Nervous System Part 1

Front 1

2 Structural Divisions

Back 1

CNS - brain and spinal cord
PNS - cranial nerves and spinal nerves

Front 2

2 Functional Systems or Divisions

Back 2

Somatic NS - skeletal muscles
Autonomic NS - Smooth and cardiac muscles

Front 3

2 arms of the autonomic

Back 3

sympathetic - F and F
parasympathetic - R and R

Front 4

Afferent neurons

Back 4

Sensory - TO CNS

Front 5

Efferent neurons

Back 5

Motor - away from CNS

Front 6

Neurons

Back 6

The excitable, impulse transmitting cells which are the primary functional cells or units of the NS

Front 7

Astrocytes

Back 7

Blood brain barrier

Front 8

Microglia

Back 8

Immune cells

Front 9

ependymal

Back 9

epethelial cells, cerebrospinal fluid

Front 10

Oligodendrocytes

Back 10

myelinate

Front 11

Schwann cells

Back 11

in PNS, produce Myelin

Front 12

Satellite cells

Back 12

in PNS, structural support

Front 13

Input zone

Back 13

soma, dendrites

Front 14

Summation zone

Back 14

axon hillock

Front 15

conduction

Back 15

axon

Front 16

output zone

Back 16

telodendria and synaptic knobs

Front 17

Where are nerves found?

Back 17

in the PNS

Front 18

Where are tracts found?

Back 18

in the CNS

Front 19

epineurium

Back 19

surrounds entire nerve

Front 20

perineurium

Back 20

around fasicles of fibers

Front 21

endoneurium

Back 21

around each individual nerve fiber (axon)

Front 22

resting membrane potential

Back 22

-70mV

Front 23

charge inside of cells

Back 23

Negative

Front 24

charge outside of cells

Back 24

positive

Front 25

Why is the potassium-sodium pump important?

Back 25

transport Na OUT and K IN, to maintain polarity

Front 26

What is the nerve impulse called?

Back 26

Action potential

Front 27

Threshold potential

Back 27

-59 mV to -55mV

Front 28

What does the opening of Na+ channels produce?

Back 28

ion movement and changes in membrane potential.

Front 29

What happens when the threshold potential is reached?

Back 29

Voltage regulated Na channels are opened and the Action Potential Occurs. (going only one direction, down the axon away from the cell body) called DEPOLARIZATION

Front 30

Peak potential of the action potential

Back 30

+30mV

Front 31

What happens when the peak potential is reached?

Back 31

the Na+ channels are closed and the K+ channels are opened, so that K+ ions go OUT of the cells, so as to return the potential back to the -70mV resting level. Called REPOLARIZATION.

Front 32

2 types of conduction of the Action potential

Back 32

Continuous conduction - unmyelinated
and Saltatory conduction - myelinated, faster, jump

Front 33

What is the synapse?

Back 33

The junction or connection, the site where nerve impulses are transmitted from neuron to the next neuron or to the effector

Front 34

What are the components of the synapse? (3)

Back 34

1. The synaptic bulb
2. a Synaptic cleft or space
3. plasma membrane of the Post synaptic cell

Front 35

When does synaptic transmission occur?

Back 35

When the impulse reaches the synaptic bulb.

Front 36

Synaptic transmission step 1

Back 36

Action potential arrives

Front 37

synaptic transmission step 2

Back 37

voltage gated calcium channels open and Ca++ ions rush IN.

Front 38

synaptic transmission step 3

Back 38

Ca++ ions trigger the release of neurotransmitter (Ach, acetylcholine) from vesicles at te synaptic cleft

Front 39

synaptic transmission step 4

Back 39

Ach, diffuse across the cleft, and are bound to receptors at the post synaptic cell membrane

Front 40

synaptic transmission step 5

Back 40

in the post synaptic cell membrane, the neurotransmitter trigger opening of ion channels producing 'local' or gated potentials. These may be either excitatory or inhibitory, depending on the type of channels which are triggered

Front 41

synaptic transmission step 6

Back 41

neurotransmitter molecules are either removed and broken down, and recycled

Front 42

Acetylocholine

Back 42

the most common and most important of the neurotransmitters