Nervous System

Question 1

What is the primary function of the nervous system?

Answer 1

communication

Question 2

What are the two anatomical divisions of the nervous system and what are they composed of?

Answer 2

CNS- brain and spinal cord
PNS- all neural tissue outside PNS

Question 3

What are the three functions of the CNS?

Answer 3

1. sensory data
2. motor commands
3. higher function of brain

Question 4

What are the two functions of the PNS?

Answer 4

deliver sensory info and carry motor commands

Question 5

When referring to the PNS, what does the afferent division refer to? What about the efferent division?

Answer 5

Afferent= from PNS to CNS
Efferent= from CNS to PNS

Question 6

What are the three divisions of the PNS? What do they control?

Answer 6

1. Somatic nervous system: controls voluntary actions (skeletal muscles)
2. Autonomic nervous system: controls involuntary action (visceral organs)
   3.Enteric Nervous System: controls gastrointestinal tract

Question 7

What are the two efferent subdivisions of the ANS?

Answer 7

Sympathetic= fight of flight
Parasympathetic= rest and digest

Question 8

What are the two general types of cells in the nervous system and what are their functions?

Answer 8

Neurons: cells that send and receive signals
Neuroglial cells: cells that support, insulate, and provide nutrients for neurons.

Question 9

Dendrites

Answer 9

branched extensions of cytoplasm that conducte electrical signals toward cell body

Question 10

Cell Body

Answer 10

contains nucleus, perikaryon

Question 11

Axon

Answer 11

conduct nerve impulses away from cell body to another neuron, muscle, or gland

Question 12

Cell bodies inside CNS

Answer 12

Nucleus

Question 13

Cell bodies outside CNS

Answer 13

Ganglion

Question 14

Axons and Dendrites in cylindrical bodies within CNS

Answer 14

tract

Question 15

Axons and Dendrites found in cylindrical bodies outside CNS

Answer 15

Nerve

Question 16

Axon Hillock

Answer 16

Where cellbody meets axon

Question 17

Initial Segment

Answer 17

Area adjacent axon hillock where action potential is initiated

Question 18

Synaptic terminal

Answer 18

bulb-shaped structure that contain synaptic vesicles. Filled with neurotransmitters.

Question 19

Thre functional classifications of neurons

Answer 19

1. Sensory neurons (afferent)
2. Motor neurons (efferent)
3. Interneurons

Question 20

Anaxonic Neurons

Answer 20

found in brain and special sense organs

Question 21

bipolar neurons

Answer 21

special sensory neurons found in retina

Question 22

unipolar neurons

Answer 22

general sensory neurons of PNS (afferent fibers)

Question 23

Mulitpolar nuerons

Answer 23

motor neurons found in typical spinal nerve (efferent fibers)

Question 24

What is more common in the nervous system, neurons or neuroglia?

Answer 24

neuroglia

Question 25

PNS glial cells

Answer 25

schwann cells and satellite cells

Question 26

CNS glial cells

Answer 26

astrocytes, microglia, ependymal cells, oligodendrocytes

Question 27

Astrocytes

Answer 27

florm blood brain barrier

Question 28

microglia

Answer 28

engulf wastes and destroy microbs

Question 29

ependymal cells

Answer 29

line ventricles of brain and central canal of spinal cord; produce, monitors and circulates cerebralspinal fluid

Question 30

oligodendrocytes

Answer 30

produce myeline sheath around axons of neurons in CNS

Question 31

What is the function of myelin, and what are myelin sheaths?

Answer 31

increases speed of action potential; gives axon white color

Question 32

Nodes of ranvier

Answer 32

gaps between myelin sheaths

Question 33

multiple sclerosis?

Answer 33

autoimmune disease myelin sheath in CNS attacked

Question 34

White and gray matter

Answer 34

White= region of CNS with many myelinated tracts Gray= unmyelinated areas of CNS

Question 35

Diptheria

Answer 35

Caused by corynebacterium diphtheriae. Infects respiratory tract or skin. Releases toxin that damages schwann cells and destroys myelinsheaths of PNS

Question 36

Guillain-Barre Syndrome

Answer 36

autoimmune disease, damages myelin sheaths that are produced by schwann cells in the PNS

Question 37

five main membrane potential processes involved in neural activity

Answer 37

1. Resting potential 2. graded potential 3. action potential 4. synaptic activity 5. information processing

Question 38

Transmembrane potential

Answer 38

potential difference that results from the uneven distribution of positive and negative ions across the plasma membrane

Question 39

concentration difference in sodium and potasium at resting potential

Answer 39

potassium concentrated inside cell sodium concentrated outside cell

Question 40

what passive forces are involved in causing the resting membrane potential

Answer 40

chemical gradients, electrical gradients, electrochemical gradients

Question 41

Which direction does each ion want to go with regard to each passive force?

Answer 41

chemical gradient= K out Na in Electrical gradient= K in Na in Electrochemical- K out Na in

Question 42

In mV what is the normal resting membrane potential inside the plasma membrane?

Answer 42

-70

Question 43

Which ion can cross the plasma membrane easier?

Answer 43

K

Question 44

What is equilibrium potential?

Answer 44

the transmembrane potential at which there is no net movement of a particular ion across the cell membrane

Question 45

What is the active force that acts to balance the passive forces to maintain resting potential?

Answer 45

sodium potasium exchange pump

Question 46

Depolarization

Answer 46

more positive then resting potential

Question 47

repolarization

Answer 47

coming back to resting potential after depolaraization

Question 48

hyperpolarization

Answer 48

more negative then resting potential

Question 49

how does sodium rush into cell to change resting membrane potential?

Answer 49

opening a specific membrane channel

Question 50

Two types of gated channels

Answer 50

1. chemically gated (dendrites and somas) 2. voltage-gated channels (axon)

Question 51

When are passive and gated channels open?

Answer 51

passive- always open active- open and close in response to stimuli

Question 52

what are graded potentials and where do they occur in a neuron

Answer 52

variable-strength electrical signals that travel over short distances and lose strength as they travel away from source. greater the stimulus the bigger the change in the transmembrane potential and greater the area affected

Question 53

how are graded potentials at the opposite ends of neuron linked together?

Answer 53

action potential

Question 54

What is an action potential?

Answer 54

large, uniform electric signal that can travel great distance without loosing strength. occur in axons.

Question 55

in mV what is considered threshold?

Answer 55

-60 to -55

Question 56

generation of action potential

Answer 56

1. depolarization to threshold 2. activation of Na channels 3. closing of Na voltage gated channels, opening of K voltage gated channels 4. return to normal resting potential

Question 57

electrical synapses

Answer 57

direct physical contact between cells

Question 58

chemical synapes

Answer 58

signal transmitted across gap by chemical neurotransmitters

Question 59

Excitatory neurotransmitters

Answer 59

cause depolarization of postsynaptic membranes

Question 60

inhibitory neurotransmitters

Answer 60

cause hyperpolarization of postsynaptic membranes

Question 61

cholinergic synapse

Answer 61

any synapse that releases ach

Question 62

Postsynaptic potentials

Answer 62

graded potentials developed in a postsynaptic cell in response to neurotransmitters

Question 63

excitatory postsynaptic potential

Answer 63

graded depolarization of postsynaptic membrane

Question 64

inhibitory postsynaptic potential

Answer 64

graded hyerpolarization of postsynaptic membrane

Question 65

temporal summation

Answer 65

repeated stimuli at one synapse

Question 66

spatial summation

Answer 66

many stimuli arrive at multiple synapse.