physio exam 2

action potentials

site where a signal is transmitted from one cell to the next

sending the signal

receiving the signal

gap junctions

faster conduction and synchronization

limited ability for amplification

action potential

synaptic cleft

neurotransmitter is released to stimulate a muscle fiber

amplification and communication between cell types

slower conduction

acetylcholine

active zones

20-50 nm

depression on postsynaptic cell corresponding to terminal bouton

arrival of an action potential at presynaptic terminal

synaptotagmin

ligand-gated ion channel

sodium influx causes depolarization

postsynaptic potential

end plate potential

acetylcholine esterase (AChE)

acetate and choline

it’s not enough to trigger postsynaptic AP

multiple presynaptic inputs summing at the same time

rapid successive inputs from one presynaptic cell

within dendrites or cell body

axon hillock

reduces or blocks neurotransmitter release

stimulates more neurotransmitter release

decreased neurotransmitter after repeated stimulation

chemical messengers

ligand-gated Na+ channel

closes K+ channels, depolarizes cell

opens K+ channels, hyperpolarizes cell

a catalytic domain

adds phosphates to tyrosine residues

activates or inactivates it

tyrosine kinase receptor

glucose transporter

glycogenesis

receptor that activates G-protein and second messenger

GTP

cAMP

GTPase activity

cytoplasm or nucleus

cholesterol

ligand-induced transcription factors

chaperone proteins

conformational change and nuclear translocation

DNA-binding motifs on steroid receptors

hormone response element

converting chemical energy to mechanical energy

striated vs smooth, voluntary vs involuntary

relatively stationary attachment point

movable attachment point

muscle generating the described movement

muscle that causes the opposite movement

interaction of actin and myosin

muscle cell membrane

muscle cell cytoplasm

bundles of protein in muscle fibers

contractile proteins (actin and myosin)

sarcolemma dipping deep into the cell

sarcoplasmic reticulum

2 terminal cisternae + 1 transverse tubule

epimysium

perimysium

endomysium

body awareness of position

between muscle fibers and tendon

increased tension squeezing nerve endings

among and parallel to extrafusal fibers

nuclear chain fiber

nuclear bag fiber

gamma efferent motor neuron

voltage-gated Ca++ channel, triggers RyR

releases Ca++ into cytoplasm

organized actin and myosin in myofibrils

actin filaments and Z-line

actin and myosin overlap, and M-line

Z-line to Z-line segment

myosin dimers

binds actin and hydrolyzes ATP

structural support for ATPase activity

influences actin-myosin binding kinetics

myomesin

C protein

titin

F-actin

tropomyosin

troponin

calcium ions (Ca++)

acts as a ruler for thin filament length

alpha-actin and Cap-Z

dystrophin

mutation in dystrophin

acetylcholine (ACh)

postsynaptic muscle fiber membrane

ACh binding to receptor

events linking AP to muscle contraction

Ca++ influx and vesicle fusion

sodium influx and depolarization

along sarcolemma into T-tubule

calcium into the cytoplasm

muscle contraction

myosin binding, pulling, releasing, and resetting on actin

binding of ATP

ATP hydrolysis

actin and myosin slide to shorten sarcomere

zone of overlap increases

contractionelaxation from a single stimulus

increased twitch tension with repeated stimulation

sustained contraction with high-frequency stimulation

recruitment of multiple muscle fibers coming from one single, repeated inputs

recruitment of more muscle fibers from multiple inputs

decreased ATP, ACh, and increased lactic acid

connective tissue and origin/insertion

actin and myosin interaction

passive + active tension

where maximum cross-bridges form

light loads quickly, heavy loads slowly