Hole's Anatomy and Physiology: Chapter 9: Muscles Flashcards

5023744653	Three types of muscle tissues	- skeletal muscle - cardiac muscle - smooth muscle	0
5023744654	Skeletal muscle	- usually attached to bone - voluntary - somatic - striated - multiple nuclei	1
5023744655	somatic	widely distributed	2
5023744656	Cardiac muscle	- wall of heart - involuntary - autonomic - striated - single nucleus - inter-collated disc	3
5023744657	Smooth muscle	- walls of most viscera, blood vessels, and skin - autonomic - not striated - single nucleus - spindle shaped	4
5023744658	Fascia	connective tissue surrounding each muscle	5
5023744659	Tendon	- cord-like connective tissue - collegan fibers intertwine with periosteum on bone	6
5023744660	Aponeuroses	- broad, fibrous sheet of connective tissue - may attach to bone or the coverings of adjacent muscles	7
5023744661	Muscle coverings	- epimysium - perimysium - endomysium	8
5023744662	Epimysium	thin layer of connective tissue that closely surrounds a skeletal muscle	9
5023744663	Perimysium	surrounds fascicles within muscles	10
5023744664	Endomysium	surrounds muscle fibers (cells) within fascicle	11
5023744665	Skeletal muscle fiber	a single muscle cell	12
5023744666	Sarcolemma	muscle cell membrane	13
5023744667	Sarcoplasma	- cytoplasma	14
5023744668	Myofibrils	- play a major role in muscle contraction - long, parallel structures composed of overlapping protein filaments	15
5023744669	Myosin	thick protein filament	16
5023744670	Actin	thin protein filament	17
5023744671	Myofibrils structure	- produce striations - form a repeating pattern of units called sarcomeres	18
5023744672	Sarcomeres	the functional unit of muscle contraction	19
5023744673	Striation pattern	made by arrangements of myofilaments in myofibrils	20
5023744674	I band	only thin actin filaments (light)	21
5023744675	A band	thick and thin - myosin and actin (dark)	22
5023744676	H zone	area with only thick myosin filaments	23
5023744677	Z line	in the center of I bands (where actin is attached)	24
5023744678	M line	thickening in A band (where myosin filament is anchored)	25
5023744679	A sarcomere extends	from one Z line to the next	26
5023744680	Thick filaments (myosin)	- myosin molecules - twisted protein strands called heads	27
5023744681	Thin filaments (actin)	- double strand of actin - troponin - tropomyosin	28
5023744682	Double strand of actin	each molecule has a binding site for the myosin head	29
5023744683	titin	elastic myofilament - myosin filaments are attached to z line by this large protein	30
5023744684	Troponin	attached to actin	31
5023744685	Tropomyosin	long rod-like, lie in grooves on the actin helix	32
5023744686	Sarcoplasmic reticulum	network of membranous channels that surround the myofibril (= endoplasmic reticulum of other cells)	33
5023744687	Muscle contraction	- movement within the myofibrils - the actin and myosin filaments slide past one another - shortening the sarcomeres - muscles fibers shortens	34
5023744688	Neurons	conduct action potentials (impluses) along axons to target organs	35
5023744689	Synapse	neuromuscular junction / myoneural junction - site where a motor neuron axon and muscle fiber meet	36
5023744690	neurotransmitters	cross the synaptic cleft and bind to receptors on the motor end plate of the muscle cell	37
5023744691	Parts of a synapse	- motor neuron - motor end plate - synaptic cleft - synaptic vesicles - neurotransmitters	38
5023744692	Motor neurons	- cause a reaction - transmit impulses to effector	39
5023744693	Motor end plate	area of muscle cell where neuron and muscle meet (indention)	40
5023744694	Synaptic cleft	space between the neuron and the muscle fiber	41
5023744695	Synaptic vesicles	- contain neurotransmitters - located at the end of the axon	42
5023744696	Axon terminal	end of axon	43
5023744697	acetylcholine (ACh)	the neurotransmitter that motor neurons use to control skeletal muscle contraction	44
5023744698	ACh (Acetylcoline)	_______ generates a muscle impulse which reaches the SR and triggers release of calcium ions into sarcoplasm of muscle fiber which leads to muscle contraction	45
5023744699	Calcium	binds to troponin to change its shape	46
5023744700	Troponin	pulls the tropomyosin off the binding sites - exposing binding sites on actin	47
5023744701	sliding filament model	when sarcomeres shorten, thick and thin filaments slide past one another - H zones and I bands narrow - Z lines move closer together	48
5023744702	cross bridge cycling	myosin head attaches to actin binding site - pulls thin filament - ADP and phosphate released from myosin - linkage between actin and myosin break - ATP splits - goes back to original position	49
5023744703	Acetylcholinesterase	rapidly decomposes ACh remaining in the synapse - stopping muscle impulse	50
5023744704	Relaxation	- muscle impulse stops - calcium moves back into sarcoplasmic reticulum (SR) - myosin and actin binding prevented	51
5023744705	Energy sources for contraction	- creatine phosphate - cellular respiration	52
5023744706	Creatine phosphate	- stores energy that quickly converts to ADP and ATP - stored in cells	53
