MSK Midterm Flashcards
condyle
rounded process that articulates w/another bone
ex- occipital condyle
crest
narrow, ridge-like projection
ex- iliac crest
epicondyle
projection situated above a condyle
ex- medial epicondyle of humerus
facet
small, smooth surface
ex- rib facet of thoracic vertebra
foramen
opening for passage of blood vessel/nerves
ex- foramen magnum
fossa
relatively deep pit or depression
ex- olecranon fossa
fovea
tiny pit or depression
ex- fovea capitis
head
enlargement at end of bone
ex- femoral head
linea
narrow, line-like ridge
ex- linea aspera of femur
process
prominent projection of a bone
ex- mastoid process of temporal bone
ramus
branch-like process
ex- ramus of mandible
sinus
cavity w/in a bone
ex- frontal sinus
spine
sharp projection
ex- spine of scapula
styloid
pen-like projection
ex- styloid process of ulna
suture
interlocking junction b/w cranial bones
ex- coronal suture
trochanter
relatively large process
ex- greater trochanter of femur
tubercle
small, knob-like process
ex- tubercle of rib
tuberosity
knob-like process larger than a tubercle
ex- tibial tuberosity
meatus
tube-like passageway w/in a bone
ex- external auditory meatus
diaphysis
shaft
epiphysis
joint surface end
epiphyseal plate
hyaline cartilage plate in the metaphysis at each end of a long bone
Articulation
place of contact between bones, bone/cartilage, or bone/teeth
use names of articulating bones
structure-> mobility and stability
more mobile-> less stable
more mobile articulation
less stable
joint classification
- type of conn tissue
- space between
- degree of movement
Structural Joint classification
Fibrous
Cartilaginous
Synovial
Fibrous joint
structure classification bones held together by dense regular conn tissue synarthroses (immovable) or amphiarthroses (slightly movable) No joint cavity 3 Types 1. Gomphoses (synarthroses) 2. Sutures (synarthroses) 3. Syndesmoses (amphiarthroses)
Cartilaginous joint
structure classification bones joined by cartilage no joint cavity 2 Types 1. Synchondroses 2. Symphyses
Synovial joint
structure classification Fluid-filled synovial cavity separates bones Bones enclosed w/in capsule Bones joined by various ligaments freely movable diarthroses most commonly known ex- glenohumeral (shoulder), temporomandibular, elbow, knee
Functional joint classification
Synarthrosis
Amphiarthrosis
Diarthrosis
Synarthrosis
functional classification
immovable joint
Amphiarthrosis
functional classification
slightly movable joint
Diarthrosis
functional classification
freely movable joint
Gomphosis
fibrous synarthrosis
no joint cavity
ex- tooth root
Suture
fibrous synarthrosis
no joint cavity
ex- skull
Syndesmosis
fibrous amphiarthrosis
no joint cavity
ex- interosseous membrane
Synchrondrosis
cartilagenous synarthrosis
no joint cavity
Symphysis
cartilagenous amphiarthrosis
no joint cavity
Synovial features
articular capsule (joint capsule) joint cavity synovial fluid articular cartilage ligaments (bone to bone) nerves blood vessels bursae
bursae
fibrous, saclike structure that contains synovial fluid and is lined by synovial membrane
fatpads
distributed along periphery of synovial joint
act as packing material: provide joint protection
fill spaces when bones move and joint cavity changes shape
tendons
attaches muscle to bone/skin/muscle
helps stabilizes joints
thick, cord-like
aponeurosis=thin, flat sheet of tendons
dermatome
area of skin supplied w/afferent nerve fibers by a SINGLE POSTERIOR spinal ROOT
Epaxial (on axis) + Hypaxial (below axis)
each nerve can have multiple dermatomes
T/F: Dermatomes and nerve maps differ.
