Lower Limb

The Lower Limb
Pelvis, Thigh, Leg
and Foot
Surface Anatomy

• Gluteal region / posterior pelvis
• Iliac crest
• Gluteus maximus
• Cheeks
• Natal/gluteal cleft
• Vertical midline; “Crack”
• Gluteal folds
• Bottom of cheek; “prominence”

 
Surface Anatomy

• Anterior thigh and leg
• Palpate
• Patella
• Condyles of femur
• Femoral Triangle
• Boundaries:
• Sartorius (lateral)
• Adductor longus (medial)
• Inguinal ligament (superior)
• Contents:
• Femoral artery, vein and nerve, lymph nodes

Surface Anatomy

• Posterior leg
• Popliteal fossa
• Diamond-shape fossa behind knee
• Boundaries
• Biceps femoris (superior-lateral)
• Semitendinosis and semimembranosis (superior-medial)
• Gastrocnemius heads (inferior)
• Contents
• Popliteal artery and vein
• Calcaneal (Achilles) tendon
 Surface Anatomy

• Anterior leg bones
• Tibia
• Tibial tuberosity
• Anterior crest
• Medial surface
• Medial malleolus
• Fibula
• Lateral malleolus
Bones of the Lower Limb

• Function:
• Carry weight of entire erect body
• Support
• Locomotion
• Points for muscular attachments
• Components:
• Thigh
• Femur
• Knee
• Patella
• Leg
• Tibia (medial)
• Fibula (lateral)
• Foot
• Tarsals (7)
• Metatarsals (5)
• Phalanges (14)
Thigh

• Femur
• Largest, longest, strongest bone in the body!!
• Receives a lot of stress
• Courses medially
• More in women!
• Articulates with acetabulum proximally
• Articulates with tibia and patella distally
Knee

• Patella
• Triangular sesamoid bone
• Protects knee joint
• Improves leverage of thigh muscles acting across the knee
Leg

• Tibia
• Receives the weight of body from femur and transmits to foot
• Second to femur in size and weight
• Articulates with fibula proximally and distally
• Interosseous membrane
• Fibula
• Does NOT bear weight
• Muscle attachment
• Not part of knee joint
• Stabilize ankle joint
Foot

• Function:
• Supports the weight of the body
• Act as a lever to propel the body forward
• Parts:
• Tarsals
• Talus = ankle
• Between tibia and fibula
• Articulates with both
• Calcaneus = heel
• Attachment for Calcaneal tendon
• Carries talus
• Metatarsals
• Phalanges
 

• Function:
• Supports the weight of the body
• Act as a lever to propel the body forward
• Parts:
• Tarsals
• Talus = ankle
• Between tibia and fibula
• Articulates with both
• Calcaneus = heel
• Attachment for Calcaneal tendon
• Carries talus
• Metatarsals
• Phalanges
• 3 arches
• Medial
• Lateral
• Transverse
• Has tendons that run inferior to foot bones
• Help support arches of foot
Joints of Lower Limb

• Hip (femur + acetabulum)
• Ball + socket
• Multiaxial
• Synovial
• Knee (femur + tibia)
• Hinge (modified)
• Biaxial
• Synovial
• Contains menisci, bursa, many ligaments
• Knee (femur + patella)
• Plane
• Gliding of patella
• Synovial
Joints of Lower Limb

• Proximal Tibia + Fibula
• Plane, Gliding
• Synovial
• Distal Tibia + Fibula
• Slight “give” (synarthrosis)
• Fibrous (syndesmosis)
• Ankle (Tibia/Fibula + Talus)
• Hinge, Uniaxial
• Synovial
• Intertarsal & Tarsal-metatarsal
• Plane, synovial
• Metatarsal-phalanges
• Condyloid, synovial
• Interphalangeal
• Hinge, uniaxial
Muscles of Hip and Thigh

• Gluteals
• Posterior pelvis
• Extend thigh
• Rotate thigh
• Abducts thigh
• Anterior Compartment Thigh
• Flexes thigh at hip
• Extends leg at knee
• Medial/Adductor Compartment
• Adducts thigh
• Medially rotates thigh
• Posterior Compartment Thigh
• Extends thigh
• Flexes leg
Gluteals

• Gluteus maximus
• Origin - Ilium, sacrum and coccyx
• Insertion - Gluteal tuberosity of femur, iliotibial tract
• Action - Extends thigh, lateral rotation & abduction
• Innervation - Inferior gluteal nerve
• Gluteus medius & Gluteus minimus
• Origin – posterior Ilium
• Insertion - Greater trochanter of femur
• Action - Abduction, medial rotation
• Innervation - Superior gluteal nerve
• Lesser Gluteals help stabilize hip to allow fluent bipedal walking
• Tensor fasciae latae
• Origin – iliac crest and ASIS
• Insertion – iliotibial tract
• Action - Flex thigh, abduct thigh, medial rotation of thigh
• Innervation – Superior gluteal nerve
Anterior Compartment Thigh

• Quadriceps femoris
• Rectus femoris
• Origin – anterior inferior iliac spine, margin of acetabulum
• Insertion – patella and tibial tuberosity via the patellar ligament
• Action – extends knee, flexes thigh
• Vastus lateralis
• Origin-lateral proximal femur, linea aspera
• Vastus medialis
• Origin-medial proximal femur, linea aspera
• Vastus intermedius
• Origin – ant & lateral femur
• Insertion for all– patella and tibial tuberosity via the patellar ligament
• Action – extends knee
Anterior Compartment Thigh

• Quadriceps femoris
• Rectus femoris
• Origin – anterior inferior iliac spine, margin of acetabulum
• Insertion – patella and tibial tuberosity via the patellar ligament
• Action – extends knee, flexes thigh
• Vastus lateralis
• Origin-lateral proximal femur, linea aspera
• Vastus medialis
• Origin-medial proximal femur, linea aspera
• Vastus intermedius
• Origin – ant & lateral femur
• Insertion for all– patella and tibial tuberosity via the patellar ligament
• Action – extends knee
• All above innervated by the femoral nerve!!!
 
Anterior Compartment Thigh

• Sartorius
• Origin - anterior superior iliac spine
• Insertion – medial tibia
• Action - flex, abduct, lat rotate thigh; weak knee flexor
• Iliopsoas
• Origin - Ilia, sacrum, lumbar vertebrae
• Insertion – lesser trochanter of femur
• Action – flexor of thigh
• Innervation – femoral nerve
Adductors

• Adductor longus
• Adductor brevis
• Adductor magnus
• Origin – inferior pelvis (details on pg 564)
• Insertion – linea aspera of femur
• Action – adducts and medial rotates
• Innervation – Obturator nerve
• Pectineus
• Origin – pectineal line of pubis
• Insertion – lesser trochanter of femur
• Action – adducts, medial rotates
• Innervation – femoral, sometimes obturator
• Gracilis
• Origin – inferior pubic ramus
• Insertion – medial tibia
• Action – adducts thigh, flex, medial, rotates leg
• Innervation – Obturator nerve
Posterior Compartment - Hamstring

• Biceps femoris (2 heads)
• Origin – ischial tuberosity (long) linea aspera of femur (short)
• Insertion - lateral tibia, head fibula
• Action - thigh extension, knee flexion, lateral rotation
• Semitendinosus
• Semimembranosus
• Origin - ischial tuberosity
• Insertion –proximal, medial tibia
• Action - thigh extension, knee flexion, medial rotation
Sciatic nerve innervates all of the above muscles!!!

