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1504 > Exam 3 > Flashcards

Exam 3 Flashcards

1
Q

1- muscle
2-muscle fiber
3-myofibril
4-myofilament

A

1-muscle attached to bones and the contraction is responsible for the support and movement of skeleton.

2-single skeletal muscle cell. large, elongated and cylinder shaped. run up the entire length of muscle

3-contractile elements of muscle fibers. numerous myofibrils make up one muscle fiber—each myofibril consists of repeating units called sarcomeres

4-ultramicroscopic filamentous structures where the contractile proteins are arranged into. Thick= myosin and thin= actin

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2
Q

Sarcomere

A
  • functional unit
  • has cytoskeletal elements made up of thick and thin
  • bounded by Z lines—(anchors thin filaments)
  • causes triations in skeletal and cardiac
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3
Q

Thick filament

A
  • made up of myosin
  • each myosin has 2 golf club shaped subunits w/ tails intertwined and has globular heads that have an actin binding site and an ATPase site.
  • thick filament = myosin molecules lying parallel to one another
  • half oriented in 1 direction while other half in other
  • globular head= protrude= cross bridges
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4
Q

Thick Filaments
1-titin
2-myomesin
3-creatine kinase
4-c-protein
5-MLCK (myosin light chain kinase)

A

1-stretches entire length of half sarcomeres from M line to Z line and controls both length of sarcomere and its elasticity

2-found in M line and helps titin and myosin to maintain their 3D structure

3-found in M line and is enzyme that transfers phosphate group from creatine phosphate to ADP= energy fo muscle contraction

4-maintains width of thick filaments by restricting them to 200-400 molecules each

5-binds to thick filament and phosphorylates the light chain of myosin. sensitizes myosin to Ca activation

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5
Q

Thin Filament
1-Actin
2-Tropomyosin
3-Troponin (Tn)

A

1-specherical shaped protein w/ bidning site for myosin. molecules bind together to make 2 stranded actin helix string

2-threadlike regulatory protein in the groove between the 2 actin strands. when relaxed= blocks myosin binding sites on actin

3-regulatory protein thats bound to tropomyosin. has 2 subunits: TnI, TnT, TnC. binding of Ca to TnC= conformational change that displaces TnI, exposing myosin biding sites on actin molecules

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6
Q

Hexagonal Arrangement

A

w/in A bands (thick and thin)

  • each thick furrounded by hexagon of 6 thin filaments
  • each thin filament surrounded by triangle of 3 thick filaments
  • w/in I band = thin filaments
  • w/in H zone= thick filaments
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7
Q

Muscle Receptors

A
  • joint movements, muscle tension, and muscle length is monitored by sensory receptors (propioreceptors) in muscle sent to CNS by neurons
  • efferent info (CNS to periphery) is conducted by somatic alpha motor neurons for either contraction or relaxation of main contractile cells of skeletal muscle i.e. extrafusal muscle fibers
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8
Q

Proprioreceptor in Skeletal Muscle
—Muscle Spindles

A
  • stretch receptors w/in muscle that monitor both absolute muscle length and the change in length
  • muscle spindle arranged in parallel to extrafusal fibers
  • ex= knee jerk reflex= external force passively stretches quads, pulls on intrafusal fibers of spindle = inc in firing rate. sends more AP to spinal cord via sensory neuron. sensory neuron synapses directly onto alpha motor neuron that excites the quad contraction= lower leg swinging.
  • —while that is happening, the hamstring relaxes bc it is inhibited of alpha motor neuron. inhibition is bc of interneuron activation in spinal bc of same sensory neuron
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9
Q

Propioreceptors in skeletal muscle
-Golgi Tendon Organs

A
  • w.in tendons near junction w/ muscle
  • connection in series w/ extrafusal fibers, when the muscle contracts there is tension upon the tendon
  • golgi tendon organ discharges in response to tension generated by contracting muscle
  • activation of golgi tendon organs= widespread inhibition of contracting muscle and stimulation of antagonistic muscles
  • protects muscle when large tension is generated
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10
Q

Sliding Filament Theory

A
  • contraction of muscle occurs by sliding of thin filaments over thick. actual length=unchanged
  • relaxed = low crossbridge cycling because the myosin bidning site on actin is covered by troponin-tropomyosin complex.
  • excited= Ca binds w/ troponin pullin troponin-tropomyosin complex aside to expose crossbridge binding.
  • bidning of actin + myosin crossbridges triggers power stroke, pulling thin inward during contraction
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11
Q

Cross Bridge Cycle

A
  • during each cycle the myosin head binds w/ actin molecule, bending to pull the thin filament inward during the power stroke…it will then detach and return to resting conformation= repeat of cycle
  • during muscle contraction, each sarcomere shortens as thin filaments slide closer together between thick filaments so that the Z lines are pulled closer together
  • A bands width dont change, but the I and H zones become shorter
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12
Q

Cross Bridge Cycling

A

1-myosin head is activated—ATP is hydrolyzed so myosin has ADP bound to it. Myosin ADP is activated form of myosin. but it cant yet to bind to actin because myosin is blocked by troponin-tropomyosin complex.
2-Cross bridge formation—Cat2 binds to troponin and troponin-tropomyosin complex moves, exposin myosin binding sites on actin. myosin binds actin
3-power stroke—release of ADP and P from myosin head. Head undergoes conformational change. thin filament sliding along thick filament. thin pulled 10 nm
4-cross bridge detachment—ATP binds to myosin, so myosin dissociates from actin and the cross-bridge breaks. hydrolysis of ATP to ADP and P returns myosin to original activated confromation
5-if there isnt enough ATP then myosin wont dissociate from actin…so cross bridge remains intact.

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13
Q

Rigor Mortis

A
  • ATP insufficiency in skeletal muscle
  • stiffness in skeletal muscle after death
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14
Q

ATP in skeletal muscle contraction

A

-ATP gives energy for 2 actions
1-binding of ATP to myosin dissociates the cross bridge between actin and myosin. the hydrolysis of ATP into ADP and P by myosin ATPase activates myosin heads
2-Ca-ATPase in SR transports Ca ions into SR which lowers cytosolic free Ca. terminates contraction and allows muscle fiber to relax

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15
Q

Velocity of Muscle Contraction

A
  • rate of ATP hydrolysis is determinant of rate of cross bridge cycling= determines maximal muscle contraction velocity
  • fast twitch fibers have isoform of myosin ATPase that splits ATP into ADP and Pi quickly
  • slow twitch fibers have isoform of myosin ATPase that split ATP into ADP slowly
  • cardiac and smooth muscles have diff isoforms of myosin ATPase
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16
Q

Neuron Muscle Synapse—Neuromuscular Junction

A
  • muscle fiber plasma membrane beneath nerve terminal = motor end plate
  • axon terminal + motor endplate= neuromuscular junction
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17
Q

Neuromuscular Junctions
1-neurotransmitter
2-Ach Receptors
3-Neurotrans Degradation/Removal
4- Acetylcholinesterase

A

1-Ach is a transmitter used at NM junctions. synthesized from acetyl coA and choline and is w/in vesicles in the axon terminal
2-on motor end plate w/in Ach receptros (nicotinic) receptors are ligand gated, cation selective channels that open when bound to Ach. amount of Ach released during AP will open 400000 channels in motor end plate
3-activation of Ach receptors terminates Ach degradation
4-post synaptic membrane degrades Ach. choline is taken back into presynaptic motor nerve for resynthesis of Ach. some diffuse away from cleft

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18
Q

Transmission at Neuromuscular Junction

A
  • AP generated in motor neuron
  • depolarization of motor neuron axon terminal by AP opens VG Ca channels and Ca moves into axon terminal
  • exocytosis of ACh containing vesicles-# of vesicles released is dependent upon con of Ca in terminal
  • Ach diffuses across synapse and binds to nicotinic Ach receptors on motor end plate of muscle membrane
  • sarcolemma is folded to synaptic cleft, and Ach receptors are present in junctional folds
  • after binding of Ach the nicotinic Ach receptor opens allowing an influx of Na and effluc of K= depolarizing end-plate potential (EPP)
  • EPP= AP down muscle membrane
  • Achesterase breaks down ACH in junction to stop contraction
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19
Q

End Plate Potentials

A
  • EPP are special excitatory Post synaptic potential at motor end plate
  • EPP is analogous to EPSP at neuron neuron synapse
  • binding of Ach to post syn receptor= electrical response of muscle cell membrane—depends only on Ach not voltage
  • large magnitude (50mv) of EPP= exceed membrane threshold of adjacent muscle plasma membrane to trigger AP. EPP= only 20 mv above membrane threshold= safety to ensure AP in motor neuron= AP in muscle
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20
Q

Muscle Membrane Action Potentials

A
  • EPP produces inward current flow at motor end plate
  • initiates AP in muscle membrane that is propagated over surface of fiber
  • Na current through VG Na channels generates the upstroke of AP in muscle membrane while K generates repolarization of muscle membrane
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21
Q

1-Alters release of Ach
2-blocks Ach receptors sites
3-prevents inactivation of Ach

A

1

  • black widow spider venom
  • clostridium botulinum toxin
  • lamber-eaton syndrome

