Topic 18: Nervous System Organization

Question 1

What does the nervous system enable organisms to do?

Answer 1

sense and react to the enviornment

Question 2

What kind of nervous system structure do cniderians have?

Answer 2

nerve net: interconnected neurons for movement

Question 3

What kind of nervous system do echinoderms have?

Answer 3

nerve ring: central control structure

Question 4

What are the nervous system components of bilaterians?

Answer 4

lots of variation
anterior end
- eyespots that detect light
- brain
ladder type nervous system
- 2 longitudinal nerve cords
transverse nerves

Question 5

Define ganglia

Answer 5

segmentally arranged clusters of neurons

Question 6

What are the main components of the CNS?

Answer 6

brain and spinal cord

Question 7

What are the main components of the PNS?

Answer 7

nerves and ganglia

Question 8

What are neurons? What do they do?

Answer 8

basic functional unit of nervous system

conduct electrical signals, integrate information

Question 9

What does the cell body contain?

Answer 9

organelles

Question 10

What are dendrites?

Answer 10

“trees”
cytoplasmic extensions from cell body - usually many, short
receive information

Question 11

What are axons? What do they do?

Answer 11

cytoplasmic extensions from cell body

send information

Question 12

What is the axon hillock?

Answer 12

base of axon, where signals are generated

Question 13

What are glial cells? What do they do?

Answer 13

non-neuron cells of the nervous system
functions:
- neuron support, protection, maintenance
- embryonic NS development

Question 14

What is myelin sheath? What is its purpose?

Answer 14

bundles of insulation around axons

faster signaling

Question 15

What is myelin sheath produced by in CNS?

Answer 15

oligodendrocytes

Question 16

What is myelin sheath produced by in PNS?

Answer 16

schwann cells

Question 17

What do radia glia do?

Answer 17

form tracks in developing embryos

-> help newly formed neurons migrate from neural tube

Question 18

Where are interneurons found and what do they do?

Answer 18

in the CNS

responsible for integration and processing of information

Question 19

What is gray matter mostly composed of?

Answer 19

neuron cell bodies

Question 20

What is white matter mostly composed of?

Answer 20

bundled axons

Question 21

What is the brain composed of?

Answer 21

ventricles with cerebrospinal fluid
white matter
gray matter

Question 22

Where is the spinal cord located?

Answer 22

within the spine

Question 23

What is the function of the spinal cord?

Answer 23

links brain and the rest of us

transmits impulses to/from brain

Question 24

What is the structure of the spinal cord?

Answer 24

small central canal with cerebrospinal fluid
gray matter surrounds canal - inside
white matter surrounds gray - outside

Question 25

What are reflex actions?

Answer 25

rapid, involuntary response to stimulus | knee jerk reflex

Question 26

What does the PNS do?

Answer 26

transmits info to/from CNS

Question 27

What are nerves?

Answer 27

axons of many neurons held together with connective tissue

Question 28

What do afferent neurons do?

Answer 28

send info from sensory receptor to CNS

Question 29

What are the two types of senses?

Answer 29

visceral and somatic

Question 30

Describe visceral senses

Answer 30

senses you aren't aware of | blood pressure, thyroid, hormone levels

Question 31

Describe somatic senses

Answer 31

senses you are aware of | vision, hearing, taste, etc

Question 32

What do efferent neurons do?

Answer 32

send info from CNS to effectors: no receptors | target the motor system and autonomic NS

Question 33

How does the motor system work?

Answer 33

efferent neurons -> skeletal muscle voluntary and reflexes no receptors

Question 34

How does the autonomic nervous system work?

Answer 34

efferent neurons -> glands, heart, smooth muscle

Question 35

What are the 3 divisions of the autonomic nervous system?

Answer 35

enteric: controls digestive tract, pancreas, gall bladder parasympathetic: "rest and digest" sympathetic: "fight or flight"

Question 36

What are the 3 broad regions of brains?

Answer 36

forebrain, midbrain, hindbrain

Question 37

What does the forebrain control?

Answer 37

sensory input, learning, complex processing

Question 38

What does the midbrain control?

Answer 38

coordinates routing of sensory input

Question 39

What does the hindbrain control?

Answer 39

involuntary activities

Question 40

Where is the cerebrum derived from? What does it control?

Answer 40

forebrain most prominent part of the brain voluntary movement learning, emotion, memory, perception

Question 41

What is the corpus callosum?

Answer 41

thick band of axons, connects 2 halves

Question 42

Where is the cerebellum derived from? What does it control?

Answer 42

from hindbrain movement, balance motor skills/ coordination

Question 43

Where is the diencephalon derived from? What does it include?

Answer 43

from forebrain thalamus: routes sensory info to correct part of cerebrum hypothalamus: regulates homeostaisis

Question 44

What does the brainstem do?

Answer 44

control basic life functions - respiration, heartbeat, blood pressure

Question 45

What are the 3 components of the brainstem? Where are they derived from?

Answer 45

midbrain - midbrain pons - hindbrain medulla oblongata - hindbrain