Chapter 2

Question 1

Cell Body

Answer 1

the part of neuron that contains the nucleus and carries out the metabolic functions of the neuron

Question 2

Dendrites

Answer 2

branch-like extensions of the cell body that receive signals from other neurons

Question 3

axon

Answer 3

the slender, tail-like extension of the neuron that transmits signals to the dendrites or cell body of other neurons and to muscles, glands, and other parts of the body

Question 4

axon terminal

Answer 4

bulbous end of the axon where signals move from the axon of one neuron to the dendrites or cell body of another

Question 5

Myelin Sheath

Answer 5

the fatty coating on some axons that acts as insulation

Question 6

synaptic clefts

Answer 6

the gaps between axon terminal and receiving neurons, across which signals are transmitted

Question 7

synapse

Answer 7

the junction where the axon terminal of a sending neuron communicates with a receiving neuron across the synaptic cleft

Question 8

Function of Neurotransmitters

Answer 8

Specialized chemicals that can facilitate or inhibit the transmission of impulses from one neuron to the next

Question 9

How does neurotransmitters work?

Answer 9

Neurotransmitters flow in to the synaptic cleft and move toward the receiving neuron. The receptors will bind only neurotransmitters whose molecular shapes match their enclosed volumes.

Question 10

Communications within the neuron

Answer 10

When an axon membrane carries a negative electrical potential it is referred to as resting potential. Ion channels open allowing positive ions to flow when neuron reach certain threshold. This sudden reversal of resting potential is the action potential. Ion channels open admitting positive ions close and other ion channels open forcing positive ions out of the axon. The opening and closing of ion channels continues down the length of the axon causing action potential to move along the axon.

Question 11

All or none law

Answer 11

a neuron either fire completely or does not fire at all

Question 12

Communications between neurons

Answer 12

When an action potential arrives at the axon terminal, synaptic vesicles move toward the cell membrane, fuse with it, and release neurotransmitter molecules. Each neurotransmitter with distinctive shape will bind with receptors which are protein molecules on the surfaces of dendrites and cell bodies.

Question 13

Hypothalamus

Answer 13

Controls functions such as hunger, thirst, body temperature; helps control endoctrine system; involved in emotion

Question 14

Cerebrum

Answer 14

The thinking part of the brain

Question 15

Cerebral cortex

Answer 15

Convoluted covering of the cerebral hemispheres that is responsible for higher mental processes

Question 16

Corpus Callosum

Answer 16

Band nerve fibers that connects the two sides of the brain

Question 17

Limbic system

Answer 17

Group of structures involved in emotional expression, memory, and motivation

Question 18

Pons

Answer 18

Plays a role in relaying motor messages between cerebellum and motor cortex; exerts influence on sleep and dreaming

Question 19

Medulla

Answer 19

Control center for heartbeat, breathing, blood pressure, swallowing, and coughing