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
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