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Biology 116 > Nervous System Organization > Flashcards

Flashcards in Nervous System Organization Deck (41):
1

what is the big picture of the nervous system?

enable organisms to sense and react to the environment.
-has been evolving for billions of years
-increase survival and reproduction in changing environments

2

cnidarians

-simplest animals with NS
-nerve net: interconnected neurons for movement
-NO CENTRAL CONTROL ORGAN

3

echinoderms

-nerve ring: central control structure
-signal radial nerve (signals muscles)

4

bilateria

-lots of variation
-Platyhelminthes (Planarians)
-anterior end; eyespots for detecting light and brain
-ladder-type NS; 2 longitudinal nerve cords and transverse nerves ("rungs")

Annelids and Arthopods
-more complex brain
-ganglia: segmentally arranged clusters of neurons

5

vertebrates (NS)

CNS- brain and spinal cord
PNS - nerves and ganglia

6

chiton

slowing moving -> simple

7

squid

fast moving -> complex

8

what is special about chiton and squid?

they are both molluscs, but they live different lifestyles

9

neuron

basic functional unity of NS
-conduct electrical signals, integrate info

10

neuron anatomy

-cell body: contains organells and nucleus
-dendrites (="trees"); cytoplasmic extension from cell body - usually many and short, receive info

11

axons

-also cytoplasmic extensions from cell body - but usually one and long
-send info
-axon hillock: base of axon - where signals are generated
-synaptic terminals: end of axon - often branched

12

glia

-non-neuron cells of the NS
-MANY functions; neuron support, protections, maintenance, embryonic NS development

13

myelin sheath

bundles of insulation around axons - faster signaling
-in CNS: produced by oligodendrocytes
-in PNS: produced by Schwann Cells

14

radial glia

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

15

CNS

-contains interneurons -responsible for integration and process of info
-gray matter - mostly neuron cell bodies
-white matter - mostly bundled axons

16

brain

-ventricles with cerebrospinal fluid
-white matter (axons) inside
-gray matter (cell bodies) outside

17

spinal cord

-within spine
-links brain and rest of NS

18

spinal cord structure

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

19

spinal cord functions

-transmit impulses to/from brain
-reflex actions: rapid, involuntary response to stimulus
-ex: knee-jerk reflex; quad stretched unexpectedly -> helps you stay upright

20

PNS

-all remaining nervous tissue not part of CNS
-transmit info to/from CNS
-includes nerves: axons of many neurons held together with connective tissue`

21

what do sensory receptors do?

they detect stimuli

22

afferent neurons

send info from sensory receptor -> CNS

23

what are the two types of senses

visceral and somatic

24

visceral

not aware of - BP, thyroid hormone levels

25

somatic

are aware of - vision

26

efferent neurons

CNS -> effectors: no receptors

27

what are the two target systems of efferent neurons?

motor system and autonomic nervous system

28

motor system

-efferent neurons -> skeletal muscle
-voluntary and reflexes
-no receptors

29

autonomic nervous system

-efferent neurons -> glands, heart, smooth muscle
-what CNS controls that we are not aware of

30

what are the three divisions of the autonomic nervous system

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

31

what are the three broad regions/categories of the vertebrate brain

forebrain, midbrain, and hindbrain

32

forebrain

sensory input, learning, complex processing

33

midbrain

coordinates routing on sensory input

34

hindbrain

involuntary activities

35

cerebrum

-derived from forebrain
-most prominent part of brain
-voluntary movement
-learning, emotion, memory, perception

36

divisions of the cerebrum

-right/left hemisphere
-left/right reversed perception/control
-corpus callosum: thick band of axons, connects 2 halves

37

cerebellum

-from hindbrain
-movement. balance, motor skills/coordination

38

diencephalon

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

39

brainstem

-basic life functions - respiration, heartbreat, BP
-3 components: midbrain, pons, and medulla oblangata

40

pons

from hindbrain; respiratory and sleep centers

41

medulla oblongata

from hindbrain; continuous with spinal cord