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Chapters 10 and 12

produce skeletal movement, maintain posture and body position, support soft tissues, guard entrances and exits, maintain body temperature, and store nutrient reserves

list the functions of the skeletal muscles

epimysium

the dense layer of collagen fibers that surround an entire skeletal muscle

whole muscle, fasicle, muscle fiber/cell, myofibril, myofilaments

list in order the layers of a muscle tissue starting witht the whole muscle

long, develop through fusion of myoblasts, contain hundreds of nuclei

list the distinctive features of skeletal muscle fibers

endomysium

surround individual muscle cells, contain capillaries and nerve fibers contracting muscle cells, contains satellite cells that repair damage

perimysium

surrounds muscle fiber bundles (fasicles), contains blood vessel and nerve supply to fasicles

CNS

skeletal muscles are controlled by nerves of the _________

sarcolemma

considered the cell membrane of the a muscle cell, surrounds the sarcoplasm of muscle fiber, a change in transmembrane potential begins contractions

T tubules

transmit action potential through cell, allow entire muscle fiber to contract simultaneously

myofibrils

lengthwise subdivisions with muscle fibers, made up of bundles of protein filaments (myofilaments) which are responsible for muscle contraction

thin filaments

made up of protein actin

thick filaments

made up of protein myosin

sarcoplasmic reticulum

a membranous structure surrpounds each MYOFIBRIL, helps transmit action potential to myofibril, forms terminal cisternae which are attached to t tubules

a triad

formed by a t tubule and 2 terminal cisternae; release calcium ions into sarcomeres to begin muscle contraction

sarcomeres

contractile units of muscle, structural units of myofibrils

titin

strands of protein that reach from tips of thick filaments to the z line, also help in stablizing the filaments

muscle contraction

___________ is caused by the interactions of thick and thin filaments

nebulin

holds f actin strands together

tropomyosin

double stranded and prevents actin-myosin interaction

myosin

active sites on gactin strands bind to _______

troponin

globular protein that binds tropomyosin to g actin and controlled by calcium ions

calcium and troponin complex forms, tropomyosin moves away from sites of actin, site exposed, actomyosin bridge forms

troponin and tropomyosin initiates contraction how?

thick filaments

contain twistin myosin subunits and titin strands that recoil after stretching

mysoin tail

part of myosin molecule that binds to other myosin molecules

myosin head

part of myosin molecule that is made up of 2 globular protein subunits; interacts with the nearest thin filament

myosin heads interact with actin filaments during contraction

how are cross-bridges formed?

sarcolemma

cell membrane of skeletal muscle

sarcoplasm

cytoplasm of skeletal muscle fiber

myofilaments

consist of bundles of protein fibers

a bands

consist of thick and thin filaments, are in the center of sarcomeres, account for dark colorations in the banded appearence of myofibrils

tropomyosin molecules

at rest, active sites on the actin are blocked by___________molecules

troponin molecules

at rest, the tropomyosin molecule is held in place by __________molecules

sarcolemma

neural stimulation of _______ caused excitation-contraction coupling

cisternae of sarcoplasmic reticulum

__________ release _______ which triggers interactions of thick and thin filaments consuming ATP and producing tension

synaptic terminal

contains vesicles filled with acetylcholine

synaptic cleft

space between neuron and muscle

motor end plate

location for acetylecholine receptors

acetlecholine, sodium

the transmembrane potential of the motor end plate changes when the binding of ________ to receptors on the motor end plate increases the permeability of the cell membrane to ______.

rigor mortis

fixed muscular contraction after death caused by ion pumps ceasing to function causing calcium ions to build up in sarcoplasm

ATP into ADP and P

myosin reactivation after contraction occurs when the free myosin head splits ____ into ____ and ____. the energy released is used to recock the myosin head

twitch

single stimulus-contraction-relaxation sequence in a muscle fiber is described as?

treppe

increase in peak tenion after relaxation phase is described as?

wave summation

increas in tension or summation of twitches

incomplete tetanus

a muscle producing peak tension during rapid cycles of contraction and relaxation is said to be?

motor unit

all the fibers controlled by a single motor neuron is defined as?

recruitment

smooth, but steady increase in muscular tension produced by an increase in number of motor units is defined as?

isotonic

tension rises and skeletal muscles length changes to overcome resistance is what kind of contraction? ex: lifting an object, running, walking

aerobic metabolism

a resting muscle generates most of its ATP by?

creatine phosphate

what acts as an energy reserve in muscle tissue?

