NeuroScience: Neural and Hormonal Systems

Question 1

neuroplasticity

Answer 1

the brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

Question 1

biological psychology

Answer 1

the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes.

Question 2

neuron

Answer 2

a nerve cell; the basic building block of the nervous system.

Question 3

cell body

Answer 3

the part of a neuron that contains the nucleus; the cell’s life-support center.

Question 4

dendrites

Answer 4

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

Question 5

axon

Answer 5

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

Question 6

myelin [MY-uh-lin] sheath

Answer 6

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 7

glial cells (glia)

Answer 7

cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.

Question 8

action potential

Answer 8

a neural impulse; a brief electrical charge that travels down an axon.

Question 9

threshold

Answer 9

the level of stimulation required to trigger a neural impulse.

Question 10

refractory period

Answer 10

resting pause after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.

Question 11

all-or-none response

Answer 11

a neuron’s reaction of either firing (with a full-strength response) or not firing.

Question 12

synapse [SIN-aps]

Answer 12

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

Question 13

neurotransmitters

Answer 13

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

Question 14

reuptake

Answer 14

a neurotransmitter’s reabsorption by the sending neuron.

Question 15

endorphins [en-DOR-fins]

Answer 15

“morphine within”—natural, opiate-like neurotransmitters linked to pain control and to pleasure.

Question 16

agonist

Answer 16

a molecule that increases a neurotransmitter’s action.

Question 17

antagonist

Answer 17

a molecule that inhibits or blocks a neurotransmitter’s action.

Question 18

central nervous system (CNS)

Answer 18

the brain and spinal cord.

Question 19

peripheral nervous system (PNS)

Answer 19

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

Question 20

nerves

Answer 20

bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sensory organs.

Question 21

sensory (afferent) neurons

Answer 21

neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord.

Question 22

motor (efferent) neurons

Answer 22

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.

Question 23

interneurons

Answer 23

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

Question 24

somatic nervous system

Answer 24

the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system.

Question 25

autonomic [aw-tuh-NAHM-ik] nervous system (ANS)

Answer 25

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

Question 26

sympathetic nervous system

Answer 26

the division of the autonomic nervous system that arouses the body, mobilizing its energy.

Question 27

parasympathetic nervous system

Answer 27

the division of the autonomic nervous system that calms the body, conserving its energy.

Question 28

reflex

Answer 28

a simple, automatic response to a sensory stimulus, such as the knee-jerk reflex.

Question 29

endocrine [EN-duh-krin] system

Answer 29

the body’s “slow” chemical communication system; glands and fat tissue that secrete hormones into the bloodstream.

Question 30

hormones

Answer 30

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

Question 31

adrenal [ah-DREEN-el] glands

Answer 31

a pair of glands that sits just above the kidneys and secretes hormones that help arouse the body in times of stress. (adrenaline)

Question 32

pituitary gland

Answer 32

the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.