Muscles of the Leg

• Anterior Compartment
• Dorsiflex ankle, invert foot, extend toes
• Innervation: Deep fibular nerve
• Lateral Compartment
• Plantarflex, evert foot
• Innervation: Superficial Fibular nerve
• Posterior Compartment
• Superficial and deep layers
• Plantarflex foot, flex toes
• Innervation: Tibial nerve
Anterior Compartment

• Tibialis anterior
• Origin - tibia
• Insertion - tarsals
• Action - dorsiflexion, foot inversion
• Extensor digitorum longus
• Origin – tibia and fibula
• Insertion - phalanges
• Action – toe extension
• Extensor hallucis longus
• Origin – fibula, interosseous membrane
• Insertion – big toe
• Action - extend big toe, dorsiflex foot
• All innervated by deep fibular nerve
Lateral Compartment

• Fibularis (peroneus) longus
• Origin – lateral fibula
• Insertion – 5 th metatarsal, tarsal
• Action - plantarflex, evert foot
• Fibularis (peroneus) brevis
• Origin – distal fibula
• Insertion - proximal fifth metatarsal
• Action – same as above!!
All innervated by the superficial fibular nerve

Superficial Posterior Compartment

• Triceps surae
• Gastrocnemius (2 heads)
• Origin - medial and lateral condyles of femur
• Insertion - posterior calcaneus via calcaneal tendon
• Soleus
• Origin – tibia and fibula
• Insertion – same as above
• Action of both – plantarflex foot
• Plantaris
• Origin – posterior femur
• Insertion – same as above!
• Action – plantarflex foot, week knee flexion
All innervated by the tibial nerve
Deep Posterior Compartment

• Popliteus
• Origin - lateral condyle femur
and lateral meniscus

• Insertion – proximal tibia
• Action – flex and medially rotate leg
• Flexor digitorum longus
• Origin - tibia
• Insertion - distal phalanges of toe 2-5
• Action – plantarflex and invert foot, flex toe
• Flexor hallucis longus
• Origin - fibula
• Insertion - distal phalanx of hallux
• Action - plantarflex and invert foot, flex toe
• Tibialis posterior
• Origin – tibia, fibula, and interosseous membrane
• Insertion - tarsals and metatarsals
• Action - plantarflex and invert foot
All innervated by the tibial nerve
Muscles of the Foot

• Dorsum of Foot
• Extensor digitorum brevis
• O: calcaneus, I: prox phalanx of hallux
• Action: extend MT-P joint
• Innervation = Deep Peroneal (Fibular) n.
• Plantar Surface of Foot (= sole): 4 layers
• O: Tarsals and/or Metatarsals, I: Phalanges
• Action: Flex, Ext, ABduct, ADduct
• Innervation: Medial + Lateral Plantar n. (from Tibial n.)
Plexuses of the Lower Limb

• “Lumbosacral plexus”
• Lumbar Plexus
• Arises from L1-L4
• Lies within the psoas major muscle
• Sacral Plexus
• Arises from spinal nerve L4-S4
• Lies caudal to the lumbar plexus
Lumbar Plexus

• Femoral nerve
• Cutaneous branches
• Thigh, leg, foot (e.g. saphenous nerve)
• Motor branches
• Anterior thigh muscles (e.g. quadriceps, sartorius, iliopsoas)
• Obturator nerve
• Sensory
• Skin medial thigh; hip, knee joints
• Motor
• Adductor muscles
• Lateral femoral cutaneous
• Sensory
• Skin lateral thigh
• Genitofemoral
• Sensory
• Skin scrotum, labia major, anterior thigh
• Motor
• Cremaster muscle
Sacral Plexus

• Sciatic
• Motor:
• Hamstring
• Branches into:
• Tibial nerve
• Cutaneous
• Posterior leg and sole of foot
• Motor
• Posterior leg, foot
• Common fibular (peroneal) nerve
• Cutaneous
• Anterior and lateral leg, dorsum foot
• Motor
• Lateral compartment, tibialis anterior, toe extensors
• Superior gluteal nerve
• Motor
• Gluteus medius and minimus, tensor fasciae latae
Sacral Plexus

• Inferior gluteal nerve
• Motor
• Gluteus maximus
• Posterior femoral cutaneous nerve
• Sensory
• Inferior buttocks, posterior thigh, popliteal fossa
• Pudendal nerve
• Sensory
• External genitalia, anus
• Motor
• Muscles of perineum
Arteries

• Common iliac (from aorta) branches into:
• Internal iliac
• Supplies pelvic organs
• External iliac
• Supplies lower
Arteries

• Internal iliac branches into:
• Cranial and Caudal Gluteals
(Superior and Inferior)

• Gluteals
• Internal Pudendal
• Perineum, external genitalia
• Obturator
• Adductor muscles
• Other branches supply rectum, bladder, uterus, vagina, male reproductive glands
Arteries

• External iliac becomes…….
• Femoral
• Once passes the inguinal ligament
• Lower limb
• Branches into Deep femoral
• Adductors, hamstrings, quadriceps
• Branches into Medial/lateral femoral circumflex
• Head and neck of femur
• Femoral becomes……
• Popliteal (continuation of femoral)
• Branches into:
• Geniculars
• Knee
• Splits into:
• Anterior Tibial
• Anterior leg muscles, further branches to feet
• Posterior Tibial
• Flexor muscles, plantar arch, branches to toes
Veins

• Deep Veins: Mostly share names of arteries
• Ultimately empty into Inferior Vena Cava
• Plantar
• Tibial
• Fibular
• Popliteal
• Femoral
• External/internal iliac
• Common iliac
• Superficial Veins
• Dorsal venous arch (foot)
• Great saphenous (empties into femoral)
• Small saphenous (empties into popliteal)

Pelvis and Contents

Pelvis and Contents

Reproductive Organs

Bones of the Pelvis

Pelvic / hip girdle

Function:

Attaches the lower limbs to spine

Supports the viscera of the pelvis

Transmits the weight of the upper body

Contents:

Paired hip bones (coxal bone)

Unite with each other anteriorly and with the sacrum posteriorly

Bony pelvis:

Os coxae, sacrum and coccyx

Use lab work to learn bony landmarks of pelvis

Os Coxae

Each pelvic bone during childhood:

Ilium

Superior region

Ishium

Posteroinferior region

Pubis
Anterior region

True and False Pelves

Separated by the pelvic brim

False Pelvis

Superior to the pelvic brim

Iliac blades

contains abdominal organs

attachment for muscles and ligaments to body wall

True Pelvis

Inferior to the pelvic brim

Space contains

part colon

rectum

bladder

uterus/ovaries (females)


Pelvic Diaphragm

levator ani and coccygeus muscles

Supports pelvic organs

Seals inferior opening of bony pelvis

Lifts to help release feces during defecation

Sexual Dimorphism

Females

Tilted forward

Cavity is broad, shallow

Pelvic inlet oval and outlet round

Bones are lighter, thinner

Pubic angle larger

Ischial tuberosities shorter, more everted

Coccyx more moveable, straighter

Males

Cavity is narrow, deep

Smaller inlet and outlet

Bones heavier, thicker

Pubic angle more acute

Ischial tuberosities longer, face more medially

Coccyx less moveable, more curved

Perineum

Anus and external genitalia

Diamond shaped

Pubic symphysis anteriorly

Ischial tuberosities laterally

Coccyx posteriorly

Females:

External genitalia

Anus

Males:

Scrotum

Root of penis

Anus 

Embryonic Development of the Sex Organs

Begin at week 5 as masses of gonadal ridges

Develop into the gonads

Sexually indifferent!