2

  • curare
  • myasthenia gravis

3
-organophosphates

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22
Q

1-black widow spider venom
2-clostridium botulinum toxin
3-lambert-eaton syndrome
4-curare
5-myasthenia gravis
6-organophosphates

A

1-explosive release of Ach
2-blocks release of Ach
3-self Ab to Ca diminishes Ca influx into presynaptic term during AP= reduced Ach release
4-reversibly binds w/ Ach receptors
5-self AB inactivate ACh receptor
6-irreversibly inhibits Ach

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23
Q

Excitation Contraction Coupling

A
  • events linking electrical phenomena in plasma membrane to the cell shortening that results in muscle contraction
  • delay (altent) between electrical signal (AP) and mechanical response (contraction) reprsents the excitation-contraction coupling
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24
Q

Steps of Excitation Contraction Coupling

A

1-Ach released by axon of motor neuron crosses cleft and binds to nicotinic receptors on motor end plate that form cation selective channels. if depolarization= threshold then AP is generated
2-AP is propagated across surface membrane and down T-tubulues of muscle cells. t-tubules are invaginations of surface membrane= deep into interior of muscle. they conduct AP into cells center to activate entire cell in sync
3-T-tubules AP activates VG Ca channels that associate w/ Ca release channels in SR. AP triggers Ca release from SR. Free Ca of sarcoplasm inc from resting to antive
4-Ca ions released from SR bind to troponin (tn-c) on actin filaments. tropomyosin is physically moved aside to uncover cross bridge binding sites on actin. myosin able to make crossbridge w/ actin
5-myosin heads bend, pulling actin towards center of sarcomere= shortening sarcomere. energy is provided by hydrolysis of ATP into ADP & P. cross bridge binding, power stroke, and detachment will continue if ATP and Ca are present. Single contraction= cross bridge attaches, pulls, & detaches many times as it progresses along actin towards Z
6-AP termination (repolarization) VG Ca channels in T-tubules close, terminating SR Ca release. Ca ions in cytosol are pumped back into SR by Ca-ATPase, Ca is reduced. Low Ca favors dissociation of Ca from TnC.

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25
Q

Role of Ca in Skeletal Muscle Contraction

A
  • w/in skeletal muscles, the SR is main source of Ca. Ca is needed for cross bridging attachment of myosin to actin bc it removes blocking of the myosin binding by troponin
  • Ca & ATP = cross bridge cycling
  • but when SR removes Ca from cytoplasm there will be relaxation
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26
Q

Slow Oxidative FIbers

A
  • Type 1 w/in muscles for low-intensity contractions for longperiods of time w/o fatigue
  • muscles of back and legs that support bodys weight against gravity
  • high oxidative capacity bc of many mitochondria
  • high capillary density and low fatigability
  • oxidative phosphorylation for ATP
  • high myoglobin
  • low glycogen
  • ​slow contraction velocity
  • small fiber diameter, small motor unit size and small motor neuron innervating fiber
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27
Q

Fast Oxidative Glycolytic Fibers

A
  • Type IIa- share characteristics of both fibers.
  • contract quicker than slow oxidativefibers and maintain contraction for longer than fast glycolytic
  • medium oxidative w/ moderate fatigue
  • oxidative phosphorylation
  • many mitochondria, high myoglobin
  • intermediate glyocgen, intermediate fatigue, intermediate contraction velocity
  • intermediate contraction velocity
  • intermediate fiber and motor unit size and innervating fiber
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28
Q

Fast Glycolytic FIbers

A
  • type IIb- whire- w/in muscles for high intensity contraction for short periods of time
  • arm muscles for heavy lifting
  • low oxidative capacity
  • few mitochondria
  • low capillary density
  • high fatigability
  • glycolysis for ATP
  • low myoglobin
  • high glycogen
  • low contraction velocity
  • large fiber, motor size and inenrvating fiber
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29
Q

1-tension
2-load
3-types of contraction

A

1-force exerted on object by a contracting muscle
2-force on the muscle exerted by the weight of an object

3-isotonic, isometric, and eccentric (lengthening)

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30
Q

Isotonic Contraction

A
  • muscle tension remains constant as the muscle changes length
  • muscle shortens, causing a load to be moved
  • concentric contraction
  • muscle tension is greater than load
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31
Q

Isometric Contraction

A
  • muscle is prevented from shortening so tension develops at constant muscle length
  • contraction occurs when muscle supports a load in a constant position (doesnt move)
  • muscle tension is equal to the opposing load
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32
Q

Lengthening Contraction

A
  • load pulls the muscle to a longer length in spite of opposing forces being made by cross bridges
  • eccentric contraction
  • not an active process but is a consequence of external forces being applied to the muscle
  • muscle tension is less than the opposingl oad
  • ex: knees extensor muscles in your thighs are used to lower you to a seat from a standing position—-the muscle lengthens
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33
Q

Latent Period

A
  • delay between muscle stimulation and onset of contraction
  • AP in skeletal muscle fiber lasts less than 5 ms
  • onset of resultant contractile response lags behind the action potential because the entrie excitation-contraction coupling process must be before cross bridge activity
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34
Q

Frequency Tension Relationship
-summation of contractions

A
  • inc in muscle tension from successive AP occurring during the phase of mechanical activity
  • caused bc Ca removal from cytoplasm takes time
  • tension (force) being summated not voltage
  • AP of muscles DONT summate, but the contractions do
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35
Q

Frequency Tension Relationship
-Tetanus

A
  • sustained contraction where the individual twitches are no longer distinguishable from each other
  • rapid, repetitive stimulus
  • inc the frequency of stimulation doesnt allow muscle fiber to fully relax between successive APs
  • = an inc in produced muscle tension as individual twitches summate
  • fused tetanus= maximal tension is reached
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36
Q

Role of Ca in muscle fiber force production

A
  • cutosolic Ca levels remain elevated after the AP terminates
  • if 2nd AP excites the muscle during this period, the new Ca release from SR will inc the cytosolic Ca= larger muscle tension
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37
Q

Single Muscle Twitch

A
  • w/in individual muscle a single AP = maximal release of Ca from SR= single muscle twitch
  • each single muscle twitch= produced by same amount of Ca releases from SR (Ca release is NOT regulated)
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38
Q

High Cytosolic Ca

A
  • duration is important in development of graded forces w/ summation.
  • w/ single AP the duration of the high Ca is short even tho Ca released from the SR is maximal=single AP doesnt make maximal tension in muscle
  • –however at high frequency, Ca rises= inc in cytosolic Ca during summation.—if elevated for a long time= maximal tension in muscle
  • muscle tensions depends on amt of cytoplasmic Ca
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39
Q

Length Tension Relationship

A
  • max tension is achieved when muscle fiber length at the beginning of twitch, allows max overlapping between actin and myosin
  • resting length is the optimum length
  • if muscle is overstretched then there is no overlap of A & M so there are no crossbridges
  • if overshortenedand A & M physically overlap= interference w/ crossbridges
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40
Q

Whole Muscle Contraction
-Motor Unit

A
  • when reaching a muscle the axon of a motor neuron divides into branches and each branch makes a single junction w/ a muscle fiber
  • single motor neuron innervates many muscle fibers but each fiber is controlled by one motor neuron
  • motor neuron + muscle fibers innervates motor unit
  • AP generated in motor neuron all fibers in unit contract
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41
Q

Motor Unit Recruitment

A
  • determines total tension that a muscle can develop is number of fibers contracting at any one time
  • # of fibers contracting at one time depends on # of fibers in each motor unit and # of motor units
  • motor units w/ lowest threshold activate first and then the recruitment adds additional units =’ing greater force
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42
Q

Motor Unit Order of Recruitment

A
  • excitable first===slow oxidative type 1 (w/in postural muscles and fine motor movememnts)
  • intermediate
  • least excitable= fast glycolytic type 2b white—during high intensity when quick bursts of power are needed
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43
Q

Control of Whole Muscle Tension

A
  • tension developed in muscle depends upon amt of tension developed by each fiber and # of fibers contracting at a time
  • graded force production w/in muscle is determined by AP frequency w/ summation of contractions and the recruitment of motor units

-length tension relationship isnt imp. for force generation bc attachment to bone limits muscles ability to change length

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44
Q

1-frequency tension (summation)
2-length tension (fiber length)
3-fiber diameter (#of myofibrils)
4-fatigue

A

1-# of fibers per motor unit
2-#of active motor units (recruitment)

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45
Q

1-Soleus
2-extraocular muscles

A

1-fatigue resistant & maintain tension for a long time
2-contract rapidly but infrequently

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46
Q

1-slow twitch
2-fast twitch a
3-fast twitch b

A

1-type 1, fatigue resistant, red (myo), oxidative, high mito, low glyco

2-type 2a, fatigue resistant, red (myo), oxidative, higher mito, abundant glyco

3-type 2b, fatigable, white (low myo), anaerbox, few mito, high glyco

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47
Q

Sources of Energy

A
  • cell processes provide biochemical energy to contractile mechanisms, dependent on ADP–>ATP
  • metabolic pathway used to supple ATP depends on type of muscle and conditions
  • Phosphocreatine= readily available energy. creatine phosphotransferase transfers hhigh energy phosophate to ADP making ATP
  • glycogen= abundant energy source—into pyruvate then lactate via anerobic= 2 ATP
  • pyruvate w/ O2= CAC=36 ATP
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48
Q

