Bio Bases

Central nervous system (CNS)

Consists of the brain and spinal cord; controls and processes information.

Hindbrain

The part of the brain that includes the medulla, pons, and cerebellum, controlling basic biological functions.

Medulla

Controls basic biological functions such as breathing, swallowing, and balance.

Pons

Controls facial expressions, sleep, and dreaming.

Cerebellum

Controls fine motor movements.

Midbrain

Coordinates basic movements with sensory information.

Forebrain

Large in humans; includes the cerebral cortex and subcortical structures such as the thalamus, hypothalamus, and basal ganglia.

Basal ganglia

Regulates muscle contractions/movements.

Thalamus

Incorporates and relays sensory information to the cortex.

Hypothalamus

Controls motivated behavior such as eating, drinking, and sex.

Hippocampus

Helps process and receive long-term and spatial memory.

Amygdala

Controls emotion and evaluation of stimuli.

Cerebral cortex

Receives sensory information and transmits motor information; consists of four lobes.

Occipital lobe

Processes vision.

Temporal lobe

Processes sound.

Parietal lobe

Integrates sensory systems and is involved in attention.

Frontal lobe

Controls speech, learning, thinking, decision-making, and abstract thought.

Peripheral nervous system

Includes all nerves spreading through the body from the brain and spinal cord; has somatic and automatic divisions.

Somatic division

Controls voluntary muscle movements and sense organs.

Automatic division

Controls involuntary actions and the internal organs, divided into sympathetic and parasympathetic divisions.

Sympathetic nervous system

Prepares the body for emergency action.

Parasympathetic nervous system

Becomes active during states of relaxation.

Neuron

The basic unit of the nervous system, composed of soma, dendrites, and axon.

Soma

The cell body of a neuron that stores energy.

Dendrite

Receives messages from other neurons and conducts them toward the soma.

Axon

Sends messages to other neurons.

Axon terminals

The end of the axon that contains neurotransmitters.

Myelin sheath

Insulates axons so signals can travel quickly.

Glial cell

Creates myelin, supports and guides neurons, and helps repair neurons.

Synapse

The small gap between neurons where information is exchanged.

Synaptic vesicles

Holds neurotransmitters until they are released into the synapse.

Neurotransmitters

Chemicals that stimulate neurons for communication.

Excitatory neurotransmitters

Make neurons more likely to fire.

Inhibitory neurotransmitters

Make neurons less likely to fire.

Excitation threshold

The voltage difference (-55 millivolts) necessary to trigger an action potential.

Action potential

The brief change in electrical charge that destabilizes a neuron, triggering a neuron to fire.

Endocrine system

Made up of hormone-secreting glands that affect internal communication.

Hormones

Chemicals that help regulate bodily functions, produced by glands.

Glands

Produce hormones and release them into the bloodstream.

Long-lasting effects

Hormones act more slowly than neurotransmitters but produce longer-lasting effects.