Unit 1: Biological Bases of Behavior

Source: AP Classroom Course Guide, Unit 1

Epigenetics

Enviroment can alter our genetics

Heritability

Amount of variation among individuals that we can attribute to

Somatic Nervous System

Voluntary Movements

Autonomic Nervous System

Involuntary Movements

Sympathetic Nervous System

NS that triggers Fight or Flight

Parasympathetic Nervous System

NS that triggers rest; parachute, slowing down the system

Main 3 parts of a Neuron

• cell body

• axons

• dendrites

Myelin Sheath

Protects and insulates the axons

Synaptic Gap

Neurotransmitters cross the gap and lock into the dendrite of the postsynaptic neuron

Glial Cells

Send and receive chemical signals to and from each other and to and from neurons

Sensory Neurons

Have Afferent signals that Arrive at the brain

Motor neurons

Have Efferent signals that Exit the brain

Firing Threshold

Min. to fire a neuron

All or None Law

Once at threshold, neuron will fire

Action Potential

An electrical impulse that travels down the axon

Refractory Period

Brief period where the neuron can’t fire again

Reuptake

Sending neuron recollects neurotransmitters

Excitatory

Makes the next neuron more likely to fire

Inhibitory

Makes the next neuron less likely to fire

Neurotransmitters

Chemical messangers of the nervous system

Psychoactive Drugs

Drugs that alter mental states

Depressants

• Slows CNS functions

• Creates drowsiness

• Relieves anxiety

Opiates/Opioids

Agonist for endorphines, incredibly addictive

Stimulates

• activates sympathetic NS

• Increases brain activity

• arouses behavior

• increases mental alterness

Hallucinogens

Creates sensory and perceptual distortions, alters mood, and affects thinking

Agonists

Enhances/Mimics the actions of neurotransmitters

Antagonists

A substance that prevents the function of a neurotransmitter

Medulla Functions

• heart rate

• breathing

• blood pressure

Medulla reflexes

• swallowing

• sneezing

• vomiting

Pons

• connects brainstem and cerebellum

• helps coordinate and integrat movement

Recticular Activating System (RAS)

A network of nerve fibers involved in attention, arousal, and alertness

Cerebellum

• Balance and eqilibrium

• Coordinated sequences of movement

• Implicit memory

Midbrain

Connects higher and lower portions of brain, relays info between brain, ears, and eyes

Limbic System

• Thalamus

• Hypothalamus

• Amygdala

• Hippocampus

Thalamus

receives and sorts sensory info, then sends it to the cortex for further interpretation

Hypothalamus

fight or flight, hunger, sex

Amygdala

anger, agression, fear response

Hippocampus

Processes and retrieves declarative memory

Brain lobes

Frontal, Parietal, Occipital, Temporal

Contralateral

Left hemisphere controls right side of body and vice versa

Frontal Lobe

Prefrontal Cortex, Motor Cortex

Prefrontal Cortex

• Involved in thinking, planning, decision-making, impulse control

• Massive reorginization from 18-25 yrs of age

• In Frontal Lobe

Motor Cortex

• involved in initiating voluntary movement

• Contralateral

• In Frontal Lobe

Parietal Lobe

sense of touch, contralateral

Occipital Lobe

How your brain processes visual input

Temporal Lobe

Processes auditory input

Broca’s Area

Area involved in expressive speech

Wernicke’s Area

Area involved in understanding language

Corpus Callosum

Connects the two hemisphers, allowing constant communication between them

Neuroplasticity

The ability for the brain to grow new connects and neurons; the ability for it to rewire itself

Neurogenisis

Creation of new cells

Long-Term Potentiation

When a network of neurons fires together repeatedly, that neural pathway becomes smoother and more efficient

Sleep Cycle

1. NREM 1

2. NREM 2

3. NREM 3

4. REM

Restoration Theory of Sleep

Body repairs and reenergizes when asleep

Memory Consolidation Theory

Sleep restores and consolidates memory from throughout the day

Energy Conservation Theory

Sleep keeps us from danger

Freud’s Dream Theory

Dreams are the road to the unconscious mind

Biological & INformation Processing Theories

Dreams are your brain trying to sort out what happened during the day

Insomnia

most common sleep disorder, where you can’t sleep

Narcolepsy

Involves sudden sleep attacks

Sleep Apnea

Breathing stops intermittently throughout the night

Night Terrors

Intense fear during NREM sleep

Somnambulism

Sleep Walking

Bruxism

Involuntary teeth grinding during sleep

Sclera

White part of eye; shell

Cornea

Front of eye

Lens

Clear, flexible “M&M” that bends depending on the distance of the object you are looking at

Iris

Color part of the eye

Pupil

Light Hole

Retina

Rods, black & white, peripheral

Fovea

Center, Cones, Color

Blind Spot

Area where the optic nerve enters the eye

Trichromatic Theory

Sensation - Color is objectively observes and measured

Opponenet Processing Theory

Perception - nobody can independently measure what color another person pperceives

Ear Drum

Tympanic Membrane

3 Bones in the Ear

1. Malleus

2. Incus

3. Stapes

Cochlea

size of a pea, filled with fluid

Corti

Membrane with tiny hairs sticking out of it

Cilia

The tiny hairs on the organ of Corti

Place Theory

When a wave of cochlear fluid crashes on the corti, cilia are stimulated

Frequency Theory

Frequency of neural signals tells the brain which pitch to interpret

Auditory Disparity

Difference in volume and arrival times

Smell

Olfaction

Taste

Gustation

Papilla

Bumps on tongue

Taste Buds

Found on papilla

Feedback Loop

1. Body gives the brain info

2. Brain tells body info

3. Body adjusts according to info from brain

Kinesthetic Awareness

awareness of how your body moves

Vestibular System

Sense of Balance

Gate Control Theory of Pain

limits how much pain you can feel at a time