Muscle Fatigue

A
  • end of muscle activity the creatine phosphate and glycogen stores will have decreases and need to be replenished—need energy so muscle uses O2 at inc rate (o2 debt) for time after activity stopped
  • when muscle is repeatedly stimulated the max tension that muscle produces will decrease=muscle fatigue
  • additional characteristics of fatigue= decreased shortening velocity and slower rate of relaxation
  • onset + rate of fatigue depends on fiber type and intensity and duration of stimulation
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49
Q

1-Growth of Skeletal Muscle
2-Lengthening
3-Hypertrophy
4-hyperplasia

A

1-# is determined prenatally and is constant through life
2-growth by adding new sarcomeres at the ends of the myofibrils
3-formation of added myofibrils w/in cells
4-adding new cells

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50
Q

Hypertrophy

A
  • total mass of muscle to increase
  • adds more sacomeres in parallel = inc in size of individual muscle fibers and inc force that is developed by muscle fiber
  • short duration, high intesity resistance exercise= hypertrophy in fast glycolytic fibers while low intensity but long duration = changes in slow oxidative and fast oxidative glycolytic fibers
  • maybe bc cell damage bc of overloading= hypertrophy to prevent future muscle damage
  • muscle fibers in men are thicker, larger, and stronger than womenthis is bc of androgenic steroid = inc in males
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51
Q

1-Atrophy
2-disuse atrophy
3-denervation atrophy

A

1-total muscle mass to decrease
2-if muscle not used for long periods of time (immobile) there is a dec in muscle size
3-motor neurons innervating muscle are destroyed the denervatied fibers become smaller—if not reinnervated then fibers degenerate and eliminate

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52
Q

Hyperplasia

A
  • # of muscle fibers increase
  • limited ability to form new fibers
  • new fibers from differentiation of satellite cells w/in tissues
  • major destruction= scar tissue replacement
  • may happen as result of high volume moderate intesnity weightlifting protocol by body builder—but overall= minimal
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53
Q

Postnatal growth

A

-lengthening and hypertrophy

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54
Q

Smooth Muscle

A
  • surrounds hollow organs and tubes (BV, bronchi, GI, reproductive, and urinary)
  • eye for pupil diameter and hairs in skin
  • propels contents through tubes
  • maintains pressue against contents w/in organ and tube
  • regulates internal flow of contents by changing tube diameter (resistance)
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55
Q

1- Muscle Contraction
2-Basal Tone
3-Phasic Contraction
4-Tonic Contraction

A

1-changes in Ca control muscle: high Ca= more cross bridge + stronger force…SM is slower than Skeletal

2-low level of contraction in absence of extrinsic factors. intrinsic of SM (mygenic). Cytosolic Ca is sufficient for low level cross bridging

3-brief stimulurus w/ rapid force (contraction) and rapid relaxation as Ca goes back to basal. GI, urogenital

4-continous production of force in presence of falling Ca that remain above basal levels. cross bridge cycling continues at low levels. Lungs, BV and GI sphincters have tonic contractions

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56
Q

Contraction of SM

A
  • lacks striations but has order just doesnt detect small ordered arrays of overlapping filaments
  • SM doesnt have t tubules, sarcomeres, troponin, and has less SR
  • has myosin thick filaments and actin w/ thin
  • regulation of cross bridge cycling in SM occurs on the thick myosin filament
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57
Q

Contraction of SM
steps

A

1- increase cytosolic Ca
2-Ca binds to calmodulin (binding protein) in cytosol
3-Ca calmodulin complex binds & activates enzyme MLCK (myosin light chain kinase)
4-MLCK uses ATP to phosphorylate myosin cross bridges
5-phosphorylated myosin forms cross bridges w/ actin filaments
6-cross bridge cycle produces tension and shortening
7-power stroke—release of ADP Pi from myosin head
8-cross bridge detachment needs ATP

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58
Q

Inc of Intracellular Ca

A
  • extracellular Ca plays major role in inc of cytosolic Ca
  • influc of extracell Ca into SM causes release of more Ca from SR===Ca induced Ca release
  • small amt of extracell Ca= large inc in cyotosolic Ca
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59
Q

Extracellular Ca entering

A
  • voltage gated Ca channels
  • ligand (2nd messengers) gated Ca channels
  • receptor gated Ca channels
  • stretch activated Ca channels

-autonomic, hormones and paracrine control SM tone, contraction and relaxation

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60
Q

1-RMP
2-AP
3-AP definition

A

1-Em= not constant but variable…from -65 mV to -45 mV, RMP is determined by Na and K fluxes

2-Ca dependent rather than Na dependent. single unit SM fires AP, most multiunit SM dont fire AP

3-depolarization of RMP to generate AP = activation of VG Ca channels in membrane of SM and an increase in intracellular Ca

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61
Q

spontaneous depolarization (of single unit)
1-pacemaker potential
2-slow wave potential

A

1-membrane potential graduall depolarizes until it reaches threshold for firing a single AP. spontaneous depolarization= from activation of small cationic current (mostly Na)

2-membrane potential slowly oscillates, alternating small depolarizations and slow hyperpolarizations. when threshold is reached the cell fires a burst of AP

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62
Q

RMP
1-depolarization
2-hyperpolarization

A

1-of RMP w/o generating AP = activation of VG Ca channels, intracellular Ca and force of contraction inc

2-of RMP = closing of VG Ca. intracellular Ca and force of contraction dec

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63
Q

Pharmaco Mechanical Coupling

A

-agonist (hormone, neurotransmitter) binds to receptor and inc/dec cytosolic Ca through 2nd messenger, w/o changing membrane potential

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64
Q

1-receptor operated channels
2-mechano mechanical coupling

A

1-receptors are coupled (direct/indirect) to Voltage independent channels which then open bc of voltage change (depol or hyperpol) the change in membrane potential will alter cytosolic Ca that same neurotrans may contract or relax

2-stretch acitvated channels (mixed cation) open when the SM cell membrane is distorted by stretch of the organ…depolarization inc the cytosolic Ca—contraction opposes the stretch

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65
Q

Relaxation of SM

A

1-dec in cytosolic Ca from:

  • return of Ca into SR by SR Ca ATPase
  • extrusion of Ca out of SM by: -sarcolemma Na/Ca exchanger—energy for extrusion of Ca against concentration gradient from inward driving force for Na (atpase retains gradient) -sarcolemman Ca ATPase

2-MLCK returns from inactive
3-enzyme myosin phosphatase removes phosphate from myosin
4-cross bridge reattachment is inhibited—dec in contractile force occurs when intracellular Ca decreases

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66
Q

1-Smooth Muscle Drugs
2-Ca Antagonisms
3-K Channel Openers

A

1-affect excitation-contraction coupling in vascular SM cells—drugs treat hypertension
2-drugs block VG dependent Ca. Reduce Ca influx and Ca induced Ca release——nifedipine, verapamil, diltiazem
3-drugs cause hyperpolarization of SM cells. hyperpolarization promotes relaxation of SM and vasodilation of peripheral vascular SM—pinacidil

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67
Q

Smooth Muscle Drugs
Nitric Oxide/Cyclic GMP Stimulator

A
  • vasodilators produce NO or stimulate nitric oxide cyclic GMP pathway= elevated cGMP conc in cyotosol
  • cyclic GMP relaxes SM= nitrovasodilators=nitroglycerin
  • NO = imp physiological regulatior of vascular smooth muscle tone and BP
  • NO= impor regulatory mechanis in cardio
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68
Q

Single Unit SM

A
  • function syncitium bc of gap junction
  • phasic contractions—superimposed on basal tone
  • spontaneos contraction due to pacemakers or enteric nervous system
  • common stretch initiated contactions (SI)
  • common stretch initiated relaxations (rectum, bladder)
  • modulate ongoing phasic contractions, altering basal tone (extrinsic factors)
  • ex= GI tract, ureter, bladder, uterus, small diameter BV
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69
Q

Multiunit SM

A
  • each cell is independent of its neighbor
  • tonic contraction dependent on external stimuli
  • controlled by extrinsic—ANS, hormones, and local paracrines
  • stretch initiated contraction/relaxation= not common
  • extrinsic factors= strong influence on contraction
  • large diameter BV, airways of lungs, eye muscle, piloerector in skin
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70
Q

Shoulder and Pectoral Girdle

A
  • clavicle
  • scapula
  • sternum
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71
Q

Scapula

A
  • glenoid cavity (fossa)
  • supraglenoid and infraglenoid tubercles
  • fossae—shallow depressions for joint articulations or muscle attachments
  • spine and acromion process
  • suprascapular notch (foramen when bridged by suprascapular ligament)
  • coracoid process
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72
Q

Arm (brachium)

A

Humerus:

  • head and bicipital (intertubercular) groove
  • greater and lesser tubercle
  • deltoid tuberosity
  • radial (spiral) groove
  • olecranon fossa
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73
Q

Forearm (antebrachium)

A

-Ulna

  • olecranon process
  • coronoid process
  • ulnar tuberosity

-Radius

  • head
  • radial (bicipital) tuberosity
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74
Q

