Chapter 9: Nervous System

Question 1

A subdivision of the PNS, called the ____ ____, or ANS, consists of structures that regulate the body’s automatic or involuntary functions

Answer 1

autonomic nervous system

Question 2

Each neuron consists of three parts: a main part called the neuron ___ ___, one or more branching projections called ____, and one elongated projection known as an ____.

Answer 2

cell body, dendrites, axon

Question 3

_____ conduct impulses from sensory neurons to motor neurons.

Answer 3

Interneurons

Question 4

Along with the walls of the blood vessels, astrocyte branches form a two-layer structure called the ___ ____ ____.

Answer 4

blood-brain barrier (BBB)

Question 5

____ are smaller than astrocytes. They usually remain stationary, but in inflamed or degenerating brain tissue, they enlarge, move about, and act as microbe-eating scavengers.

Answer 5

Microglia

Question 6

The _____ help to hold nerve fibers together and produce the fatty myelin sheath that envelops nerve fibers located in the brain and spinal cord.

Answer 6

oligodendrocytes

Question 7

____ ____ are glial cells that also form myelin sheaths but do so only in the PNS.

Answer 7

Schwann cells

Question 8

How are glia different from neurons?

Answer 8

Neurons conduct impulses, whereas glia support neurons.

Question 9

A word for a bundle of peripheral axons.

Answer 9

Nerve

Question 10

Each axon in a nerve is surrounded by a thin wrapping of fibrous connective tissue called the _____.

Answer 10

endoneurium

Question 11

Each fascicle is surrounded by a thin, fibrous _____.

Answer 11

perineurium

Question 12

A tough, fibrous sheath called the _____ covers the whole nerve.

Answer 12

epineurium

Question 13

A basic type of neuron pathway is called a ____ ____.

Answer 13

reflex arc

Question 14

___ ___ ___ consist of sensory neurons synapsing in the spinal cord with interneurons that synapse with motor neurons.

Answer 14

Three-neuron arcs

Question 15

A ___ ___ is a self-propagating wave of electrical disturbance that travels along the surface of a neuron’s plasma membrane.

Answer 15

nerve impulse

Question 16

If the traveling impulse encounters a section of membrane covered with insulating myelin, it simply “jumps” around the myelin to the next gap in the myelin sheath. This is called ___ ____.

Answer 16

saltatory conduction

Question 17

What 3 structures is a Synapse made of?

Answer 17

1) Synaptic knob 2) Synaptic cleft 3) Plasma membrane

Question 18

What are neurotransmitters?

Answer 18

Chemicals by which neurons communicate

Question 19

How does myelin increase the speed of nerve impulse conduction?

Answer 19

If the traveling impulse encounters a section of membrane covered with insulating myelin, it simply “jumps” around the myelin to the next gap in the myelin sheath. Called saltatory conduction, this type of impulse travel is much faster than is possible in nonmyelinated sections.

Question 20

What is a postsynaptic neuron?

Answer 20

By definition, a synapse is the place where impulses are transmitted from one neuron, called the presynaptic neuron, to another neuron, called the postsynaptic neuron.

Question 21

How do neurotransmitters transmit signals across the synapse?

Answer 21

A synaptic knob is a tiny bulge at the end of a terminal branch of a presynaptic neuron’s axon. Each synaptic knob contains many small sacs or vesicles. Each vesicle contains a very small quantity of a chemical compound called a neurotransmitter. When a nerve impulse arrives at the synaptic knob, neurotransmitter molecules are released from the vesicles into the synaptic cleft.

Question 22

What are the 4 major regions of the brain?

Answer 22

1) Brainstem 2) Cerebellum 3) Diencephalon 4) Cerebrum

Question 23

What are the 3 portions that make up the Brainstem?

Answer 23

1) Medulla Oblongata 2) Pons 3) Midbrain

Question 24

What are the 3 portions that make up the Diencephalon?

Answer 24

1) Hypothalamus 2) Thalamus 3) Pineal Gland

Question 25

Why is the hypothalamus said to be a link between the nervous system and endocrine system?

Answer 25

Because the hypothalamus also makes the hormones that the posterior pituitary gland secretes into the blood.

Question 26

In which part of your brain does thinking and memory occur?

Answer 26

The Cerebrum

Question 27

What are the major functions of the spinal cord?

Answer 27

Its three major roles are to relay messages from the brain to different parts of the body, to perform an action, to pass along messages from sensory receptors to the brain, and to coordinate reflexes that are managed by the spinal cord alone.

Question 28

What is cerebrospinal fluid?

Answer 28

It’s the fluid that fills the subarachnoid spaces between the pia mater and arachnoid in the brain and spinal cord.

Question 29

What is a Dermatome?

Answer 29

Skin surface area supplied by a single cranial or spinal nerve.

Question 30

What is a Plexus?

Answer 30

When nerve fibers from several spinal nerves are reorganized to form a single peripheral nerve. This reorganization can be seen as a network of intersecting or “braided” branches. A different definition: “A nerve plexus is a network of intersecting nerves that serve the same part of the body.”

Question 31

The exterior of a resting neuron has a slight ________ charge, whereas the interior has a slight _______ charge.

Answer 31

positive, negative

Question 32

During a nerve impulse, ________ is the ion that rushes into the neuron.

Answer 32

Sodium (Na+)

Question 33

The knee jerk is a type of neural pathway called a _______.

Answer 33

reflex arc

Question 34

A group of peripheral axons bundled together in an epineurium is called a ________.

Answer 34

Nerve

Question 35

The preganglionic axons of the sympathetic nervous system release the neurotransmitter ________. The postganglionic axons release ________.

Answer 35

acetylcholine (ACh), norepinephrine (noradrenaline)

Question 36

The preganglionic axons of the parasympathetic nervous system release the neurotransmitter ________. The postganglionic axons release ________.

Answer 36

acetylcholine (ACh), acetylcholine (ACh)

Question 37

The autonomic nervous system consists of neurons that conduct impulses from the brain or spinal cord to ________ tissue, ________ tissue, and ________ tissue.

Answer 37

cardiac, smooth, glandular epithelial

Question 38

Part of the brainstem that contains cardiac, respiratory, and vasomotor centers

Answer 38

medulla oblongata

Question 39

part of the brainstem that is a conduction pathway between areas of the brain and body; influences respiration

Answer 39

pons

Question 40

part of the brainstem that contains relays for visual and auditory impulses

Answer 40

midbrain

Question 41

regulates body temperature, water balance, sleep-wake cycles, appetite, and sexual arousal

Answer 41

hypothalamus

Question 42

sensory relay station from various body areas to the cerebral cortex; also involved with emotions and alerting and arousal mechanisms

Answer 42

thalamus

Question 43

regulates muscle coordination, maintenance of equilibrium, and posture

Answer 43

cerebellum

Question 44

sensory perception, willed movements, consciousness, and memory are mediated here

Answer 44

cerebrum