BSC 109: Chapter 11 Nervous System Homework Answers

Which of the following statements correctly characterizes an action potential? Action potentials reverse the membrane potential so that the interior is negatively charged and the exterior is positively charged. Action potentials are more likely to result when the membrane is hyperpolarized. Action potentials are initiated by depolarization of the membrane to threshold. A stronger action potential will travel faster than a weaker action potential.

Action potentials are initiated by depolarization of the membrane to threshold.

Which of the following would cause an acceleration of heart rate, an increase in blood pressure, and a slowing of digestive processes? parasympathetic division of the autonomic nervous system sensory branch of the central nervous system sympathetic division of the autonomic nervous system motor division of the somatic nervous system

sympathetic division of the autonomic nervous system

Which of the following is true of the peripheral nervous system (PNS)? It includes a sensory division and a motor division. The motor division carries from the body to the CNS. The somatic division controls smooth muscle activity.

It includes a sensory division and a motor division.

What type of cell makes up the myelin sheath of a motor neuron?

Schwann cells

Oligodendrocytes are similar to Schwann cells in that they conduct nerve impulses are located in the peripheral nervous system are a type of neuroglial cell

are a type of neuroglial cell

A neuron's nucleus is located in its _____.

cell body

transmit impulses within the central nervous system sensory motor interneurons

interneurons

An action potential __________. is self-propagating travels faster in response to larger stimuli is larger in response to larger stimuli can travel in both directions down an axon or dendrite

is self-propagating

Cells that provide direct protection and physical support to neurons are located only in the spinal fluid myelinated found primarily in lymphatic fluids nodes of Ranvier neuroglial cells

neuroglial cells

Which of the following is characteristic of psychoactive drugs? They can alter the amplitude of action potentials. They alter levels of neurotransmitters. They alter the speed with which action potentials travel.

They alter levels of neurotransmitters.

The central nervous system is enclosed by membranes or meninges called the glial, Schwann, and interstitial dura mater, pia mater, and arachnoid dura mater, alma mater, and pia mater

dura mater, pia mater, arachnoid

Neurotransmitters always cause depolarization of the postsynaptic membrane. True or false?

false

The two major subdivisions of the nervous system are the central nervous system and the limbic nervous system. true or false

false

The three main anatomical and functional divisions of the brain are the hypothalamus, thalamus, pituitary ventricles, meninges, nerve tracts frontal, parietal, occipital cerebellum, medulla oblongata, pons forebrain, midbrain, hindbrain

forebrain, midbrain, hindbrain

Convergence occurs when several presynaptic cells depolarize sequentially activate the sodium-potassium pump of a Schwann cell depolarize simultaneously form a synapse with a single postsynaptic cell

form a synapse with a single postsynaptic cell

Which component of the nervous system is divided into the somatic and autonomic divisions? parasympathetic central sensory motor

motor

transmit impulses away from the central nervous system sensory motor interneurons

motor

The somatic division of the peripheral nervous system (PNS) controls skeletal muscles. true or false

true

Which one of the following activities would be facilitated by the sympathetic nervous system? decreased heart rate increased bladder contraction increased blood pressure decreased respiratory rate increased digestion and absorption

increased blood pressure

Which one of the following divisions of the nervous system predominates during the relaxed state? endocrine division somatic division sensory division sympathetic division parasympathetic division

parasympathetic

What do multiple sclerosis and ALS (amyotropic lateral sclerosis) have in common? They both impair nerve function in the peripheral nervous system. They both are more common in young men than in young women. They both damage the myelin sheath, slowing action potential transmission. They both impair the initiation of action potentials.

They both damage the myelin sheath, slowing action potential transmission.

During a brain surgery, a surgeon passes an instrument through the dura mater. Which one of the following does the surgeon pass through next? pia mater bones of the skull vertebrae cerebrospinal fluid arachnoid

arachnoid

Control of smooth muscle and internal organs is the role of the ________ division of the nervous system? postsynaptic sensory endocrine autonomic

autonomic

A nerve impulse moves away from a neuron's cell body along _____.

axons

An __________ neurotransmitter causes __________ of the postsynaptic membrane. inhibitory; depolarization excitatory; depolarization inhibitory; hyperpolarization both excitatory; depolarization and inhibitory; hyperpolarization are correct

both excitatory; depolarization and inhibitory; hyperpolarization are correct

Which of the following influence(s) the speed of an action potential? the diameter of the axon the extent of depolarization that initiates the action potential the presence of a myelin sheath both the presence of a myelin sheath and the diameter of the axon

both the presence of a myelin sheath and the diameter of the axon

Axons branch into axon terminals, which have ________ located at the terminal ends. bulbs dendrites Schwann cells hillocks nodes of Ranvier

bulbs

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? cerebrum thalamus cerebellum

cerebellum

A spinal reflex requires the participation of each of the following, EXCEPT __________. motor sensory interneurons cerebral cortex

cerebral cortex

Conscious thought is associated with which one of the following? medulla oblongata hypothalamus thalamus cerebral cortex

cerebral cortex

A nerve impulse moves toward a neuron's cell body along _____. dendrites synaptic terminals oligodendrocytes axons nodes of Ranvier

dendrites

Which part of the brain is responsible for regulating the heart and respiratory rates and blood pressure? cerebellum cerebral cortex medulla oblongata thalamus

medulla oblongata

Which one of the following cells transmits impulses away from the central nervous system to the muscles and other organs? neuroglia dendrites interneurons motor neurons sensory neurons

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 motor neurons; sensory neurons meninges; cerebrospinal fluid

myelinated nerves; unmyelinated cell bodie

Which of the following cell types makes up the majority of cells in the nervous system? motor neurons neuroglial cells interneurons sensory neurons

neuroglial cells

An impulse relayed along a myelinated axon "jumps" from _____ to _____.

node of Ranvier ... node of Ranvier

Graded potentials __________. occur in a local area of the membrane grow stronger as they spread through the cell body are permanent changes in the resting potential of a membrane always depolarize the membrane

occur in a local area of the membrane

transmit impulses toward the central nervous system sensory motor interneurons

sensory

Which one of the following provides the central nervous system with information about the outside environment? sensory division motor division sympathetic division autonomic division parasympathetic division

sensory division

Neurons of the PNS that transmit information to the CNS are __________. See Section 11.2 (Page 247) View Available Hint(s) sensory neurons interneurons motor neurons sympathetic neurons

sensory neurons

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 neurons; motor neurons sensory neurons; interneurons motor neurons; sensory neurons neuroglial cells; motor neurons

sensory neurons; motor neurons

Which one of the following establishes and maintains the resting potential? repolarization sodium-potassium pump depolarization K+ leak channel

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 sensory parasympathetic reflexive

sympathetic

What part of a neuron relays signals from one neuron to another neuron or to an effector?

synaptic terminal

Motor neurons of the peripheral nervous system transmit impulses away from the central nervous system. true or false

true