Both ducts are present in embryo, but only one develops:

Male

Mesonephric (Wolffian) ducts

Vas deferens, epididymis

Female

Paramesonephric (Müllerian) ducts

Uterus, oviduct, vagina

External genitalia develops from same structures

Embryonic structure Male Female

Labioscrotal swelling Scrotum Labia major

Urethral folds Penile Urethra Labia minor

Genital tubercle Penis Clitoris


Descent of the Gonads

Male Development:

Testes partially descend at 3 months, finish at 7 months

Enter the scrotum

Vaginal process

Outpocketing of the peritoneal cavity

Eventually closes off

Forms tunica vaginalis

Gubernaculum

Fibrous cord

Extends from the testis to floor of scrotal sac

Final teste descent:

Shortening of gubernaculum

Increase in intra-abdominal pressure

Testosterone stimulation

Descent of the Gonads

Female Development

Descend only into the pelvis

Broad ligament blocks further descent

Gubernaculum

Guides ovaries

Attached to labia major

Becomes:

Round ligament of the uterus (inferior portion)

Ovarian ligament (superior portion)

Vaginal process

Outpocketing of peritoneum guides descent

Puberty

Between ages 10 and 15

Reproductive organs grow to their adult size

Reproduction becomes possible

Changes occur due to the increase in reproductive hormones in each individual

Testosterone in males

Estrogens in females

Dimporhism at Puberty

Males

Age 13

Enlargement of the testes and scrotum

Secondary sex characteristics

Appearance of pubic, axillary, and facial hair

Enlargement of larynx

Oily skin 

Increase in body size and musculature

Females 

Age 11

Budding of breasts

Secondary sex characteristics

Increase in subcutaneous fat (hips and breasts)

Widening and lightening of the bones

Oily skin

Hair in pubic and axillary region

Menarche

Menstruation

Happens 1-2 years later

Reproductive System

Overall function is to produce offspring

Genitalia = sex organs

Primary = Gonads

Ovaries, testes

Produce the sex cells / gametes

Eggs, sperm

Secrete sex hormones

Secondary = Accessory

Glands, ducts, external genitalia

Nourish and transport of gametes

Male Reproductive System

Primary sex organ

Gonads = testes

Lie in the scrotum

Sperm-producing

Secondary sex organs

External Genitalia

Penis

Scrotum

Ducts

Epididymis

Efferent ductules

Duct of epididymis

Vas deferens

Ejaculatory duct



Urethra



Glands

Seminal vesicle

Prostate

Bulbourethral

Scrotum

Sac of skin and fascia

Hangs at the root of the penis

Contains the testes

Septum in midline divides right and left halves

Muscles:

Dartos

Inside skin of scrotum

Smooth muscle

Responsible for wrinkling of scrotal skin (warms)

Cremaster

Extends into scrotum from spermatic cord

Fibers from internal oblique

Skeletal muscle

Responsible for elevating and lowering the testes (warming and cooling)

Testes

Lie within the scrotum

Tunica vaginalis

Light sac partly covering each testes

Tunica albuginea

Fibrous capsule of the testes

Deep to tunica vaginalis

Divides testes into lobules

Lobules contain seminiferous tubules

Reproductive Duct System

Seminiferous tubules

“sperm factories”

Location of spermatogenesis

Converge into…….

Tubulus rectus

Straight tube that conveys sperm into….

Rete testis

Lead to the……

Efferent ductules

Lead to epididymis ….

Reproductive Duct System

Epididymis

Site of sperm maturation

Smooth muscle layer leads to ejaculation

Contains:

Head 

Contain the efferent ductules

tube from rete testes to duct of epididymis

Ciliated simple columnar epithelium

Body and Tail

Duct of epididymis

Highly coiled

Leads into the vas deferens

Pseudostratified columnar epithelium with stereocilia

Resorb testicular fliud

Transfer nutrients and secretions to sperm stored in the epididymis

Reproductive Duct System

Vas Deferens (Ductus Deferens)

Stores and transports sperm during ejaculation

Runs from epididymis to ejaculatory duct

ED then runs within the prostate gland and empties into the prostatic urethra

Layers:

Pseudostratified epithelium

Lamina propria

Thick muscularis

Adventitia

Vasectomy

Cut vas deferens, close off ends

Sperm STILL produced, but cannot exit the body

Reversible sometimes!

Reproductive System

Spermatic Cord

Collective name for structures associated with the scrotum

Passes through inguinal canal

Includes

Vas Deferens

Testicular arteries and veins (pampiniform plexus)

Lymphatic vessels

Cremaster muscle fibers

Nerves

Cell Division

Mitosis

Events in which replicated DNA of original cell is divided into 2 new cells

Cell division with chromosome duplication and division à2 daughter cells = parent

Have Diploid = 2n number of chromosomes

Occurs in body (somatic) cells

Meiosis = Reductional division

Events that reduce the number of chromosomes (1/2 of the parent)

Have Haploid = n number of chromosomes

Occurs in sex cells
Spermatogenesis

Production of sperm

Stages:

Stem cells = Spermatogonia (2n)

Mitosis

Formation of 2 daughter cells

Type A become precursor cells (2n)

Type B become primary spermatocytes (2n)

Meiosis

Primary spermatocytes undergo Meiosis I

2 secondary spermatocytes (n)

Secondary spermatocytes undergo Meiosis II

4 spermatids (n)

Spermiogenesis

Spermatids differentiate into sperm

Sperm cell (spermatozoan)

Head (acrosome), tail and midpiece

Controlled by FSH (pituitary gland) and testosterone (testes)

Within Seminiferous Tubules

Sustentacular cells (Sertoli cells)

Surround the spermatogenic cells in the lumen

Provide nutrients to spermatogenic cells

Move cells toward tubule lumen

Secrete testicular fluid

Phagocytize cytoplasm shed by developing spermatids

Secrete Androgen-binding protein (concentrates testosterone)

Secrete Inhibin (hormone slows rate of sperm production)

Blood-testis barrier

In tight junctions between the sustentacular cells

Prevent escape of membrane antigens from sperm into the bloodstream

Within Seminiferous Tubules

Myoid cells

Layers of smooth muscle cells

Contract to squeeze sperm thru tubules and out of testis

Interstitial cells (Leydig cells)

Make and secrete male sex hormone (androgens)

In CT between tubules

Accessory Glands

Seminal Vesicles (2)

Lie on posterior surface of the bladder

Joins the vas deferens to form an ejaculatory duct

Contracts during ejaculation to empty

Secretion contains:

Fructose to nourish sperm

Prostaglandins to stimulate contraction of the uterus

Suppress immune response in females

Sperm motility enhancers

Enzymes that clot ejaculated semen in vagina, then liquefy it so sperm can swim out

Accessory Glands

Prostate gland

Inferior to bladder, anterior to rectum

Encircles the first part of the urethra

Contracts during ejaculation

Secretion contains:

Substances that enhance sperm motility

Enzymes that liquefy ejaculated sperm

Bulbourethral gland (2)

Inferior to prostate gland

Within urogenital diaphragm

Empties into spongy urethra

Produce a mucus

Neutralize urine in urethra

Lubricate semen for passage

Penis

Male external genitalia

Delivers sperm into the female reproductive tract

Anatomy:

Root

Attached end

Crura

Anchored to pubic arch, covered by ischiocavernosus muscle

Bulb

Secured to urogenital diaphragm

Body / Shaft

Free; not attached

Glans penis

Enlarged tip

Prepuce / Foreskin

Loose cuff around glans

Spongy urethra

Tube within penis

Penis

Erectile bodies

3 cylindrical bodies around the spongy urethra

Thick tube covered by DCT

Filled with smooth muscle, CT, and vascular spaces

Corpus spongiosum

Midventral erectile body

Distally forms the glans penis

Proximally forms the bulb of the penis

Corpora cavernosa

Paired, dorsal erectile bodies

Proximal ends are the crura of the penis (crus)

