Unit A part 2

Question 1

what are dendrites

Answer 1

short extensions that recieve signals from other neurons or environment.

Question 2

what is the axon

Answer 2

long extension that transits impulses away to other neurons or effectors

Question 3

what is the myelin sheath

Answer 3

peripheral neurons have white insulation around the axon which is formed by schwaan cells

Question 4

what is the role of the myelin sheath

Answer 4

act as an insulator preventing loss of charged ions from axon, allowing conduction of faster nerve impulses.

Question 5

what is a neurilemma

Answer 5

membrane surrdoing axon that promotes regeneration

Question 6

what is a reflex arc

Answer 6

involuntary response that bypasses interpretation by brain

Question 7

what are the two states of nerves

Answer 7

resting potential and action potential

Question 8

what is resting potential

Answer 8

-polarized
-resting nerve
-charge inside is -70mV

Question 9

what is action potential

Answer 9

-depolarized
-charge inside jumps to +40mV

Question 10

when is a neuron polarized

Answer 10

when pumps pump 3 Na and 2 K which leads to an unequal distribution and eventual polarized membrane.

Question 11

What causes an electrical potential difference across a membrane?
(polarized)

Answer 11

A separation of electrical charge, with positive on one side and negative on the other.

Question 12

What happens to sodium when an action potential is going to come in effect?

Answer 12

It rushes inside the membrane, making it positive (depolarization)

Question 13

What is repolarization?

Answer 13

Na channels close, K gates open and K diffuses out, restoring original polarization

Question 14

What is the refractory period?

Answer 14

Recovery time required before a neuron can return to resting potential

Question 15

What is hyperpolarization

Answer 15

K gates close slowly, allowing more to move out than normal causing inside to become more negative

Question 16

What is saltatory conduction?

Answer 16

Action potentials seem to jump from node to node

Question 17

What is the threshold?

Answer 17

Minimum level of stimulus required to produce a response

Question 18

What happens when there’s a higher number of impulses reaching the brain?

Answer 18

There will be a greater intensity in response

Question 19

what are presynaptic neurons

Answer 19

they release neurotransmitters into the synapse

Question 20

what are postsynaptic neurons

Answer 20

recieve neurotransmitters from the synapse

Question 21

what is the dopamine neurotransmitter associated with

Answer 21

-sensation of pleasure
-body movement

Question 22

what is the neurotransmitter seratonin associated with

Answer 22

-regulates temp
-perception
-mood control

Question 23

what is the neurotransmitter endorphins associaed with

Answer 23

-natural pain killer
-emotions

Question 24

what is the neurotransmitter norepinephrine associated with

Answer 24

works with epinephrine (fight or flight response)

Question 25

what is summation

Answer 25

effect produced by accumulation of neurotrasmitters from two or more neurons

Question 26

what is parkinsons disease

Answer 26

inadequate dopamine (inhibitory) causes involuntary muscle contraction

Question 27

what is alzheimers disease

Answer 27

inadquate actelycholine (excitory) deterioration of memory and mental capacity

Question 28

what protects the control centre consisting brain and spinal cord

Answer 28

the skull and vertebrae (bone coverings)

Question 29

what is the protective membrane surrounding the brain called

Answer 29

meninges

Question 30

what are the three parts of the meninges

Answer 30

-dura mater (outer) -arachoid (middle) -pia mater (inner)

Question 31

what is the cereberal spinal fluid

Answer 31

shock absorber between inner and middle meninges and central canal of spinal cord

Question 32

what is the foramen magnum

Answer 32

opening in skull for spinal cord

Question 33

what is the gray space

Answer 33

unmyelinated neurons/axons

Question 34

what is the white space

Answer 34

myelinated neurons

Question 35

what do dorsal nerves do

Answer 35

bring sensory info in

Question 36

what are the 3 regions of the brain

Answer 36

-forebrain -midbrain -hindbrain

Question 36

what do ventral nerves do

Answer 36

carries motor info out to effectors (muscles/glands)

Question 36

what does the forebrain control

Answer 36

reason, intellect, memory, language and peronality

Question 37

what does the midbrain control

Answer 37

relay center for eye and ear

Question 38

what does the hindbrain control

Answer 38

balance, muscle control, autonomic control

Question 39

what is the cerebrum

Answer 39

largestportion of brain, surface is the cerebral cortex (gray matter)

Question 40

what is the cerebrum a coordinating center for?

Answer 40

motor actions, speech, memory, reasoning and personality

Question 41

is the forbrain 2 distinct?

Answer 41

2 distinct hemispheres, left and right side linked by the corpus callosum (communication bridge)

Question 42

what does each hemisphere of the cerebrum have

Answer 42

4 lobes -frontal, temporal, parietal and occiptal lobes

Question 43

What does the thalamus do

Answer 43

Interprets sensory information(relay station)

Question 44

What does the hypothalamus do?

Answer 44

Interprets internal environment & tells pituitary to release hormones or medulla to release a nerve signal (autonomic)

Question 45

What do the oflactory bubls do?

Answer 45

Detect smell

Question 46

What does the frontal lobe do?

Answer 46

-Voluntary muscles (walking, speech) -personality -memory

Question 47

What does the temporal lobe do?

Answer 47

Interprets sensory info (hearing, smell)

Question 48

What does the parietal lobe do?

Answer 48

Touch, pain, taste, temperature

Question 49

What does the occipital lobe do?

Answer 49

Vision

Question 50

What does the hindbrain contain?

Answer 50

-cerebellum -pons -medulla oblongata

Question 51

What does the cerebellum do?

Answer 51

Controls limb movement, balance and muscle tone

Question 52

What do the pons do?

Answer 52

(Bridge) relay station between two regions of cerebellum and medulla

Question 53

What does the medulla oblongata do?

Answer 53

Joins spinal cord to cerebellum, site of autonomic nerve control

Question 54

What does the broccas area do?

Answer 54

Coordinates speech muscles and translates thoughts into speech (frontal lobe)

Question 55

What is wernickes area?

Answer 55

Language comprehension and storage (left temporal lobe)