Ch 33 -- Nervous System

Question 1

neurons

Answer 1

specialized cells that help you gather information about your environment, interpret information, and react to it

Question 2

dendrites

Answer 2

receive signals called impulses from other neurons and conduct the impulses to the cell body

Question 3

cell body

Answer 3

where the nucleus of a neuron and many of the cells organelles are found

Question 4

axon

Answer 4

carries the nerve impulse from the cell body to other neurons and muscles

Question 5

reflex arc

Answer 5

a nerve pathway that consists of a sensory neuron, an interneuron, and a motor neuron : the brain is not involved

Question 6

action potential

Answer 6

another name for a nerve impulse

Question 7

threshold

Answer 7

the minimum stimulus to cause an action potential to be produced

Question 8

nodes (of Ranvier)

Answer 8

the gaps in the myelin sheath along the axon

Question 9

myelin sheath

Answer 9

a covering of lipid around the axon

Question 10

synapse

Answer 10

a small gap between the axon of one neuron and the dendrite of another neuron

Question 11

neurotransmitter

Answer 11

a chemical that diffuses across the synapse and binds to receptors on the dendrite of a neighboring neuron

Question 12

Central Nervous System (CNS)

Answer 12

the interneurons of the brain and spinal chord

Question 13

Peripheral Nervous System (PNS)

Answer 13

consists of the sensory neuron and motor neurons that carry information to and from the CNS

Question 14

Cerebrum

Answer 14

the largest part of the brain; is divided into two halves called hemispheres

Question 15

Cerebellum

Answer 15

controls balance, posture, and coordination, and is located at the back of the brain

Question 16

Medulla Oblongata

Answer 16

relays signals between the brain and the spinal cord

Question 17

Pons

Answer 17

relays signals between the cerebrum and the cerebellum; controls rate of breathing

Question 18

Hypothalamus

Answer 18

essential for maintaining homeostasis; regulates body temp, thirst, appetite, and water balance

Question 19

Spinal Cord

Answer 19

a nerve column that extends from the brain to the lower back

Question 20

Spinal Nerves

Answer 20

extend from the spinal cord to parts of the body and connect them to the CNS

Question 21

Nerve

Answer 21

a bundle of axons

Question 22

Somatic Nervous System

Answer 22

has nerves that relay info from external sensory receptors to the CNS; VOLUNTARY

Question 23

Autonomic Nervous System

Answer 23

Carries impulses from the CNS to the heart and other internal organs; fight or flight; INVOLUNTARY; has two branches (Sympathetic and Parasympathetic Nervous Systems)

Question 24

Sympathetic Nervous System

Answer 24

is most active in times of emergency or stress, when the heart rate and breathing increase

Question 25

Parasympathetic Nervous System

Answer 25

is most active when the body is relaxed; counterbalances the effects of the sympathetic nervous system and restores the body to a resting state after a stressful experience

Question 26

Drug

Answer 26

a substance, natural or artificial, that alters the functions of the body

Question 27

Dopamine

Answer 27

A neurotransmitter found in the brain that is involved with the control of body movements and other functions; strongly involved with the feelings of pleasure or reward

Question 28

Stimulants

Answer 28

drugs that increase alertness or physical activity (Ex : Nicotine and Caffeine)

Question 29

Depressants

Answer 29

drugs that tend to slow down the CNS (Ex : Alcohol and Inhalants)

Question 30

Tolerance

Answer 30

occurs when a person needs more and more of the same drug to get the same effect; tolerance leads to addiction

Question 31

Addiction

Answer 31

the psychological and physiological dependence on a drug