True
Calcaneal Tendon reflex tests…
S1 and S2
if cut-> reflex absent
Patellar reflex tests…
fxn of femoral nerve
L2, L3, L4
absence = Westphal’s sign
C1-C2 lesions cause…
probably death b/c too close to brain stem
if not-> quadriplegia
C2-C3 lesions cause…
diaphragmatic paralysis-> life-threatening
C5-C6 lesions cause
incomplete quadriplegia
T1-T2 lesions cause
complete paraplegia
posterior head/neck/shoulder dermatomes
CN, V
C2, C3, C4
opthalmic nerve
anterior neck/chest/arm/forearm/hand dermatomes
C3, C4, C5, C6
C7, C8
anterior forearm, posterior arm/upper back dermatomes
T1
chest/arm/torso/back dermatomes
T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12
groin/back dermatomes
L1
S2
anterior groin/thigh, posterior back/leg dermatomes
L2, L3, L4
leg/foot dermatomes
L5
leg/back/butt dermatomes
S1, S2, S3, S4, S5
Autonomic nerve plexuses
thoracic
abdominal aortic
mesenteric
Somatic nerve plexus
spinal nerves Cervical Brachial Intercostal Lumbar Sacral
Cervical plexus
C1, C2, C3, C4, C5
Brachial plexus
C5, C6, C7, C8, T1
Upper extremity
Intercostal nerves
T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12
Lumbar plexus
L1, L2, L3, L4 Lower extremity (lumbosacral)
Sacral plexus
L5, S1, S2, S3, S4 Lower extremity (lumbosacral)
Upper extremity nerves
Brachial plexus Musculocutaneous nerve Median nerve Ulnar nerve Radial nerve Medial Brachial Cutaneous nerve Medial Antebrachial Cutaneous nerve
Musculocutaneous nerve
C5, C6, C7
Median nerve
C6, C7, C8, T1
Ulnar nerve
C8, T1 (same as med antebrach cut n)
Radial nerve
C5, C6, C7, C8, T1
Medial Brachial Cutaneous nerve
C8, T1, T2
Medial Antebrachial Cutaneous nerve
C8, T1 (same as ulnar n)
Lower extremity nerves
Lumbosacral plexus Femoral nerve Obturator nerve Sciatic nerve (Tibial n + Common Fibular n) Lateral Femoral Cutaneous nerve Posterior Femoral Cutaneous nerve
Femoral nerve
L2, L3, L4 (same as obturator n)
Obturator nerve
L2, L3, L4 (same as femoral n)
Sciatic nerve
Tibial n: L4, L5, S1, S2, S3
Common Fibular n: L4, L5, S1, S2
Lateral Femoral Cutaneous nerve
L2, L3
Posterior Femoral Cutaneous nerve
S1, S2, S3
multisegmental myotome
multiple nerves/myotomes supply one muscle
severing nerves at root different than distal severing
most muscles
monosegmental
entire muscle supplied by 1 ventral nerve root
severing-> complete paralysis of muscle
segmental innervation
one nerve goes to one dermatome
ex- skin of trunk
plexus innervation
nerves form plexus-> combine to become peripheral nerve-> split again to supply multiple dermatomes
ex- skin of limbs
Muscle functions (5)
Movement Posture Temperature regulation Storage/movement of material Support
Deep Fascia
expansive sheet of dense irregular connective tissue
Separates individual muscles
Binds muscles w/sim fxn
Forms sheaths to help distribute nerves/blood vessels/lymphatic vessels
Fills spaces b/w muscles (intermuscular septa)
aponeurosis
tendons forming a thin, flat sheet
Muscle contraction mechanism
muscles extend b/w bones and cross movable joints
contraction: 1 bone moves (insertion), other remains fixed (origin)-> insertion pulled toward origin
Origin typically proximal to insertion
origin
less movable attachment of a muscle
usually proximal to insertion
insertion pulled towards origin
insertion
more movable attachment of a muscle
usually distal to origin
pulled towards origin
Fascicle organizational patterns
- Circular
- Convergent
- Parallel
- Pennate
Circular fascicle
sphincter
contraction closes off opening
Convergent fascicle
widespread muscle fascicles that converge on common attachment site
often triangular
ex- pectoralis major
Parallel fascicle
fascicles run parallel to long axis
central body/belly/gaster
strap-like (ex- SCM muscle) or fusiform (biceps brachii)
Pennate fascicle
1+ tendons extend through body
fascicles arranged at oblique angle to tendon
unipennate (ex- anterior forearm) or bipennate (rectus femoris) or multipennate (deltoid)
Bipennate most common
Lever system types
Lever= long bone
Fulcrum= joint
Effort=muscle
- Fulcrum in middle
- Resistance in middle
- Effort in middle
First-class lever
