Chapters 3.2

Question 1

Neurons

Answer 1

One of the major cells found in the nerves system, that are responsible for sending and receiving messages throughout the body.

Question 2

cell body

Answer 2

(or soma) the part of the neurone that contains the nucleus.

Question 3

dendrites

Answer 3

small branches radiating from the cell that receive messages from other cells and transmit those messages towards the rest of the cell.

Question 4

axon hillock

Answer 4

located at the base of the cell body. if the hillock receives enough stimulation, it will stimulate a chemical reaction.

Question 5

axon

Answer 5

a tail like structure that transports information in the form of electrochemical reactions from the cell body to the end of the neurone.

Question 6

axon terminal

Answer 6

bulb like extensions filled with vesicles at the end of the axon.

Question 7

neurotransmitters

Answer 7

found in vesicles. are the chemicals that function as messengers allowing neurones to communicate with each other.

Question 8

sensory neurons

Answer 8

receive information from the body senses and bring it TOWARD the brain.

Question 9

motor neurons

Answer 9

carry messages AWAY from the brain and spinal cord towards muscles

Question 10

glial cells

Answer 10

specialized cells of the nervous system that are involved in mounting immune responses in the brain, removing waste, and synching neutron activity

Question 11

myelin sheath

Answer 11

a white fatty substance produced by certain glial cells, that increases speed and efficiency in neural communications.

Question 12

multiple sclerosis

Answer 12

is a disease where the immune system does not recognize myelin and attacks it. which can devastate the functional integrity of the nervous system.

Question 13

Neural activity

Answer 13

based on changes in the concentrations of ions. when a neurone is not transmitting information, the outside has a high concentration of positive ions, while the inside has a negative concentration.

Question 14

Resting potential

Answer 14

the relatively stable state(-70mv) during which the cell is not transmitting messages.

Question 15

electrostatic gradient

Answer 15

inside and outside of the cell have different charges.

Question 16

concentration gradient

Answer 16

different types of ions are more densely packed on one side

Question 17

ion channel

Answer 17

When a neuron is stimulated, and ion channels open up, the influx of positive ions in the cell causes the potential to change to -68mV. If enough of these positive ions reach the axon hillock and push its charge past its threshold (eg. -55mV), the neuron will activate.

Question 18

action potential

Answer 18

a wave of electrical activity that originates at the base of the axon and rapidly travels down its length. charge reaches +35mv at the specific point.

Question 19

hyper polarized

Answer 19

once the positive ions are pumped out of the axon, the charge becomes more negative than usual. (-72mv)

Question 20

refractory period

Answer 20

the brief 3-3ms period where the neurone cannot fire.

Question 21

synapses

Answer 21

the microscopically small spaces that separate individual nerve cells and receive the neurotransmitters.

Question 22

presynaptic cells

Answer 22

the cells that release neurotransmitters

Question 23

postsynaptic cells

Answer 23

the part that receives the neurotransmitters.

Question 24

all-or-none principle

Answer 24

individual nerve cells fire at the same strength every time an action potential occurs.

Question 25

excitatory neurotransmitter

Answer 25

increases the probability of the neurone firing by increasing the charge from -70mv to -68mv.

Question 26

inhibitory neurotransmitter

Answer 26

decreases the probability of it firing by decreasing its charge from -70mv to -72mv

Question 27

synaptic cleft

Answer 27

the minute space between the axon terminal and dendrite where discarded neurotransmitters are released

Question 28

re-uptake

Answer 28

neurotransmitters are either broken down by enzymes or go through reuptake, where they are reabsorbed into the axon terminals of the presynaptic neurone.

Question 29

glutamate

Answer 29

the most common excitatory neurotransmitter in the brains of invertebrates. also involved in process of forming new memories.

Question 30

GABA (gamma-amino butyric acid)

Answer 30

is the primary inhibitory neurotransmitter of the nervous system.

Question 31

Acetylcholine

Answer 31

is one of the most win spread neurotransmitters within the body, found at the functions between nerve cells and skeletal muscles. very important for voluntary movement.

Question 32

neuromuscular junction

Answer 32

the link between our nervous system and our muscles.

Question 33

monoamines

Answer 33

class of neurotransmitter which includes: dopamine, norepinephrine, and serotonin

Question 34

dopamine

Answer 34

is involved in varied functions, like mood, control of voluntary movement and processing of rewarding experiences.

Question 35

norepinephrine

Answer 35

is involved in regulating stress responses, including increasing arousal, attention, and heart rate; it is also sent down the spine when involved with the fight-or-flight response. regulates wakefulness and attention.

Question 36

serotonin

Answer 36

is involved in regulating sleep, mood, aggression, and appetite

Question 37

agonists

Answer 37

are drugs that enhance or mimic the effects of a neurotransmitters actions.

Question 38

direct agonist

Answer 38

physically binds to that neurotransmitters receptor on the postsynaptic cell.

Question 39

indirect agonist

Answer 39

facilitates the effects of a neurotransmitter, but does not physically bind to the same receptor as the neurotransmitter.

Question 40

antagonists

Answer 40

inhibit neurotransmitter activity by blocking receptors or preventing synthesis of a neurotransmitter.

Question 41

direct antagonists

Answer 41

physically blocks the neurotransmitter receptor.

Question 42

indirect antagonist

Answer 42

reduces the effects of neurotransmitters without physically blocking receptors.

Question 43

hormones

Answer 43

are chemicals secreted by the glands of the endocrine system

Question 44

homeostasis

Answer 44

the balance of energy, metabolism, body temperature, and other basic functions that keep the body working properly.

Question 45

hypothalamus

Answer 45

the brain structure that regulates basic biological needs . releases specialized chemicals called releasing factors that stimulate the pituitary gland

Question 46

pituitary gland

Answer 46

the master gland of the endocrine system that produces hormones that sends commands about hormone production to the other glands of the endocrine system.

Question 47

adrenal gland

Answer 47

a pair of endocrine glands located adjacent to the kidneys that release stress hormones.

Question 48

endorphin

Answer 48

a hormone produced by the pituitary gland and the hypothalamus that functions to reduce pain and induce feelings of pleasure