produce skeletal movement, maintain posture and body position, support soft tissues, guard entrances and exits, maintain body temperature, and store nutrient reserves
list the functions of the skeletal muscles
whole muscle, fasicle, muscle fiber/cell, myofibril, myofilaments
list in order the layers of a muscle tissue starting witht the whole muscle
long, develop through fusion of myoblasts, contain hundreds of nuclei
list the distinctive features of skeletal muscle fibers
surround individual muscle cells, contain capillaries and nerve fibers contracting muscle cells, contains satellite cells that repair damage
surrounds muscle fiber bundles (fasicles), contains blood vessel and nerve supply to fasicles
considered the cell membrane of the a muscle cell, surrounds the sarcoplasm of muscle fiber, a change in transmembrane potential begins contractions
transmit action potential through cell, allow entire muscle fiber to contract simultaneously
lengthwise subdivisions with muscle fibers, made up of bundles of protein filaments (myofilaments) which are responsible for muscle contraction
a membranous structure surrpounds each MYOFIBRIL, helps transmit action potential to myofibril, forms terminal cisternae which are attached to t tubules
formed by a t tubule and 2 terminal cisternae; release calcium ions into sarcomeres to begin muscle contraction
strands of protein that reach from tips of thick filaments to the z line, also help in stablizing the filaments
calcium and troponin complex forms, tropomyosin moves away from sites of actin, site exposed, actomyosin bridge forms
troponin and tropomyosin initiates contraction how?
part of myosin molecule that is made up of 2 globular protein subunits; interacts with the nearest thin filament
consist of thick and thin filaments, are in the center of sarcomeres, account for dark colorations in the banded appearence of myofibrils
cisternae of sarcoplasmic reticulum
__________ release _______ which triggers interactions of thick and thin filaments consuming ATP and producing tension
the transmembrane potential of the motor end plate changes when the binding of ________ to receptors on the motor end plate increases the permeability of the cell membrane to ______.
fixed muscular contraction after death caused by ion pumps ceasing to function causing calcium ions to build up in sarcoplasm
ATP into ADP and P
myosin reactivation after contraction occurs when the free myosin head splits ____ into ____ and ____. the energy released is used to recock the myosin head
a muscle producing peak tension during rapid cycles of contraction and relaxation is said to be?
smooth, but steady increase in muscular tension produced by an increase in number of motor units is defined as?
tension rises and skeletal muscles length changes to overcome resistance is what kind of contraction? ex: lifting an object, running, walking
ATP, pyruvic acid, and lactic acid if pyruvic acid accumulates
during anaeorbic glycolysis what is produced?
lactic acid removal and recycling; oxygen debt; heat production and loss
what are the three steps involved in the recovery period? LOH
growth hormone, testosterone, thyroid hormone, epinephrine
list all the hormones that help in muscle contraction (GTTE)
heat energy produced from muscle contraction is released through _______ system
contains neurons that are under involuntary control, uninucleate, and contain thin filaments that are attached to dense bodies
length of time muscular contraction can continue to be supported by glycolysis and by the existing energy reserves of ATP and C
The depolarization phase of an action potential results from the opening of _______ channels
the opening of voltage gated potassium channels
The repolarization phase of an action potential results from __________.
Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated
an electrical impulse that is propagated along the surface of an axon and does not diminish as it moves away from its source
steps involved in the generation of action potential: (place in order)
1) depolarization to threshold
2) potassium channel activation-t.m. potent. reached, Na channels close/inactivate, K channels open and K moves out causing repolarization
3) sodium channel activation-large influx of sodium ions causing depolarization, action potential rises
4) return to normal permeability-once membrane reaches threshold levels (-70mv) sodium channels are ready to be opened and potassium channels are ready to be closed, K ions swim out of cell quickly causing hyperpolarization, K channels finally close and action potential is over
the process that conducts along an axon at a high speed rate is called ____________conduction
pre and post synaptic cells bound by interlocking membrane proteins (occur in some areas of the brain and eye)
excitatory neurotransmitters that cause depolarization and promote action potential generation
at an electrical synapse, the presynaptic and postsynaptic membranes are locked together at __________
excitatory neurotransmitters can _________ and promote the generation of action potential and neuroinhibitory neurotransmitters cause _________ and suppress the generation of action potentials
compounds that alter the rate of neurotransmitter release by the presynaptic neuron or change the postsynaptic cell's response to neurotransmitters.
addition of stimuli occurring in rapid succession at a single synapse that is actively repeated.
occurs when simultaneous stimuli applied at different location have a cumulative effect on the transmembrane potential (involves multiple synapses that are active simultaneously)