endothelial cell layer surrounded by basal lamina (no tunica media or externa)
• Deliver O 2 and nutrients to cells and remove waste
• Capillary Beds: networks of capillaries
• Regulating amount of blood going to cells throughout tissues
• Supply tissues and organs that otherwise have poor capillary circulation
• Epithelium, cartilage has no capillaries

Vessels of Cardiovascular System:
Veins

• Carry blood from capillaries INTO the heart
• Systemic Circuit: O 2 poor blood
• Pulmonary Circuit: O 2 –rich blood
• Pressure in Veins less than that in arteries
• Thinner walls than arteries (tunica externa > tunica media, less elastin)
• Larger lumen than arteries
• Contain valves (made of T. intima)
• Normal movement, Muscular contraction push blood through
• Venules- smallest veins

Cardiovascular Blood Flow

• Portal System: Special vascular circulation where blood goes through 2 capillary beds before returning to the heart to achieve 2 nd function
• (eg) Hepatic Portal System: aids digestion by picking up digestive nutrients from stomach + intestines and delivers to liver for processing/storage
• Pick-up occurs at capillaries of stomach and intestine
• Via Hepatic Portal Vein goes to capillaries of liver
• Via Hepatic Vein blood goes back to heart

Vascular Anastomoses

• Vessels unite and connect
• Arterial Anastomoses
• Communication between arteries
• Joints, Abdominal Organs, Brain, Heart
• Venous Anastomoses
• Communication between veins
• More common
• (eg) back of hand

Fetal Circulation

• All major vessels in place by third month
• 2 main differences:
• 1. Fetus must supply blood to placenta
• 2. Lungs do not need much blood because respiratory organ is the placenta
• Blood to Placenta
• Umbilical vessels
• Run in umbilical cord
• 2 umbilical arteries
• Carry blood (little oxygen and waste) to placenta
• 1 umbilical vein
• Returns this blood (with oxygen and nutrients) to fetus and to portal vein (to liver)

2. Bypassing the Lungs:
Foramen Ovale

• Hole in the inter-atrial septum
• Allows blood to flow from RA to LA
• Bypasses the RV
• Would usually bring blood to lungs
• Becomes the fossa ovalis postnatally

2. Bypassing the Lungs:
Ductus Arteriosus

• Carries blood from pulmonary trunk to aortic arch
• Empties distal to coronary arteries
• This enables the heart and brain to receive the most highly oxygenated blood
• Bypasses the lungs
• Becomes the ligamentum arteriosum postnatally

First Breath!!

• Lungs inflate
• Ductus arteriosus constricts and closes
• Oxygenated blood begins pouring into LA for first time
• Raises the pressure within the LA
• This pushes the 2 flaps of foramen ovale together and closes it

  download lecture presentation Heart & Circulation

Thoracic Cavity lecture presentation

The Thoracic Cavity

Boundaries of and Structures Within

 Body Cavities

• Dorsal body cavity
• Ventral body cavity
• Thoracic
• 2 Pleural
• Mediastinum
• Divided by Diaphragm
• Abdominopelvic
• Abdominal
• Pelvic

Serous membrane = Serosa

• Simple squamous epithelium + areolar connective tissue
• 2 Layers
• Outer layer = PARIETAL serosa
• Inner layer = VISCERAL serosa
• Between them = Serous Cavity containing Serous Fluid
• Serous fluid is blood filtrate + secretions by 2 layers of membrane
• Allows movement of organs with reduced friction
• Types of Serous Membranes
• Pleural = surrounds lungs
• Pericardium = surrounds heart, slightly modified
• Peritoneal = surrounds some abdominal organs

Pleural Cavities

• Surround the lungs
• Pleural fluid secreted by pleural membranes
• Holds layers together
• Reduces friction of organs
• Benefit of Compartmentalization

Pleural Cavities

• 2 Layers
• Visceral pleura (inner)
• root of lungs marks transition
• external surface of lungs
• Parietal pleura (outer)
• inner surface of thoracic wall
• superior surface of diaphragm
• lateral surface of mediastinum

Pleural Abnormalities

• Pleural Effusion
• Excess fluid in the pleural cavity
• More than 20X
• Usually less than 1 ml of fluid
• Pneumothorax
• Air located in pleural space
• Superior (to heart)
• Contains: thymus, cranial vena cava, trachea, esophagus, nerves
• Inferior
• Anterior (to heart)
• Contains: thymus
• Posterior (to heart)
• Contains: aorta, esophagus, trachea, bronchi, nerves, caudal vena cava,
• Middle
• Contains: heart + pericardium
• Boundaries of Mediastinum
• Lateral
• parietal pleura of lungs
• Anterior
• ventral parietal pleura
• Posterior
• dorsal parietal pleura
• Superior
• dome of the neck
• Inferior
• diaphragmatic pleura

