Lecture 31 - Nervous System Introduction

Question 1

What are the 3 main functions of the nervous system?

Answer 1

1. sensory input
2. integration
3. motor output

Question 2

Functions that can be controlled voluntarily are referred to as _____ and those that are involuntary are referred to as _____

Answer 2

somatic; autonomic

Question 3

What two parts is the nervous system divided into? what do they encompass?

Answer 3

1. Central (CNS) - brain and spinal cord
2. Peripheral (PNS) - cranial nerves, nerves extending away from CNS

Question 4

What are the two functional divisions of the PNS

Answer 4

1. sensory (afferent)
2. motor (efferent)

Question 5

what are the two divisions of the efferent PNS

Answer 5

1. somatic
2. autonomic

Question 6

the sensory (afferent) division conducts impulses from ____ to ____

Answer 6

receptors; CNS

think “arriving”

Question 7

the motor (efferent) division conducts impulses from ____ to ____

Answer 7

CNS; muscles/glands

think “exiting”

Question 8

the somatic system conducts impulses to what kind of muscle

Answer 8

skeletal

Question 9

the autonomic system conducts impulses to what kind of muscle

Answer 9

cardiac + smooth

Question 10

T/F: the parasympathetic division conserves energy

Answer 10

TRUE

Question 11

where are afferent neurons located in regard to the spinal cord

Answer 11

outside

Question 12

where are efferent neurons located in regard to the spinal cord

Answer 12

within ventral horn

Question 13

where is the enteric system found

Answer 13

within the walls of the entire gastrointestinal tract

Question 14

Myenteric plexus

Answer 14

found in muscularis externa of GI

Question 15

Submucosal plexus

Answer 15

found in submucosa of GI

Question 16

What are the two types of principal cells

Answer 16

1. Neuroglia
2. Neurons

Question 17

Neuroglia (glial cells)

Answer 17

small cells that surround and wrap delicate neurons

Question 18

Neurons (nerve cells)

Answer 18

excitable cells that transmit electrical pulses

Question 19

Astrocytes

Answer 19

most abundant
cling to neurons, synaptic endings, capillaries

Question 20

summarize the functions of:

astrocytes

Answer 20

• support + brace neurons
• exchange between capillaries and neurons
• guide the migration of young neurons
• control chemical environment
• respond to nerve impulses
• influence neuronal functioning
• information processing
• maintain blood-brain barrier

Question 21

Microglia

Answer 21

small ovoid cells with thorny processes that touch/monitor neurons

Question 22

summarize the functions of:

microglia

Answer 22

• migrate towards injured neurons
• phagocytize neuronal debris

Question 23

Ependymal cells

Answer 23

cuboidal to columnar
lines central cavities of brain and spinal column

Question 24

summarize the functions of:

ependymal cells

Answer 24

• CSF production
• facilitate movement of CSF via cilia

Question 25

Oligodendrocytes

Answer 25

branched cells, few processes, wrap nerve fibers ("fried egg")

Question 26

summarize the functions of: oligodendrocytes

Answer 26

structural framework produce myelin in CNS

Question 27

Satellite cells

Answer 27

surround neuronal bodies

Question 28

Schwann cells

Answer 28

surround nerve fibers form myelin sheath in PNS

Question 29

What are the neuroglia of the PNS

Answer 29

1. Satellite cells 2. Schwann cells

Question 30

perineurium

Answer 30

thin connective tissue surrounding a cluster of axons (nerve fascicle)

Question 31

epineurium

Answer 31

thick connective tissue binding fascicles together

Question 32

what are the structural units of the nervous system

Answer 32

neurons

Question 33

what are the special characteristics of neurons

Answer 33

- extreme longevity - amitotic - high metabolic rate

Question 34

T/F: neuron dendrites convey messages as graded potentials over long distances

Answer 34

FALSE - short distances

Question 35

What important activities take place in cell body (soma) of neurons

Answer 35

synthesize proteins, membranes, chemicals contains nissl bodies (rough ER)

Question 36

nuclei

Answer 36

clusters of neuron cell bodies in CNS

Question 37

ganglia

Answer 37

clusters of neuron cell bodies in PNS

Question 38

Neuron Axon Hillock

Answer 38

projection from cell body to axon summation site of action potentials

Question 39

EPSPs

Answer 39

excitatory post-synaptic action potential increases chance

Question 40

IPSPs

Answer 40

inhibitory post-synaptic action potential decreases chance

Question 41

What is the conducting region of the neuron

Answer 41

axon

Question 42

what do myelin sheaths do

Answer 42

insulation of axon that speed up conduction broken up by gaps (nodes of ranvier)

Question 43

Multipolar

Answer 43

most abundant in body major type in CNS 3 or more processes

Question 44

Bipolar

Answer 44

rare sensory 2 processes - one axon, one dendrite

Question 45

Unipolar

Answer 45

PNS T-like projection

Question 46

T/F: the most neurons are classified as interneurons

Answer 46

TRUE

Question 47

what is the main excitatory neurotransmitter of CNS

Answer 47

glutamatergic

Question 48

what is the main inhibitory neurotransmitter of CNS

Answer 48

gabaergic

Question 49

what is produced in the PNS and CNS by cholinergic cells

Answer 49

acetylcholine

Question 50

what is produced mainly in the midbrain, hypothalamus, and olfactory bulb

Answer 50

dopamine

Question 51

Which term is used to describe signals from internal organs?

Answer 51

visceral

Question 52

After receiving a signal from another neuron, which outlines the path of an electrical impulse through a neuron?

Answer 52

dendrites --> cell body --> axon --> axon terminal

Question 53

True or false: Ependymal cells use flagella to facilitate movement of CSF

Answer 53

FALSE