Glenohumeral (GH:Shoulder) joint

A

-between glenoid fossa of scapula and head of the humerus

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75
Q

Shoulder Muscles

A
  • deltoid
  • supraspinatus
  • infraspinatus
  • subscapularis
  • teres minor
  • rotator cuff
  • teres major
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76
Q

Deltoid

  • origin
  • insertion
  • action
  • innervation
  • blood supply
A

1-lateral 1/3 of clavicle, acromion and spine of scapula
2-deltoid tuberosity
3-abducts arm
anterior fibers assist w/ flexion & medial rotation posterior fibers extend & lateral rotate the arm
4-axillary n
5-posterior circumflex humeral a

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77
Q

Supraspinatus
1-origin
2-insertion
3-action
4-innervation
5-blood supply

A

1-supraspinous fossa
2-greater tubercle of humerus
3-abduction of arm
4-suprascapular n
5-suprascapular a

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78
Q

Infraspinatus
1-origin
2-insertion
3-action
4-innervation
​5-blood supply

A

1-infraspinous fossa
2-greater tubercle (inferior to supraspinatus insertion)
3-lateral rotation of arm
4-suprascapular n
5-suprascapular a

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79
Q

Subscapularis
1-origin
2-insertion
3-action
4-innervation
​5-blood supply

A

1-subscapularis fossa
2-lesser tubercle
3-medial rotation of arm
4-upper and lower subscapular n
5-subscapular a

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80
Q

Teres Minor
1-origin
2-insertion
3-action
4-innervation
​5-blood supply

A

1-lateral portion of axillar border
2-greater tubercle (inferior to inraspinatus insertion tendon)
3-lateral rotation of arm
4-axillary n
5-circumflex scapular a and scapular anastomoses

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81
Q

Rotator Cuff

A

-musculotendinous ring around GH join formed by tendons of the:

  • supraspinatus
  • infraspinatus
  • teres minor
  • subscapularis
  • tendons of rotator cuff fuse w/ and reinforce fibrous capsule of GH joint
  • tonic contractions of cuff muscles help hold head of humerus against glenoid fossa
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82
Q

Teres Major
1-origin
2-insertion
3-action
4-innervation
​5-blood supply

A

1-lateral portion of axillar border inferior to teres minor
2-medial lip of intertubercular groove
3-extends, adducts, and medially rotates the arm
4-lower subscapular n
5-circumflex scapular and thoracodorsal aa

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83
Q

Pectoral Region Muscles

A
  • pectoralis major
  • pectoralis minor
  • subclavius
  • serratus anterior
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84
Q

Pectoralis Major
1-origin
2-insertion
3-action
4-innervation
​5-blood supply

A

1-sternum, ribs 2-6, clavicle
2-lateral lip of intertubercular groove
3-adducts and medially rotates arm, flexes arm and extends it when you flexed, depresses and protracts shoulder by pulling on humerus
4-medial & lateral pectoral nn
5-thoracoacromial, lateral thoracic, and perforating internal thoracic

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85
Q

Pectoralis Minor
1-origin
2-insertion
3-action
4-innervation
​5-blood supply

A

1-Ribs 2-5
2-coracoid process of scapula
3-depresses and protracts pectoral girdle
4-medial pectoral n
5-thoracoacromial and lateral thoracic a

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86
Q

Subclavius

A
  • from 1st costal cartilage to inferior portion of clavicle
  • depresses and resists lateral dislocation of clavicle
  • innervated by ‘nerve to subclavius’
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87
Q

Serratus Anterior
1-origin
2-insertion
3-action
4-innervation
​5-blood supply

A

1-ribs 1-9
2-ventral surface of scapular medial border
3-protracts and superiorly rotates scapula
4-long thoracic n
5-lateral thoracic and subscapular a

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88
Q

Serratus Anterior Clinical

A
  • powerful protractor of pectoral girdle and responsible fo rmaintaining contact with the scapula and posterior wall of thorax
  • long thorac runs on superficial of it and is prone to injury
  • paralysis of SA canc ause the scapula to fall away for thoracic= winging of scapula that will become more pronounce when patient presses upper extemity foward against resistance
89
Q

Arm Muscles

A
  • *Anterior—flexors, innervated by musculocutaneous w/ blood via brachial artery**
  • biceps brachii
  • coarcobrachialis
  • brachialis
  • *Posterior—extensors, innervated by radial nerve w/ blood via deep brachial (profunda brachii)
  • **triceps brachii
90
Q

Brachial fascia

A
  • deep fascia of arm, medial and lateral intermuscular septa attach to humerus and divide arm into Anterior and Posterior compartments
  • fibrous and dense
91
Q

Biceps Brachii
1-origin
2-insertion
3-action

A

1-long head= supraglenoid tubercle of scapula; tendon courses through bicipital groove of humerus
short head= corocoid process of scapula

2-bicipital tuberoisity and antebrachial fascia (bicipital aponeurosis)

3-flexes and sipinates forearms
long head is a weak flexor of arm

92
Q

Corachobrachialis
1-origin
2-insertion
3-action

A

1-corocid process
2-anterior surface of humeral midshaft
3-flexes and adducts arm

93
Q

Brachialis
1-origin
2-insertion
3-action

A

1-anterior surface of humerus shaft inferior to coarcobrachialis m
2-ulnar tuberosity and coronoid process
3-flexes the forearm

94
Q

Triceps Brachii

1-origin
2-insertion
3-action

A

1-long head= infraglenoid tubercle of scapula
lateral head= posterior surface of humerus superior to spiral groove
medial head= posterior surface of humerus inferior to spiral groove

2-olecranon process
3-extend forearm, long head= weakly extend and adduct the arm

95
Q

Nerve Supply

A
  • myotomes are groups of muscles innervated compeltely or in part by 1 spinal segment
  • most upper limb receive motor fibers from multiple spinal segments following proximodistal
  • C5-6 supplies shoulders and arm
96
Q

Shoulder Nerve Supply

A

-**Suprascapular Nerve- **C5-C6 posterior divisions of brachial plexus—passes inferior to suprascapular ligament to reach supraspinous fossa

-Axillary Nerve- C5-C6 posterior divisions—accompanies posterior circumflex humeral a inferiour to infraglenoid tubercle of scapula and gives branches to teres minor before going deep to supply deltoid m

97
Q

GH joint Clinical

A
  • GH joint has no ligamentous or musculotendinous support inferiorly
  • majority of shoulder dislocations involve inferior displacememnt of humeral head
  • proximitiy of axillary n to joint capsule places it in danger of injury in case of severe inferior dislocations
98
Q

Pectoral Region Nerves

A

-somatic motor and sensory innervation in pectoral by branches of brachial plexus

  • medial pectoral
  • lateral pectoral
  • long thoracic
  • nerve to subclavius
99
Q

1-medial pectoral
2-lateral pectoral
3-long thoracic
4-nerve to subclavius

A

1-pieces pectoralis minor giving fibers both to it and overlying pectoralis major m

2-passes superior to pectoralis minor to reach deep surface of pectoralis major m

3-runs inferiorly along the superficial surface of serratus anterior m

4-small branch from upper trunk of brachial plexus

100
Q

Arm: Anterior Muscles

A
  • musculocutaneous— C5-C6 anterior divisions—innervates all muscles in anterior compartment of arm
  • terminal continuation of lateral cord, pierces coracobrachialis and goes inferiorly between biceps brachialis and brachialis mm
  • emerges superior to elbow where it becomes lateral antebrachial cutaneous n
101
Q

Arm Posterior Muscles

A
  • Radial—C6-T1 posterior divisions—terminal branch of posterior cord
  • supplies all muscles of posterior compartment of arm
  • courses in spiral (radial) groove of humerus between lateral and medial heads of triceps brachii
102
Q

Cutaneous Sensory Innervation

A

-dermatomes–regions of skin supplied by single spinal segment—pectoral girdle and arm are supplied by named peripheral nerves carrying fibers from seberal spinal segments

103
Q

1-Shoulder Cutaneous (sensory) innervation
2-Pectoral Region Cutaneous (sensory) innervation

A

1-via branches of supraclavicular C4 and axillary C5-6
2-via anterior and lateral cutaneous branches of intercostal nn

104
Q

Arm Cutaneous (Sensory) Innervation

A
  • Medial Brachial Cutaneous- C8-T1-branch of medial cord, supplies anterior and medial arm
  • Intercostobrachial- lateral cutaneous branch of T2 intercostal n supplies medial and posterior arm
  • Inferior Lateral Brachial Cutaneous-C5-6- from radial n supplies inferolateral arm
105
Q

Shoulder Arteries

A
  • suprascapular a
  • circumflex scapular a
  • posterior circumflex humeral a

-veins named by arteries they accompany (when w/in scapular region)

106
Q

1-suprascapular a
2- circumflex scapular a
3-posterior circumflex humeral a

A

1-branch of thyrocervical trunk (from subclavian a)—passes superior to suprascapular ligament en route to supraspinous fossa

2-branch of subscapular a (from axillary a) supplies teres major and minor mm

3-accoompanies axillar n inferior to infraglenoid tubercle and runs deep to deltoid m to supply it and the triceps brachii m

