chapter 8

three types of muscle in the body

skeletal smooth and cardiac

each___ is an organ comprised of skeletal muscle tissue, connective tissues, nervous tissues and blood

muscle

the layer of dense connective tissue that surrounds and seperates each muscle.

fascia

muscles that are connected to each other with broad sheets of connective tissue.

aponeuroses

the layer of tissue connective tissue that is around each whole muscle is ____

epimysium

surrounds individual bundles within each muscle

perimysium

within each muscle and each muscle cell is covered my connective tissue layers called

endomysium

each___ fiber is a single long cylindrical muscle cell

muscle

the sarcoplasm contains

myofibrils

thick filaments of myofibrils are made up of the protien....

myosin

thin filaments of myofibrils are made up of the protien....

actin

the oragnization of these filaments produces ...

striations

___extends from one z line to the next

sarcamere

______ bands are anchored to z lines

i

____bands are made up of thick and thin filament

a

beneath the sarcolemma of a muscle fiber lies the ...

sarcoplasmic reiculum (endoplasmic reitculum)

each____ lies between the two cisternae of the sarcoplasmic reticulum and is open to he outside of the muscle fiber.

t-tubules

the sarcoplasmic reticulum and transverse tubules activate the ________ _____ _____when the fiber is stimulated

muscle contraction mechanism

the site where the motor neuron and muscle fiber meet is the _______ ______

neuromuscular junction

the muscle fiber membrane forms a in which the sarcolemma is tightly folded and where nuclei and mitochondria are abundant

motor end plate

the cytoplasm of the motor neuron contains numerous mitochondria and synaptic vesicles storing ..

neurotransmitters

motor neuron and the muscle fibers it controls make up a .... when stimulated muscle fibers contract at once

motor unit

involves several compnents that result in the shortening of sarcomeres and the pulling if muscle against attachments

muscle contraction

two proteins associated with the surface of the actin filaments.

tropomysosin and troponin

consists of two twisted strands with globular cross-bridges projected outward along the strands

role of myosin

is a globular protein with myosin binding sites

role of actin

according to the _____ ____ ____ of mucle contraction the myosin crossbridges attaches to the binding site on the actin filaments and bends pulling on the actin filament.

slinding filament theory

-___ causing them to in a cocked position

atphase

sotres excess energy released by the mitochondria is present to regenerate atp from adp and phophate

creatine phospahte

____ in red blood cells carries oxygen to muscle

hemoglobin

the pigment ___ stores oxygen in muscle tissue

myoglobin

what accumulates as an end product of an anearobic respiration.

lactic acid

refers to the amount of oxygen that liver cells require to convert the accumulated lactic acid into glucose

oxygen debt

when the muscle loses its ability to contract during strenuous exercise ___

fatigue

usually arises fomr the accumulation of lactic acid i nthe muscle

muscle fatigue

a____ ___ occurs due to a lack of atp required to return calcium ions back to the sarcoplasmic reticulum so muscle fibers can relax

muscle cramp

contraction of ______ ______represents an important source of heat for the body

skeletal muscle

a muslce fiber remains unresponsive to stimulation unless that stimulus is of a certain strength called the.....

threshold stimulus

when a muscle fibersintracts it contracts to its full extent cannot extract partially

all-or-none response

recording of an electrically stimulated muscle contraction

myogram

single short contraction involving only a few motor units is referred to as a

twitch

time delay between when the stimulus is applied and when the muscle contracts is called

latent period

a point when it is unable to relax completely and the force of individual tiwitches combine the process of

summation

sustain contraction lacks any relaxation

tetanic contraction

increase in the number of activated motor units within a muscle at higher intsities of stimulation

recruitment

summation and recruitment together can produce a _____ ____ of increasing strength

sustained reaction

achieved by a continuous state of sustained contraction of motor units within a muscle

muscle tone

cells are elongated with tapered ends lack striations and have a relatively undeveloped sarcoplasmic reticulum

smooth muscle

two types of smooth muscle

muliunit and visceral

in blood vessels and iris of the eye fibers occur seperatly rather then in sheets

multiunit smooth muscle

in sheets is found in the walls of hallow organs

visceral smooth muscle

extra calcium contracts for a longer time, complex membrane junctions, self exiting and rythmatic contracts as a unit

cardiac muscle

immovable end of a muscle

origin

movable end of a muscle

insertion

contraction pulls the insertion toward the ___

origin