A&P: REGULATION: NERVOUS SYSTEM

Question 1

Nervous System

Answer 1

Directly regulates body functions and responds to environmental stimuli

Question 2

Neuron

Answer 2

-the functional unit of the nervous system
-at rest, neurons have an electrical potential due to differences in sodium and potassium ion concentrations across the cell membrane
-generally an impulse is generated when the dendrites of the neuron are stimulated by the environment or by another neuron
-the stimulus results in a moving electrical charge
-the impulse travels from the cell body along the axon until it reaches the ends, or axon terminals
-this triggers the release of neurotransmitters, which travel across synapses and may trigger other neurons or muscles
-axons may have myelin sheaths, which help transmit impulses faster

Question 3

[three main type of neurons: sensory neurons, inter neurons, motor neurons]
Sensory neurons

Answer 3

Transmit impulses from sense organs and receptors

Question 4

[three main type of neurons: sensory neurons, inter neurons, motor neurons]
Interneurons

Answer 4

Make up the brain and spinal cord

Question 5

[three main type of neurons: sensory neurons, inter neurons, motor neurons]
Motor neurons

Answer 5

Carry impulses from interneurons to skeletal and visceral muscles and glands

Question 6

Nerves

Answer 6

-Groups, or bundles, of the axons of sensory and/or motor neurons
-The nervous system includes other types of cells that nourish and support the neurons

Question 7

[the nervous system is divided into two subsystems,CNS and PNS]
Central nervous system (CNS)

Answer 7

-Includes the brain and spinal cord
-Responsible for processing information

Question 8

[the nervous system is divided into two subsystems,CNS and PNS]
Peripheral nervous system (PNS)

Answer 8

-Includes the nerves and sense receptors
-responsible for transmitting information to and from the CNS
-the PNS is further divided into two branches: the somatic branch is concerned with the external environment, and the autonomic branch is concerned with the internal environment

Question 9

[the nervous system is divided into two subsystems,CNS and PNS]
Peripheral nervous system (PNS)
What is the somatic branch concerned with?

Answer 9

The external environment

Question 10

[the nervous system is divided into two subsystems,CNS and PNS]
Peripheral nervous system (PNS)
What is the autonomic branch concerned with?

Answer 10

The internal environment

Question 11

Reflex arc

Answer 11

-carries out simple, quick, and automatic responses to certain stimuli
-reflex actions are commonly defensive and do not necessarily involve the brain
-ex. the reaction to stepping on a sharp object or touching a hot stove

Question 12

Spinal cord

Answer 12

-extends from the brain downward and is enclosed by the bones of the vertebral column, or spine
-openings between the vertebrae allow nerves to join with the spinal cord
-the spinal cord passes messages to and from the brain, and acts as the center for reflex actions
-damage to the spinal cord may result in paralysis and may be permanent

Question 13

Label the brain

Answer 13

Question 14

Neuron labeled

Question 15

Brain

Answer 15

Protected and enclosed within the craneum and is divided into three areas: cerebrum cerebellum, and brain stem, or medulla

Question 16

[brain: divided into three areas: cerebrum, cerebellum, and brainstem (or medulla)]
Cerebrum

Answer 16

-makes up the largest portion of the human brain and is the site of complex and high–level thinking
-conscious and involuntary actions are controlled here, as are other functions such a speech, vision, hearing and memory

Question 17

[brain: divided into three areas: cerebrum, cerebellum, and brainstem (or medulla)]
Cerebellum

Answer 17

-located below and behind the cerebrum
-responsible for muscular coordination and balance

Question 18

[brain: divided into three areas: cerebrum, cerebellum, and brainstem (or medulla)]
Brain stem, or medulla

Answer 18

Controls basic homeostatic functions such as body temperature, blood pressure, and breathing