ch 2 pt 1

Question 1

dendrites

Answer 1

a neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body

Question 2

axon

Answer 2

the neuron extension that passes messages through its branches to other neurons or to muscles or glands

Question 3

myelin sheath

Answer 3

a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next

Question 4

neurotransmitters

Answer 4

chemical messengers that cross the synaptic gaps between neurons. when released by the sending neuron, they travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse

Question 5

synapse

Answer 5

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Question 6

reuptake

Answer 6

a neurotransmitter’s reabsorption by the sending neuron

Question 7

endorphins

Answer 7

morphin within - natural, opiate- like neurotransmitters linked to pain control and to pleasure

Question 8

agonist

Answer 8

a molecule that increases a neurotransmitter’s action

Question 9

antagonist

Answer 9

a molecule that inhibits or blocks a neurotransmitter’s action

Question 10

nervous system

Answer 10

the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

Question 11

afferent neuron

Answer 11

(sensory) neurons that carry incoming information form the body’s tissues and sensory receptors to the brain and spinal cord

Question 12

efferent neurons

Answer 12

(motor) neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Question 13

interneourns

Answer 13

neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs

Question 14

hormones

Answer 14

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream and affect other tissues

Question 15

acetylcholine

Answer 15

enables muscle action, learning and memory, Malfunctions; alzheimer’s

Question 16

dopamine

Answer 16

influences movement, learning, attention and emotion Malfunction: oversupply- schizophrenia, undersupply: linked to tremors and decreased mobility in parkinson’s disease

Question 17

GABA

Answer 17

a major inhibitory neurotransmitter, Malfunctions: undersupply linked to seizures, tremors and insomnia

Question 18

mirror neurons

Answer 18

frontal lobe neurons that some scientists believe fire when we perform certain actions or observe another doing so. the grains mirroring of another’s action may enable imitation and empathy

Question 19

neuroplasticity

Answer 19

the brain’s ability to modify, change, and adapt both structure and function throughout life and in response to experience