Muscculoskeletal, Skin, and Connective Tissue - Physiology 90% exhaustive

evolv3's version from 2015-06-21 00:28


Question Answer
Epidermis layers from surface to baseCalifornians Like Girls in String Bikinis
Corneum (keratin)
Spinosum (spines=desmosomes)
Basale (stem cell site)
Sebaceous glandHolocrine secretion of sebum
Assoc w hair follicle
Eccrine glandSecretes sweat
Found throughout the body
Apocrine glandSecretes milky viscous fluid
Found in axillae, genitalia, areolae
Does not become functional until puberty
Malodorous because of bacterial action
Which cell jct uses actin filaments?Adherens jct (zonula adherens)
Just below tight jcts
Connects actin cytoskeletons of adjacent cells
CADherins (CA-dependent ADhesion proteins) - Loss of E-cadherin promotes metastasis
Which cell jct uses keratin?Desmosome
Autoantibodies → pemphigus vulgaris
Which cell jct uses connexons?Gap jct (closest to basement membrane)
Allows electrical and chemical communication between cells
Where are "integrins"?Basement membrane
Integrins bind to laminin in BM
HemidesmosomeConnects keratin in basal cells to underlying BM
Autoantibodies → bullous pemphigoid (hemidesmosomes are "bullow")
Landmark for pudendal nerveischial spine - given during childbirth
McBurney's pointLocation of appendix - 2/3rds of the way from the umbilicus to the anterior superior iliac spine
Lumbar punctureIliac crest (~L3-L5)
Wrist bones mnemonicSome Lovers Try Positions That They Can't Handle
Read from thumb to pinky, proximal row first then distal
Triquetrum is on the bottom (proximal)
Acute tunnel syndrome can be caused by which carpal bone?Dislocation of the lunate
A fracture of which carpal bone can injure a major nerve?Fracture of the hook of hamate → Ulnar nerve
Cutaneous innervation of the median nervePalm: thumb-mid 4th finger
Dorsum:tips of 2, 3, and half of 4th finger
C6 dermatomeRadius-area of the forearm, thumb and 1st finger
C7 dermatomemiddle finger
C8 dermatome4/5th finger
T1 dermatomeUlnar-area of the forearm and lower arm
C5 dermatomeDeltoid insertion area
C4 dermatomeShoulder cap
Order of brachial plexus "sections"Randy Travis Drinks Cold Beer
Which nerve exists just after leaving the vertebrae (with the roots)?Long thoracic
Waiter's tip injury (Erb's palsy)Damage to the upper trunk: C5/C6
Done by violently stretching the head away from the shoulder - usually during birth
Claw hand (Klumpke's palsy)Damage to the lower trunk: C8/T1
Done when stretching the arm above the head: pulling a baby out by the hand, catching yourself by grabbing a branch as you fall out of a tree
Total claw handCan also present with Horner's syndrome
Wrist dropDamage to the posterior cord (Radial n + Axillary n - before they split)
can also be caused by damage to the radial nerve
Winged scapulaDamage to the Long thoracic n which innervates the Serratus anterior (C5-C7)
Could also be injured in mastectomy → lymphedema
Deltoid paralysiscaused by damage to the Axillary n after it splits from the radial nerve after the posterior cord
"Saturday night palsy" (wrist drop)Palsy of the radial nerve often caused by falling asleep in a position that would normally be uncomfortable or by sleeping with your head on your arm
Difficulty flexing the elbow w variable sensory lossDamage to the musculocutaneous branch of the brachial plexus
Decreased thumb function, "Pope's blessing"Damage do the median branch of the brachial plexus
Cannot flex 2/3rd finger when trying to clench fist and thumb remains unopposed
Decreased fn of the intrinsic muscles of the hand, claw handDamage to the ulnar nerve branch of the brachial plexus
How is the brachial plexus protected from the common clavicle fracture?Subclavius muscle
In addition to the extensors, damage to the radial nerve would dec the fn of...Supination
Fractured surgical neck of the humerus can damage what nerve?Axillary n
Fracture of the supracondylar humerus can damage what nerve?Median nerve
Motor deficit of median nerve injuryOpposition of thumb
Lateral wrist deviation
Wrist flexion
Fracture of medial epicondyle of humerus can damage what nerve?Ulnar n
Thoracic outlet syndromeAtrophy of the thenar and hypothenar eminences
Atrophy of the interosseous muscles
Sensory deficits on the medial side of the forearm and hand
Disappearance of the radial pulse upon moving the head toward the ipsilateral side
"Ape hand"damage to proximal median nerve → loss of opponens pollicis muscle fn
Unopposable thumb (inability to abduct thumb)
Dorsal interosseous muscles do what?abduct the fingers
Palmar interosseous muscles do what?Adduct the fingers
Lumbrical muscle fnFlex at teh MCP joint
Extend PIP and DIP joints
Thenar/hypothenarOppose, Abduct, Flex
Thenar - median nerve - thumb
Hypothenar - ulnar - digiti minimi
Obturator nerve - cause of injuryAnterior hip dislocation
Femoral nerve cause of injurypelvic fracture
Superior gluteal nerve - cause of injuryPosterior hip dislocation
Motor deficit of obturator nerve injurythigh adduction
Motor deficit of superior gluteal nerve injuryThigh abduction
Positive Trendelenburg sign - contralateral hip drops when standing on leg ipsi to site of injury
Motor deficit of inferor gluteal nerve injuryCan't push inferiorly
Can't jump, climb stairs, or rise from seated position
Cause of injury to inferior gluteal nerveposterior hip dislocation
Cord levels of obturator nL2-L4
Cord levels of femoral nL2 - L4
Cord levels of common peroneal nL4-S2
Cord levels of tibial nerveL4-S3
Cord levels of superior gluteal nL4-S1
Cord levels of interior gluteal nL5-S2

