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48 terms


skeletal, smooth, cardiac
list 3 types of muscle tissue
a projection of connective tissue beyond the ends of the muscle that attaches to bone
a broad fibrous sheet of connective tissue that connects muscles to adjacent muscles
muscle fibers are grouped together in fascicles that are surrounded by a layer of connective tissue
the fascicles are bundled together and surrounded by another layer of connective tissue, which also fills the spaces between the fascicles
epimysium, perimysium
several layers of fibrous connective tissue called the ___ which surrounds the entire muscle, then cover the ____
deep fascia
the portion of the network of the fasciae that surrounds and penetrates the muscles
subcutaneous fascia
the portion that lies just beneath the skin forming the subcutaneous layer
subserous fascia
the portion that forms the connective tissue layer of the serous membranes covering organs in various body cavities and lining those cavities
nerve fibers
the ___ of a motor neuron are highly branched
motor end plate
each of the branches is connected to the ____ of a single muscle fiber
when the motor neuron is ___, the impulse is carried to all of the muscle fibers attached to its branches
single motor neuron
in a way, a ___ controls the contractions of many muscle fibers
motor unit
all the muscle fibers attached to the motor neuron and the motor neuron itself constitute a
fewer, finer
the ___ muscle fibers in the motor unit, the __ the movements that can be produced
ATP molecules
the basic energy source for muscle contraction comes from ___ supplied by the mitochondria
the cross bridges of myosin contain the enzyme ___ that causes ATP to decompose into ____ and phosphate, thereby releasing energy
creatine phosphate
the primary source of regeneration of ATP from ADP is
high energy phosphate bonds
creatine phosphate contains ____ and is 4-6 times more abundant in the muscle fibers than ATP
create phosphate cannot directly supply energy to the muscle fiber, it acts as a ___ of energy for the ADP
mitochondria, ATP synthesis
in the __, the enzyme creatine phosphokinase creates creatine phosphate to be used for ___
the creatine phosphate converts ___ into ___ by resupplying the phosphate molecule
oxygen is carried from the lungs by ___ in the blood
when the hemoglobin reaches the muscle, the oxygen is transferred to the __ in hte muscle fiber
is similar to hemoglobin in its oxygen capacity, and reduces the muscles need for continuous blood supply during contraction
oxygen debt
the amount of oxygen needed by the liver to convert the lactic acid back into glucose, plus the amount needed by the muscles to resynthesize ATp and create phosphate and return them to their original concentrations
threshold stimulus
a muscle fiber remains unresponsive until a certain amount of stimulus is applied. the minimal strength required is __
all or none response
when a muscle fiber contracts, it always contracts to the fullest extent possible. because of a muscle fiber cannot contract partially, the phenomenon is ___
staircase effect
a muscle fiber that has been inactive can be subjected to a series of stimuli, such that it undergoes a series of twitches with complete relaxation in between. the strength of each successive contraction increases, reaching a maximum
motor unit recruitment
the ability to cause more than one motor unit to respond to a stimulus
tetanic contraction
results when a sustained forceful contraction lacks even partial relaxation
muscle tone
reponse to nerve impulses originating repeatedly from the spinal cord, and traveling to small numbers of muscle fibers within a muscle
muscle tone
responsible for maitaning posture
shortening occurs; muscle ends pull closer together and the object is moved. the muscle contracts with force greater than resistance and shortens
lengthening occurs; muscle contracts with less force than resistance and lengthens
consists of alternating contractions and relaxations of the longitudinal and circular muscle fibers. it functions to force the contents of a tube along its length
smooth and skeletal muscles
contractions involve the reactions of actin and myosin, are triggered by membrane impulses and the release of calcium ions, and use energy from ATP molecules
skeletal muscles
use acetylcholine as the neurotransmitter`
smooth muscles
uses acetylcholine and norepinephrine as its neurotransmitters.
smooth muscles
Several hormones that cause either contractions or alter the amount of response to the neurotransmitters
smooth muscle
muscle is slower to contract and relax
smooth muscle
can maintain a forceful contraction for a longer period of time with a given amount of ATP.
smooth muscle
fibers can change length without changes in tautness. as the hollow organs become filled, the muscles can stretch without internal pressure changing.
skeletal muscle
can contract individually
cardiac muscle
works in a network. When one portion of the
network is stimulated, the impulse travels to the other fibers in the network. It then contracts as a unit. It is self-exciting and rhythmic, and the entire network responds in an all-or-none manner.
of a muscle is the end of the muscle attached to an immovable part.
is the end of a muscle attached to a moveable part.
insertion, origin
when a muscle contracts, the ___ is pulled toward the ___