Covered by ischiocavernosus muscle

Make up most of the mass of the penis

Penis Innervation and Vasculature

Arterial supply

Branches of internal pudendal

Innervation

Branches of pudendal from sacral plexus provides sensory innervation

Parasympathetic

Engorgement of blood in erectile bodies = erection

Sympathetic

Contraction of smooth muscle in ducts and glands and bulbospongiosum muscle = ejaculation

Autonomic from inferior hypogastric plexus

Female Reproductive System

Primary Sex Organs

Ovaries = gonads

Secondary Sex Organs

External Genitalia = vulva

Labia major + minor

Mons pubis

Clitoris

Ducts

Uterine tube = oviducts

Vagina

Glands

Greater vestibular gland

Anatomy

Ovaries (2)

Produce and store ova (eggs)

Produce estrogen

Tunica albuginea

Fibrous capsule that surrounds the ovary

Germinal epithelium

Covers the tunica albuginea

Mesothelium

Anatomy

Ovaries

Held in place by mesentery and ligaments made of peritoneum

Ligaments

Broad ligament

Supports uterus and oviducts

Suspensory ligament

Attaches ovaries to lateral pelvic wall

Ovarian ligament

Anchors the ovary to the uterus medially

Round ligament

Part of broad ligament

Attaches uterus to labia majorum

Oogenesis: production of eggs (ova)

Stem cells = oogonia undergo Mitosis

All of female’s oogonia produced while fetus

Oogonia become oocytes

Oogonia begin Meiosis I are called primary oocytes (2n)

Meiosis I is stalled before birth and until ovulation

During ovulation, Meiosis I completed and Meiosis II begins

Once Meiosis II begins, primary oocytes now called secondary oocytes (n)

Meiosis II is completed when sperm penetrates plasma membrane of the egg

When Meiosis II is completed, secondary oocyte is now called ovum (egg)

Meiosis II results in 4 daughter cells

1 ovum and 3 polar bodies (degenerate)

Uterine Tubes

Also called oviducts, fallopian tubes

Begins laterally near ovary and ends medially at uterus

3 parts:

Infundibulum

Lateral, funnel shaped portion

Fimbrae on edges

Ampulla

Medial to infundibulum

Expanded portion

Site where fertilization occurs

Isthmus

Medial part of the tube

Layers

Visceral Peritoneum

Smooth Muscle

Ciliated simple columnar epitheliu

Movement of Ova

Through the oviduct

Receives oocyte after ovulation

Peristaltic waves

Cilia lining tube

Contains cells to nourish ova

Ectopic pregnancy 

Implantation of embryo outside of the uterus

Uterus

Function: 

Receive, retain, nourish fertilized egg (=zygote)

3 layers of wall:

Perimetrium (outer)

Myometrium (middle)

Endometrium (inner)

Portions:

Body

Fundus

Isthmus

Location:

Anterior to rectum

Posterosuperior to bladder

Cervix

Location:

Below the isthmus of the uterus

Considered the narrow neck of the uterus

Projects into the vagina

Function:

Keeps uterus closed and fetus within it during pregnancy (collagen)

Vagina

Location:

Inferior to the uterus

Anterior to the rectum

Posterior to the urethra and bladder

Birth canal

3 layers:

Adventitia

Muscularis

Mucosa

Rugae


Vaginal orifice

Hymen

Extension of mucosa

Incomplete wall / diaphragm

Female External Genitalia = “Vulva”

Mons pubis

Rounded pad over the pubic symphysis

Labia

Major

Fatty skin folds with hair

Minor

Smaller, hairless folds inside major

3 parts:

Vestibule

created by labia minor

opening for urethra and vagina

Central tendon

Fourchette

Junction of labia minor

Female External Genitalia = “Vulva”

Clitoris

Superior to vestibule

Composed of erectile tissue

Homologous to the penis

Components:

Crura

Prepuce

Corpus cavernosa

No corpus spongiosum

Bulbs of vestibule

Engorge with blood to help grip the penis

Greater vestibular glands

Either side of vaginal opening

Secrete mucus to make intercourse possible

Vasculature and Innervation

Vasculature

Uterine arteries from internal iliac and arcuate branches = uterus

Ovarian arteries from abdominal aorta and ovarian branches of uterine arteries = ovaries

Innervation

Branches of Pudendal nerve (hypogastric plexus & pelvic splanchnic nerves)

Fertilization: sperm meets egg

Path of sperm:

Seminiferous tubules àtubulus rectus àrete testis àefferent ductules à duct of epididymis à vas deferens à ejaculatory duct à urethra àfemale’s vagina à uterus àoviduct

Path of egg:

ovary àperitoneal cavity àinfundibulum (oviduct) àoviduct

The meeting:

Sperm + egg meet in uterine tube àsperm penetrates egg = fertilization

Zygote à uterus for implantation in uterine wall

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 Pelvis and Contents

Organs of Abdomen lecture presentation

The Abdomen
Surface Anatomy, Vessels, Muscles, and Peritoneum
Abdominopelvic Cavity

• Ventral body cavity
• Thoracic
• Abdominopelvic
• Abdominopelvic
• Abdominal
• Liver
• Stomach
• Kidneys
• Pelvic cavity
• Bladder
• Some reproductive organs
• Rectum

Abdominopelvic Cavity

• Surrounded by the abdominal walls and pelvic girdle
• The two cavities are continuous
• Most organs surrounded by a peritoneal cavity
• Visceral peritoneum
• Parietal peritoneum
• Peritoneal cavity

Abdominal Quadrants

• Surrounded by the abdominal walls and pelvic girdle
• The two cavities are continuous
• Most organs surrounded by a peritoneal cavity
• Visceral peritoneum
• Parietal peritoneum
• Peritoneal cavity

 
Surface Anatomy

• Anterior abdominal wall extends from costal margin to inferior boundaries:
• Iliac crest
• Anterior superior iliac spine
• Inguinal ligament
• Pubic crest
• Superior boundary
• Diaphragm
• Central landmark
• Umbilicus
• Linea alba (white line)
• Tendinous line
• Extends from xiphoid process to pubic symphysis

Muscles

• Function:
• Help contain abdominal organs
• Move trunk
• Forced breathing
• Increase intra-abdominal pressure
• Abdominal wall
• Anterior (4)
• Innervated by intercostal nerves
• Continuous with layers of intercostal muscles
• Fibers of layers run in different directions for strength
• Ends in aponeurosis which contains rectus abdominis muscle
• Posterior (3)

Anterior Abdominal Wall Muscles

• External oblique
• Origin
• Lower 8 ribs
• Insertion
• Aponeurosis to linea alba, pubic and iliac crest
• Function
• Flex trunk, compress abdominal wall (together), Rotate trunk (separate sides)
• Internal oblique
• Origin
• Lumbar fascia, iliac crest, inguinal ligament
• Insertion
• Linea alba, pubic crest, last 3-4 ribs, costal margin
• Function
• Same for external obliques

Anterior Abdominal Wall

• Transversus Abdominis
• Origin
• Inguinal ligament, lumbar fascia, cartilage of last 6 ribs, iliac crest
• Insertion
• Linea alba, pubic crest
• Function
• Compress abdominal contents