Muscle conduction to contraction

Question Answer
Dihydropyridine receptorVoltalge-sensitive, mechanically coupled to ryanodine receptor on the sarcoplasmic reticulum
depolarization induces a conformational change that causes Ca release from the SR
Released Ca from the SR does what?binds to troponin C, causing a conformational change that moves tropomyosin out of the myosin-binding groove on actin filaments
Power stroke of muscle cell contractionPi is released from ADP/Pi
Contraction shortens which lines and bands in muscle cell?H & I bands, and shortens distance between Z lines
(A band remains the same length)
Type 1 muscle fiberSlow twitch
Red fibers d/t ↑ mitochondria and myoglobin concentration (↑ oxidative phosphorylation) → sustained contraction
1 slow red ox
Type 2 muscleFast twitch
White fibers d/t ↓ mitochondria and myoglobin concentration (↑ anaerobic glycolysis)
Weight training results in (hypertrophy or hyperplasia?) of which muscle types?Hypertrophy of fast-twitch muscle fibers
What "cocks" the myosin head preparing for next connection between myosin head and tropomysin/actinATP hydrolysis (now ADP and Pi are attached to myosin head)
How do myosin and actin/tropomyosin connect?Ca binds to troponin C → conformational change that displaces tropomyosin → exposing actin allowing for myosin to attach
Endochondral ossification - which bones?Bones of axial and appendicular skeleton and base of the skull
Endochondral ossification mechanism of constructionCartilaginous model of bone is first made by chondrocytes
Osteoclasts/blasts later replace it with woven bone and then remodel to lamellar bone
Woven bone occurs after what (in adults)?Fractures and Paget's disease
Membranous ossification - which bones?Calvarium and facial bones
Membranous ossification mechanism of constructionWoven bone formed directly without cartilage
Later remodeled to lamellar bone
Osteoblastsbuild bone
Osteoclastsresorb bone
Effect of parathyroid hormone at low, intermittent levelsanabolic - builds bone
Parathyroid hormone effect at chronically high levelscatabolic - destroys bone
Estrogen and bonesinhibits apoptosis in bone-forming osteoblasts
induces apoptosis in osteoclasts