Respiratory Tract

• Upper Respiratory Tract
• Superior to Larynx
• Lower Respiratory Tract
• Larynx
• Trachea
• Primary Bronchi
• Secondary Bronchi
• Rest of Bronchial Tree
• Lungs

Trachea = windpipe

• Starts at Larynx and travels through mediastinum
• Located Anterior to Esophagus
• Trachea terminates into 2 primary bronchi entering lungs
• Walls contain 16-20 “C” shaped rings Hyaline Cartilage
• Trachealis Muscle (smooth muscle and soft CT)
• Layers (deep to superficial)
• Mucosa = Ciliated Psuedostratified Epithelium
• Submucosa- contains seromucous glands
• Adventitia – made of connective tissue, contains cartilage rings

Bronchial Tree

• Primary (main) Bronchi
• Bifurcation of trachea
• Basically the same structure
• Cartilage rings
• Posterior to pulmonary vessels
• Right is wider, vertical, shorter
• Secondary (lobar) Bronchi
• Each primary bronchi divides
• Same structure as primary bronchi
• Right lung has 3, Left has 2
• Tertiary (segmental) Bronchi
• Up to 23 divisions

Bronchial Tree (continued)

• Bronchioles
• further divisions, < 1 mm diameter
• Terminal Bronchioles
• further divisions, 0.5 mm diameter
• Respiratory Zone
• Respiratory Bronchioles
• Alveolar Ducts
• Alveolar Sacs
• Terminal bunches of Alveoli
• Respiratory exchange chamber
• Among alveoli are blood vessels, nerves, lymphatics

Respiratory Zone (continued)

• Lining the Walls of Alveoli
• Respiratory Membrane
• Type I cells = simple squamous epithelial cells
• Basal lamina and fine areolar CT
• Covered with capillaries and elastic fibers
• Type II cells = cuboidal epithelial cells
• Secrete fluid containing surfactant
• Dust Cells (macrophages)
• Gas exchange
• Oxygen into blood
• Carbon Dioxide into alveoli

Throughout Bronchial Tree

• Psuedostratified columnar changes to simple columnar to simple cuboidal
• Cartilage rings replaced by cartilage plates once bronchi enter the lungs
• Smooth muscle and Elastic fibers remain important
• In Bronchioles
• Ciliated mucosa disappears, replaced by macrophages in alveoli
• Cartilage disappears
• Smooth muscle forms bands around smallest bronchi and bronchioles (not found around alveoli)

LUNGS (continued)

• Located in Pleural Compartments
• Lateral to Mediastinum
• Location
• Apex posterior to clavicle
• Base lays on Diaphragm
• Costal Surface = Ant, Lat, Post surfaces contact ribs
• Left Lung = 2 lobes
• Upper
• Lower
• Oblique Fissure
• Cardiac Notch
• Right Lung = 3 lobes
• Upper
• Middle
• Lower
• Oblique fissure
• Horizontal fissure

LUNGS

• Hilus- medial indentation
• Root of Lung = structures enter each lung
• 2 Pulmonary Veins = carries O 2-rich blood from each lung to heart
• 1 Pulmonary Artery = carries O 2-poor blood to each lung
• Primary Bronchus
• Nerve plexus

Lymph Vessels

• Lobes are anatomically + functionally separate
• Lung lobes divided into Lobules
• Functionally separate
• Separated by dense CT
• Vary in size
• Stroma = lung tissue
• Areolar CT
• Many elastic fibers

Esophagus

• Esophagus
• Pharynx to Stomach
• Passes thru diaphragm at esophageal hiatus
• Anterior to vertebrae, Posterior to trachea
• Layers of Esophagus (deep to superficial)
• Mucosa
• Stratified squamous epithelium
• Lamina propria (loose CT)
• Muscularis mucosae
• Submucosa
• Loose connective tissue
• Secretes mucus
• Muscularis Externa
• Circular/Longitudinal layers
• Skeletal m, Mix, then Smooth m
• Adventitia
• Fibrous CT

The Diaphragm

• Skeletal Muscle
• Dome-shaped (relaxed)
• Flattens (contracts)
• Divides thoracic & abdominopelvic cavities
• Attachments
• O: Inferior Internal rib cage, Lumbar vertebrae (by crura)
• I: Central tendon
• Innervated by right + left PHRENIC Nerves

