Structure and Function of the Systems Flashcards
(201 cards)
Which of the following is not a component of the central nervous system (CNS) ?
cranial nerves
Gaps in the myelin sheath of neurons are known as __
nodes of ranvier
Which of the following has the greatest influence on resting membrane potential?
potassium leak currents
Oligodendrocytes are found in the __
central nervous system
Which of the following is an effect of sympathetic stimulation of the liver?
increased glycoogenolysis
What is the resting potential of a neuron?
-70mV
Place the following sections of an action potential in order:
- Na+ channels open
- Na+ channels close and K+ channels open
- K+ channels close
A sensory neuron of the PNS takes impulses to __
the spinal cord
Which of the following is not true regaurding the somatic nervous system?
it is regulated by both acetylcholine and epinephrine
The part of the peripheral nervous system which directs the body’s rapid involuntary response to danger or stress is the __
sympathetic nervous system
An action potential arrives at the axon terminal at a synaptic junction. Which of the following events then causes release of a neurotransmitter into the synaptic cleft?
Ca2+ uptake at the axon terminal
Voluntary skeletal muscle contraction is controlled by which part of the brain?
frontal lobe of the cerebral cortex
Which of the following is released at the synapse between a somatic motor neuron and a muscle fiber to stimulate muscular contraction?
acetylcholine
Which of the following best describes the function of myelin in a neuron?
increases the speed of nerve signal transmission
Which of the following best describes what happens to excess neurotransmitter in the synapse following synaptic transmission?
is it absorbed by the presynaptic neuron
Place the following sections of synaptic transmission in order:
- nerve signal arrives at the axon terminal (pre)
- Ca2+ channels open in presynaptic membrane
- Ca2+ enters the axon terminal
- neurotransmitter is released into the synaptic cleft
- neurotransmitter binds to postsynpatic membrane
Which of the following membrane potentials represents the approximate peak depolarization of the action potential of a neuron?
+40mV
The part of the peripheral nervous system which regulates involuntary bodily functions such as heart rate, blood pressure and respiration is the __
autonomic nervous system
Which of the following amino acids also functions as a CNS neurotransmitter?
glutamate
Which of the following affects on the action potential may result if the relative stimulation of a neuron increases?
the action potentials increase in frequency
Epinephrine and norepinephrine hormones are derived from __
tyrosine
The effect of somatostatin on glucose metabolism is __
decreased glycogenolysis and glycogen synthesis
Which of the following hormones enters the target cell rather than binding to transmembrane receptors?
estrogen
Insulin is produced by __
beta cells in the pancreas