Chapter 9 Nervous System

Question 1

Composition of the diencephalon

Answer 1

connects midbrain to the forebrain, lies above the brain stem; contain thalamus, hypothalamus, epithalamus, and subthalamus

Question 2

Describe function and purpose of dendrites and axons

Answer 2

axons help messages move throughout the body systems; dendrites receive and process those messages

Question 3

Describe the cells of the nervous system

Answer 3

neurons - transmit nerve impulses along nerve fibers to other neurons, typically have a cell body, axons, and dendrites; neuroglia - carry out a variety of functions to aid and protect components of the nervous system

Question 4

Describe the function of motor (efferent) neurons and sensory (afferent) neurons

Answer 4

sensory neurons - conduct impulses from peripheral receptors to the CNS, usually unipolar; motor neurons - conduct impulses from the CNS to effectors, multipolar

Question 5

Describe the functions of the major lobes of the brain

Answer 5

Frontal - voluntary movement, expressive language; Parietal - sensory perception, in charge of taste, hearing, sight, touch, and smell; Temporal - auditory processing, encoding of memory; Occipital - visual perception, color, form, and motion

Question 6

Describe the composition of the meninges

Answer 6

lie between bone and soft tissue; three layers to protect brain and spinal cord; delicate inner layer - pia mater; middle layer - arachnoid, web-like structure filled with fluid to cushion the brain; tough outer layer - dura mater

Question 7

During an action potential, what causes repolarization?

Answer 7

the closing of sodium ion channels and the opening of potassium ion channels

Question 8

Know the parts of a reflex arc

Answer 8

sensory receptor, sensory neuron, interneuron in the spinal cord, motor neuron, and an effector

Question 9

Know all the divisions of the nervous system and their functions

Answer 9

The CNS - brain and spinal cord, brain controls how we think, feel, learn, and move, spinal cord carries messages back and forth between the brain and the rest of the body; Peripheral Nervous System - sensory, connects brain and spinal cord to skin in order to feel pain and other sensations; autonomic - controls involuntary movement (i.e. digestion, heart rate, blood pressure, etc.) motor - connects brain and spinal cord to muscles to stimulate movement

Question 10

action potential

Answer 10

the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell

Question 11

autonomic nervous system

Answer 11

the part of the nervous system responsible for control of the bodily functions not consciously directed (i.e. breathing, heartbeat, digestive processes)

Question 12

axon

Answer 12

the long, threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells

Question 13

central nervous system

Answer 13

the complex of nerve tissues that controls the activities of the body; comprises brain and spinal cord

Question 14

convergence

Answer 14

when two or more things come together to form a new whole

Question 15

dendrite

Answer 15

any of the usually branching protoplasmic processes that conduct impulses toward the body of a nerve cell

Question 16

divergence

Answer 16

where a main presynaptic neuron splits its neurotransmitters to affect a large number of postsynaptic neurons

Question 17

effector

Answer 17

a cell that performs a specific function in response to a stimulus

Question 18

facilitation

Answer 18

the lowering of the threshold for reflex conduction along a particular neural pathway, especially from repeated use of that pathway

Question 19

ganglion

Answer 19

a collection of neuronal bodies found in the voluntary and autonomic branches of the peripheral nervous system

Question 20

meninges

Answer 20

the three thin layers of tissue that cover and protect the brain and spinal cord

Question 21

myelin

Answer 21

an insulating layer or sheath that forms around nerves, including those in the brain and spinal cord

Question 22

neurilemma

Answer 22

the thin sheath around a nerve axon

Question 23

parasympathetic nervous system

Answer 23

a network of nerves that relaxes your body after periods of stress or danger

Question 24

peripheral nervous system

Answer 24

part of your nervous system that lies outside your brain and spinal cord

Question 25

plexus

Answer 25

an intricate network of nerves or vessels in the body

Question 26

reflex

Answer 26

an involuntary or automatic action that your body does in response to something - without you even having to think about it

Question 27

sensory receptor

Answer 27

detect changes in the internal as well as external environment

Question 28

synapse

Answer 28

the places where neurons connect and communicate with each other