Action of the Diaphragm

• Primary muscle of respiration (involuntary)
• Contraction during inspiration
• Increases volume of thoracic cavity
• Decreases pressure of thoracic cavity
• Air moves into lungs (high àlow pressure)
• Forced contraction (voluntary)
• Used for defecation, urination, labor
• Decreases volume of abdominal cavity
• Increases pressure in abdominal cavity
• Pushes on abdominal organs to move contents out

Thoracic Cavity Capacity is Increased by:

• Contraction of diaphragm
• Intercostal muscles elevate ribs
• Rib elevation causes the sternum to move anteriorly

Openings of Diaphragm

• Posterior àAnterior
• Aortic Hiatus
• Aorta
• Azygos vein
• Thoracic duct
• Esophageal Hiatus
• Esophagus
• Vagus nerves
• Caval Opening
• Inferior Vena Cava
• Right Phrenic Nerve

Vena Cava

• Superior Vena Cava
• in Superior mediastinum, right side
• Receives blood from regions above diaphragm
• Formed from Rt + Lft Brachiocephalic Veins cranially
• Azygos Vein empties into it just superior to heart
• Empties into Right Atrium
• Inferior Vena Cava
• in Inferior mediastinum (right side), runs through abdomen
• Returns blood to heart from regions below diaphragm
• Formed from Rt + Lft Common Iliac Veins
• Empties into Right Atrium
• Widest blood vessel in body

Veins of Thoracic Cavity

• Vena Cavae
• Azygos Vein
• “unpaired”
• right side of vertebral bodies (at level of T 12)
• runs superiorly
• empties into Sup. Vena Cava
• drains right posterior intercostal veins
• Connects to hemiazygos and accessory hemiazygos that drain left side

Thymus Gland

• Lymphatic Organ
• 2-lobed w/lobules
• Sits on heart and great vessels
• Immature lymphocytes mature into T-lymphocytes
• Secretes Thymic Hormones: help T-lymphocytes gain immunocompetence
• Decreases in size w/age
• Functional tissue is replaced with fatty tissue
• Contains lobes and lobules
• Capsule
• Cortex
• Medulla

  download lecture presentation Thoracic Cavity
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Thorax lecture presentation

The Thorax
Axial & Appendicular Skeleton
Mammary Glands
Surface Anatomy

Axial vs. Appendicular Skeleton
• Axial Skeleton
• Skull = Cranium + Facial bones
• Vertebrae
• Ribs
• Sternum
• Appendicular Skeleton
• Bones of upper/lower limbs
• Limb Girdles
The Bony Thorax
• Sternum
• Manubrium, Body (Gladiolus), Xiphoid Process
• Ribs
• 7 True Ribs
• 5 False Ribs
• Clavicle
• Scapula
• Vertebrae
• Cervical,Thoracic, Lumbar, Sacral (Sacrum), Coccygeal (Coccyx)

Projections and Depressions

• Site of muscle and ligament attachments
• Spine
• Process
• Help form joints
• Head
• Facet
• Allow BV, nerves, and muscles to pass
• Notch
• Fossa
Thoracic Cage
• Borders:
• Thoracic vertebrae posteriorly
• Ribs laterally
• Sternum and costal cartilages anteriorly
• Forms protective cage around heart, lungs, and other organs
• Composed of:
• Sternum
• Ribs
• Vertebrae
The Sternum
(Composed of fused sternebrae)

