Unit 3- Biological Bases of Behavior

Nucleus

Nucleus

Contains genetic material for the cell

Cell Body (Soma)

Directs actions of the cell

Axon Hillock

Part of the Soma that connects to the axon

Dendrite

Enables neuron to receive information

Axon

Carry electrical signals out of the cells, send chemical messages to adjacent neurons via Axon/Terminals

Myelin Sheath

Insulates and protects Axons, helps speed neural impulses

Sensory Neurons

Bring stimuli in from other senses

Interneurons

Also called associative neurons, provide links between neurons

Motor Neurons

Send info onward to control muscles

Synapse

The gap between neurons where nerve impulses are relayed and neurons communicate by releasing neurotransmitters

Reuptake

The reabsorption of excess neurotransmitters by the neuron sending them out

Resting Potential

Neuron’s normal state

Threshold

Stimulation required to trigger depolarization

Depolarization

Message from another neuron causes inside of the neuron to allow positive sodium ions to flood an aon and open channels in the axon to send messages through

Action Potential

Neural Impulse- brief electrical charge that travels down an axon and is generated by movement of positively charged atoms in and out of channels in axon’s membrane

Refractory Period

Period of time where an axon cannot fire, neuron returns to resting potential

All-or-None Response

Neuron fires each time with the same intensity or not at all

Neurotransmitters

Chemical messengers which send signals between neurons

Excitatory Neurotransmitters

Stimulate the brain, excites the neuron and increases the likelihood of the neuron firing

Inhibitory Neurotransmitters

Calm and slow the brain, inhibits the neuron and decreases likelihood of the neuron firing

Acetylcholine

Excitatory neurotransmitter that is involved in voluntary muscle movement and processes such as memory, thinking, and learning.

• Excess- associated with depression

• Lack of- associated with demtia/alzheimer’s

Dopamine

Inhibitory and excitatory neurotransmitter that plays role in memory, movement, motivation, mood, attention, pleasurable reward, behavior, etc,

• Excess- associated with schizophrenia

• Lack of- associated with depression, tremors, rigid muscles

Endorphins

Inhibitory neurotransmitter that plays role in pain relief, pleasure, and sedation

GABA

Inhibitory neurotransmitter that plays role in calming anxiety and excitation

• Excess- associated with over relaxation and sedation

• Lack of- associated with anxiety

Glutamate

Excitatory neurotransmitter that plays role in memory and mood regulation, is the key excitatory neurotransmitter

• Excess- associated with Parkinson’s, Alzheimer's, and Huntington’s

• Lack of- can lead to psychosis, comas, or death

Norepinephrine

Excitatory neurotransmitter that plays role in alterness and arousal

• Excess- associated with schizophrenia

• Lack of- associated with depression

Serotonin

Inhibitory neurotransmitter that influences learning, memory, happiness, body temperature, sleep, hunger, and sexual behavior

• Excess- can lead to heart issues and confused mental state

• Lack of- associated with depression, anxiety, and obsessive-compulsive disorder (OCD)

Endocrine System

System of body, consists of glands that release hormons into the blood stream

Pituitary Gland

Called the master gland, controlled by the hypothalamus, is responsible for calling other glands into action, and releases hormons that control activity

HGH (Human Growth Hormone)

Influences height, helps build bones and muscle

ACTH

Produced in response to stress, triggers the production of cortisol in adrenal gland

Pineal Gland

Regulates awake/sleep cycle of circadium rhythm, secretes serotonin during the day and melatonin at night

Melatonin

Key hormone that plays a role in sleep to produce sleepiness

Thyroid Glands

Regulates metabolic rate by producing thyroxine

Parathyroid

Helps regulate the level of calcium in the blood

Adrenal Glands

Regulates the body during states of alarm, helps arouse the body and enables the body to cope with stressful physical/emotional situations

Pancreas

Regulates sugar metabolism by producing insulin, controls amount of glucose in your blood stream

Insuline

Controls the amount of glucose in the blood stream

Cortisol

Primary stress hormone, supresses the immune system

Adrenaline (Epinepherine)

Key hormone in the fight or flight response, increases heart rate, enlarges pupils, stops digestion, prepares blood to clot

Noradrenaline (Norepinephrine)

Key hormone in fight or flight response, increases heart rate AND blood pressure to provide energy to the body

Gonads

Regulate bodily development, reproduction, and sexual characteristics in men/women

Testosterone

Produced by testis, reason for male sex characteristics, sex drive, aggressiveness, and physical growth

Estrogen

Produced by ovaries, reason for female sex characterstics, regulates menstrual cycle and feelings of well-being

Central Nervous System

Consists of brain and spinal cord, responsible for spinal reflexes that are automatic and require no conscious effort (touching something hot and immediately pulling the hand away)

Peripheral Nervous System

Consists of cranial and spinal nerves, handles the CNS’s input and output

Sensory Nerves

Type of nerve responsible for carrying messages from receptors to brain

Motor Nerves

Type of nerve responsible for carrying messages from the central nervous system to muscles, glands, and internal organs

Somatic Nervous System

Branch of the peripheral nervous system that controls voluntary movements of skeletal muscles

Automatic Nervous System

Branch of the peripheral nervous system that controls functions of internal organs, has two branches