Load, fulcrum, effort
Load, JOINT, muscle
ex- posterior muscle of neck (pulls down to keep head from falling forward on other side of OA joint)
Second-class lever
Fulcrum, load, effort
Joint, LOAD, muscle
ex- calf muscle (lifts up on load in center of foot, rotating on ball of foot)
Third-class lever
Load, effort, fulcrum
Load, MUSCLE, joint
ex- biceps brachii (lifts up in between hand holding something heavy and elbow joint)
Muscle action
- Isometric- no movement (steady contraction)
- Concentric- muscle shortens
- Eccentric- muscle lengthens
Bone
Type I Collagen specialized conn tiss Cells, fibers, ground substance Hydroxyapatite (mineralized ECM) Dynamic- constant remodeling
Compact Bone
Lamellar
Outer solid cortex of bone enclosing inner layer of spongy bone
Spongy/travecular/cancellous bone
Lamellar or woven
Trabeculae
Inner layer of bone w/spaces for bone marrow
Bone classification
Lamellar v Spongy/non-lamellar
Lamellar bone
mature/secondary regular parallel collagen only visible as dried/ground section (no H/E dye) Most adult bone strong slow development
Spongy bone (non-lamellar)
immature/secondary, usually replaced by lamellar
loose collagen
low minerals, high cells
less matrix (ground substance/fibers)
Fracture repair/remodeling: alveolar sockets (teeth-> braces remodel), tendon insertions
osteopontin
made by osteoblasts
binds calcium, helps mineralize bone (calcium hydroxyapatite
Bone Matrix composition
65% organic (mostly Type I coll, then proteoglycans and osteocalcin/pontin/nectin)
35% inorganic (calcium hydroxyapatite, Mg, Na, K, CO3, PO4
Noncollagenous proteins
made by osteoblasts
osteocalcin, osteopontin, osteonectin
bind calcium to help mineralize bone (Ca hydroxyapatite)
Types of lamellae
interstitial
circumferential
concentric
Lamellar bone composition
Lamellae (interstitial/circumferential/concentric)
Osteocytes (in b/w lamellae)
Haversian canal (longitudinal, at center of osteon)
Volkmann’s canal (transverse, connects Hav. canals, ends at bone surface)
Lamellar bone osteocytes
bone cells that support the matrix
occupy a lacuna
have radiating canaliculi that penetrate the lamellae
use gap junctions
Haversian canal
longitudinal canals in lamellar bone that house capillaries and post-capillary venules
center of osteons
connected by volkmann’s canals
Volkmann’s canal
transverse vascular channels that connect haversian canals
end up on outer surface of bone, aid in distributing blood throughout inner/outer areas
canaliculi
radiates from lacunas to house radiating cytoplasmic processes of osteocytes (for communication w/each other)
lacuna
houses an osteocyte
interstitial lamellae
between osteons
separated from osteon by cement line
remnants from remodeling osteons
cement line
separates interstitial lamellae from osteons
Osteon
haversian system
concentrically arranged lamellae around a longitudinal vascular channel (haversian canal)
lamella rings alternate orientation to prevent shearing forces and provide mechanical strength
Outer circumferential lamellae
external surface of compact bone
under periosteum
inner circumferential lamellae
internal surface of bone subjacent to (surrounded by) endosteum
woven bone
mineralized, but weaker than osteon formation
non-lamellar
Periosteum
2 layers
Inner: preosteoblasts, osteogenic
Outer: blood vessel/nerve-rich, fibroblasts, collagen fibers, Sharpey’s fibers
Sharpey’s fibers
part of outer layer of periosteum
anchor periosteum to lamellae
anchoring collagen fibers penetrate outer circumferential lamellae
Endosteum
covers spongy walls
extends into all bone cavities
osteoprogenitor cells, reticular stromal cells (bone marrow), conn tiss fibers
by marrow
Osteoprogenitor cells
precursor cells that self-replicate, or differentiate into bone-forming cells
Adult stem cells
Osteoblast
bone-forming cell that deposits osteoid and controls mineralization
High ALKALINE PHOSphatase on cell membrane to help mineralize Ca hydroxyapatite
Marks bone disease
Endosteum and periosteum
Involved in growth/fracture repair
Osteocyte
modified osteoblast that becomes surrounded by newly formed bone
