3.2 nervous system

Question 1

structure of neurons

Answer 1

• soma
• dendrites
• axon
• myelin sheath
• axon terminals

Question 2

neurons job is to fire or not to fire

Answer 2

-firing decreses the chance the adjacent neurons will fire

Question 3

soma

Answer 3

cell body

houses cell nuceleus

Question 4

neurons receive messages from other neurons

Answer 4

dendrites

-tiny branches projecting from cell body

Question 5

as dendrites recieve messages

Answer 5

they send them to the rest of the cells which travel to the base of the cell body called axon hillock with enough stimulation chemical reactions happen here and flows through the rest of the neuron to the axon

Question 6

axon

Answer 6

when the chemical reaction reaches the end of the axon they reach the axon terminals which are little bulbs filled with molecules called neurotransmitters, activity reaching the axon terminals will stimulate the release of neurotransmitters which react with the dendrites of other neurons

Question 7

diff types of neurons

Answer 7

motor- send messages from brain down spinal cord to limbs to muscles
sensory-receive neurons from the senses, and deliver messages to the brain for farther processing, pressure signals, or pain

Question 8

glial cells

Answer 8

responsible for maintenance activities
-ex activating immune response, facilitate neurons
10* the amount of neurons
-to coat neurons that are responsible for sending rapid messages throughout the brain
-they coat the axon in myelin (insulates axons so that the activity travels much faster)

Question 9

M S

Answer 9

is a debilitating neurological disorder that produces a range of symptoms
-happens because of lack of myelin

Question 10

neural firing

Answer 10

• resting potential (not firing) (-vely charged)
• positively charged ions rush into the cell during an action potential
• after the nerve has fired, the positively charged ions are pumped back out of the cell

Question 11

electrostatic gradient

Answer 11

the inside and outside of the neuron have different charges

Question 12

concentration gradient

Answer 12

there are different types of ions dominating the inside vs.outside of the neuron
-thee imbalances keep the neuron in a state of tension

Question 13

when stimulated, a neuron…

Answer 13

ion channels open and positive ions rush in and may result in the neuron firing
AKA as generating an action potential

Question 14

back to resting potential the +ve ions are pumped out

Answer 14

hyper polarization occurs and the neuron is more negatively charged than before the action potential
-this means that the neuron is briefly unable to fire, which is a phase called, the refractory period

Question 15

once the action potential reaches an axon terminal is stimulates a release of neural transmitters into a gap b/w the axon terminal and of the firing neuron and the dendrite of an adjacent neuron

Answer 15

gap is called the synapse
presynaptic sends the message
post synaptic receives messages

Question 16

postsynapitic cell has special receptors for

Answer 16

receiving neurons

Question 17

excitatory neurotransmitters

Answer 17

increase the chance that the postsynaptic neuron will fire by causing the charge inside the neuron to be less negative

Question 18

inhibitory neurotransmitters

Answer 18

decrease the chance that the postsynaptic neuron will fire by causing the charge inside the neuron to be more negative

Question 19

all or non principle

Answer 19

a neuron either generates an action potential or doesn’t generate one, but the magnitude of the action potential is the same every time

Question 20

a neuron can represent higher intensity stimulation by firing more…

Answer 20

frequently over time rather than how strongly they fire each time

Question 21

synaptic cleft

Answer 21

reuptake

neurotransmitters get reabsorbed into the axon terminal

Question 22

common neurotransmitters

Answer 22

glutamate-responsible for brain functions (excitatory)
GABA-inhibitory for sleep, reducing arousal
acetylcholine-control voluntary movement

Question 23

drug effects on neural activity

Answer 23

agonist-stimulate receptor sites for a particular neurotransmittor
-increase stimulation for post synaptic neurons
- bind to receptor
antagonist-block receptor
-prevent production
(look up direct and indirect)

Question 24

the endocrine system

Answer 24

hormones are secreted from structures called endocrine glands and enter the blood stream
-delivers hormones to modify physiological processes and maintaining body homeostasis

Question 25

hypthatlamus is the control system in the endocrine system

Answer 25

brain structure that delivers messages about out biological needs to the pituitary gland

Question 26

pituitary gland

Answer 26

brain structure that releases hormones and stimulates the production of hormones by the other glands that form the endocrine system

Question 27

arousal glands

Answer 27

stimulates the production of hormones, such as cortisol and epinephrin,that generate arousal responses

Question 28

pituitary glands also release endorphins

Answer 28

stimulate pleasure centers in the brain and inhibit signals of pain and displeasure

Question 29

central nervous system

Answer 29

brain

spinal cord

Question 30

peripheral nervous system

Answer 30

somatic nervous stystem

autonomic nervous system

Question 31

somatic nervous system

Answer 31

consists of nerves that control the muscles and others that receive signals from sensory organs

Question 32

autonomic nervous system

Answer 32

consists of the sympathetic nervous system and the parasympathetic nervous system

Question 33

sympathetic nervous system

Answer 33

generates heightened arousal to prepare the body to respond to threats

Question 34

parasympathetic nervous stystem

Answer 34

maintains balance in body systems when there is no need to respond to a threat and suppresses arousal responses after a state of heightened arousal

Question 35

cells that form structure of brains

Answer 35

thoughts actions and feelings and life sustaining functions rely on the function of neurons