Parasympathetic Nervous System

Calms and relaxes the body, conserves the body’s energy, causes heart beat to slow, pupils to constrict/shrink, and airways to tighten

Sympathetic Nervous System

Mobilizes body for action, increases energy output, causes heart beat to quicken, pupils to dialte, and airways to open

Forebrain

Largest part of the brain, contains the thalamus, cerebrum, and limbic system

Thalamus

Relay station for transmitting sensory info to other parts of the brain

Cerebrum

Makes up 70% of brain weight, made up of the cerebral cortex and corpus callosum

Cerebral Cortex

Intricate fabric of wrinkles ridges/valleys covering 2 cerebral hemispheres, contains body’s control and information processing center

Corpus Callosum

Fibers that connect cerebral hemispheres, allows info to pass from left to right hemisphere

Limbic System

Contains the amygdala, hypothalamus, hippocampus, and pituitary gland

Amygdala

Linked to controlling aggression and fear

Hypothalamus

Maintainance center, controls body temp, hunger, thirst, and motivation

Hippocampus

Involved in process of memory (processing new memories)

Midbrain

Located between the forebrain and hindbrain, associated with hearing and vision

Reticular Activating System

Filters stimuli as it travels to the thalamus and relays it to other areas of the brain

Medulla

Part of the brain stem, controls breathing, heart beat, and blood circulation

Pons

Part of the brain stem, bridge that communicates sensory messages from cerebellum to cerebrum, controls movement, sleep, and alterness

Cerebellum

Located in the back of the brain, controls balance and muscle coordination

Brain Stem

Regulates vital cardiac and respitory functions, motor/sensory neurons travel through it and allow for relay of signals between the brain and spinal cord

Frontal lobe

Lobe located behind the forehead, the thinking and doing lobe: plays a role in decision making, cognition, judgement, and reasoning

Primary Motor Cortex

Key structure of the frontal lobe, involved with controlling and processing movements of the body

Broca’s Area

Key structure of frontal lobe, left sid of the brain, enables speech production

Parietal Lobe

Top to rear head, the feeling lobe, plays roles in senses and sensations and processing sensory information

Primary Sensory Cortex

Key structure of the parietal lobe, is responsible for processing tactile information

Temporal Lobe

Located behind the ears/temples on both sides of the brain, the listening and remembering lobe, plays roles in processing auditory information, encoding memory, and language comprehension

Primary Auditory Cortex

Key structire of the temporal lobe, responsible for hearing

Primary Olfactory Cortex

Key structure of the temporal lobe, interprets sense of smell

Wernicke’s Area

Key structure of the temporal lobe, back left side, responsible for speech comprehension

Occipital Lobe

Located in the back of the head, the seeing lobe, plays roles in processing/integrating/interpreting visual stimuli

Primary Visual Cortex

Key structure of occipital lobe, responsible for sight, recognition of size, color, light, motion, and dimensions

Brain Plasticity

Brain’s ability to change by reorganizing after damage or by building new neural pathways based on experience/knowledge

Brain Lateralization

How some neural functions/cognitive processes tend to be more dominant in one hemisphere than the other

Right Brain

Hemisphere of the brain related to creativity, intuitive thoughts, emotional thoughts, impulse, adventure, and left field vision and motor skills

Left Brain

Hemisphere of the brain related to analytical thought, rational thought, planning, logic, and right field vision and motor skills

Split brain

A condition resulting from surgery in which the two hemispheres of the brain are separated by cutting the corpus collosum

Corpus Collosum

Band of neural fibers that connect the two hemispheres of the brain

EEG

Amplified recording of the electrical waves measured by electrodes placed on the head, shows brain waves in various states

CT Scan

Several x-ray cameras rotate around the brain and combine images into a 3D picture, allows for seeing the structures of the brain in order to see brain damage. does NOT show function or activity

PET Scan

Radioactive glucose inserted into the brain through the blood stream to allow for seeing brain activity during tasks, measures the amount of a chemical various parts of the brain are using

MRI Scan

Magnetic fields and radio waves create detailed images to allow us to see soft tissues of the brain structures, measures density and location

fMRI

MRI that takes successive pics second by second that can be compared, shows brain activity AND functions during cognitive tasks

Duel Processing

Brain’s ability to process info simultaneously on the conscious and unconscious level

Psychoactive Drugs

Chemical substances that alter perceptions and mood, effect the brain synapses by inhibiting, stimulating, or mimicking neurotransmitters

Agnostic Drug

Type of psychoactive drug that MIMICS neurotransmitters

Antagonist Drug

Type of drug that BLOCKS neurotransmitters

Tolerance

Diminishing effect of a drug on an individual over time, results in needing to make more of a substance to produce the same effect

Addiction Disorder

Compulsive patters of drug use associated with physical and psychological dependence

Physical Dependence

Changes in normal body function when a person is not using

Psychological Dependence

mental and emotional changes experienced when a person is not using

Withdrawal

Negative symptons of discomfort/stress that follows discontinued drug use

Depressents

Category of psychoactive drugs, SLOW function/activity of nervous system, cause impared reflexes, lowered inhibitions, drowsiness, reduced tension (alcohol, barbituates, opiates)

Stimulants

Category of psychoactive drugs, increase function/activity of nervous system, cause dialated pupils, diminished appetite, increased energy, and increased heart/breathing rate (cocaine, meth, ecstasy)