Exam 1 Flashcards
(88 cards)
What is the order of activity that a voltage-gated Na+ channel goes through during an actionable potential: starting at the resting potential, then when membrane Vm is sufficiently depolarized, and finally during the refractory period?
Channel is closed, channel opens, channel is inactivated
A single motor neuron and the myofibrils on which it synapses is called a:
Motor unit
What neurotransmitter is NOT derived from an amino acid?
Acetylcholine (ACh)
_______ aid in regeneration of cut axons in the PNS; whereas glial scars formed from _________ will block axon regeneration in the CNS
Schwann cells; astrocytes
The primary excitatory neurotransmitter in the nervous system is?
Glutamate
Sensory neurons are an example of ________ and motor neurons are an example of ________?
Afferents; efferents
An increase in sarcoplasmic Ca++ causes muscular contraction by?
Binding to tropic, which shifts the position of tropomyosin on actin
If a neurotransmitter causes an increase in cAMP in the post synaptic cell, then the receptions are probably:
G-protein coupled receptors
The primary inhibitory neurotransmitter in the nervous system is:
GABA
Rigor Mortis is caused by?
The slow leakage of Ca++ from the sarcoplasmic reticulum
The knee-jerk reflex is usually suppressed in normal subjects because?
Descending input from the cerebral cortex inhibits the synapse in the spinal cord
Stimulus intensity is encoded by neurons as the ______?
Rate of firing of action potentials
Which of the following is NOT a difference between neuropeptides and small classical neurotransmitters (NTs)?
Neuropeptides are not co-localized in neurons with classical NTs
______________ allow for saltatory conduction
Myelin and nodes of Ranvier
Voltage-gated _______ channels are responsible for the DEpolarization of neurons; whereas ____ channels cause REpolarization of neurons.
Na+ ; K+
The _______ stimulates the fusion of synaptic vesicles that results in exocytosis of neurotransmitters into the synapse.
Ca2+ -protein complex
The mongoose is resistant to the venom of a cobra because
The venom does not bind to the evolved acetylcholine receptors of the mongoose
Gap junctions are an integral part of?
An electrical synapse
Astrocytes in the CNS provide energy for neurons by converting glucose into _______
Lactate
Positive and negative inputs are summated in the ___________ of the neuron
Dendrites
The plasma membrane is a barrier to what types of molecules?
Large
Polar molecules
EX: proteins, nucleic acids
What falls under Carrier-Mediated transport?
Facilitated diffusion
Active transport
In simple diffusion how does the solute move on the concentration gradient?
Moves down the concentration gradient
Rate of diffusion:
Increases with? (3)
Decreases with? (1)
Increases with:
Temperature
Concentration gradient
Decreases with:
Distance