107
Q

Collateral Circulation of Shoulder

A
  • all scapular arteries communicate (anastomose) w/ each other. If 1 artery is obstructed the blood can go to other areas via alternative routes/ collateral circulation
  • scapular region is supplied by branches of subclavian and axillary that forms circular anastomosis around shoulder blade
108
Q

Pectoral Region Arteries

A
  • branches of subclavian and axillary
  • thoracoacromial trunk a
  • lateral thoracic a
  • cutaneous aa
109
Q

1-thoracoacromial trunk a
2-lateral thoracic a
​3-cutaneous aa

A

1-branch of axillary a
-short arterial trunk that pierces clavipectoral fascia and divides into 4 branches—deltoid, acromial, clavicular, and pectoral

2-branch of axillary a
descends along surface of serratus anterior

3-provides segmental (to spinal level) blood supply to skin and superficial fascia of trunk—-derived from branches of internal thoracic and intercostal aa

110
Q

Arm Blood Supply

A
  • brachial artery—-continuation of axillary artery and main source of blood to upper limb
  • stops anterior to elbow by bifurcating into radial and ulnar aa
  • profunda brachii (deep brachial a) is a major branch in the middle of the arm that accompanies radial nerve in spiral groove to supply posterior compartment
111
Q

Deep Veins

A

-deep venous return follows arteries
-interconnected venous channels called venae comitantes surround arteries===countercurrent heat exchange between outgoing (warm) and incoming (cool) blood to help conserve body heat
-
deep venous return is assisted by:
— semilunar valves (superficial veins) and prevents blood from flowing backwards and pool into extremities
—-& via arterial pulsation that helps propel blood inv enae comitantes towards heart
—-&dense fascia directs force of muscular contraction inward forcing blood through deep veins

112
Q

Superficial veins

A
  • network of superficial veins communication w/ deep veins through perforating branches under normal circumstances…blood flows from superficial to deep
  • highly variable
113
Q

Superficial vein Types

A

Cephalic- along the lateral aspect of arm
empties into axillary by passing between deltoid and pectoralis major (deltopectoral triangle)

  • *Basilic-** along medial aspect of arm
  • pierces brachial fascia in lower arm and unites w/ venae comitantes of brachial a to form axillary v
114
Q

Arm (brachium) —Humerus

A
  • medial and lateral supracondylar ridges and epicondyles
  • olecranon fossa
  • trochlea and capitulum
115
Q

Forearm (antebrachium)

1-Ulna

2-Radius

A

1-olecranon process

  • coronoid process
  • interosseous
  • head
  • styloid process

2-head

  • neck
  • interosseous crest
  • ulnar notch
  • styloid process
116
Q

Wrist (carpus)
1-proximal carpal row
2-distal carpal row

A

1- lateral to medial: scaphoid, lunate, triquetrum, pisiform

2-lateral to medial: trapezium, trapezoid, capitate, hamate

117
Q

Hand and Digits

A

-19 total bones

  • 5 metacarpals (MC: I-V from lateral to medial)
  • 5 proximal phalanges (I-V)
  • 4 middle phalanges (II-V)- 1st digit (thumb) doesnt have middle phalanx
  • 5 distal phalanges (I-V)
118
Q

Joints

A
  • elbows
  • wrist
  • carpometacarpal
  • metacarpophalangeal
  • interphalangeal
119
Q

1-Elbow
2-Wrist
3-Carpometacarpal (CM)
4-Metacarpophalangeal (MCP)

A

1-between distal humerus (capitulum and trochlea) and radius and ulna

2-between radius and proximal carpal row (save for pisiform)—midcarpal- between proximal and distal carpal rows

3-between distal carpal row and proximal ends (bases) of 5 metacarpals

4-between distal ends (heads) of metacarpals and bases of proximal phalanges

120
Q

Interphalangeal (IP)

A

-between heads of more proximal phalanx and base of more distal phalanx

—proximal= PIP= between proximal and middle phalanges

—distal=DIP= between middle and distal phalanges

N.B-thumb only 1 interphalangeal join—digits II-V each have PIP and DIP joints

121
Q

Muscls
1-antebrachial fascia
2-synovial sheaths

A

1- deep fascia of forearm, along with the interosseous membrane (thin fibrous sheath that extends between interosseous crests of radius and ulna), divides forearm into anterior and posterior compartments

2-tendons of extrinsic flexors and extensors of hand are enveloped w/in thin walled fibrous sacs lined w/ synovial membrane and lubricated by synovial fluid that reduces friction and allow tendons to slide smoothly beneath the retinacula

122
Q

Retinacula

A
  • thickenings of antebrachial fascial that attaches to distal radius, ulna, and carpal bones.
  • retinacula creates osseofibrous tunnels that tendons of forearm muscles pass through—give leverage for muscle action by preventing bowstringing
123
Q

Retinacula

1-flexor retinaculum
2-extensor retinaculum

A

1-transverse carpal ligament
dense ligamentous structure that extends from tubercles of scaphoid and trapezium to pisiform and hamate

2-not as well defined as flexor

  • attaches to dorsal aspects of distal radius and ulna
  • creates series of small osseofibrous tunnels for individual tendons to go through
124
Q

Anterior Compartment of Forearm—superficial

A
  • from common flextor tendon off of medial epicondyle of humerus
  • most innervated by median and ulnar nerve and receive blood via muscular branches of radial and ulnar
  • pronator teres
  • flexor carpi radialis
  • palmaris longus
125
Q

Pronator Teres
1-origin
2-insertion
3-Action
4- Innervation

A

1-medial epicondyle and coronoid process

2-lateral side of radius midshaft

3- pronates the forearm

4-median n

126
Q

Flexor Carpi Radialis
1-origin
2-insertion
3-Action
​4- Innervation

A

1-medial epicondyle
2-base of MC II
3-flexes and abducts the wrist
4-median n

127
Q

Palmaris Longus
1-origin
2-insertion
3-Action
​4- Innervation

A

1-medial epicondyle
2-palmar aponeurosis
3-weak flexor of the wrist
4-Median n

-palmaris longus is absent in 10% of arms, given its weak action its tendon is often repurposed for reconstructive ortho surheries

128
Q

Flexor Carpi Ulnaris
1-origin
2-insertion
3-Action
​4- Innervation

A

1-medial epicondyle and olecranon process
2-pisiform, hamate, base of MC V
3-flexes and adducts the wrist
4-Ulnar n—–exception

129
Q

Flexor Digitorum Superficialis
1-origin
2-insertion
3-Action
​4- Innervation

A

1-medial epicondyle, coronoid process, and anterior surface of radius shaft

2-divides into 4 tendons that insert onto bases of middle phalanges of digits II-V

3-flexes proximal interphalangeal PIP, metacarpophalangeal MCP joints, and the wrist

4-median n

130
Q

Anterior Compartment of Forearm

deep

A

-deep layer, all receive blood from anterior interosseous a (branch of ulnar)

  • flexor digitorum profundus
  • flexor pollicis longus
  • pronator quadratus
131
Q

Flexor Digitorum profundus
1-origin
2-insertion
3-Action
​4- Innervation

A

1-upper 3/4th of ulnar shaft and adjacent interosseuous membrane
2-divides into 4 tendons that insert onto bases of distal phalanges of digits II-V
3-flexes PIP and DIP and MCP joints and the wrist
4-lateral half (digits II & III) median n; medial half (digits IV and V)—Ulnar—-Exception****

132
Q

Flexor Pollicis Longus
1-origin
2-insertion
3-Action
​4- Innervation

A

1-anterior radial shaft and interosseuous membrane
2-base of distal pollical (thumb) phalanx
3-flexes thumb IP, MCP, and CM joints…flexes and abducts the wrist
40anterior interosseous n (branch of median n)

133
Q

Pronator Quadratus

A
  • from lower 1/4 of ulnar shaft to lower 1/4 of radial shaft
  • weak pronator of arm
  • innervated by anterior interosseous n
134
Q

Posterior Compartment of Forearm—superficial

A
  • lateral to medial
  • origin from common extensor tendon from lateral supracondylar ridge and lateral epicondyle of humerus
  • innervated by radial n and one of its branches—deep radial n
  • all receive blood from deep brachial and radial aa
  • brachioradialis
  • extensor carpi radialis longus
  • extensor carpi radialis brevis
  • extensor digitorum
  • extensor digiti minimi (quinti)
  • extensor carpi ulnaris
  • anconeus
135
Q

Brachioradialis
1-origin
2-insertion
3-Action

A

1-lateral supracondylar ridge
2-distal end of radius near styloid process
3-flexes forearm and partially supinates pronated forearm

136
Q

Extensor Carpi Radialis Longus
1-origin
2-insertion
3-Action

A

1-lateral supracondylar ridge
2-Base of MC II
3-extends and weakly abducts wrist also weakly flees forearm

137
Q

Extensor Carpi Radialis Brevis
1-origin
2-insertion
3-Action

A

1-lateral epicodnyle
2-base of MC III
3-extends and weakly abducts the wrist, also assists in forearm extension

138
Q

Extensor Digitorum
1-origin
2-insertion

A

1-lateral epicondyle

2-tendons go to digits II-IV and sometimes V each tendon flattens and inserts weakly onto base of proximal phalanx before splitting into central band to middle phalanx and 2 collateral bands to base of distal phalanx
extensor assembly—tendons of interosseuous and lumbrical unite w/ central and collateral bands
extensor expansion–union of all tendons form aponeurotic sheet over MCP joint and proximal phalanx

