chapt 2 (part 2)

define dendrite

Treelike fibers projecting from a neuron, which receive information and orient it toward the neuron’s cell body.

define cell body

The part of the neuron that contains the nucleus, which directs the manufacture of substances that the neuron needs for growth and maintenance.

define Axon

The part of the neuron that carries information away from the cell body toward other cells.

define myelin sheath

A layer of fat cells that encases and insulates most axons.

define synapse

Tiny spaces between neurons; the gaps between neurons are referred to as synaptic gaps.

resting potential

The stable, negative charge of an inactive neuron.

Action Potential

The brief wave of positive electrical charge that sweeps down the axon.

all-or-nothing principle

The principle that once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity.

What are neurotransmitters?

Chemical substances that are stored in very tiny sacs within the neuron’s terminal buttons and involved in transmitting information across a synaptic gap to the next neuron.

agonist

A drug that mimics a neurotransmitter’s effects by binding to a neurotransmitter’s receptors.

antagonist

A drug that blocks a neurotransmitter’s effects.

medulla

functions you dont have to think abt like breathing

cerebellum

It controls balance, coordination, and smooth movement.

brain stem?

The stemlike brain area that includes much of the hindbrain (excluding the cerebellum) and the midbrain; connects with the spinal cord at its lower end and then extends upward to encase the reticular formation in the midbrain.

reticular?

A system in the midbrain comprising a diffuse collection of neurons involved in stereotyped patterns of behavior such as walking, sleeping, and turning to attend to a sudden noise.

limbic system?

A set of subcortical brain structures central to emotion, memory, and reward processing.

amygdala

An almond-shaped structure within the base of the temporal lobe that is involved in the discrimination of objects that are necessary for the organism’s survival, such as appropriate food, mates, and social rivals.