PSY 200 - Module 2 - Neuropsychology

Neuron

Brain cell that sends and receives information.

Glial Cell

Supports neurons and keeps them healthy.

Soma

Neuron’s cell body; contains the nucleus.

Dendrite

Branches that receive signals from other neurons.

Axon

Long part of a neuron that sends signals out.

Myelin Sheath

Fat layer around axon that speeds up signals.

Node of Ranvier

Gap in myelin where signals jump.

Terminal Button

End of axon; releases chemicals to pass messages.

Synaptic Vesicle

Small sacs that hold neurotransmitters.

Synapse

Tiny gap between neurons where messages pass.

Receptor

Protein on dendrites that catches neurotransmitters.

Semipermeable Membrane

Lets some molecules in/out of neuron, blocks others.

Action Potential

Electrical signal moving down the neuron.

Resting Potential

Neuron’s ready state between signals.

Depolarization

Neuron becomes less negative; sodium enters.

Repolarization

Neuron returns to resting state; potassium leaves.

Hyperpolarization

Neuron becomes a bit more negative than normal.

All-or-None

Neuron either fires completely or not at all.

Reuptake

Neuron takes back neurotransmitters after sending a signal.

Central Nervous System (CNS)

Brain and spinal cord.

Peripheral Nervous System (PNS)

Nerves connecting CNS to the body.

Somatic Nervous System

Controls voluntary movement and senses.

Autonomic Nervous System

Controls organs automatically.

Sympathetic Nervous System

“Fight or flight”; gets body ready for stress.

Parasympathetic Nervous System

Calms body back to normal.

Homeostasis

Body’s balance; keeps conditions steady.

Endocrine System

Glands that release hormones into blood.

Hormone

Chemical messenger that travels in blood.

Pituitary Gland

“Master gland”; controls other glands and growth.

Thyroid

Controls metabolism, growth, and appetite.

Hyperthyroidism

Too much thyroid hormone; causes weight loss and agitation.

Hypothyroidism

Too little thyroid hormone; causes fatigue and feeling cold.

Adrenal Glands

Sit on kidneys; release stress hormones.

Pancreas

Controls blood sugar with insulin and glucagon.

Gonads

Ovaries/testes; make sex hormones.

Behavioral Endocrinology

Study of how hormones affect behavior.

Fight or Flight Response

Sympathetic system reaction to danger.