Mature osteoblast now surrounded by matrix
Osteoclast
macrophage-type cells (differentiate from monocyte) that resorb bone in remodeling process
Multi-nucleated
High ACID PHOSphatase and COLLAGENASE
Howship’s lacuna (small)
red marrow
hematopoietic
yellow marrow
adipocytes
Osteomalacia
bone disorder characterized by dec mineralization of newly formed osteoid at sites of bone turnover (bone-> soft)
No Ca-> muscle contraction probs and weak bones
Causes: low dietary vit D, lack of sun, GI disease (USA)
S/Sx: bone/joint pain, musc weakness/spasms/cramps, fracture, walking probs, waddling gait
Cells most affected: osteoblasts (no Ca for bone mineralization)
Blood levels: Low Ca, Low/normal P, High Alk Phosphatase, High PTH
X-ray: Looser-Milkman psuedofractures
Parathyroid hormone
PTH
activates osteoclasts to increase Ca in bloodstream
Looser-Milkman pseudofractures
X-ray indication of osteomalacia
thin areas of bone that show up as dark on x-ray, usually in weight-bearing areas of bone
Osteomalacia- affected cells
osteoblasts
No Ca-> no mineralization of bone (by osteoblasts)
Osteomalacia- blood Ca
decreased due to lack of vitamin D
MAY be normal
Osteomalacia- blood P
decreased or normal
need vit D to absorb P
Osteomalacia- blood Alkaline Phosphatase
Increased b/c osteoblasts are trying hard to inc Ca
Osteomalacia- blood PTH
increased b/c osteoblasts are trying hard to inc Ca
Osteomalacia X-ray
Looser-Milkman pseudofractures (thin areas of bone that show up as dark on x-ray, usually in weight-bearing areas of bone)
Osteogenesis
Intramembranous Ossification- mesenchymal template-> frontal/parietal bones, part of occipital/temporal/mandible/maxilla/clavicle
Endochondral Ossification- cartilage template-> portions of basicranium, long bones, pelvic/pectoral girdles, ribs
mesenchyme
embryonic conn tissue
mesoderm + other cells
Intramembranous ossification
type of osteogenesis that uses a MESENCHYMAL template
forms frontal/parietal bones, part of occipital/temporal/mandible/maxilla/clavicle
Endochondral ossification
type of osteogenesis that uses a CARTILAGE template
forms portions of basicranium, long bones, pelvic/pectoral girdles, ribs
Intramembranous Ossification steps
- mesenchyme cells condense-> soft sheet permeated w/capillaries
- Osteoblasts secrete osteoid tissue on mesenchyme, trapped osteoblasts become osteocytes, periosteum forms around osteoblasts, osteoblast border/periosteum forms trabecula
- Cont mineral deposition (by osteoblasts/cytes) -> trabeculae fuse-> form spongy bone
- Bone deposition-> surface spongy bone becomes compact (middle stays spongy), periosteum still on surface
Endochondral Ossification steps
- Mesenchyme-> hyaline cartilage + perichondrium covering
- Perichondrium stops making chondrocytes, starts making osteoblasts
Chondrocytes in middle enlarge (1 oss center), dye
Osteoblasts form thin collar around diaphysis - Blood vessels enter collar and 1 oss center-> 1 marrow cavity (diaphysis)
- Osteoblasts-> osteoid-> spongy bone
- Cartilage death + osteoclasts towards bone ends (+ chondrocytes enlarge)-> enlarged marrow cavity-> 2 oss center at ends
- Blood vessels enter collar and 2 oss center-> 2 marrow cavity (epiphysis)
- Osteoblasts-> osteoid-> spongy bone
- Cartilage death + osteoclasts (+ chondrocytes enlarge)-> enlarged marrow cavity
- Epiphysis fills w/spongy bone, cartilage at epiphyseal plate
chondrocyte
cartilage cell
Zones of Endochondral Ossification
at epiphyseal plate (from inside out)
- Reserve cartilage
- Cell prolif
- Cell hypertrophy
- Calcification
- Bone deposition
Zone 1 of Endochondral Ossification
Reserve cartilage
resting hyaline supply for Zone 2
Zone 2 of Endochondral Ossification
Cell Prolif (growth in length) chondrocytes multiply, line up in rows (vertical and parallel columns) of small/flat lacunae
Zone 3 of Endochondral Ossification
Cell Hypertrophy
chondrocytes stop mitosis, start enlarging
lacuna walls thin
Zone 4 of Endochondral Ossification
Calcification
temporary calcification of cartilage matrix b/w lacunae
Zone 5 of Endochondral Ossification
