bsc 109 chapter 11 homework
bulbs
Axons branch into axon terminals, which have ________ located at the terminal ends
During synaptic transmission, the influx of ________ causes vesicles in the axon bulb to fuse with the cell membrane, releasing ________.
Ca2+, neurotransmitter
An impulse relayed along a myelinated axon "jumps" from _____ to _____.
Node of ranvier...node of ranvier
What type of cell makes up the myelin sheath of a motor neuron?
Schwann cells
During a brain surgery, a surgeon passes an instrument through the dura mater. Which one of the following does the surgeon pass through next?
arachnoid
Oligodendrocytes are similar to Schwann cells in that they
are a type of neurololial cell
Control of smooth muscle and internal organs is the role of the ________ division of the nervous system?
autonomic
A nerve impulse moves away from a neuron's cell body along _____.
axons
An __________ neurotransmitter causes __________ of the postsynaptic membrane.
both excitatory; depolarization and inhibitory; hyperpolarization are correction
A neuron's nucleus is located in its _____.
cell body
People who are intoxicated cannot coordinate their movements or walk a straight line because alcohol disrupts the normal function of which region of the brain?
cerebellum
Conscious thought is associated with which one of the following?
cerebral cortex
A nerve impulse moves toward a neuron's cell body along _____.
dendrite
the central nervous system is enclosed by membranes or meninges called the
dura mater, pia mater, and arachnoid
neurotransmitters always cause depolarization of the postsynaptic membrane
false
the three main anatomical and functional divisions of the brain are the
forebrain, midbrain, hindbrain
Convergence occurs when several presynaptic cells
form a synapse with a single postsynaptic cell
Which one of the following activities would be facilitated by the sympathetic nervous system?
increased blood pressure
an action potential
is self propagating because its depolarization of the membrane brings the next region of the axon to threshold
which of the following is true of the peripheral nervous system
it includes a sensory division and a motor division
Which part of the brain is responsible for regulating the heart and respiratory rates and blood pressure?
medulla oblongata
which component of the nervous system is divided into the somatic and autonomic divisions
motor
which one of the following cells transmits impulses AWAY from the CNS to the muscles and other organs
motor neurons
Axons insulated by a(n) _____ are able to conduct impulses faster that those not so insulated.
myelin sheath
White matter of the spinal cord contains __________, whereas gray matter contains __________.
myelinated nerves; unmyelinated cell bodies
Cells that provide direct protection and physical support to neurons are
neuroglial cells
Which of the following cell types makes up the majority of cells in the nervous system?
neuroglial cells
graded potentials
occur in a local area of the membrane
Which one of the following divisions of the nervous system predominates during the relaxed state?
parasympathetic division
which of the following provides the central nervous system with information about the outside environment
sensory division
Information coming into the central nervous system arrives via __________, while information going from the central nervous system to the muscles, glands, and organs travels via __________.
sensory neurones; motor neurons
Neurons of the PNS that transmit information to the CNS are __________
sensory neurons
which one of the following establishes and maintains the resting potential?
sodium-potassium pump
If your heart rate and blood pressure increase in response to a crisis, you are experiencing the immediate effects of the __________ nervous system (NS).
sympathetic
Which of the following would cause an acceleration of heart rate, an increase in blood pressure, and a slowing of digestive processes?
sympathetic division of the autonomic nervous system
What part of a neuron relays signals from one neuron to another neuron or to an effector?
synaptic terminal
central nervous system
the brain and spinal cord make up the
a spinal reflex requires the participation of each of the following... except
the cerebral cortex
Which of the following influence(s) the speed of an action potential?
the presence of a myelin sheath and the diameter of the axon
which of the following is a characteristic of psychoactive drugs
they alter levels of neurotransmitters
Which of the following statements correctly characterizes an action potential?
they are initiated by depolarization of the membrane to threshold
What do multiple sclerosis and ALS (amyotropic lateral sclerosis) have in common?
they both damage the myelin sheath, slowing action potential transmission
motor neurons
transmit impulses AWAY from the central nervous system
sensory neurons
transmit impulses TOWARD the central nervous system
interneurons
transmit impulses WITHIN the central nervous system
Motor nuerons of the peripheral nervous system transmit impulses away from the central nervous system
true
The two major subdivisions of the nervous system are the central nervous system and the peripheral nervous system.
true
the somatic division of the peripheral nervous system (PNS) controls skeletal muscles
true