ATP, pyruvic acid, and lactic acid if pyruvic acid accumulates

during anaeorbic glycolysis what is produced?

lactic acid removal and recycling; oxygen debt; heat production and loss

what are the three steps involved in the recovery period? LOH

growth hormone, testosterone, thyroid hormone, epinephrine

list all the hormones that help in muscle contraction (GTTE)

type I fibers (slow fibers)

the type of muscle with low fatigue resistance

fast fibers

white muscles

slow fibers

red muscles

integumentary system

heat energy produced from muscle contraction is released through _______ system

smooth muscle

contains neurons that are under involuntary control, uninucleate, and contain thin filaments that are attached to dense bodies

placisity

the ability of smooth muscle to function over a wide range of lengths

anaerobic endurance

length of time muscular contraction can continue to be supported by glycolysis and by the existing energy reserves of ATP and C

voltage-gated sodium

The depolarization phase of an action potential results from the opening of _______ channels

axon hillock

Where in the neuron is an action potential initially generated?

the opening of voltage gated potassium channels

The repolarization phase of an action potential results from __________.

slow closing of potassium channels

Hyperpolarization results from __________.

ACh

Cholinergic synapses release the neurotransmitter

hyperpolarizations

IPSPs (inhibitory postsynaptic potentials) are local

spatial summation

Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated

CNS

cranial and spinal nerves comprise the _________

afferent divisions

brings sensory info from PNS to CNS

receptors

sensors that detect changes in the environment

efferent divisions

brings sensory info from CNS to PNS

somatic nervous system

controls skeletal muscle contractions

ANS

provides automatic regulation of smooth and cardiac muscles

sympathetic

accelerates heart rate

parasympathetic

slows heart rate

somatic nervous system

controls skeletal muscle contractions (voluntary)

passive

membrane channels that are always open are called __________

active and passive

at normal resting potential (-70mV) _____ and _____ processes are in balance

graded potential

change in resting potential that decreases with distance

active potential

an electrical impulse that is propagated along the surface of an axon and does not diminish as it moves away from its source

1,3,2,4,

steps involved in the generation of action potential: (place in order)
1) depolarization to threshold
2) potassium channel activation-t.m. potent. reached, Na channels close/inactivate, K channels open and K moves out causing repolarization
3) sodium channel activation-large influx of sodium ions causing depolarization, action potential rises
4) return to normal permeability-once membrane reaches threshold levels (-70mv) sodium channels are ready to be opened and potassium channels are ready to be closed, K ions swim out of cell quickly causing hyperpolarization, K channels finally close and action potential is over

hyperpolarization

inside of cell loses most of its positive ions

absolute refractory period

Na channels open or inactivate and no action potential is possible

relative refractory period

membrane potential almost normal and stimulus initiates action potential

diameter

axon _______ effects action potential speed

type a fibers

large in diameter, myelinated, high speed, carry rapid info from/to CNS

type b fibers

medium diameter, myelinated, intermediate speed (18m/sec), carry intermediate signals

type c fibers

small in diameter, unmyelinated, slower speed (1m/sec), carry slower info

saltatory conduction

the process that conducts along an axon at a high speed rate is called ____________conduction

electrical synapse

pre and post synaptic cells bound by interlocking membrane proteins (occur in some areas of the brain and eye)

chemical synapse

excitatory neurotransmitters that cause depolarization and promote action potential generation

gap junctions

at an electrical synapse, the presynaptic and postsynaptic membranes are locked together at __________

depolarize, hyperpolarize

excitatory neurotransmitters can _________ and promote the generation of action potential and neuroinhibitory neurotransmitters cause _________ and suppress the generation of action potentials

ACh

what type of neurotransmitter is found in cholinergic response?

centriole

neurons lack _________, therefore, do not divide once formed.

calcium

extracellular _________ is required for triggering ACh exocytosis

sodium

_________ions are required for the cause of depolarization

AChE

surplus acetylecholine is removed by an enzyme called _______.

GABA

produced presynaptic inhibition and appears to reduce anxiety

serotonin

effects emotial states

dopamine

inhibitory or excitatory effects (controls movements)

norepinephrine

has an excitatory/depolarizing effect on the post synaptic membrane

endophine

endogenous morphine is called ________.

IPSP

transient hyperpolarization of the postsynaptic membrane

neuromodulators

compounds that alter the rate of neurotransmitter release by the presynaptic neuron or change the postsynaptic cell's response to neurotransmitters.

temporal summation

addition of stimuli occurring in rapid succession at a single synapse that is actively repeated.

spatial summation

occurs when simultaneous stimuli applied at different location have a cumulative effect on the transmembrane potential (involves multiple synapses that are active simultaneously)

facilitated

a neuron whose transmembrane potential shifts closer to threshold is said to be _________.

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