Exam 3: chapter 10 - MUSCLE TISSUE

__ muscle is voluntary striated muscle

skeletal

__ muscle is involuntary striated muscle

cardiac

__ muscle is involuntary nonstriated muscle

smooth

__ cells are elongated and have a high density of myofilaments

specialized

__ means it receives messages and responds to stimulus

excitability

__ means it shortens and produces force upon stimulation

contractility

__ means can be stretched

extensibility

__ means it recoils after stretching

elasticity

a __ __ is an organ composed of skeletal muscle cells, CT, nerves and blood vessels

skeletal muscle

functions of __ __ include: produce movement, maintain posture/ upright position, stabilize joints, support soft tissue, guard entrances/ exits, and generate heat

skeletal muscles

three __ __ hold muscle together

CT sheaths

the ___ covers the muscle, separates muscle from other tissues. it is made from collagen and connects to deep fascia

epimysium

the __ is made from collagen and elastin. it also has fascicles

perimysium

__ are groups of bundles of muscle fibers

fascicles

the __ is made of reticular fibers, with nerve fibers and satellite cells. they contain capillaries

endomysium

each muscle is innervated by one __

nerve

__ are cord like

tendons

__ are sheet like

aponeurosis

skeletal muscle fibers are formed by fusion of 100s of ___

myoblasts

unfused myoblasts in adults are called __ __

satellite cells

satellite cells are capable of ___ and __. they repair but cannot generate new fibers

division, fusion

the cell membrane of skeletal muscle fibers is called ___

sarcolemma

the sarcolemma maintains separation of electrical charges to make a _ __

transmembrane potential

__ charge from proteins on the inside give muscle fibers a resting potential of -85mV

negative

change in potential will signal muscle to ___

contract

tubes of sarcolemma called __ __ transmit changes in transmembrane potential to inside of cell

transverse tubules

__ is rich in glycosomes and myoglobins (cytoplasm)

sarcoplasm

actin is __ filament

thin

myosin is __ filament

thick

__ are bundles of myofilament (actin and myosin)

myofibrils

when thick and thin filaments interact __ occurs

contraction

sarcoplasm contains a network of SER called ____ (SR) that store calcium

sarcoplasmic reticulum

SR has 1000x more __ than sarcoplasm

Ca

__ are t-tubules wrapped around a myofibril between 2 terminal cisternae of SR

triads

__ are located near the ends of a sarcomere

triads

a __ is the smallest functional unit of a myofibril. least amount of myofilaments necessary to contract

sarcomere

thick filament = __

myosin

thin filament = __

actin

__ proteins hold thick and thin filament in place

stabilizing

__ proteins control thick and thin filament interactions

regulatory

protein organization in sarcomere gives it its ___ appearance

striated

__ filament is made of actin, nebulin, tropomyosin, troponin

thin

f- actin means ___

filamentous

g- actin means ___

globular

__ are rows of g-actin connected by nebulin

f-actin

g- actin has a __ __ to bind myosin

active site

__ covers active sites to prevent myosin binding

tropomyosin

__ holds tropomyosins on actin

troponin

__ is formed by contraction

crossbridge

__ filament is made from myosin bundles

thick

the __ of myosin makes the length of thick filament and point toward the M- line

tail

the __ of myosin is the flexible part that allows movement for contraction

hinge

the __ of myosin hangs off the tail by the hinge. it binds actin at active sites. there is none in the H-zone

head

the __ core is elastic protein that attaches thick filament to the Z-line

turin

__ holds thick filament in place for elastic recoil of muscle after stretching

titin

H-zones and I-bands __ width during contraction

decrease

zones of overlap __ width

increase

Z-lines move ___ together

closer

A-band remains __

constant

sliding causes ___ if every sarcomere in every myofibril in every fiber.

