Topic 18: Nervous System Organization Flashcards Preview

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Flashcards in Topic 18: Nervous System Organization Deck (45):
1

What does the nervous system enable organisms to do?

sense and react to the enviornment

2

What kind of nervous system structure do cniderians have?

nerve net: interconnected neurons for movement

3

What kind of nervous system do echinoderms have?

nerve ring: central control structure

4

What are the nervous system components of bilaterians?

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

5

Define ganglia

segmentally arranged clusters of neurons

6

What are the main components of the CNS?

brain and spinal cord

7

What are the main components of the PNS?

nerves and ganglia

8

What are neurons? What do they do?

basic functional unit of nervous system
conduct electrical signals, integrate information

9

What does the cell body contain?

organelles

10

What are dendrites?

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

11

What are axons? What do they do?

cytoplasmic extensions from cell body
send information

12

What is the axon hillock?

base of axon, where signals are generated

13

What are glial cells? What do they do?

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

14

What is myelin sheath? What is its purpose?

bundles of insulation around axons
faster signaling

15

What is myelin sheath produced by in CNS?

oligodendrocytes

16

What is myelin sheath produced by in PNS?

schwann cells

17

What do radia glia do?

form tracks in developing embryos
-> help newly formed neurons migrate from neural tube

18

Where are interneurons found and what do they do?

in the CNS
responsible for integration and processing of information

19

What is gray matter mostly composed of?

neuron cell bodies

20

What is white matter mostly composed of?

bundled axons

21

What is the brain composed of?

ventricles with cerebrospinal fluid
white matter
gray matter

22

Where is the spinal cord located?

within the spine

23

What is the function of the spinal cord?

links brain and the rest of us
transmits impulses to/from brain

24

What is the structure of the spinal cord?

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

25

What are reflex actions?

rapid, involuntary response to stimulus
(knee jerk reflex)

26

What does the PNS do?

transmits info to/from CNS

27

What are nerves?

axons of many neurons held together with connective tissue

28

What do afferent neurons do?

send info from sensory receptor to CNS

29

What are the two types of senses?

visceral and somatic

30

Describe visceral senses

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

31

Describe somatic senses

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

32

What do efferent neurons do?

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

33

How does the motor system work?

efferent neurons -> skeletal muscle
voluntary and reflexes
no receptors

34

How does the autonomic nervous system work?

efferent neurons -> glands, heart, smooth muscle

35

What are the 3 divisions of the autonomic nervous system?

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

36

What are the 3 broad regions of brains?

forebrain, midbrain, hindbrain

37

What does the forebrain control?

sensory input, learning, complex processing

38

What does the midbrain control?

coordinates routing of sensory input

39

What does the hindbrain control?

involuntary activities

40

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

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

41

What is the corpus callosum?

thick band of axons, connects 2 halves

42

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

from hindbrain
movement, balance
motor skills/ coordination

43

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

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

44

What does the brainstem do?

control basic life functions - respiration, heartbeat, blood pressure

45

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

midbrain - midbrain
pons - hindbrain
medulla oblongata - hindbrain