• Rectus Abdominis

• Origin
• Pubic crest, symphysis
• Insertion
• Xiphoid process, costal cartilages of ribs 5-7
• Function
• Flex, rotate trunk, fix and depress ribs, stabilize pelvis, compress abdomen

Posterior Abdominal Wall

• Iliopsoas
• Psoas major
• Origin
• Lumbar vertebrae, T 12
• Insertion
• Lesser trochanter of femur via iliopsoas tendon
• Function
• Thigh flexion, trunk flexion, lateral flexion
• Innervation
• Ventral rami L1-L3
• Iliacus
• Origin
• Iliac fossa, ala of sacrum
• Insertion
• Lesser trochanter of femur via iliopsoas tendon
• Function
• Thigh flexion, trunk flexion
• Innervation
• Femoral nerve (L2 and L3)
• Psoas minor – variable (40-60% do not have)
• Quadratus lumborum
• Origin
• Iliac crest and lumbar fascia
• Insertion
• Transverse process of upper lumbar vertebrae, lower margin of rib 12
• Function
• Flex vertebral column, maintains upright posture, assists in inspiration
• Innervation:
• T12 and upper lumbar spinal nerves (ventral rami)

Peritoneum

• Mesenteries
• Double layer of peritoneum (2 serous membranes fused together)
• Extend to the digestive organs from the body wall
• Function:
• Hold organs in place
• Sites of fat storage
• Provide a route for vessels and nerves
• Ventral mesenteries:
• Lesser omentum and Falciform ligament
• Dorsal mesenteries:
• Greater omentum, Transverse mesocolon, Mesentery proper, and Sigmoid mesocolon

Peritoneum

• Intraperitoneal
• Organs remain surrounded by peritoneal cavity
• Liver, stomach, ileum and jejunum, transverse colon
• Retroperitoneal
• Some organs lay behind/outside peritoneum
• Primarily retroperitoneal
• Organs NEVER within the cavity
• Kidneys, bladder, ureter
• Secondarily retroperitoneal
• Organs once suspended within the abdominal cavity by mesentery
• Migrate posterior to the peritoneum during the course of embryogenesis to become retroperitoneal
• Lack mesenteries
• Duodenum, ascending and descending colon, rectum, pancreas

Urinary System

• Kidney (2)
• Purify blood
• Ureter (2)
• Drains urine from kidney to bladder
• Urinary Bladder
• Stores urine
• Urethra
• Drains urine from bladder to outside body

Kidneys

• Filter waste from blood
• Water, toxins, urea, uric acid, creatinine, metabolic waste, ions
• Excretion of waste
• Homeostasis
• Acid-base balance
• Blood pressure
• Plasma volume
• Filter waste from blood
• Water, toxins, urea, uric acid, creatinine, metabolic waste, ions
• Excretion of waste
• Homeostasis
• Acid-base balance
• Blood pressure
• Plasma volume

Kidneys: Gross Anatomy

• Lie in retroperitoneal, superior lumbar region
• Extend from T11 or T12 to L3
• Laterally convex, medially concave
• Hilum
• Where blood vessels, ureters, and nerves enter and leave kidney
• Adrenal gland
• On superior portion
• Endocrine
• Cortisol
• Aldosterone
• Adrenaline

Kidney: Gross Anatomy
Internal

Extcernal

• Supportive tissue
• Renal capsule
• DCT
• Adheres directly to kidney surface
• Maintains shape and forms barrier
• Adipose capsule
• Perirenal fat
• Cushions kidney
• Keeps kidney in place
• Renal fascia
• Pararenal fat
• Cushions kidney
• Keeps kidney in place

Kidney: Internal Gross Anatomy

• Cortex
• Superficial
• Lighter zone
• Functional portion
• Medulla
• Deep
• Darker zone
• Pyramid shaped
• Contains collecting tubules

Kidney: Gross Anatomy

• Separated into lobes
• Medulla pyramid & associated cortex
• Blood supply
• Renal artery and vein
• Innervation
• Branches of renal plexus

Kidney: Internal Gross Anatomy

• Medullary pyramid
• Makes up the medulla
• Base: against cortex
• Apex: inward
• Papilla = tip
• Drips urine into minor calyx
• Calices
• Collect urine draining from papillae and empty into renal pelvis
• Minor calices
• Collect urine from papilla
• Surround papilla of pyramids
• Empty into major calices
• Major calices
• Receive urine from several minor calices
• Empty into renal pelvis
• Renal pelvis
• Funnel-shaped
• Empties urine into ureter

Kidney: Microscopic Anatomy

• Uriniferous tubules
• Produces urine through filtration, reabsorption, and secretion
• 2 major part:
• Nephron
• Collecting duct

Ureters

• Carry urine from the kidneys to the bladder
• Begins superiorly at L2 as a continuation of renal pelvis
• Opens into the bladder
• Retroperitoneal
• Enters the bladder at an oblique angle
• This prevents backflow into the ureters
• Increased pressure in bladder lead to the distal end of ureter closing
• Not only gravity at work here!!

Ureters: Microscopic Anatomy

• Another tubular organ!!
• Mucosa
• Lamina epithelialis
• Transitional epithelium
• Stretches when ureters are full
• Lamina propria
• Muscularis
• Inner longitudinal
• Outer circular
• External longitudinal layer (inferior third)
• Function in peristalsis
• Adventitia
• CT

Urinary Bladder

• Full bladder expands into abdominal cavity
• Empty bladder lies within pelvic cavity
• Vasculature:
• Internal iliac branches of arteries and veins
• Innervation:
• Branches of the hypogastric plexus

Urinary Bladder: Internal Anatomy

• Tubular organ!!!!!
• Trigone area
• 3 layers:
• Mucosa
• Transitional epithelium
• Lamina propria
• Muscular layer
• Detrusor muscle (smooth);
• 3 layers:
• Inner and outer longitudinal, middle circular
• Adventitia
• Fibrous CT
• Parietal peritoneum on superior surface

Urethra

• Drains urine from bladder to outside of body
• Opens at the external urethral orifice
• Female:
• Short tube
• Male
• 3 regions
• Prostatic urethra
• Membranous urethra
• Spongy/penile urethra
• Also carries ejaculating semen
• Internal urethral sphincter
• At bladder/urethral junction
• Thickening of detrusor muscle
• Involuntary; keeps urethra closed when urine is not being passed
• Prevents dribbling!
• External urethral sphincter
• Surrounds urethra within the urogenital diaphragm
• Inhibits voluntary urination until ready
• External urethral orifice
• Males:
• End of the penile urethra
• Females:
• Anterior to vaginal opening and posterior to clitoris

Micturition = Urination

• Contraction of the detrusor muscle to raise intra-abdominal pressure
• Controlled by the brain
• Urine accumulation leads to distention of the bladder
• Activates stretch receptors
• Send sensory impulses to micturition center (MC) in the pons
• MC sends signals to parasympathetic neurons
• Stimulate detrusor muscle to contract (involuntary)
• Internal urinary sphincter opens (also inhibits sympathetic pathways that would prevent urination)

Micturition = Urination

• Other brain receptors (pons, cerebral cortex) can inhibit urination
• Relaxing of the detrusor, keeping external urinary sphincter closed
• Voluntary contraction of abdominal wall muscles increases abdominal pressure
• Voluntary relaxation of external urethral sphincter

Digestive System

• Alimentary Canal
• Mouth
• Pharynx
• Esophagus
• Stomach
• Small Intestine
• Large Intestine
• Accessory Organs
• Teeth, Tongue
• Salivary Glands
• Gallbladder
• Liver
• Pancreas

