What is the composition of grey matter in the CNS?
A. Lightly myelinated nerve fibres that connect entirely within the CNS
B. Mainly non-myelinated neurones, glial cells, and blood vessels
C. Non-myelinated sensory nerve fibres going from the spinal cord to the thalamus
D. Connective tissue and blood vessels supplying the white matter
E. Slightly pigmented non-myelinated nerve fibres
The autonomic nervous system is subdivided into theSelect one:
A. Central and enteric divisions.
B. sympathetic, parasympathetic, and enteric divisions.
C. visceral and somatic divisions.
D. somatic and enteric divisions.
E. central and peripheral divisions.
Presynaptic inhibitionSelect one:
A. Always involves neurons acting in each other
B. Modulates the amount of neurotransmitter released.
C. Reduces the rate of neurotransmitter synthesis
D. Occurs only in the autonomic nervous system
E. Occurs only in the central nervous system
Presynaptic modulation of neurotransmitter release involves modifying ________ at the axon terminal.Select one:
A. sodium channels
B. potassium channels
C. the amount of neurotransmitter in the vesicle
D. the vesicles selected for release
E. calcium influx
Myelin is formed bySelect one:
A. C and D
D. ependymal cells.
E. Schwann cells.
The two divisions of the efferent side of the peripheral nervous system areSelect one:
A. somatic motor neurons and autonomic neurons.
B. somatic motor neurons and voluntary neurons.
C. voluntary nervous system and somatic motor neurons.
D. the sympathetic and parasympathetic divisions.
E. central efferent and peripheral efferent systems.
The afferent and efferent axons together form theSelect one:
A. peripheral nervous system.
B. somatic motor division of the nervous system.
C. autonomic division system.
D. visceral nervous system.
E. central nervous system.
Voltage-gated calcium channels in the axon terminal open in response to ________.Select one:
A. initiation of an action potential in the cell body
B. paracrines released from the post-synaptic cell
C. neurotransmitter binding to receptors
D. summation of graded potentials at the cell body
E. arrival of an action potential at the axon terminal
When an action potential reaches a nerve ending it:Select one:
A. triggers uptake of neurotransmitters in vesicles
B. returns back to the cell body
C. inhibits release of transmitters
D. triggers neurotransmitter synthesis
E. triggers the release of chemical transmitters
The brain and spinal cord together compose theSelect one:
A. central nervous system.
B. visceral nervous system.
C. somatic motor division of the nervous system.
D. peripheral nervous system.
E. autonomic division system.