sliding

the sliding filament theory results in shortening of the whole ___ ___

skeletal muscle

during __ of muscle contraction, muscle fiber is controlled by nervous system at neuromuscular junction using neurotransmitters

excitation

the ___ ___ is where a nerve terminal interfaces with a muscle fiber at the motors end plate

neuromuscular junction

the ___ ___ is the expanded end of the axon that has vesicles of neurotransmitters (Ach) acetylcholine

synaptic terminal

the ___ ___ ___ is a specialized sarcolemma that contains Ach receptors and the enzyme AchE (acetylcholinesterase)

the ___ ___ is the space between the synaptic terminal and the motor and plate, where neurotransmitters are released

synaptic cleft

during ___, an action potential arrives at the synaptic terminal and Ach is released. Ach then binds receptors at the motor end plate and the Na channel opens. the action potential goes down the transverse tubules and AchE breaks down Ach. at the end it returns to its initial state

excitation

during ___ ___ coupling, action potential on transverse tubules reaches triads and releases calcium from cisternae of SR into sarcoplasm around zones of overlap of sarcomeres

excitation contraction

calcium binds to ___ on thin filament

troponin

troponin pulls ___ off active sites of actin so the crossbridge can form

tropomyosin

during ___, myosin heads bind to actin active sites and attach to cross bridges. myosin heads pivot toward the M-line (power stroke) and pulls thick fil. along thin fil., the cross bridges detach by ATP and myosin is reset and reactivated

contraction

during ____, calcium is absorbed by SR and calcium ions detach from troponin. the troponin covers active sites so no crossbridge can form and sarcomeres stretch back out. muscles return to resting length

relaxation

__ ___ happens what you die. all ATP is used up and cross bridges form, but there is to ATP to detach myosin heads making a fixed crossbridge until ___ releases lysosomal enzymes to digest it

rigor mortis, necrosis

__ occurs when bacteria prevents the release of Ach at the neurotransmitter junction. flaccid paralysis is the result

botulism

__ occurs when a toxin causes over stimulation of motor neurons resulting in spastic paralysis

tetanus

__ __ is an autoimmune diease that causes a loss in Ach receptors leaving muscles non-responsive

myasthenia gravis

__ ___ is force exerted by contracting muscle

muscle tension

a __ is the weight of an object being acted upon

load

__ tension depends on resting length of fiber and frequency of stimulation

contracting

__ __ is the greatest tension produced at optimal resting

resting length

a __ is a single contraction due to single stimulus. it has 3 phases

twitch

the first phase of a twitch is the __ period. it occurs post stimulation but has no tension and releases calcium

latent

the second phase of the twitch is the ___ phase. it has peak tension production and forms cross bridges

contraction

the last phase of a twitch is the ___ phase. it has a decline in tension and cross bridges decline

relaxation

a __ increases tension production to max level with repeat stimulation

treppe

__ __ is the repeat of a stimulus before relaxation ends resulting in more tension production than max treppe

wave summation

__ tetanus has rapid cycles of contraction and relaxation and produces max tension

incomplete

__ tetanus eliminates relaxation and is in a prolonged state of contraction. it is quick to fatigue

complete

__ tension is produced by sarcomeres, some is lost due to elasticity of muscle tissues

internal

__ tension is tension that is applied to the load

external

in a __ __ all fibers are controlled by a single motor neuron

motor unit

__ control activates eye muscles (4/unit)

fine

__ control activates legs (1000/unit)

gross

activation from one unit will produce __ tension across whole muscle

equal

__ is the order of activation of motor units . slower/ weaker first, stronger units produce steady increase in tension

recruitment

__ __ is the maintenance of shaping/defining muscle. some units are always contracting

muscle tone

__ contractions changes muscle length and results in movement

isotonic

__ contractions produce tension but no movement

isometric

when ATP is unstable, muscles store respiration energy on creatine as __ __

creatine phosphate

__ __ transfers P from CP to ADP when ATP needs to reset myosin for the next contraction

creatine phosphokinase