Bone Deposition lacuna walls breakdown-> open channels chondrocytes die osteoblasts deposit bone-> trabeculae-> spongy bone Vascular zone
Rickets
deficient mineralization of cartilage at growth plate
architectural disruption of growth plate
Ca deficiency-> Calcipenic Rickets
Causes: low vit D intake or insufficient vit D metabolism OR low Ca intake/absorption (but normal vit D)
S/Sx: delayed fontanelle closure, parietal/frontal bossing, craniotabes (soft skull bones), wrist widening, distal radial/ulnar bowing, progressive lateral femur/tibia bowing
Cells most affected: chondrocytes of growth plate (can’t mineralize cartilage)
Blood levels: low/normal Ca and P, high Alk Phosphatase and PTH
bossing
frontal/parietal bones bow out/protrude-> prominent forehead
symptom of Rickets
craniotabes
soft skull bones
symptom of Rickets
Calcipenic Rickets causes
low vit D intake or insufficient vit D metabolism OR low Ca intake/absorption (but normal vit D)
Calcipenic Rickets symptoms
delayed fontanelle closure, parietal/frontal bossing, craniotabes (soft skull bones), wrist widening, distal radial/ulnar bowing, progressive lateral femur/tibia bowing
Calcipenic Rickets- cells affected
chondrocytes of growth plate
can’t mineralize cartilage (in hypertrophic zone)
Calcipenic Rickets- blood Ca
decreased/normal
Calcipenic Rickets- blood P
decreased/normal
Calcipenic Rickets- blood Alkaline Phosphatase
increased
trying to grow more bone, but can’t
Calcipenic Rickets- blood PTH
increased
trying to grow more bone, but can’t
Achondroplasia
most common skeletal dysplasia that causes short-limb dwarfism
Long bones affected (cranial/vertebral bones spared)
Cause: overexpression of FGFR3 (chrom 4)-> early signal for stopping chondrogenesis-> inhibited cartilage synth-> dec endochondral bone formation, premature ossification of growth plates
Proliferative zone affected
Ass symptoms: obesity, trident hands (short fingers in 3 groups), short/broad feet, frontal/parietal bossing, limb bowing, lumbar lordosis, limited elbow flexion
Achondroplasia mechanism
overexpression of FGFR3 (chrom 4)-> early signal for stopping chondrogenesis-> inhibited cartilage synth-> dec endochondral bone formation, premature ossification of growth plates
Proliferative zone affected
trident hands
short fingers in 3 groups
symptom of achondroplasia (short-limb dwarfism)
Osteoporosis
low bone mass, microarchitectural disruption, skeletal fragility -> decreased bone strength, inc fracture risk
postmenopausal Caucasian women, elderly
S/Sx: none until fracture (or low bone density on bone density test)
Cells: osteoblasts and osteoclasts (osteoblast activity
Osteoporosis- cells affected
osteoclast activity outweighs osteoblast activity
Osteoporosis- blood Ca
normal
Osteoporosis- blood P
normal
Osteoporosis- blood alkaline phosphatase
normal
cells aren’t doing anything differently (like in Rickets), just doing a little more, but not enough to cause overcompensation
Osteoporosis- blood levels
Ca/P/alk phosphatase normal
vitamin D could be low or normal (based on person)
Dietary absorption still functioning, covering up any physiological process problems
Will see HORMONE imbalance
Trabecula-> Osteon
- Ridges in periosteum-> groove for periosteal blood vessel
- Periosteal ridges fuse-> endosteum-lined tunnel
- Osteoblasts in endosteum-> build new CONCENTRIC lamellae INWARD (towards center of tunnel)
- Bone grows OUTWARD, osteoblasts in periosteum build new CIRCUMFERENTIAL lamellae
- New periosteal ridges fold over blood vessels-> repeat process
Bone Remodeling
Compact bone (w/in osteon) Trabecular bone (on endosteal surface)
Compact bone remodeling
- Osteoclast precursors recruited to haversian canal-> differentiate, line lamella facing canal-> resorb bone from inner to outer lamellae
- More precursors recruited-> lamellar resorption slightly past orig osteon boundary, (occupy Howship’s lacunae)-> recruit osteoblasts
- Osteoblasts organize layer inside resorption cavity-> secrete osteoid (cement line=newly organized lamella)-> bone deposition towards osteon center