139
Q

Extensor Digitorum:::Action

A

-extend MCP joint and assists in extension of wrist and elbow. Extends PIP and DIP joints if MCP joins is below 180 extension. if MCP joints are extended beyond 180, extensor digitorum cant overcome passive resistance of forearms digital flexors causing PIP and DIP joints to flex…extension of tehse joints in this situation can only be achieved by interosseuous and lumbrical

140
Q

Extensor Digiti Minimi (quinti)
1-origin
2-insertion
3-action

A

1-lateral epicondyle
2-joins extensor digitorum tendon to digit V
3-same as extensor digitorum but only for digit V

141
Q

Extensor Carpi Ulnaris
1-origin
2-insertion
​3-action

A

1-lateral epicondyle and posterior border of ulna
2-base of MC V
3-extends and adducts the wrist and assists in extension of elbow

142
Q

Anconeus
1-origin
2-insertion
​3-action

A

1-posterior side of lateral epicondyle
2-lateral side of proximal part of ulna including olecranon
3-assists triceps brachii to extend forearm, stabilize the elbow joint and abduct the ulna during pronation

143
Q

Posterior Compartment of Forearm

deep

A
  • deep layer.
  • deep radial changes names to posterior interosseous n and innervates all deep posterior compartment forearm mm …posterior interosseous a (from ulnar a) supplies blood
  • supinator
  • outcropping muscles
144
Q

Supinator
1-origin
2-insertion
​3-action

A

1-lateral epicondyle and the lateral side of the proximal ulna
2-spirals around proximal part of the radius to insert on its posterior, lateral and anterior sides
3-supinates the forearm by swiveling the radius, less powerful than biceps brachii unless the elbow is extended

145
Q

Outcropping Muscles

A
  • original from interosseous membrane and adjacent parts of radius/ulna
  • tendons come from superficial muscle tendons
  • –abductoor pollicis longus
  • –extensor pollicis brevis
  • –extensor pollicis longus
  • –extensor indicis
  • –anatomical snuffbox
146
Q

Abductor Pollicis Longus
1-insertion
2-action

A

1-base of MC I (laterally)
2-abducts and extends the first carpometacarpal (CMP) joint and abducts the wrist

147
Q

Extensor Pollicis Brevis
1-Insertion
2-Action

A

1-base of proximal phalanx of thumb
2-extends the CMP and MCP joints of thumb and abducts the wrist

148
Q

Extensor Pollicis Longus
1-insertion
2-Action

A

1-base of distal phalanx of thumb, tendon bends around dorsal tubercle of the radius
2-extends teh CMP, MCP, and IP joints of the thumb and extends the wrist

149
Q

Extensor Indicis
1-insertion
2-action

A

1-joins the extensor digitorum tendon to digit II (index finger)
2-same as extensor digitorum, but only for the 2nd digit

150
Q

Anatomical Snuffbox

A
  • naturally occurring depression between tendons of extensor pollicis brevis and longus
  • tenderness will be localized in this location when scaphoid is fractured (most common fracture)
  • radial artery passes through snuffbox but palse is hard to palpate through tough overlying fascia
151
Q

Intrinsic Muscle of the Hand
-Thenar Eminence Muscles

A
  • intrinsic muscles of the thumb
  • common origin site at flexor retinaculum and its bony attachments
  • innervated by recurrent branch of median n
  • abductor pollicis brevis
  • flexor pollicis brevis
  • opponens pollicis
152
Q

Abductor Pollicis brevis
1-insertion
​2-action

A

1-base of proximal pollical phalanx
2-abducts the thumb

153
Q

Flexor Pollicis Brevis
1-insertion
2-Action

A

1-base of proximal pollical phalanx
2-flexes the CM and MCP joints of the thumb

154
Q

Opponens Pollicis
1-insertion
2-Action

A

1-lateral shaft of MC I
2-opposes the thumb

155
Q

Intrinsic Muscles of the Hand
-hypothenar eminence muscles

A
  • intrinsic muscles of digit V–
  • share common origin site at flexor retinaculum and its bony attachments
  • innervated by deep branch of ulnar n.
  • abductor digiti minimi
  • flexor digiti minimi
  • opponens digiti minimi
156
Q

Abductor Digiti Minimi
1-Insertion
2-Action

A

1-Medial base of the 5th proximal phalanx
2-abducts Digit V

157
Q

Flexor Digiti Minimi
1-Insertion
2-action

A

1-base of 5th proximal phalanx
2-flexes MCP joints of digit V

158
Q

Opponens Digiti Minimi
1-insertion
2-action

A

1-shaft of MC V
2-Opposes digit V

159
Q

Intrinsic Muscles of the Hand:
Central and Interosseous Muscles

A
  • adductor pollicis
  • lumbricals
  • palmar interosseous mm
  • dorsal interosseous mm
  • PAD/DAB
160
Q

Adductor Pollicis
1-origin
2-insertion
​3-action
4-Innervation

A

1-capitate, bases of MC II & III, shaft of MC III
2-medial base of 1st proximal phalanx
3-adducts and flexes the thumb
4-deep branch of ulnar n

161
Q

Lumbricals (4 numbered from lateral to medial)
1-origin
2-insertion
​3-action
4-Innervation

A

1-tendons of flexor digitorum profundus
2-lateral side of proximal phalanges of digits II-V
3-flexes MCP and extends PIP and DIP joins
abducts digits II & III laterally and adducts digits IV & V
4-I & II- Median n. III & IV-deep branch of ulnar

162
Q

Palmar Interosseous mm (3 # from lateral to medial)
1-origin
2-insertion
​3-action
4-Innervation

A

1-medial shaft of MC II, lateral shafts of MC IV & V
2-extensor expansions of corresponding digits
3-adducts and flexes MCP, extends PIP and DIP of digits II, IV, and V
4-deep branch of ulnar n

163
Q

Dorsal Interosseous mm (4 # lateral to medial)
1-origin
2-insertion
​3-action
4-Innervation

A

1-bipennate muscles from shafts of MC 1 &2, 2&3, 3&4, 4&5
2-proximal phalanges and extensor expansions of digits II-IV
3-abducts and flexes MCP. extends PIP and DIP joints of digits II-IV
4-deep branch of ulnar

164
Q

PAD/DAB

A

Palmar interosseous muscles
ADducts digits
II, IV, V

Dorsal interosseous muscles
ABducts digits
II, III, IV

165
Q

Nerve Supply

A
  • forearm by C7-C8
  • hand= T1
166
Q

Median Nerve

A
  • C6-T1 anterior—innervates all in anterior forearm except flexor carpi ulnaris and medial portion of flexor digitorum profundus
  • terminal continuation of roots from lateral/medial cords of brachial plexus…courses through medial portion of arm but doesnt innervate anything in arm
  • passes deep to bicipital aponeurosis and enters forearm
  • passes through hiatus in flexor digitorum superficialis and descends in plane between superficial and deep
  • crosses wrist medial to tendon of flexor carpi radialis and goes deep to flexor retinaculum
  • recurrent branch supplies thenar muscles
  • gives off common and proper palmar digital nn- provides motor innervation to first 2 lumbricals and cutaenous innervation to first 2 digits and radial side of digit 4
167
Q

Carpel Tunnel Syndrome

A

-median n may be compressed as it passes deep to flexor retinaculum

carpelt tunnel is most commonly caused by repetitive flexion/extension of wrist and fingers

168
Q

Ulnar Nerve

A
  • C7-T1 anterior
  • innervates flexor carpi ulnaris and medial half of flexor digitorum profundus
  • terminal continuation of root from medial cord, passes through arm by piercing medial intermuscular septum and courses in posterior compartment deep to triceps
  • winds around posterior aspect of medial epicondyle of humerus to enter anterior compartment of forearm
  • goes deep the flexor carpi ulnaris
  • crosses wrist superficial to flexor retinaculum and lateral to pisiform
  • deep branch gives motor innervation to intrinsic muscles of hand not supplied by median n
  • superficial branch gives cutaenous innervation to 5th digit and ulnar side of digit 4
169
Q

Ulnar Nerve Clinical

A
  • exposed position of ulnar posterior to medial epicondyle leaves in suceptible to injury resulting from blows to the medial portion of the elbow
  • funny bone phenomenon—fractures to medial epicondyle
170
Q

Radial Nerve

A

-C6-T1 posterior- terminal branch of posterior cord
-supplies all muscles of posterior comp of arm
-courses in spiral (radial) groove of humerus between lateral and medial heads of triceps
-pierces lateral intermuscular septum above elbow to course between brachialis and brachioradialis
-gives off posterior cutaneous n of forearm and passes anterior to lateral epicondyle deep to brachioradialis
-innervate anconeus, brachioradialis, and extensor carpi radialis longus —-dividies into 1-superficial radial n= supplies skin on dorsum of lateral surface of hand
2-deep radial n= penetrates supinator muscle and supplies other dorsal forearm mm becomes posterior interosseous n

