8.2 Nervous System Notes - exam

Question 1

what is the purpose of the nervous system?

Answer 1

• senses and responds to changes within the body + external environment
• regulates thousands of activities simultaneously
• motor coordination, learning and thought

Question 2

central nervous system (CNS)

Answer 2

consist of the brain and spinal cord
- encased in connective tissue

Question 3

Peripheral nervous system (PNS)

Answer 3

• nerves that carry sensory messages to the CNS
• nerves that sends messages from CNS to the effectors

Question 4

somatic nervous system

Answer 4

• motor nerves controls skeletal muscle
• sensory nerves relay info about environment
• voluntary

Question 5

autonomic nervous system

Answer 5

• motor nerves that control the internal organs of the body
• controls glandular secretions
• involuntary
• sympathetic and parasympathetic

Question 6

sympathetic systems

Answer 6

• fight or flight
• prepares body for stress
• increases heart rate
• increases release of glucose
• dilates pupil
• increase blood flow to skin

Question 7

parasympathetic systems

Answer 7

• rest & digest
• returns body to normal state
• restores balance
• lower heart rate
• more active digestive system
• pupils constrict

Question 8

neurons

Answer 8

• basic structural and functional units of the nervous system
• responds to physical & chemical stimuli
• conduct electrochemical signals
• releases chemicals to regulate body

Question 9

glial cells

Answer 9

• nourish neurons, removes waste, and defends against infections
• provide a supporting framework for all neurons
• not conductive

Question 10

structure of a neuron

Answer 10

• dendrites
• cell body
• axon
• branched ends
• myelin sheath
• nodes of ranvier

Question 11

describe the neuron structure’s dendrites

Answer 11

short, branching terminals that receive impulses and relays the impulses to the cell body

Question 12

describe the neuron structure’s cell body

Answer 12

contains nucleus and is the site of the cell’s metabolic reactions

Question 13

describe the neuron structure’s axon

Answer 13

conducts impulses away from the cell body and varies in length from 1mm to over 1 m

Question 14

describe the neuron structure’s branched ends

Answer 14

found on dendrites and axons, they increase the surface areas available for receiving and sending info

Question 15

describe the neuron structure’s myelin sheath

Answer 15

• fatty, insulating layer composed of Schwann cells
• protects and increases the rate of nerve impulses transmission

Question 16

describe the neuron structure’s nodes of ranvier

Answer 16

gaps between myelin sheaths

Question 17

functional neuron classifications

Answer 17

1. sensory neurons
2. interneurons
3. motor neurons

Question 18

what does sensory neurons do

Answer 18

receive input and transmit impulses from sensory receptors to the CNS

Question 19

what does interneurons do?

Answer 19

found in CNS, links the sensory and motor neurons

Question 20

what does motor neurons do

Answer 20

transmits info from CNS to effectors

Question 21

structural classification of neurons

Answer 21

1. multipolar
2. bipolar
3. unipolar

Question 22

multipolar neuron

Answer 22

• several dendrites
• single axon
• found in brain and spinal cord

Question 23

bipolar neuron

Answer 23

• single main dendrite
• single axon
• found inner ear, retina, and olfactory area of the brain

Question 24

unipolar neuron

Answer 24

• single process that extends from cell body
• dendrite and axon are fused
• found in PNS