Chapter 12-Intro to Nervous System

Question 1

Rapid, specific signals cause ___ responses by the body.

Answer 1

Immediate

Question 2

3 Overlapping functions of the nervous system

Answer 2

Sensory input, integration, motor output

Question 3

Sensory Receptors

Answer 3

Monitor changes inside and outside body

Question 4

CNS

Answer 4

Receives and interprets sensory input

Question 5

Effector organs

Answer 5

Motor neurons elicit responses using effector organs

Question 6

Central Nervous System

Answer 6

Brain and Spinal chord, functioning in integration and command

Question 7

Peripheral Nervous System

Answer 7

Divided into somatic and autonomic systems, functioning in communication

Question 8

Afferent

Answer 8

Towards

Question 9

Efferent

Answer 9

Away

Question 10

Somatic

Answer 10

Areas outside of ventral body cavity e.g. skin, skeletal musculature, bones,

Question 11

Visceral

Answer 11

Structures in the ventral cavity e.g. digestive tubes, lungs, heart, bladder

Question 12

Somatic Sensory

Answer 12

touch, pain, pressure, vibration, temp, hearing, equilibrium, vision

Question 13

Visceral sensory

Answer 13

Taste, smell, stretch, pain, temperature, chem changes, irritation of viscera, nausea, and hunger

Question 14

Somatic motor

Answer 14

motor innervation to skeletal muscles

Question 15

visceral motor (autonomic nervous system)

Answer 15

motor innervation to smooth muscle, cardiac muscle and glands (involuntary)

Question 16

Nervous tissue is made of

Answer 16

neurons and neuroglia

Question 17

neuroglia

Answer 17

nonexcitable supporting cells that surround and wrap the neurons

Question 18

Characteristics of neurons

Answer 18

• Conduct electrical Signals- able to send electrical signals from one body part to another
• extreme longevity- last a lifetime (typically)
• do not divide- cannot be replaced
• high metabolic rate- require constant supply of O2 and nutrients

Question 19

Parts and Functions of a Neuron

Answer 19

Dendrites- processes that extend from the cell body acting as receptive sites for signal recognition
Cell body- single nucleus surrounded by cytoplasm and is the focal point for the outgrowth of neuron processes
Axon- arising from the axon hillock, a neuron process which ends in terminal boutons and covered by schwann cells that act as impulse generators and conductors

Question 20

Structural Classification of Neurons

Answer 20

• Know difference between dendrites and axon in multipolar
• Know difference between fused dendrite and axon in bipolar
• know difference between the peripheral and central processes which comprise an axon in unipolar (psuedounipolar)

Question 21

Functional Classification of Neurons

Answer 21

grouped according to direction nerve impulse travels relative to CNS

Question 22

Sensory Neurons

Answer 22

(afferent neurons) towards the CNS

Question 23

Motor Neurons

Answer 23

(efferent neurons) away from the CNS

Question 24

Association Neurons

Answer 24

Interneurons- within the CNS

Question 25

Axodendritic synapse

Answer 25

neuron-neuron synapse

Question 26

axosomatic synapses

Answer 26

neuron-cell body synapse

Question 27

Neuroglia

Answer 27

Support cells

Question 28

Types of CNS Neuroglia

Answer 28

Astrocytes, Microglia, Ependymal cells, Oligodendricytes

Question 29

Types of PNS neuroglia

Answer 29

Satellite Cells, Schwann cells

Question 30

Astrocyte

Answer 30

( attaches to capillaries) Most abundant CNS neuroglia

Question 31

Microglial Cells

Answer 31

(attaches to neurons) Defensive Cells in the CNS

Question 32

Ependymal Cells

Answer 32

(look like teeth with cilia) line cerebrospinal fluid-filled cavities

Question 33

Oligodendrocytes

Answer 33

processes which form myelin sheaths around CNS nerve fibers

Question 34

Satellite cells

Answer 34

cover neuronal cell bodies in the PNS

Question 35

Schwann cells

Answer 35

form myelin sheaths in the PNS

Question 36

Schwann cell vs. oligodendricyte

Answer 36

Schwann cells wrap around 1 axon of 1 neuron in PNS whereas Oligodendricyte can wrap around many axons of many neurons in the CNS

Question 37

Myelin

Answer 37

multilayered lipoprotein structure that wraps pieces of axons - electrical inulation - speeds rate of action potential - Schwann cells in PNS - Oligodendricytes in CNS

Question 38

Nodes of Ranvier

Answer 38

Gaps in myelin Sheath

Question 39

Neurilemma

Answer 39

the outer, nucleated, cytoplasmic layer of the schwann cell... outermost layer of myelin sheath

Question 40

Myelinated Axon (PNS)

Answer 40

schwann cell wraps several times around an axon

Question 41

Unmyelinated Axon (PNS)

Answer 41

Schwann cell surrounds and encircles many axons

Question 42

Neurilemma Function (PNS vs CNS)

Answer 42

- When Axons are damaged in PNS, neurilemma forms a regeneration tube which acts as a tunnel - This does not happen in the CNS because oligodendricytes do not forma neurilemma

Question 43

Grey matter vs white matter

Answer 43

Grey matter (where cell bodies are clustered) surounds white matter (consist of axons running between different parts of CNS) in the brain whereas white matter surrounds grey matter in the spinal cord

Question 44

What is a ganglion?

Answer 44

Cluster of soma in the PNS

Question 45

What is a nerve?

Answer 45

Cluster of axons in the PNS

Question 46

What is a nucleus?

Answer 46

Cluster of soma in the CNS

Question 47

What is a tract?

Answer 47

Cluster of axons in the CNS

Question 48

Nerves in the PNS are...

Answer 48

cable-like organs in the PNS; many parallel axons arranged in bundles called fascicles; within each nerve, each axon is covered by Schwann cells (myelinated and unmyelinated axons)

Question 49

3 layers of CT in the PNS

Answer 49

Endoneurium- CT surrounding the Schwann Cells Perineum- CT surrounding fascicles Epineurium- CT surrounding an entire nerve * each axon is surrounded by Schwann cell, then covered by CT

Question 50

Reflex

Answer 50

Rapid, automatic, motor responses to stimuli

Question 51

Reflex arc

Answer 51

simple chain of neurons that cause reflexes

Question 52

Monosynaptic Reflexes

Answer 52

No interneuron, one synapse | Stretch reflex

Question 53

Polysynaptic Reflex

Answer 53

``` Multiple interneurons, multiple synapses Withdrawal reflex (pain withdrawal), activates flexor muscles ex. bicep flexes, tricep must be relaxed neuron also inhibits antagonist muscle ```