• Manubrium
• Jugular (sternal) notch
• Articulation with rib #1 & 2
• Clavicular Articular facets
• Sternal Angle – 2 nd rib
• Body (Gladiolus)
• Articulates w/ribs 2-7
• Xiphosternal joint
• Xiphoid process
• Cartilage-calcifies thru time
• Partial attachment of many muscles
The Ribs
• Usually, 12 pairs
• 7 True ribs-direct attachment to sternum
• 5 False ribs-indirect or no attachment to sternum
• Floating ribs-make up 2 of 5 False ribs, no ventral attachment
• Typical Ribs
• Ribs # 2-9
• Atypical Ribs
• Ribs #1, 10, 11, 12
• Reinforce thoracic cage
Rib Anatomy
• Typical Ribs
• Head
• Neck
• Tubercle
• Angle
• Shaft
• Subcostal Groove
Rib Anatomy
• Atypical Ribs
• #1-short, flat (S-I), wide, Supports Subclavian vessels
• #1, 10-12 articulate with only = # vertebra
• #11, 12 don’t articulate with transverse processes, or anteriorly at all
Typical Rib Articulation
• Dorsal (P) Attachment Thoracic Vertebrae
• Head of Rib à 2 costal facets
• Superior costal facet
• Inferior costal facet of vertebra above it
• Intervertebral disc
• Tubercle of Rib à Transverse Costal Facet
• e.g. Rib #4 articulates with Superior Costal Facet and Transverse Costal Facet of T4 & Inferior Costal Facet of T3
• Ventral (A) Attachment to Sternum
• Via costal cartilage
Pectoral Girdle
• Attaches upper extremity to axial skeleton
• Holds upper extremity away from skeleton for mobility
Intercostal Muscles
• External Intercostals
• O: Inferior border of rib above I: Superior border of rib below
• Fibers run OBLIQUE (down and forward)
• Aid in Inspiration (lift ribcage, increase dimensions)
• Internal Intercostals
• O: Superior border of rib below I: Inferior border of rib above
• Fibers run at RIGHT ANGLES to external intercostals
• Aid in forced expiration (depress ribcage, decrease dimensions)
• Innermost Intercostals, Subcostals, Transversus thoracis
• Attachments similar to Internal Intercostals, Attach ribs
• Small, variable, function unclear
Neurovascular Bundle of Intercostal Muscles
• VAN (vein, artery, nerve)
• Intercostal vein
• Intercostal artery
• Intercostal nerve
• Sit in Subcostal Groove
• Between Internal Intercostal and Innermost intercostal layer
Vertebral Column
• Humans’ made of 26 bones
• Cervical 7
• Thoracic 12
• Lumbar 5
• Sacrum (5 fused sacral vertebrae)
• Coccyx (4 fused coccygeal vertebrae)
• Extends from skull to pelvis
• Supports body, muscle attachment
• Vertebral Canal
• Created by vertebral foramen
• Contains + protects spinal cord
• Intervertebral foramina
• **Transverse Foramen **
• Superior Articular Facets face superoposteriorly
• Inferior Articular Facets face inferoanteriorly
• Allows wide range of motion
• Spinous process fairly short, bifid (except for C7)
• Vertebral Foramen is Triangular
• Body is wider laterally than in A-P direction
Atypical Cervical Vertebrae
• C1 – Atlas
• No body
• No Spinous Process
• Superior Articular facets are kidney shaped
• C2 – Axis
• Odontoid Process = Dens
• Other features typical
Thoracic Vertebrae (12)
• **Transverse Costal Facets **
• *S/I Costal facets on vertebral body*
• Spinous Processes long, point inferiorly
• Superior Articular Facets face Dorsally/Posteriorly
• Inferior Articular Facets face Ventrally/Anteriorly
• Vertebral Foramen is Circular
• Body is Heart-shaped
Thoracic Vertebrae (12)
• **Transverse Costal Facets **
• *S/I Costal facets on vertebral body*
• Spinous Processes long, point inferiorly
• Superior Articular Facets face Dorsally/Posteriorly
• Inferior Articular Facets face Ventrally/Anteriorly
• Vertebral Foramen is Circular
• Body is Heart-shaped
Lumbar Vertebrae (5)
• Spinous process is short, rectangular, projects dorsally
• Superior Articular Facets face Medially
• Inferior Articular Facets face Laterally
• Vertebral Foramen is Triangular
• Body is large and Kidney-shaped
Sacrum & Coccyx
• 5 fused Sacral Vertebrae
• Articulates with
• 5 th Lumbar vertebra
• Coccyx
• Ilia of coxal bones
• Functions in weight transfer
• Has a body, sacral canal, sacral foramina
• Remnants of other typical vertebrae features visible
• Lateral & median sacral crest
• 3-4 fused Coccygeal vertebrae
• Articulations
• #1 articulates with 5 th Sacral Vertebra
• Some muscle + ligament attachment
• Slightly different orientation in males vs. females
• No canal
Intervertebral Discs
• Absent between
• C1 and C2
• Sacrum and coccyx
• Annulus Fibrosus
• Outer collar of concentric rings
• Outer rings = ligaments
• Inner rings = fibrocartilage
• Supportive/Structural
• Nucleus Pulposus
• Inner disc, cushiony pad
• Remnants of notocord
• Shock Absorber
Vertebral Column
IN
OUT
IN
OUT

