Anatomy and Physiology I - Chapter 10 Learnsmart

when you are cold or have a fever your muscles will often contract and relax rapidly to produce heat. this rapid relaxation and contraction can result in a phenomenon commonly known as ______

shivering

the muscle that surrounds the opening to your esophagus and opens reflexively to allow you to swallow food is what type of muscle

sphincter

a nerve impulse travels through an axon to its _______

synaptic knob

spread of a muscle impulse along the sarcolemma, then down the ______,causes calcium ions to leak out of the DR into the sacroplasm of the muscle fiber

transverse tubules

a single contraction and relaxation of a muscle fiber is referred to as a muscle ______

twitch

when a muscle fiber contracts, which parts of the sarcomere maintain a constant length throughout contraction?

A-band

the ______ line is a thin, transverse, protein meshwork structure in the center of the H zone of a sarcomere

M

contraction of a muscle fiber requires that the myosin heads in the thick filament bind to active sites on ______ molecules within the thin filaments

actin

a muscle cell obtains ATP in the short term via what process

anaerobic respiration

a tendon that forms a thin, flattened sheet is called a/an ______

aponeurosis

the shortening of muscle cells results in either a pull on bones of the skeleton or the movement of specific body parts. the process of shortening of muscle cells is called ______

contraction

a persons tolerance for exercise ______ with age

decreases

myosin head attachment and pivoting do not require energy, but ATP is needed for the myosin head cross bridge to ______ from actin and re-cock

detach

a sacromere is defined as the distance from one Z ______ to the next

disc

the epimysium of a muscle surrounds the ______

entire skeletal muscle

muscle cells are said to have what characteristic because they can respond to stimulation from the nervous system

excitability

true or false: after diffusing across the synaptic cleft, ACh binds to receptors on the synaptic knob

false

which of the three skeletal muscle fiber has the largest diameter and provides both power and speed

fast glycolytic

multiunit smooth muscle cells are stimulated ______

individually

cardiac muscle cells form Y-shaped branches and join to adjacent muscle cells at junctions called ______ discs

intercalated

during an ______ contraction, the length of the muscle does not change

isometric

if you strain to push on a wall that does not move, your muscles are in what type of contraction

isometric

the motor neuron transmits the effect of a nerve impluse to the muscle fiber at a neuromuscular ______

junction

each muscle fiber is controlled by one _______ neuron

motor

skeletal muscle contraction is controlled by ______ neurons

motor

aerobic respiration requires the presence of what molecule

oxygen

the immediate supply of ATP for use in muscle contraction is generated by the ______ system

phosphagen

if a skeletal muscle experiences markedly ______ _______, it loses both mass and tone

reduced stimulation

an internal membrane complex in skeletal muscle cells that is similar to the smooth endoplasmic reticulum of other cells is called the sarcoplasmic ______

reticulum

a contracting skeletal muscle fiber typically shortens as all of its ______ shorten in length

sarcomeres

the plasma membrane of a skeletal muscle fiber is called the ______

sarocloemma

type I muscle fibers contract more _____ than type IIa and IIb muscle fibers

slowly

what type of muscle forms the majority of the walls of the digestive tract

smooth

the motor end plate has folds and indentations to increase the membrane surface area adjacent to the ______

synaptic knob

the striated appearance in skeletal muscle cells is due to size and density differences between ______ and ______ filaments

thick/ thin

true or false: a single myofibril runs the length of the muscle fiber

true

true or false: skeletal muscle is usually attached to the skeleton, but it is also found at the opening between the digestive tract and the external environment and the urinary tract and the opening to the external environment

true

true or false: smooth muscle cells lack transverse tubules

true

in smooth muscle cells, the sarcoplasmic reticulum is sparse, and ______ tubules are absent.

T

in a muscle there are concentric layer of connective tissue. from deep to superficial these connective tissue layers are the ______, the ______, and the _______

endomysium/ perimysium/ epimysium

smooth muscle cells have a ______ mechanism that allows them to contract with more power and use less ATP than a skeletal muscle cell

latch bridge

aerobic respiration requires the presence of what molecule

...