Ch.11 The Nervous System

Question 1

Nervous System

Answer 1

receive sensory input, interpret it,

and send out appropriate commands

Question 2

3 interconnected functions:

Answer 2

sensory input, integration, motor output

Question 3

sensory input

Answer 3

conduct signals from sensory receptors

Question 4

integration

Answer 4

interpret sensory signals and formulation of response.

Question 5

motor output

Answer 5

conduction of signals to effector cells

Question 6

CNS consists of:

Answer 6

brain, spinal cord

Question 7

PNS consists of:

Answer 7

cranial nerves, ganglia, spinal nerves

Question 8

CNS

Answer 8

interpretation

Question 9

PNS

Answer 9

relay messages. afferent (sensory info in) and efferent (motor commands out).

Question 10

Efferent leads to:

Answer 10

somatic (voluntary movement) EAT A BANANA and autonomic (unconscious responses) DIGEST BANANA

Question 11

autonomic leads to :

Answer 11

parasympathetic (rest and digest) and sympathetic (fight or flight/ getting excited)

Question 12

two main cell types:

Answer 12

glial cells and neurons

Question 13

glial cells (neuroglia)

Answer 13

supporting cells that wrap around neurons

Question 14

neurons

Answer 14

transmit electrical signals

Question 15

CNS neuroglial cells (4 types):

Answer 15

Astrocytes, Microglial, Ependymal, Oligodendroctyes

Question 16

astrocytes (star,big)

Answer 16

support, transport glucose, metabolize neurotransmitters

Question 17

Microglial (small)

Answer 17

branched (processes). Immunity, macrophages (digest/ engulf/ breakdown)

Question 18

Ependymal

Answer 18

cilia, circulates cerebrospinal fluid (CSF). Cuboidal columnar. (cushoning) inbetween skull and brain

Question 19

Oligodendrocytes

Answer 19

generates myelin sheath.

Question 20

PNS Neuroglial cells (2 types):

Answer 20

Shwann Cells, Satellite Cells

Question 21

Shwann cells: (no arms)

Answer 21

flattened cells, wrap around axons that form myelin sheath in PNS

Question 22

Satellite cells: (flat, no arms)

Answer 22

flattened cells surround cell bodies to provide support framework.

Question 23

Neurons

Answer 23

structural unit of nervous system

Question 24

Neurons consist of :

Answer 24

dendrites, axon, myelin sheath, cell body (nucleus/ nucleolus), axon terminals

Question 25

Cell body (soma/ perikaryon):

Answer 25

Amitotic nature (repair not divide), Axon hillock (axon originates), Neurofibrils (intermediate filaments maintain shape)

Question 26

dendrites:

Answer 26

short, branching, pass electrical impulse on to cell body. electrical signals passed along GRADED POTENTIAL.

Question 27

Axons:

Answer 27

slender long processes, conduct electrical impulses. (collaterals= side branches)

Question 28

Axons 2 movements:

Answer 28

anterograde (towards axon terminus), retrograde (towards cell body).

Question 29

synapse:

Answer 29

gap between dendrites of one neuron and axon terminals of another neuron

Question 30

Myelination:

Answer 30

myelin sheath (insulates to protect elecritcal impulse from shorting out). White matter.

Question 31

Two cells giving rise to myelin sheath:

Answer 31

shwann cells in PNS and Oligodendrocytes in CNS

Question 32

Nodes of Ranvier:

Answer 32

myelin sheath gaps

Question 33

structural classification (3):

Answer 33

Multipolar, Bipolar, Unipolar.

Question 34

Multipolar

Answer 34

many dendrties, one axon (Most in CNS). purkinje fibres (heart), pyrimidal cells, granule.

Question 35

Bipolar

Answer 35

one fused dendrite and axon.

Question 36

Unipolar

Answer 36

one process emerging from cell body

Question 37

Nuclei:

Answer 37

CNS cluster of cell bodies on the neurons

Question 38

ganglia :

Answer 38

PNS cluster of cell bodies on the neurons

Question 39

Afferent

Answer 39

sensory

Question 40

Efferent

Answer 40

motor

Question 41

Interneurons

Answer 41

association neurons

Question 42

membrane ion channels:

Answer 42

leakage (always open), Gated Channels (chemically, voltage, mechanically)

Question 43

chemically gated channels:

Answer 43

open with the binding of specific neurotransmitters (sodium/ potassium)

Question 44

voltage gated channels:

Answer 44

open and close in response to membrane potential

Question 45

mechanically gated channels:

Answer 45

open and close to physically deformation of receptors

Question 46

resting membrane potential

Answer 46

K+ greater intracellular and membrane more permeable to K+ so "leaks" or diffuse out of cell. SODIUM POTASSIUM PUMP (moves K+ back into cell) And sodium moves in (pump moves it out) . -70mv

Question 47

polar

Answer 47

unequal sharing of electrons. (opp charges at both ends)

Question 48

polarization:

Answer 48

-70mv (depolarization) -80mv (hyperpolarization) -60 (repolarization)

Question 49

2 types of electrical signals :

Answer 49

graded potential, action potentials

Question 50

graded potential

Answer 50

decreases with distance travelled.

Question 51

action potentials

Answer 51

occurs in muscle cells. always the same "wave" regardless of stimilus. (DOES NOT DECREASE OVER TIME) de-polarizing, hyperpolarizing, polarizaing.

Question 52

4 stages of action potential:

Answer 52

resting state, depolarization, repolarization, hyperpolarization

Question 53

Resting state:

Answer 53

Na and K channels closed. activation gates closed / inactivation gates open.

Question 54

Depolarization:

Answer 54

moving up. Na+permeability increases; membrane potential reverses. Na+ gates open; K+ gates remain closed.

Question 55

Repolarization:

Answer 55

dropping back down to close. Na+ gates close, K+ gates open.

Question 56

Hyperpolarization:

Answer 56

"undershoot" takes a little while to close. K+ gates close.

Question 57

propagation of action potential:

Answer 57

constantly being attracted to the negatives. impulses will only travel in one direction away from the trigger zone.

Question 58

speed up impulse:

Answer 58

temperature (warmer), myelin sheath (insulation/ prevent leakage), larger diameter

Question 59

Synapses

Answer 59

as

Question 60

neurotransmitters:

Answer 60

bind to receptors and trigger opening or closing of ion channels. Examples: Acetylcoholine, Dopamine, Serotoni, GABA, Epineprhine.