- Trapped osteoblasts in center of mineralized bone matrix-> differentiate-> osteocytes
- Newly formed osteon leaves behind interstitial lamellae
Trabecular bone remodeling
- Osteoclast precursors recruited to trabecular endosteal surface-> differentiate-> form resorption space limited by cement line
- Osteoblasts recruited-> line cement line surface-> deposit osteoid
- New bone closes resorption space
Bone Fracture Healing
- Fracture hematoma
- Fibrocartilaginous callus
- Bony callus
- Bone remodeling
Fracture hematoma formation
1st phase of bone fracture healing
Blood accumulates b/w fracture ends
Osteocytes + marrow cells -> necrosis-> INFLAMMATION
Macrophages + Granulocytes -> form granuloma-> STABILIZATION of fracture
Fibrocartilaginous callus formation
2nd (reparative) phase of bone fracture healing Periosteal-derived and medullary artery-derived capillary buds extend into granuloma-> form cartilage (soft callus)-> STABILIZES fractured ends Woven bone (trabeculae) replaces cartilage-> MINERALIZATION
Bony callus formation
3rd (reparative) phase of bone fracture healing
Osteoblasts form bony/hard callus
Periosteal + internal hard callus envelope fractured ends
Bone remodeling phase
last phase of bone fracture healing
Osteoclasts reabsorb excessive/misplaced trabeculae
Osteoblasts lay down new bone-> compact bone along stress lines
Haversian systems/osteons and Volkmann’s canals formed-> house blood vessels
X-Ray mechanism
W photons pass through body-> recording plate
More exposure=dark (ex- air)
More absorption=white (ex- bone)
Cons: hard to observe thickness/depth/overlay
Positioning: object further from plate (closer to x-ray source) = enlarged
Fluoroscopy
view real-time movement w/continuous stream of x-rays
X-ray source below, image intensifier/data capture above
C-arm allows rotation for 3D info
Peripheral vascular studies: 2-3 frames/sec
Coronary artery studies: 15-30 frames/sec
Computed Tomography
CT Scan (usually Iodine contrast) Rotating x-ray tube-> pass through body helically-> collected on opposite side Math: reconstruct transverse plan images from data-> 3D images Hounsfield Scale: capture image, then mess with data (window width) to produce diff contrasts
Hounsfield Scale
density numbers used in computed tomography
water=0, air=-1000, compact bone=+3095
most soft tissue -100 to +100
window width: range of gray scale mapped (only 256 shades, below=black, above=white)
window width (Hounsfield Scale)
range of gray scale mapped in computed tomography (only 256 shades)
below=black, above=white
wide window for bone (large changes in density)
narrow window for soft tissue (small changes in density)
Magnetic Resonance Imaging
MRI
No ionizing radiation
Manipulate magnetic fields around patient-> H protons-> radiofreq energy as they return to equilibrium from spin alignment w/field (relaxation time)
Nuclear spin: atoms align w/magnetic field
Diff tissues have diff relaxation time
T1 weighted and T2 weighted
T1 Weighted MR
Dark: inc water/edema, tumor, inflam/infection, hyperacute/chronic hemorrhage
Light: fat, subacute hemorrhage, melanin, protein-rich fluid, slow blood
T2 Weighted MR
Dark: Calcification, fibrous tissue, protein
Bright: water/edema, tumor, inflam, infection, subdural collection
Femoral Sheath
funnel-shaped fascial tube w/femoral artery, vein, and canal
allows vessels to glide smoothly during hip movement
continuous w/loose conn tissue/fascia
ends 4-10 cm distal to inguinal ligament
Femoral sheath compartments
2 vertical septa
- Lateral- artery
- Intermed- vein
- Medial/Femoral canal- lymph node
Femoral Canal
short, conical medial compartment of femoral sheath lymph vessels, loose conn tiss, fat allows fem vein expansion extends distally-> saph opening prox opening = FEMORAL RING
Femoral Ring
proximal opening of femoral canal (medial compartment of femoral sheath
~1 cm wide
covered by parietal peritoneum
can find herniations of abdominal viscera here
Femoral Hernia
femoral ring is weak area in anterior abdominal wall
loop of small intestine can protrude through ring into femoral canal
Inguinal herniae
