Anatomy › Help with Proteins and Signals in the Central Nervous System
Which of the following neurotransmitters generally has an inhibitory effect on the postsynaptic neuron?
GABA
Dopamine
Serotonin
Norepinephrine
Glutamate
GABA is the only neurotransmitter to actively suppress the formation of an action potential when binding to the dendrites on the postsynaptic neuron.
Norepinephrine, dopamine, serotonin, and glutamate have various physiological effects in different regions of the body, but all acts to stimulate the formation of an action potential.
The electrical impulse that a neuron conveys to other neurons begins at the cone-shaped __________ and travels at high speed along the axon toward the __________.
axon hillock . . . axon terminal
dendrite . . . axon
dendrite . . . cell body
axon . . . dendrite
axon . . . terminal
The axon hillock is the last place where membrane potentials are summated before the generation of an action potential. The newly-created action potential travels down the axon to the axon terminal.
The autonomic nervous system consists of three divisions.
Which of the following is not a division of the autonomic system?
Somatic
Sympathetic
Parasympathetic
Enteric
The autonomic nervous system (ANS) consists of a set of pathways to and from the central nervous system (CNS) that innervate and regulate smooth muscle, cardiac muscle, and glands. The ANS is distinct from the somatic nervous system, which innervates skeletal muscle. The ANS has three divisions the sympathetic, parasympathetic, and enteric nervous systems.
Where are cell bodies for preganglionic neurons located?
Central nervous system (CNS)
Paravertebral chain
Autonomic ganglia
Effector organs
Synapses between neurons are made in the autonomic ganglia. Parasympathetic ganglia are located in or near the effector organs, while sympathetic ganglia are located in the paravertebral chain. Preganglionic neurons have their cell bodies in the CNS and synapse in autonomic ganglia.
What enzyme is responsible for removing norepinephrine and epinephrine from the synaptic cleft?
Monomaine oxidase
Cholinesterase
Lactase
Protease
None of these
Norepinephrine and epinephrine are both classified as monoamines. Thus, the enzyme that destroys norepinephrine and epinephrine at the synaptic cleft is monoamine oxidase. Cholinesterase is the enzyme that terminates acetylcholine activity. Lactase is an enzyme that is involved in the breakdown of the sugar lactose. A protease is an enzyme that degrades proteins by breaking peptide bonds found between amino acids.
What is the cell that is responsible for myelination in the central nervous system?
oligodendrocyte
astrocyte
schwann cell
glial cell
ependymal cell
The cell responsible for myelination in the central nervous system is known as the oligodendrocyte. Myelination of neurons in the peripheral nervous system are made possible by Schwann Cells.
Which of the following is not a function of the hypothalamus?
Distributes sensory information to the brain cortex
Thirst and water balance
Regulates hunger
Temperature regulation
All of these are functions of the hypothalamus
The hypothalamus has several key functions. It is responsible for regulating thirst and water balance, anterior pituitary control, and posterior pituitary hormone synthesis and release. The hypothalamus also regulates hunger, body temperature, the autonomic nervous system, and sexual responses.
The thalamus is the major relay center for all ascending sensory information (expect smell/olfaction) and distributes sensory information to the appropriate part of the brain cortex.