171
Q

Saturday Night Palsy

A
  • radial nerve in spiral groove makes it vulnerable to injury by fractures of humeral shaft or sustained pressure against posteromedial arm
  • lesions of radial nerve= wrist drop= devastating functional deficit
172
Q

Sensory Innervation

A

1-medial antebrachial cutaneous n- C8-T1
medial cord—supplies anterior posterior portions of medial forearm

2-lateral antebrachial cutaneous n- C6-7
cutaneous continuation of musculocutaneous n—supplies anterior and posterior portions of lateral forearm

3-posterior antebrachial cutaneous n- C5-8
from radial nerve, supplies central strip of posterior forearm

173
Q

Brachial Artery

A
  • deep brachial= branches in middle of arm and accompanies radial n in spinal groove= rise to radial and middle collateral aa
  • superior ulnar collateral a= accompanies ulnar n towards posterior aspect of medial epicondyle
  • inferior ulnar collateral a- small branch arising just above cubital fossa, passing anterior to medial epicondyle
174
Q

Ulnar Artery

A
  • medial terminal branch of brachial
  • goes inferomedially between superficial and deep muscles of forearm= superficial just proximal to wrist= palpated pulse
  • accompanies ulnar n into hand and curves laterally to form principal protion of superficial palmar arch…gives off deep palmar branch that accompanies the deep branch of ulnar n that joins the radial artery to form deep palmar arch
175
Q

Ulnar Artery Branches
1-anterior/posterior ulnar recurrent
2-Common interosseous a

A

1-ascents to anterior posterior aspects of medial epicondyle
2-short arterial branch that divides into:
anterior interosseous- descends on anterior surface of interosseous membrane and supplies deep flexor muscles of forearm
posterior interosseous- passes superior to interosseous membrane and descends along posterior surface to supple posterior forearm

176
Q

Radial Artery

A

-lateral terminal branch of brachial a.
-descends in lateral forearm deep to brachioradialis= superficial just proximal to wrist where pulse= palpated
Branches=
-radial recurren—comes from distal to where radial a begins and ascends anterior to lateral epicondyle to anastomose w/ branches of profunda brachii
-gives deep palmar branch—penetrates thenar eminence to anastomose w/ ulnar to make superficial palamr
-winds dorsally across floor of anatomical snuffbox and passes between heads of 1st dorsal intero and into central compartment of hand
-gives off 2 major branches to first 2 digits= princeps pollicis and radialis indicis
-curves medially—deep to adductor pollicis and anastomoses w/ ulnar to make deep palmar arch

177
Q

Collateral Circulation

A

-branches from major arteries of arm and forearm from a circular anastomotic network of interconnected arterial pathways around elbow joint
1-inferior and anterior ulnar recurrent aa
2-superior and posterior ulnar collateral aa
3-radial collateral & recurrent aa
4- middle collateral and recurrent interosseous aa (posterior interosseous)

178
Q

1-Cephalic Vein
2- Basilic Vein
3-Median Cubital Vein

A

1-along lateral aspect of forearm
2-along medial aspect of forearm
3-short venous channel that connects the cephalic and basilic vv w/in cubital fossa
blood flow is usually from cephalic to basilic v

179
Q

Cubital Fossa

A
  • triangular depression anterior to elbow joint
  • bounded by pronator teres m (medially), brachioradialis m (laterally), and an imaginary line connection medial and lateral epicondyles (superiorly)
  • tendon of biceps brachii, median n, terminal portion of brachial a, radial and ulnar beginning w. venae comitantes are w/in cubital fossa
  • median cubital vein is superficial to the superficial fascia ontop of cubital fossa—used for venipuncture= prominence at site, fascia protexts structures lying w/in cubital fossa
180
Q

Cartilage

A
  • form of CT characterized by cells embedded in ECM
  • found at sites that need ferm yet flexible support
  • at movable joints (TMJ)
  • immovable joints (pubic symphasis, costosternal
  • support of other structures (nose cartilage, ear cartilage, larynx, trachea, epiglottis)
  • vertebral column (IV discs)

w/in skelton it serves as a model for development for the majority of bones and gives mechanism that bones grow in length

181
Q

Cartilage made up of

A

-ECM is made up on collagen Type 2
Aggrecan (has side chains of chondroitin sulfate and keratan sulfate)
and hyaluronic acid —proteoglycans bind noncovalently link to proteins of the acids and then too collagen 2

182
Q

Collagen features

A
  • avascular and dont have nerves
  • chondronectin–glycoproteins w/ multiple binding sites
  • Water- most of weight is fresh hyaline cartilage

-cartilage is compressible and resilient bc of fibers, anionic charge (glycosaminoglycans GAGs attached to core), amount of hydration

183
Q

Cartilage Cells

A
  • Chondroblast- proliferating undifferentiated cell that begins to synthesize ECM elements
  • Chondrocyte- fully differentiated ECM forming cells w/ reduced mitotic cells
  • chondrocytes are w/in ECM
  • spaces of the ECM occupied by chondrocytes are called lacunae
  • group of condrocytes derived from same cell= isogenous unit (groups)
184
Q

Perichondrium what it is and its structure

A

-CT surrounding cartilage—except there is no perichondrium aroum articular cartilage and fibrocartilage

-Structure–outer fibrous layer–fibroblasts and collagen 1
inner cellular layer–undifferentiated flat chondrogenic and chondroblasts

185
Q

Perichondrium Function

A
  • supporting tissue containing BV, nerves, and lymphatics
  • inner cells can participate in repair and appositional growth of cartilage
186
Q

Cartilage Formation

A

1-differentiation of mesenchymal cells
2-synthesis of cartilage specific collagen, elastin, and aggrecan
3-mature matric formation—binded H20 helps nutrients and O2 to cells of the cartilage and make a gel
4-accumulation of ECM—territorial and interterritorial matrix

187
Q

Cartilage Growth

A
  • Appositional growth= by cell addition to periphery of tissue
  • Interstitial growth= by division of cells w/in tissue (formation is of isogenous groups)
188
Q

Cartilage Repair

A
  • limited ability to repair after injury
  • formation of repair cartilage from perichondrium
  • matrix of repair has mixxed hyaline and fibrocartilage
189
Q

Hyaline Cartilage

A
  • mature fibrillar protein phenotype
  • Type 2 collagen
  • most common
  • highly hydrated
  • temporary skeleton during fetal development
  • epiphyseal plates until growth is pretty much compeleted
  • ex= articular cartilage, epiphseal cartilage and tracheal rings
190
Q

1-Elastic Cartilage
2-Fibrocartilage

A

1-fibrillar protein phenotype

  • Type 2 collagen and elastin
  • epiglottins, pinna of ear

2-fibrillar protein phenotype

  • Type 1 and 2 collagen
  • IV disc and menisci in knee
191
Q

Cartilage Significance

A

Arthritis—disease of CT of diarthrodial joints
articular cartilage is subject to degeneration as result of osteoarthritis or rheumatoid arthritis
cartilage ECM is degraded=articular surface is lost= arthroplasty (replacement)

Chondrosarcome–malignant tumor derived from cartilage cells

Osteosarcoma–malignant tumor derived from osteoblasts

192
Q

Bone

A
  • rigid CT w/ limited flexibility
  • ECM of bone= impregnated w/ salts of calcium and phosphate
  • support and protection for body and organs
  • highly vascular
  • metabolically active
  • resrvoir for Ca and P ions
  • formed and undergoes constant turnover (remodeling) throughout life
  • bone formation and remodeling are controlled by local paracrine regulators (bone morphogenic and FGF), hormones present in blood stream (GH, throid, & estrogen), diet, and muscle activity
  • bone houses bone marrow where immune cells are formed
193
Q

Osteoblasts

A
  • bone forming cells
  • produced organic matrix of bone= osteoid—Collagen 1 & proteoglycans
  • control bone matrix mineralization
  • located at bone surface= w/in endosteum and periosteum
  • Vitamin D= expresses osteocalcin for bone mineralization
  • PTH= activates synthesis of factors needed for osteoclast differntiation (macriohage colony stimulating factor and RANKL)
194
Q

Osteocytes

A
  • mature bone cells
  • osteoclasts entrapped in matrix they produce
  • realtively inactive
  • no cell division
  • detect mechanical stress on bone and maintain bone matrix
195
Q

Osteoclasts

A
  • bone resorbing cells
  • multinucleated giant cells formed by fusion of monocytes
  • located at sites of active bone resorption
  • PTH increase in number and activity
  • PTH synthesized by Parathyroid glands during low blood Ca
  • receptors for calcitonin a thyroid gland hormone= dec in number and activity= reduced Ca blood levels
  • RANK receptors interact w/ RANKL
196
Q

Bone Cell Lineages

A
  • osteoblasts and Osteoclasts have different origins
  • osteoblasts: mesenchymal—>osteoblast–> osteocyte
  • local regulatory stimuli direct development
  • persist during postnatal life on bone surface
  • osteoclasts: hemaotpoietic progenitors–> fusion of monocytes
    • of bone is resorbed completely so osteoclasts undergo apoptosis
197
Q