• Lateral Curvature
(Following Dorsal Side)
• Cervical Region = Concave curve
• Thoracic Region = Convex curve
• Lumbar Region = Concave curve
• Sacrum = Convex curve
Abnormal Curves
• Scoliosis-abnormal lateral curve of more than 10°
• “twisted disease”
• Kyphosis-exaggerated thoracic curve
• “humped disease”
• Lordosis-accentuated lumbar curve
• “bent-backward disease”
Ligaments of Vertebral Column
• Anterior Longitudinal Ligaments (neck – sacrum)
• Run vertically on anterior surface of vertebral bodies + intervertebral discs
• Wide,strong
• Prevents hyperextension
• Posterior Longitudinal Ligaments (neck – sacrum)
• Run vertically on posterior surface of intervertebral discs only
• Narrow, weak
• Prevents hyperflexion
• Ligamentum Flavum (contains elastic connective tissue)
• Attaches lamina of vertebrae (one on right, one on left)
• Very strong
Muscles of Thorax

Muscle	Origin	Insertion	Action	Innervation
Pectoralis major	Sternum, Ribs 2-6	Inter-tubercular groove of humerus	Adduct, Flex, Med Rotate Arm	M & L pectorals
Pectoralis minor	Ribs 3-5	Coracoid process of scapula	Depress, Rotate scapula	M & L pectorals
Serratus anterior (ventralis)	Ribs 1-9	Scapula	Protract, Rotate scapula	Long Thoracic

 
Muscles of Thorax


Muscle	Origin	Insertion	Action	Innervation
Trapezius	Ligamentum nuchae, C 7 -T 12	Clavicle, Spine & acromion of scapula	Elevate, Adduct, Rotate, Depress	Accessory
Levator Scapulae	C 1 -C 4	Medial border of scapula	Elevate scapula	D. Scapular
Rhomboids	C 7 -T 5	Medial border of scapula	Adduct, Elevate, Rotate	D. Scapular

 

Muscles of Thorax

Muscle	Origin	Insertion	Action	Innervation
Deltoids	Clavicle, Spin & acromion of scapula	Deltoid tuberosity of humerus	Flex, Abduct, Extend, Lat & med. rotate arm	Axillary
Latissimus dorsi	Iliac crest, Sacrum, T 7-12 , Lumbar fascia	Inter-tubercular groove of humerus	Extend, Adduct, Med. rotate arm	Thoraco-dorsal

 

Rotator Cuff Muscles

Muscle	Origin	Insertion	Action	Innervation
Supraspinatus	Supraspinous fossa of scapula	Greater tubercle of humerus	Abduction of arm	Suprascapular
Infraspinatus	Infraspinous fossa of scapula	Greater tubercle of humerus	Lat rotation of arm	Suprascapular
Teres Minor	Lateral border of scapula	Greater tubercle of humerus	Lat rotation of arm	Axillary
Subscapularis	Subscapular fossa of scapula	Lesser tubercle of humerus	Med rotation of arm	Subscapular

The Breast
• Location: (female breast)
• Superior border: 2 nd rib
• Inferior border: 6 th rib
• Medial border: Sternum
• Lateral border: Midaxillary line
• Location: (male nipple)
  
  • Fourth Intercostal Space, Midclavicular line
• Underlying muscle
• Pectoralis major and minor
• Part of serratus anterior, external obliques
• Lateral Thoracic Artery, branches of Internal Thoracic A., Post. Intercostals
• Intercostal, Internal Thoracic, Axillary Veins
• Branches of Intercostal Nerve

Mammary Glands

• Lactiferous (modified sweat) Glands
• Breast made of 15-25 lobes (each a compound alveolar gland)
• Lobes made of lobules (= clusters of acini/alveoli)
• Acini/Alveoli lined w/milk-secreting simple epithelial cells
• Lactiferous Ducts of lobes open at nipple
• Areola-ring of pigmented skin around nipple
• Sebaceous gland produce sebum during nursing
• Lobes separated by adipose tissue and suspended by connective tissue = Suspensory Ligaments of the Breasts

Surface Anatomy

Use the next 3 slides and follow the book to
palpate (feel) the features listed
Anterior Surface of Thorax

• Palpate the following
• Sternum (3 parts)
• Jugular notch
• Sternal Angle (= 2 nd rib)
• Clavicle
• Costal margin
• Xiphosternal joint
• Midclavicular Line
• Midaxillary Line

Posterior Surface of Thorax

• Palpate the following
• Spinous Process of C7
• Scapula (ribs 2-7)
• Scapular spine
• Acromion Process
• Inferior Angle of Spine
• Inferior Border

Locating Internal Structures

• Pleural Cavities
• Inferior margin = adjacent to T12 in Posterior Midline
• To Rib 10 at Midaxillary line
• To Rib 8 at Midclavicular line
• To Xiphosternal joint medially
• Lungs posterior border is 2 ribs superior to pleural cavity (rib 8)
• Heart
• Deep to xiphisternal angle 

Page 206 
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