Direct: small intestine projects through inguinal ring (lateral to epigastric vessels)
Indirect: small intestine projects though abdominal wall
Hesselbach’s Triangle
Inguinal lymph nodes
drain lymph from lower limb, perineum, anal canal, anterior abdominal wall
Superficial (prox/hor and dist/vert) and Deep
Drain to external iliac lymph nodes
Superficial inguinal lymph nodes
Prox/hor: inferior to inguinal ligament
Dist/vert: along great saphenous vein
Both: deep to inguinal ligament, drain to external iliac lymph nodes
Deep inguinal lymph nodes
1-3 lymph nodes in femoral canal (medial compartment of femoral sheath)
drain to external iliac lymph nodes
Femoral Nerve
L2-L4
largest branch of lumbar plexus, in psoas major
Entry: thigh lat to inguinal ligament midpoint and femoral vessels
Inn: ant thigh musc, hip/knee jt (iliacus, sartorius, quadriceps femoris, pectineus)
terminal cutaneous branch= SAPHENOUS NERVE
Lateral femoral cutaneous nerve
may be affected by anterior hip dislocation (along w/femoral nerve) Meralgia Paresthetica (compression under ing lig)
Meralgia Paresthetica
compression of lateral femoral cutaneous nerve as it passes under inguinal ligament-> PAIN along LAT THIGH
sometimes impinged where it emerges from fascia lata
Saphenous nerve
anterior/inferior w/great saph vein
becomes superficial b/w sartorius and gracilis
Inn: skin of ant/med knee/leg, med foot
terminal cutaneous branch of femoral nerve
Adductor Canal
intermuscular passage/fascial tunnel: femoral vessels-> popliteal fossa
Start: fem triangle apex
End: adductor hiatus
saph nerve/artery (branch of desc gen art) exit medially
Adductor hiatus
opening in tendon of add magnus: fem vessels-> popliteal fossa
Femoral Artery
main arterial supply to lower limb
Enters fem triangle: lat to fem vein (deep to ing lig midpt)
Fem triangle-> iliopsoas-> pectineus-> add longus-> bisects fem triangle apex (deep to sartorius)
inferior thigh-> DESC GENICULAR ART-> articular and saphenous branch
femoral artery palpation
2-3 cm inferior to inguinal ligament midpoint (which is b/w ASIS and pubic tubercle)
used for radiographic visualization of left heart and coronary vessels
femur head posterior to femoral artery
Profunda Femoris Artery
AKA Deep Femoral Artery
largest branch of femoral artery
chief artery to thigh, descends behind add longus
-> medial/lateral CIRCUMFLEX ARTeries
Lateral Circumflex artery
branch of deep femoral artery
goes under sartorius and rectus femoris
supplies femur head and lat thigh muscle
-> 3 branches: ascending, transverse, descending
femoral artery progression
femoral a-> deep fem/profunda femoris a + fem a
deep fem a-> lat/med circumflex a + deep fem a (-> perforating a-> adductors/hamstrings)
lat circumflex a-> ascending/transverse/descending branches
deep fem a-> popliteal artery (adductor hiatus)
Medial Circumflex artery
branch of deep femoral artery
goes between iliopsoas and pectineus to posterior thigh
MAIN SUPPLY OF FEMUR HEAD/NECK
Femoral Vein
Enters fem triangle: medial to fem a
Fem triangle apex: deep to fem a
saphenous opening: just below inguinal ligament, branches anterior and down to great saphenous vein and ant fem cutaneous vein
Great Saphenous vein
Uses: administer blood/electrolytes/drugs, coronary bypass surgery
Access to veinous sys: incision anterior to medial malleolus (“saphenous cutdown”)
Saphenous cutdown
incision made anterior to med malleolus
may cause pain along medial border of foot (due to saph nerve)
anterior muscles of thigh
Iliopsoas (Psoas major/minor, iliacus) Pectineus Sartorius Rectus Femoris Vastus medialis/intermedius/lateralis
Psoas major innervation
L1/2/3 (ventral rami)
chief hip flexor
iliopsoas
Psoas minor innervation
L1/2 (ventral rami)
Iliacus innervation
L2/3/4 (femoral nerve)
iliopectineal bursitis
inflammation of bursa between iliopsoas and pectineus
due to overuse (cycling, running)
hard to treat b/c hard to access
Hilton’s law
joint is innervated by same nerves that supply muscles moving the joint and skin over the joint
adductor gait
one leg crosses in front of other due to damaged superior gluteal nerve