Digestive Processes – 6 Steps

• Ingestion
• Taking food into the mouth
• Mechanical digestion
• Prepares food for chemical digestion
• Chewing, churning, segmentation
• Propulsion
• Movement of food through GI tract
• Swallowing and peristalsis
• Chemical digestion
• Enzymes break down complex food molecules
• Absorption
• Digested end products from lumen to blood
• Defecation
• Elimination of indigestible substances

Alimentary Canal Wall

• ANOTHER tubular organ!
• Layers:
• Mucosa
• Epithelium
• Lamina propria (MALT)
• Lamina muscularis mucosa
• Submucosa
• CT with elastic fibers, nerves, vessels
• Muscularis
• Inner circular
• Outer longitudinal
• Creates sphincters
• Serosa / Adventitia

Peristalsis vs Segmentation

• Peristalsis
• Propulsion
• Adjacent segments of the alimentary canal contract and relax
• Moves food distally along the canal
• Segmentation
• Part of mechanical breakdown
• Food-mixing process
• Nonadjacent segments of the intestine alternatively contract and relax
• Moves food on and back
• Mixes rather than propels

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Innervation

• Nerve plexuses
• Occur within wall of alimentary canal
• Parasympathetic, Sympathetic, Visceral Sensory fibers
• 2 types:
• Myenteric nerve plexus
• Between 2 muscle layers of the tunica muscularis
• Controls segmentation and peristalsis
• Submucosal nerve plexus
• Between submucosa and muscularis mucosa
• Signals glands to secrete and LMM to contract

Innervation

• Enteric Nervous System (ENS)
• Internal neurons in wall of canal (100 million!!)
• Within the above plexuses
• Form independent arcs of sensory, intrinsic, and motor neurons
• Controls glandular secretion, peristalsis, segmentation
• Autonomic Nervous System speeds up or slows activity controlled by enteric system
• Allows the CNS to influence it

Stomach

• J-shaped, Temporary storage tank
• Intraperitoneal
• Regions:
• Cardiac
• Cardiac orifice
• Junction of esophagus
• Fundus
• Under diaphragm
• Body
• Large midportion
• Pyloric
• Ends at the stomach
• Pyloric sphincter
• Greater curvature
• Lesser curvature

Stomach – Internal Anatomy

• Mucosa
• Epithelium
• Simple columnar
• Rugae
• Folds that allow for volume changes
• Intrinsic glands
• Goblet cells
• Gastric glands
• Parietal cells
• Enteroendocrine cells
• Chief cells
• Submucosa
• Muscularis
• Oblique layer
• Circular layer
• Pyloric sphincter
• Longitudinal layer
• Serosa

Stomach Function

• Storage of chyme
• Food paste
• Breakdown of food proteins
• Done by pepsin
• Protein-digestion under acidic conditions
• Absorption of nutrients
• H 2O, electrolytes
• Alcohol, other drugs
• Food remains for about 4 hours
• Holds from 1.5 to 4 liters

Small Intestine

• Longest portion of GI tract
• Site of most enzymatic digestion and absorption of nutrients
• Bile: emulsifier (gallbladder, liver)
• Enzymes (pancreas)
• Undergoes segmentation
• Allows for an increase contact with intestinal walls
• Peristalsis propels chyme through in about 3 to 6 hours
• 2.6 to 6 meters long!!

www.nlm.nih.gov
Small Intestine

• Location:
• From pyloric sphincter to first part of the large intestine
• Regions:
• Duodenum (5%)
• Proximal
• Jejunum (almost 40%)
• Middle
• Ileum (almost 55%)
• Distal

Small Intestine

• Duodenum
• C – shaped , short, straight
• Mostly retroperitoneal
• Receives:
• Digestive enzymes from pancreas via main pancreatic duct
• Bile from liver via the bile duct
• Duodenal glands:
• Neutralize acid from stomach
• Jejunum and ileum
• Highly coiled
• Intraperitoneal
• Fewer modifications
• Hang by mesentery in peritoneal cavity
• Mesentery Arcades
• Arteries + veins
• Nerves

www.si.mahidol.ac.th
Small Intestine Internal Anatomy

• Intestinal flora
• produces vitamin K
• Epithelium:
• Simple columnar epithelium with many modifications for absorption
• Goblet cells
• Enteroendocrine cells
• Lymph tissue in submucosa
• Muscularis externa has 2 layers
• Innervation:
• Some parasympathetic innervation from vagus
• Arterial supply:
• Superior mesenteric
• Rt (cranial) pancreaticoduodenal

SI Absorption Modifications

• Length
• More length, more area for absorption!
• Plicae Circulares
• Transverse ridges of mucosa
• Increase surface area
• Force chyme to slow down
• Villi
• Evagination of plicae circulares
• Move chyme and increase contact
• Contain lacteals
• Remove fat
• Microvilli
• Further increasing of the surface area

Modifications decrease distally
Large Intestine

• Regions:
• Cecum
• Vermiform appendix
• Colon
• Ascending
• Transverse
• Descending
• Sigmoid
• Rectum
• Anal Canal

Large Intestine

• Overall Functions:
• Absorbs remaining nutrients
• Most material largely digested
• Absorbs water and electrolytes
• Forms, stores and expels feces from body
• Propulsion is slow and weak through LI except for mass peristaltic movements

LI: Internal Features

• Intestinal flora
• No intestinal villi or modifications for absorption
• Many goblet cells
• Simple columnar epithelium except lower half of anal canal
• Significant lymph tissue in mucosa and submucosa
• Muscularis mucosae has 2 layers
• Some parasympathetic innervation from vagus

Cecum and Vermiform Appendix

• Cecum
• Sac-like pouch (blind pouch)
• Intraperitoneal
• Ileocecal valve
• 2 raised edges of the mucosa
• Prevents reflux of feces from cecum to ileum
• Vermiform Appendix
• Tubular pouch
• Opens into cecum
• Contains large masses of lymphoid tissue

Colon Special Features

• Teniae coli
• 3 Longitudinal strips
• Thickenings of longitudinal muscle layer
• Maintain muscle tone
• Cause LI to pucker into sacs…….
• Haustra
• Saclike divisions
• Epiploic appendages
• Fat-filled pouches of visceral peritoneum
• Hang from the intestine

Colon Segments

• Ascending
• Retroperitoneal
• Right side of posterior abdominal wall
• Makes right angle turn
• Right colic / hepatic flexure
• Transverse
• Intraperitoneal
• Extends left across the peritoneal cavity
• Bends downward at the spleen
• Left colic / splenic flexure
• Descending
• Retroperitoneal
• Left side
• Sigmoid
• Intraperitoneal
• S-shaped
• “False pelvis”

Colon Functions

• Absorb H 2O and electrolytes
• Some digestion by bacteria
• Mass Peristaltic Movements (2-3x day)
• Moves through in 12-24 hours
• 1.5 meters

Rectum

• Joins with the sigmoid colon
• Descends into the pelvis
• Retroperitoneal
• Complete and well-developed longitudinal muscle layer
• Rectal valves
• 3 transverse folds
• Prevent feces from being passed along with gas
• pg 312

Anal Canal

• Begins where rectum passes through the levator ani muscle
• Releases mucus to lubricate feces
• Internal anal sphincter
• Made of smooth muscle
• Involuntary
• External anal sphincter
• Made of skeletal muscle
• Voluntary
• Toilet training!!!
• Stratified squamous epithelium at lower half

