Biological Basis of Behavior

Parts of the Brain Parts of the Brain Cells Different Brain Scans Chemicals in the Brain Sympathetic vs Parasympathetic

Dendrite

Receives information and brings it to the cell body

Axon

Passes messages through the terminal branches, away from the cell body

Terminal Branches

Form junctions with other cells

Myelin Sheath

Covers the axon and helps speed up impulses

Neural Impulse

Signal traveling through the axon (action potential)

Glial Cells

Support cells

Threshold

the level of stimulation needed to trigger a neural impulse

Refractory Period

Resting time after a impulse has fired

Synapse

The junction between two neurons

Neurotransmitters

Chemical messengers that travel between synapse of neurons

Reuptake

neurotransmitter’s reabsorption by the sending neuron

ACh

enables muscle action, learning, and memory

Dopamine

influences movement, learning, emotion, and attention

Serotonin

Affects mood, hunger, sleep, and arousal

Norepinephrine

Controls alertness and arousal

GABA

Major inhibitory neurotransmitter

Glutamate

Major excitatory neurotransmitter, involved with memory

Endorphins

Influence perception of pain or pleasure

Agonist

A molecule that increases a neurotransmitters action

Antagonist

A molecule that inhibits a neurotransmitters action

CNS (central nervous system)

brain and spinal cord

PNS (peripheral nervous system)

gathers info and transmits CNS decisions to other body parts

Sensory Neurons

Carries incoming info to the spinal cord/brain

Motor Neurons

Carries outgoing info to the body

Interneurons

Neurons within the brain/spinal cord that communicate and process info between the sensory and motor neurons

Somatic Nervous System

Voluntary control over muscles

Automatic Nervous System

Controls glands and internal organs

Sympathetic Nervous System

Fight or flight

Parasympathetic Nervous System

Calms the body, conserves energy

Adrenal Glands

Secretes norepinephrine and epinephrine to trigger fight or flight

Pituitary Gland

Controls growth and other glands

Thyroid Gland

Controls metabolism

EEG Scan

Measures electrical activity in neurons

MEG Scan

records magnetic fields from the brains natural electrical currents

CT Scan

X-rays of the head that can locate brain damage

PET

radioactive form of glucose goes into the brain, and the patient performs a task

MRI Scan

Uses radio waves to provide a map of the brain structure

fMRI Scan

Measures blood flow to brain regions by comparing MRI scans

Medulla

Controls heartbeat and breathing

Thalamus

Receives info from the senses and reroutes it to higher brain regions

Reticular Formation

Filters stimuli and relays important info to other parts of the brain

Pons

Coordinates movements and controls sleep

Frontal Lobe

Controls speaking, muscle movements, planning and judgement

Parietal Lobe

Receives sensory input for touch and body position

Occipital Lobe

Receives info from visual fields

Hippocampus

Processes consciousness and memories

Amygdala

Controls aggression, fear, emotion

Hypothalamus

Maintains homeostasis

Temporal Lobe

Receives info from auditory areas

Motor Cortex

Controls the body

Sensory Cortex

Receives input from the body

Broca’s Area

Speech production (Language comprehension, ability to speak words)

Sex Organs (parasympathetic)

Allows blood flow

Sex Organs (sympathetic)

Stimulates ejaculation in males

Bladder (parasympathetic)

Contracts bladder

Bladder (sympathetic)

Relaxes bladder

Kidney/Adrenal Gland (sympathetic)

stimulates secretion of epinephrine/norepinephrine

Liver (parasympathetic)

Stimulates gallbladder

Liver (sympathetic)

Stimulates glucose release by liver

Stomach (parasympathetic)

Stimulates digestion

Stomach (sympathetic)

Inhibits digestion

Heart (parasympathetic)

Slows heartbeat

Heart (sympathetic)

Accelerates heartbeat

Eyes (parasympathetic)

Contracts pupils

Eyes (sympathetic)

Dilates pupils

Corpus Callosum

Neural fibers connecting the two hemispheres and sending messages between them

Blindsight

Someone responds to a visual stimulus without consciously experiencing it

Parallel Processing

The brain’s natural way of processing information

Sequential Processing

Solving one problem at a time

Wernicke’s Area

Speech production (understanding the meaning of words)