Chapter 12

Question 1

3 steps for nervous system function

Answer 1

1. input
2. processing
3. output

Question 2

input

Answer 2

conduction of signals from sensory receptors to processing centers

Question 3

Processing

• what does it include
• definition

Answer 3

• brain and spinal cord

- interprets these sensory signals and forms a response

Question 4

output

Answer 4

conduction of signals to an effector (away from brain and spinal cord)

Question 5

2 main divisions of the nervous system

Answer 5

1. central nervous system

2. Peripheral nervous system

Question 6

central nervous system

-what does it include

Answer 6

brain and spinal cord

Question 7

peripheral nervous system

• what does it include
• 2 branches

Answer 7

• cranial nerves and spinal nerves

- somatic nervous system and autonomic nervous system

Question 8

somatic nervous system

• voluntary or involuntary?
• ex

Answer 8

• voluntary

- skeletal muscles

Question 9

autonomic nervous system

• voluntary or involuntary?
• 3 ex

Answer 9

• involuntary

- smooth, cardiac muscle and glands

Question 10

2 divisions of autonomic system

Answer 10

1. sympathetic (fight and flight)

2. parasympathetic (rest and digest)

Question 11

2 types of cells

Answer 11

1. Neurons

2. neuroglia

Question 12

neurons

Answer 12

conduct electrical signals or action potentials/impulses

Question 13

neuroglia

• how much percent of the nervous system
• 4 functions

Answer 13

• 90%
• 1. supports cells
     
     2. provides framework for nervous tissue
     3. protection
     4. controls composition of extracellular fluid

Question 14

extracellular fluid

Answer 14

cerebrospinal fluid in CNS (CSF)

Question 15

Ependymal cells

Answer 15

Assists with producing, monitoring, and circulation of CSF

Question 16

Microglia cells

Answer 16

Engulfs cellular debris, waste and pathogens

Question 17

Oligodendrocyte

Answer 17

• myelinates CNS axons

- structural support

Question 18

Astrocyte

-2 functions

Answer 18

1. maintenance of blood/brain barrier

2. structural support

Question 19

3 properties of a neuron

Answer 19

1. generally amitotic (cannot be replaced)
2. extreme longevity
3. high metabolic rate (many mitochondria)

Question 20

5 parts of a neuron

Answer 20

1. dendrites
2. cell body
3. axon hillock
4. axon
5. telodendria

Question 21

dendrites

• how many branches
• function

Answer 21

• 6

- receives signals

Question 22

cell body

• known as
• contains 4 things
• lacks
• abundant in
• perikaryon

Answer 22

• soma
• nucleus, golgi, mito, RER
• centrioles
• abundant in cytoskeleton components: neurofibrils
• cytoplasm surrounding nucleus

Question 23

axon hillock

Answer 23

initial segment between cell body and axon

Question 24

axon

• function
• 2 types

Answer 24

• carries signals (action potentials) away from cell body
• 1. Naked-unmyelinated
     
     2. Myelinated - covered with myelin sheath

Question 25

Telodendria

Answer 25

contains axon terminals =synaptic knobs

Question 26

myelin sheath

• formed by (general)
• cells that form myelin sheath
• how do they form it
• 2 functions

Answer 26

• neuroglia
• oligodendrocytes (CNS) and Schwann cells (PNS)
• by wrapping their cytoplasm and membranes around the axon
• 1. protection
     
     2. increases speed of action potential conduction (bc myelin is an insulating material)

Question 27

4 steps to forming a myelin sheath

Answer 27

1. neurolemmocyte starts to wrap around a portion of an axon
2. Neurolemmocyte cytoplasm and plasma membrane form consecutive layers around axon
3. the overlapping inner layers of the plasma membrane form the myelin sheath
4. the neurolemmocyte cytoplasm and nucleus are pushed to the periphery of the cell as the myelin sheath is formed

Question 28

Nodes of Ranvier

• what is it
• what happens

Answer 28

• naked axon

- action potentials are conducted from node to node =saltatory conduction

Question 29

saltatory conduction

Answer 29

very fast and efficient way to carry action potential down axon

Question 30

3 structural classifications

Answer 30

1. bipolar
2. unipolar
3. multipolar

Question 31

bipolar

• what does it look like
• how do action potentials flow
• where is it found

Answer 31

• cell body is located in between the dendrite and axon
• dendrite, cell body, and axon
• rare: generally found in areas associated with special senses

Question 32

unipolar

• what does it look it
• how do action potentials flow
• common?

Answer 32

• cell body (has an attachment) is located in between dendrite and axon
• dendrites, does not go through cell body, axon
• structure common to most sensory neurons

Question 33

multipolar

• what does it look like
• how do action potentials flow
• common in?

Answer 33

• cell body is located at the top
• dendrites (attached to soma), soma, axon
• structure of most motor neurons and interneurons

Question 34

3 functional classifications

Answer 34

1. sensory neurons
2. motor neurons
3. interneurons

Question 35

sensory neurons (affernet)

Answer 35

carries signals from periphery CNS

Question 36

motor neurons (efferent)

Answer 36

carries signals from CNS to muscles and glands

Question 37

interneurons (association)

Answer 37

• most abundant

- carries signals between sensory and motor neurons