Defecation

• Stretching of rectal wall initiates defecation reflex
• Mediated by the spinal cord
• Parasympathetic reflex signals walls of sigmoid colon and rectum to contract and anal sphincter to relax
• Involuntary
• If not ready, reflective contraction ends and rectum relaxes
• Reflex initiated again until you actually defecate
• Contraction of diaphragm, levator ani and abdominal muscles assist
• Voluntary

Liver

• Largest gland in the body!
• Weighs about 3 pounds
• Highly vascular
• Location:
• Inferior to diaphragm
• In right superior part of abdominal cavity
• Mostly under rib cage
• Functions: (Over 500!)
• Produce bile
• Pick up glucose
• Detoxify poison, drugs
• Produce blood proteins

Liver Gross Anatomy

• 2 surfaces:
• Diaphragmatic
• Visceral
• Lobes:
• Right lobe
• Left lobe
• Divided by:
• Falciform ligament on diaphragmatic surface
• Fissure on the visceral surface
• Quadrate lobe
• Caudate lobe

Liver – Visceral Surface

• Hepatic Vein (into inferior vena cava)
• Porta Hepatis
• Common Hepatic Artery (from celiac trunk)
• Hepatic Portal Vein
• Carries nutrient-rich blood from stomach and intestines to liver
• Hepatic portal system = 2 capillary beds!
• Hepatic Ducts (carry bile)

Gallbladder

• Muscular sac
• Rests in depression of right liver lobe
• Has many ducts associated with it
• Stores and concentrates bile
• Emulsification
• Produced in liver
• Stored in gallbladder
• Released into the duodenum

Gallbladder

• Mucosa
• Simple columnar epithelium
• Lamina propria
• Expandable mucosal folds
• Smooth muscle layer
• Thick connective tissue
• Covered by serosa in places

Bile Ducts

• Hepatic duct
• Carries bile from liver
• Cystic duct
• Joins hepatic duct from liver to form the bile duct
• Carries bile from gallbladder
• Common Bile duct
• Empties into the duodenum

Movement of Bile

• Bile secreted by liver continuously
• Hepatopancreatic (Vater) ampulla
• common bile + main pancreatic duct meet and enter duodenum
• Sphincter of Oddi around it
• closed when bile not needed for digestion
• Bile then backs up into gallbladder via cystic duct
• When needed gallbladder contracts, sphincters open

Pancreas

• Both exocrine and endocrine gland
• Exocrine
• Produce enzymes that digest food
• Endocrine
• Produce hormones that regulate blood sugar (insulin and glucagon)
• Secondarily retroperitoneal (mostly)
• Location:
• Curve of duodenum
• Extends to spleen

Pancreatic Ducts

• Main pancreatic duct
• Extends length of pancreas
• Joins bile duct to form the hepatopancreatic ampulla
• Empties into duodenum
• Accessory pancreatic duct
• Lies in head of pancreas
• Drains into the main duct & enters duodenum

Spleen

• Largest lymphoid organ
• Location:
• Left superior quadrant of abdominal cavity
• Posterior to stomach
• Highly vascular
• Function:
• Removes blood-borne antigens
• Removes and destructs aged blood cells
• Site of hematopoiesis in fetus
• Stores blood platelets

Arterial Blood Supply to Abdominal Viscera

• All branches of Abdominal Aorta
• Anastomoses
• Left + Middle colic
• Left + Right gastric
• Left + Right gastroepiploic
• Cranial + Caudal pancreaticoduodenal

Remember your zoological roots: YOU MUST KNOW WHAT SUPPLIES WHAT!!
Names give hints!

• Hepato = liver
• Pancreatico = pancreas
• Cystic = gallbladder
• Gastro = stomach
• Splenic = spleen
• Adreno = adrenal gl
• Lumbar = lumbar region
• Epiploic = membrane-covered
• Mesenteric = mesentery
• Duodenal = duodenum
• Ileo = ileum
• Colic = colon

Rectal = rectum

The Upper Extremity Lecture Presentation

The Upper Extremity
Bones, Muscles, Vessels,
Bones

• 30 bones!!!!
• Appendicular skeleton
• Pectoral girdle
• Glenoid cavity
• Allows for mobility
• Attachments
• Upper extremity:
• Arm
• humerus
• Forearm
• Radius, ulna (interosseous membrane)
• Hand
• Carpals, metacarpals, phalanges
• Review bones and landmarks studied in lab!!!

Joints of Upper Extremity

• Sternoclavicular
• Synovial-saddle
• Diarthrosis
• Acromioclavicular
• Synovial-plane
• Diarthrosis
• Glenohumeral joint
• Synovial-ball&socket
• Diarthrosis
• Many ligaments
• Muscle reinforcement
• Great Mobility

Joints of the Upper Extremity

• Elbow Joint
• Synovial – hinge
• Diarthrosis
• Articulations
• Humerus & Ulna
• Humerus & Radius
• Many Ligaments

Joints of Upper Extremity

• Proximal Radioulnar joint
• Synovial -  pivot
• Diarthrosis
• Distal Radioulnar joint
• Synovial – pivot
• Diarthrosis
• Allows pronation and supination of forearm

Joints of the Upper Extremity

• Radiocarpal joint
• Synovial-condyloid
• Distal radius with proximal row of carpals
• Intercarpal joints
• Synovial-plane
• Carpal-metacarpal (2-5)
• Synovial-plane
• Trapezium-metacarpal 1
• Synovial-saddle
• Metacarpal-phalangeal
• Synovial-condyloid
• Interphalangeal
• Synovial-hinge
• ALL DIARTHROSES

Review of Naming…..

• What do the following names TELL you about the muscle?
• Naming
• Flexor carpi ulnaris
• Flexor digitorum superficialis
• Flexor pollicis longus
• Pronator quadratus
• Extensor carpi radialis brevis

Scapula Muscles

• If the origin is on the scapula – moves the arm
• Subscapularis
• Supraspinatus
• Infraspinatus
• Teres Minor
• Teres Major
• Latissimus Dorsi (partial attachment)
• Coracobrachialis

Scapula Muscles

• If the insertion is on the scapula – moves the scapula
• Rhomboids
• Trapezius
• Pectoralis Minor
• Serratus Ventralis
• Levator Scapulae

Innervation of Muscles Moving Arm

Muscle		Innervation
Subscapularis Teres Major		Subscapular  N.
Infraspinatus Supraspinatus		Suprascapular N.
Teres Minor		Axillary N.
Coracobrachialis		Musculocutaneous N.

Arm Muscles

• Arm Compartments
• Anterior Compartment (3 muscles)
• Flexors of forearm and arm
• Posterior Compartment (1 muscle)
• Extensor of forearm and arm

Arm Muscles

• Anterior compartment
• Brachialis
• Coracobrachialis
• Biceps brachii
• Long head
• Short head

Arm Muscles

• Posterior compartment
• Triceps brachii
• Long head
• Medial head
• Lateral head

Forearm Muscles

• Cross elbow, wrist and finger joints
• Movement of hand and fingers
• Proximally are fleshy
• Distally have long tendons
• Flexor and extensor retinacula
• “wristbands”
• Keep tendons from jumping outwards when tensed

Forearm Muscles

• Anterior compartment
• Superficial and Deep layers
• Flexors of hand and fingers
• Most flexors have common origin on medial epicondyle
• Contains 2 pronator muscles
• Posterior compartment
• Superficial and Deep layers
• Extensors of hand and fingers
• Most extensors have common origin on lateral epicondyle
• Contains a supinator muscle

Anterior Compartment of Forearm
Muscles                                                                         Nerves

