A&P Exam 3 Flashcards
what is fascia
CT
what part of a muscle is covered by endomysium
muscle fiber
what part of muscle organ is the muscle fiber
muscle cell
4 functions of muscular system
movement, support, heat production, protection
compare isotonic and isometric contractions
isotonic- muscle contraction w movement
Isometric- muscle contraction w/o movement
what organ system controls the muscles of the body
nervous system
what structure is associated with the sarcolemma and muscle contractions
Axon
what is the function of T-tubules
Depolarize the cell
what is the result of an action potential along a muscle fiber
contraction
draw and label a sarcomere
two E’s with midlines of myosin and actin as the E lines
contractile unit of a muscle
sarcomere
what is necessary to cock a myosin head
ATP
what happens when myosin heads and actin connect
contraction
what prevents the connection of myosin heads and actin
tropomyosin
released from ER of muscle cell to remove tropomyosin blockage?
calcium ions
what causes a muscle to relax
ATP
what is a motor unit
nerve cell and muscle cells its attached to
function of neurotransmitter, acetycholine
a bridge
role acetylcholinesterase has in muscle relaxation
break down acetylcholine
function of creatine phosphate
stores ATP
function of hemoglobin
makes up RBC- carries O2
what controls function of hemoglobin
pH
relate myoglobin and hemoglobin
myoglobin-stores O2
hemoglobin- carries O2
what muscles are rich in myoglobin
long lasting muscles
result of inc lactic acid, loss of ATP, loss of creatine and low O2
muscle fatigue
how does repeated exercise overcome inc lactic acid build up
inc blood supply to muscles
what would cause muscle fatigue followed by cramping
water- dehydration
compare a muscle twitch to muscle tetany
twitch- short quick contraction
tetany- long sustained contractions
compare fast twitch and slow twitch muscle fibers
fast- short, quick contraction
slow- long, aerobics
when most muscles are a combination of slow and fast twitch muscles it means
genetics
muscles of the body that would have a small number of muscle fibers per motor unit
small
muscle that might have a large number of fibers per motor unit
large
2 parts of nervous system
PNS & CNS
parts of the peripheral nervous system
nerves & ganglia
describe neuron
nerve cell w/ dendrites, soma, and axon
4 different neuroglia cells
Schwann, astrocyte, microglia, oligodendrocyte
3 types of neurons according to structure and function
sensory, inter, motor
describe myelin sheath of peripheral neurons
myelin speeds up Schwann cells
2 ions that are necessary for nerve impulses to move through system
sodium & potassium
how does resting potential form
sodium pot pump
how much is resting potential
-70 MV
2 steps in forming a nerve impulse
depolarization and repolarization
threshold potential in order to activate the nerve impulse
-55 MV
cause of depolarization
sodium channels open
describe repolarization of the axon
potassium channels open
compare ligand channels and voltage channels
ligand- a chemical
voltage- depolarization
what is a synapse between neurons
a connection
what is a presynaptic neuron
before connection
what is postsynaptic neuron
after connection
function of a neurotransmitter
connects
explain the steps in how a nerve impulse can cross a synapse
diffusion of calcium causes secretion of acetyl COA
2 types of neurotransmitters according to how they convey an impulse
excitatory and inhibitory
what is a reflex
response w/o thinking
the paired nerves of the peripheral nervous system
spinal & cranial nerves
how many spinal neve pairs
31
how many cranial nerve pairs
12
what is a nerve
bundle of axons
