APP Neuroscience Vocab 1

Modules 9-10

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

autonomic nervous system

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart)

peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body

central nervous system

the brain and spinal cord

antagonist

a molecule that mimics a neurotransmitter acts in an inhibitory manner

dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

action potential

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

myelin sheath

a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next

synapse

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

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles (enables voluntary control)

progesterone

hormone that promotes growth of uterine lining

estrogen

the main female sex hormone

threshold

the level of stimulation required to trigger a neural impulse

androgens

male sex hormones (category)

refractory period

the time after a neuron fires during which the neuron cannot fire

epinephrine/norepinephrine

secreted by the adrenal glands; also known as adrenaline and noradrenaline

adrenal glands

a pair of endocrine glands located just above the kidneys; secrete epinephrine and norepinephrine

pituitary gland

the endocrine system's master gland. Under the influence of the hypothalamus; regulates growth and controls other endocrine glands.

axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

neuron

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

selective permeability

a property of cells that allows some substances to cross more easily than others

depolarization

sodium rushes into neuron , causing the charge to increase into the positive

resting potential

the electrical charge across the cell membrane of a neuron in its resting state (not the number; opposite of action potential)

node of Ranvier

small gap between myelinated segments where axonal membrane is exposed; increase speed of impulses

terminal buttons

small knobs at the end of the axon that secrete chemicals called neurotransmitters

nervous system

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

endorphins

natural, opiatelike neurotransmitters linked to pain control and to pleasure

acetylcholine (ACh)

a neurotransmitter that enables learning and memory and also triggers muscle contraction

reuptake

a neurotransmitter's reabsorption by the sending neuron

neurotransmitters

chemical messengers that traverse the synaptic gaps between neurons

efferent neurons

neurons that carry outgoing information from the central nervous system to the muscles and glands (motor neurons)

afferent neurons

neurons that carry incoming information from the sense receptors to the central nervous system (sensory neurons)

parasympathetic nervous system

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

hypothalamus

controls the endocrine system

hormones

chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream

reflex

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

interneurons

neurons that make up the spinal cord and the brain

agonist

molecules that mimic neurotransmitter, acting in an excitatory manner

dopamine

neurotransmitter that is active in the reward pathway (pleasure); also influences learning, attention, and emotion

serotonin

neurotransmitter that affects mood, hunger, sleep, and arousal; low levels associated with mood disorders

vesicle

membrane-bounded sac located in the terminal buttons that releases neurotransmitters

thyroid

endocrine gland that regulates the body's metabolism

pancreas

gland that regulates glucose in the blood; secretes insulin

gonads

reproductive glands-male, testes; female, ovaries

testes

the male gonads, which produce sperm and secrete male sex hormones

ovaries

the female sex glands that store the ova and produce female sex hormones

testosterone

the most important male sex hormone

repolarization

when the potassium rushes out of the axon, causing the charge to go into the negative (again)

receptor cells

specialized sensory cells; turn a stimulus into a neural signal (first neurons to fire)

effector cells

specialized motor neurons; last cell to fire, resulting in the muscle's contraction

Soma

cell body

glial cells

cells in the nervous system that support, nourish, and protect neurons