•       Superficial
• Flexor digitorum superficialis                 Median
• Flexor carpi radialis                                          Median
• Pronator teres                                       Median
• Palmaris longus                                     Median
• Flexor carpi ulnaris                                           Ulnar
•       Deep
• Pronator quadratus                                           Median
• Flexor pollicis longus                             Median
• Flexor digitorum profundus                   Ulnar (med 1/2)                                                                                    Median (lat 1/2)

Posterior Compartment of Forearm
Muscles                                                                                         Nerves

• Superficial
• Brachioradialis                                      Radial
• Anconeus                                                         Radial
• Extensor carpi radialis longus & brevis              Radial
• Extensor digitorum                                            Radial
• Extensor carpi ulnaris                            Radial
• Extensor digiti minimi                            Radial
• Deep
• Supinator                                                          Radial
• Abductor pollicis longus                                    Radial
• Extensor pollicis longus + brevis                        Radial
• Extensor indicus                                                Radial

Hand Bonesac

• Carpus (8)
• “True” wrist
• Distal to radius/ulna
• Metacarpus (5)
• Distal to carpus
• Phalanges (14)
• Distal to metacarpus

Intrinsic  Muscles of the Hand
Muscle                                                 Nerve

• Pinky = Hypothenar muscles
• All digiti minimi                                     Ulnar                            (Flexor, Abductor, Opponens)
• Thumb = Thenar muscles
• Abductor pollicis brevis                                    Median
• Flexor pollicis brevis                                         Median
• Opponens pollicis                                              Median
• Adductor pollicis                                              Ulnar
• Other Intrinsic Muscles
• Palmar + Dorsal Interossei                                Ulnar
• Lumbricals                                                        Median, Ulnar

Blood Supply - Arteries

• Subclavian (neck)
• Axillary (armpit)
• Subscapular
• Circumflex humeral arteries
• Brachial (arm)
• Deep brachial
• Radial (forearm)
• Ulnar (forearm)
• Common Interosseous
• Superficial & Deep Palmar arches
• Digital

Blood Supply - Veins

• Deep veins
• Deep palmar venous arches
• Radial - forearm
• Ulnar - forearm
• Brachial – arm/elbow
• Axillary – axilla
• Subclavian - neck

• Superficial Veins
• Digital
• Superficial palmar venous arches
• Median – forearm
• Median cubital – elbow
• Blood draws!!
• Cephalic – arm/forearm
• Basilic – arm/forearm

Axilla

• Armpit!!
• Boundaries
• Ventral
• Pectoral muscles
• Dorsal
• Latissimus dorsi, teres major, subscapularis
• Medial
• Serratus ventralis
• Lateral
• Intertubercular (Bicipital) groove of humerus
• Contents
• axillary lymph nodes, axillary vessels, brachial plexus

Surface Anatomy of Arm

• Cephalic Vein
• Biceps brachii
• Triceps brachii
• Olecrenon Process
• Medial Epicondyle
• Lateral Epicondyle

Surface Anatomy of Elbow

• Cubital Fossa
• Anterior surface elbow
• Contents          
• Median Cubital Vein
• Brachial Artery
• Median Nerve
• Boundaries
• Medial= Pronator teres
• Lateral= Brachioradialis
• Superior= Line between epicondyles

Surface Anatomy of Hand

• Carpal Tunnel
• Carpals concave anteriorly
• Carpal ligament covers it
• Contains: long tendons, Median nerve
• Inflammation of tendons = compression of Median nerve
• Anatomical Snuffbox
• Lateral = E.pollicis brevis
• Medial = E. pollicis longus
• Floor = scaphoid, styloid of radius
• Contains Radial Artery (pulse)

Brachial Plexus

• Nerve plexus
• Lies partly in neck and partly in axilla
• Gives rise to almost all nerves that supply upper limb
• Formed by intermixing of ventral rami of spinal nerves C5-C8 and T1

Brachial Plexus

• Really Tired? Drink Coffee Buddy!

• R = RAMI (ventral) (5)
• T = TRUNKS (3)
• D = DIVISIONS (2)
• C = CORDS (3)
• B = BRANCHES (Many!!)

Rami join to form Trunks! (in neck)
Ventral Rami                                Trunks

• C5                                           Upper Trunk
• C6

• C7                                           Middle Trunk

• C8
• T1                                            Lower Trunk

Trunks Split to form Divisions! (in neck)
Trunks                                            Divisions

• Upper                                      Anterior                                                                                                                        Posterior

• Middle                         Anterior                                                                                                                        Posterior

• Lower                                      Anterior                                                                                                                        Posterior

Divisions Join to form Cords! (in axilla)
Trunks       Division                               Cords
U                                 A                                             Lateral
P
M                                 A                                             Medial
P
L                                  A                                             Posterior
P
Cords Give off Branches!! (in axilla)

• Lateral                                      Musculocutaneous                                                                                                                                                                              

                                                                          Median

• Medial                                                     Ulnar

• Posterior                                                  Radial                                                                                                                           Axillary                                                                                                                 Thoracodorsal                                                                                                               Subscapulars

Lateral Cord

• Musculocutaneous nerve
• Off lateral cord
• Course:
• Anterior arm
• Becomes cutaneous and gives skin sensation to lateral forearm
• Innervates:
• Corocobrachialis (motor)
• Biceps brachii (motor)
• Brachialis (motor)
• Skin distal to the elbow (sensory)

Medial Cord

• Ulnar nerve
• Course:
• Comes off medial cord
• Descends along medial side of arm
• Passes posterior to medial epicondyle
• Follows the ulna
• Superficial to carpal tunnel into hand
• Branches to supply intrinsics and skin
• Innervates:
• Flexor carpi ulnaris (motor)
• Flexor digitorum profundus (motor)
• Most intrinsic hand muscles (motor)
• Dorsal branch supplies skin of medial 2/3 of hand (sensory)

Both Medial and Lateral Cords

• Median nerve
• Course:
• Middle of brachial plexus (from lateral and medial cords)
• Does not branch in arm
• Distal to elbow provides many branches to most forearm flexors
• Passes through carpal tunnel to hand to lateral palmar intrinsics
• Innervates:
• Anterior forearm (motor)
• Most flexors, some intrinsics (thumb)
• 2/3 Lateral palm (sensory)
• Dorsum of fingers 2 and 3 (sensory)

Posterior Cord

• Radial nerve
• Largest branch of brachial plexus
• Comes from posterior cord
• Course:
• Through arm
• Around humerus
• Around lateral epicondyle (then divides)
• Innervates:
• Posterior muscles of arm and forearm
• Triceps brachii, anconeus, brachioradialis
• Divides in forearm:
• Superficial
• Skin of arm and dorsolateral surface of hand
• Deep
• Supinator & Extensor muscles of forearm (eg ext. carpi radialis L + B)

Posterior Cord (continued)

• Axillary nerve
• Branches off posterior cord
• Course:
• Runs posterior to humerus
• Runs with caudal humeral circumflex artery
• Innervates:
• Deltoid and teres minor (motor)
• Capsule of shoulder, skin of shoulder (sensory)
• Subscapular nerve
• Innervates:
• Subscapularis, Teres major
• Thoracodorsal nerve
• Course:
• Runs with thoracodorsal artery and vein
• Innervates:
• Latissimus dorsi

Nerve Damage

• Ulnar nerve
• “Claw hand”
• Inability to extend fingers at interphalangeal joints, results in permanent flexion of hand = claw
• Median nerve
• “Ape hand”
• Inability to oppose thumb
• Radial nerve
• “Wrist drop”
• Inability to extend the hand, inability to fully extend forearm

download lecture presentation  The Upper Extremity