Quiz 4 Flashcards
What promotes release of ACh from the presynaptic neuron?
Action Potential
Sodium channels in the sarcolemma
voltage-gated ions
-55mV
threshold potential
Basic contractile unit of a muscle fiber?
Sarcomere
T-tubules are an infolding of this structure
Sarcolemma
Removes neurotransmitter from the NMJ
Acetylcholinesterase
The space between a motor neuron and a muscle
synaptic cleft
Neurotransmitter at the neuromuscular junction
Acetylcholine
What forms a triad?
Two terminal cisternae and a T-tubule.
Storehouse for calcium within a muscle fiber?
Terminal cisternae
Connection of a myosin head with the active site on an actin?
Cross bridge
A membrane potential more than -70mV
Hyperpolarization
Connective tissue covering around an entire muscle?
Epimysium
What is the cell membrane of a muscle cell called?
Sarcolemma
What is the major protein that comprises a thin filament?
Actin
What molecule covers the active sites of the thing filaments when the muscle is at rest?
Tropomyosin
What molecule is found in the thick filaments and is shaped like a golf club?
Myosin
Which component of a thin filament binds with calcium and regulates the formation of cross bridges?
Troponin
What region of a neuron is known as the “Trigger zone”?
Axon Hillock
What type of membrane protein gives the “Trigger zone” its ability to initiate an action potential?
Voltage-gated ion channels.
Which voltage-gated ion channel opens first during the propagation of an action potential?
Na+
Which component of a voltage-gated Na+ channel is open when the cell is at rest?
Inactivation gate
When does stimulation of cell #2 cease?
When neurotransmitter can diffuse from the cleft, neurotransmitter can be broken down by an enzyme, and/or neurotransmitter can be reabsorbed by the neuron for future use.