Bone Matrix

A

-organic matter is w/in Calcified inorganic matrix
-Collagen 1, present w/in proteoglyan aggregates and bone specific proteins (osteocalcin, osteopontin, and osteonectin)
-inorganic= calcium calcium hydroxyapatite and Mg, K, Na, bicarbonate, citrate
-hydroxyapatite w/ collagen= hardness and resistance
making bone a Ca reservoir

198
Q

Mineralization of Bone Matrix

A
  • osteoblasts synthesize organic compounds of matrix and control mineralization—-Vitamin D3 is crucial in mineralization it regulates osteocalcin levels that will then bind to hydroxyapatite
  • formation of hydroxyapatite in osteoid ECM outside bone= ectopic mineralization—myositis ossificans
199
Q

Bone Resorption

A
  • maturation of osteoclasts occurs in contact w/ bone
  • action of carbonic anhydrase II in osteoclasts= carbonic acid…source of H ions transported via ruggled border to extracellular space between osteoclast & bone
  • acidic environment= decalcification—released Ca enters blood stream
  • bone demineralization= degradation of organic matrix components by hydrolytic enzymes among matrix metalloproteinases
  • osteoclast activity= regulated by calcitonin, Vit D3, and regulatory molecues produced by osteoblasts
200
Q

1-Woven Bone

A
  • primary bone tissue—immature initially bone tissue
  • irregular arrangement of collagen type 1
201
Q

1-Lamellar Bone
2-Cortical (contact) bone
3-spongy (cancellous/trabecular bone)

A

1-mature bone tissue w/ regular Collagen 1 fibers making lamellae

2-80% total bone mass..made of parallel bony columns (osteons or haversian) each column has bon lamella surrounded by haversian canal that has BV, lymphatics and nerves

3-consists of interconnected trabeculae= honeycomb

  • forms interior of bones at the end of long bones, adjacent to cavities filled w/ bone marrow
  • in vertebrae, carpal and hip bones
202
Q

Woven Bone Remodeling W/in mature cortical (compact)

A
  • near BV in woven, osteoclasts remove bone matrix where osteoblasts will lay down
  • osteons are oriented in line of stress exerted on bones (in long they are parallel to longitudinal)
  • osteons in cortical bone w/ central canal of BV and nerves
  • osteocytes are entrapped in lamella and communication w/ cell to cell extensions in small chanells (canaliculi) no comm between osteons
  • osteons have vascular connections via volkmanns canals
  • BV run through volkmanns and haversian canals, anastomose w/ vessel in Bone marrow and periosteum
203
Q

1- internal remodeling of cortical bone
2-Interstitial Lamellae
3-Inner/Outer Circumferential Lamellae

A

1-osteon undergoes cyclic remodeling (resorption & reformation) from central canal outward (centrifugal) so the osteon is resorbed.
-lamellar bone formation (centripetal)—central canal containing BV never closes

2-remnants of previous lamellae

3-inner and outer surfaces of compact bone organization

204
Q

Regional Anatomy of Long Bone—1-3

4-flat bones of skull

A

1- Epiphysis—end of long bone—epiphyseal growth plate

2-Metaphysis—neck of long bone

3-Diaphysis—shaft of long bone—compact (cortical) bone

4-2 layers of compact bone = plates separated by spongy bone layer= dipole

205
Q

Periosteum

A
  • CT that envelopes a bone, consists 2 major layers—-inner cellular (osteogenic) layer and outer fibrous layer
  • periosteum forms bone during circumferential growth of diaphysis
  • periosteum is highly vascularized and has sensory nerves
206
Q

Endosteum

A
  • lines internal surface of bone adjacent to marrow cavity
  • contains osteogenic cells
207
Q

1-osteogenesis imperfect
2-osteoporosis

A

1-mutations in collagen gene result in abnormal collagen production= weak bones that fracture

2-inc in bone resportion that is not followed by inc formation= reduced bone mass and weird arch
primary osteoporosis=postmeno= low estrogen,

  • type1 primary=early postmeno=lost off trabecular
  • type 2 postmeno= loss of trabecular and cortical

secondary osteo=underlying disease, w/ men who have osteoporosis, caused by chronic corticost (anti inflam)

208
Q

1-ostemalacia
2-tetracycline

A

1-disease characterized by progressive softening and bending of bones—softens bc of defect in mineralization of osteoid due to lack of vitamin D or renal tubular dysfunction
w/in kids—defect= mineralization of cartilage ing rowth plate= rickets (juvenile osteomalacia)

2-stain teeth permanently
binds to Ca in teeth (esp at mineralization)
so dont use in 2nd/3rd trimesters of prego or kids under 8

209
Q

Intramembranous Ossification

A
  • process used in formation of flat bones
  • w/in a layer of fetal mesenchymal tissue
  • pluripotential and develop into osteoblasts—once it becomes osteoid it becomes an osteoblast
  • osteoblasts trap themselves in matrix the cell = osteocytes
  • osteoid mineralizes to become mature bone
  • happens at ossification centers w/inmesenchymal membrane= makes immature bone
  • flat bones= greater rate of bone formation on surface of developing bone = inner and outer plates of compact bone separated by spongy bone called dipole
210
Q

Endochondral Ossification

A
  • bone formation where bone replaces pre existing model made of hyaline cartilage
  • cartilage comes from mesenchyme
  • avascular cartilage is replaced by vascularized bone
  • ossification in long bone starts when bone collar appears, the collar surrounds diaphysis of cartilage and is produced by osteoblasts that emerge w/in fetal perichondrium= periosteum
  • cartilage of bone model in area adjacent to bone collar calcifies= 3D of calcified cartilage matrix so BV from perichondrium penetrate bone collar and calcified matrix=osteoprogenitor cells
  • osteoprogenitor cells adhere to calfied matrix and become osteoblasts
  • initial site= primary ossification w/in shaft and secondary oss in ends of long bones—-only cartilage that remains = articular cartilage and epiphyseal growth palte
211
Q

Endochondral Oss Histology
1-resting zone
2-prolif zone
3-zone of calcified cartilage
4-ossification zone

A

1-normal looking hyaline
2-chondrocytes quickly divide and make columns of cells parallel to lon axis of bone
3-cartialge calcifies hypertrophic chondrocytes die by apoptosis
4- empty lacunae invaded by vesses from bone marrow…vessels invade cartilage and osteoblasts take up residence on calcified cartilage matrix trabeculae and lay down osteoid…metaphysis is area below growth plate

212
Q

Endo Oss Histology—Hypertrophic Cartilage Zone
*zone of hypertrophy*

A
  • chondrocytes stop to proliferate, enlarge and become principal engine of bone growth
  • hypertrophic condrocytes mineralize surrounding matrix, attract BV, and promote transofrmation ofperichondrial to osteoblasts

proteins made:

  • type x collagen- mineralizes cartilage matrix
  • vascular endothelial growth factor VEGF- stimulates BV growth
213
Q

Epiphyseal plate & continue growth

A
  • bone grows in length when new cartilage is produced w/in epiphyseal plate (interstitial growth of cartilage)
  • width of epiphys is constant until it ossifies completely during puberty
  • epiphys plates will ossify (close)
  • epiphys plates of different bones ossify in specifc order so you can determine bones age on x ray
  • once plates close there cant be growth but bones can increase in width (appositional)—ossified by age 20
  • hyaline cartialge will remain on outer surfaces of bone epiphyses= articular cartilage of joint
214
Q

Periosteum growth

A

-responsible for growth of bone in widthe —appositional growth

215
Q

Bone remodeling

A

-partial resorption of previously formed bone and simultaneous deposition of new bone which permits shape of bone to be maintained as bone grows

1-bone first laid down in both priamry and secondary center is resorbed and remodeld= central marrow cavity in diaphysis and spngy bone in epiphyses—osteoclast= common feature=new areas
2-bones are remodeled during childhood and adulthood—-rate of bone remodeling is faster in kids
-factors cause remodeling= growth factors, pregnancy, ormones, and bone stress by muscle contraction and body movement
-growth of brain causes growth of skull bones
-ability of bone ro remodel under stress= orthodontics

216
Q

Bone Fracture Repair part 1

A
  • healing of bone fractures involves not only the bone matrix but BV and periosteum
  • w/in fractured bone= ruptured BV bleed= causing a formation of hematoma at fracture site
  • damage of matrix due to disruption of blood supply at site of fracture = death of osteocytes in area
  • phagocytic cells remove clot and damaged bone as part of repair
  • fibroblasts and BV grow into hematoma and form granulation and becomes callus—external callus around gracture and internal callus between fractured ends of bone
217
Q

Bone Fracture Repair 2

A
  • periosteum and endosteum adjacent to fracture respond to injury by producing large numbers of osteoprogenitor cells that invade the area of fracture
  • external callus grows and thickens at a rapid rate, causing inadequate blood supply in deeper parts of external callus that promotes formation of hyaline cartilage and not bone= cartilage is replaced by bone=endochondral
218
Q

Bone Fracture Repair 3

A
  • osteoprogenitor cells that invade the internal callus produce trabeculae of primary bone that unit ends of fracture
  • callus provides sufficient support to weakly unite 2 ends of bone and support—required for bone to heal property—–failure to adequately support bone during healing process can result in development of abnormal bone structure
  • normal stresses on healing bone will result in remodeling of newly laid down bone until repaired bone approximates the appearance of bone prior to fracture

1504 (5 decks)

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