5023744707	Cellular respiration - anerobic	- glycolysis - occurs in cytoplasm - produces little ATP (2)	54
5023744708	Cellular respiration - aerobic	- citric acid cycle - electron transport system - occurs in the mitochondria - produces most ATP - myoglobin stores extra oxygen	55
5023744709	myoglobin	molecule that stores oxygen until we need it - give red color to muscles	56
5023744710	oxygen debt	amount of oxygen needed by liver cells to use the accumulated lactic acid to produce glucose and to restore muscle ATP and creatine phosphate concentrations	57
5023744711	muscle fatigue	inability to contract muscle - decreased blood flow - Ion imbalances across the sarcolemma - accumulation of lactic acid	58
5023744712	cramp	sustained, involuntary muscle contraction	59
5023744713	threshold stimulus	minimal strength required to cause contraction	60
5023744714	twitch	the contractile response of a single muscle fiber to a single impulse	61
5023744715	latent period	brief delay between the time of stimulation and the beginning of contraction (2 milliseconds)	62
5023744716	myogram of a single muscle twitch	- latent period - period of contraction - period of relaxation	63
5023744717	refractory period	small time at the end of muscle twitch when muscle can not be stimulated again	64
5023744718	all-or-none response	- if a muscle fiber is going to contract it will contract completely	65
5023744719	overly shortened muscle	- length-tension relationship not optimal, no where to go	66
5023744720	overly stretched muscle	- length-tension relationship not optimal, not much strength	67
5023744721	summation	process by which individual twitches combine - produces sustained contractions - can lead to tetanic contractions	68
5023744722	tetanic	sustained contraction (think - lock jaw)	69
5023744723	motor unit	motor neuron and the muscle fibers it controls	70
5023744724	recruitment	increase number of motor units activated	71
5023744725	more precise movements	produced with fewer muscle fibers within a motor unit	72
5023744726	smaller motor units	- smaller diameter axons - recruited first	73
5023744727	larger motor units	- larger diameter axons - recruited as intensity of stimulation increase	74
5023744728	sustained contractions	allow muscle to produce smooth movements	75
5023744729	muscle tone	continuous state of partial contraction	76
5023744730	slow-twitch muscle fibers (Type I)	big muscle groups / red fibers - produce ATP oxidatively - slow to fatigue - most myoglobin - good blood supply	77
5023744731	fast-twitch glycolytic fibers (Type IIb)	white fibers / found in hands and eyes - less myoglobin - poorer blood supply - fewer mitochondria = reduced respiratory capacity - more SR - susceptible to fatigue	78
5023744732	fast-twitch fatigue-resistant fibers (Type IIa)	intermediate fibers / pink to red in color - produce ATP oxidatively - intermediate amount of myoglobin - resistant to fatigue - distributed widely throughout body	79
5023744733	smooth muscle	- shorter muscle fibers than skeletal - single, centrally located nucleus - elongated with tapering ends - lack striations - lack transverse tubules - sarcoplasmic reticula not well developed	80
5023744734	smooth muscle location	walls of hollow organs	81
5023744735	major types of smooth muscle (2)	- multi-unit - visceral	82
5023744736	multi-unit smooth muscle	found in iris of eye and walls of blood vessels - less organized - function as separate units	83
5023744737	visceral smooth muscle	found in the walls of hollow organs - single-unit smooth muscle - sheets of muscle fibers - held together by gap junctions - exhibit rhythmicity and peristalsis	84
5023744738	rhythmicity	a pattern of spontaneous repeated contractions	85
5023744739	peristalsis	wave-like motion - alternate contractions and relaxations of the longitudinal and circular muscles	86
5023744740	smooth muscle contraction	- calmodulin protein instead of troponin - two neurotransmitters - affected by hormones - stretching can trigger contraction - resistant to fatigue - can change length without changing tautness	87
5023744741	smooth muscle neurotransmitters	- acetlycholine - norepinephrine	88
5023744742	norepinephrine	- associated with fight or flight - opens blood vessels to make muscles move faster - stops digestion	89
5023744743	cardiac muscle	only in the heart - striated - muscle fibers joined together by intercalated discs - fibers branch - network of fibers contracts as a unit (syncytium)	90
5023744744	syncytium	network of fibers contracting as a unit (all-or-none manner)	91
5023744745	levers	Bones and muscles interact as simple mechanical devises called ___________.	92
5023744746	rigid bar	bones	93
5023744747	fulcrum	joint - point on which the bar moves	94
5023744748	object	weight - moved against resistance	95
5023744749	force	muscles - supplies energy for movement	96
5023744750	origin	immovable end of a muscle	97
5023744751	insertion	movable end of a muscle	98
5023744752	prime mover (agonist)	primarily responsible for movement	99
5023744753	synergist	assist prime mover	100
5023744754	antagonist	contraction causes movement in the opposite direction of the prime mover	101