AP Psyche Biological Bases of Behavior

Dendrite

Neuron’s branching extensions receiving and integrating messages, conducting impulses toward the cell body

Axon

neuron extension passing messages through its branches to other neurons or to muscles and glands

Myelin Sheath

a fatty tissue layer segmentally encasing axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next (ex. Muscle communication)

Glial Cells

Cells in the nervous system that support, nourish, and protect neurons; play a role in learning, thinking, and memory

Our brains are more ___ but have ___ reaction times than computers

complex; slower

Threshold

Level of stimulation required to trigger a neural impulse

Refractory Period

Brief resting pause occurring after a neuron has fired; subsequent action potential can’t occur until the axon returns to its resting state

all-or-none response

neuron’s reaction of either firing with a full strength response or not firing at all (like a gun)

Strong stimulus can cause ___ but doesn’t change the ___ of the action potential

more neurons to fire more often; strength/speed

Synapse

Junction between axon tip of the sending neuron and dendrite/cell body of the receiving neuron; tiny gap at junction is called the synaptic gap/cleft

Neurotransmitters

chemical messengers crossing synaptic gaps between neurons across the synapse and bind to receptors on the receiving neuron

Reuptake

neurotransmitter’s reabsorption by the sending neuron after a signal is received

The inside of an axon is ____ charged while the outside is ___ charged

Negatively (K+); Positively (Na+)

Action potential in an axon is caused when ___ enters the axon after a neuron fires

Positive Ions (Na+)

Acetylcholine

Neurotransmitter that enables muscle action, learning, and memory

Dopamine

Neurotransmitter that influences movement, learning, attention, and emotion

Serotonin

Neurotransmitter affecting mood, hunger, sleep, and arousal

Norepinephrine

Neurotransmitter that helps control alertness and arousal

GABA

Major inhibitory neurotransmitter

Glutamate

Major excitatory neurotransmitter; involved in memory

Endorphins

Perception of pain or pleasure

Agonist

Molecule increasing a neurotransmitter’s action

Antagonists

molecule inhibiting neurotransmitter’s action

Central Nervous System (CNS)

Made of the brain and spinal cord

Nervous system

Made of the peripheral and central nervous systems

Peripheral nervous system (PNS)

Sensory and motor neurons connecting the CNS to the rest of the body through veins and nerves

Nerves

Bundled axons forming neural cables between CNS, muscles, glands, and sense organs

Sensory neurons

Carry info INTO the CNS from tissues and sensory receptors

Motor neurons

Carry info OUT of the CNS to muscles and glands

Interneurons

Neurons within CNS communicating internally and processing info between sensory inputs and motor outputs

Somatic Nervous System

Division of the PNS controlling voluntary movement within skeletal muscles

Autonomic Nervous System (ANS)

Division of PNS controlling involuntary movement through glands and muscles of internal organs

Sympathetic Nervous System

Division of ANS that arouses and mobilizes energy

Parasympathetic Nervous System

Division of ANS that calms and conserves energy

Endocrine System

Body’s “slow” but longer lasting chemical communication system; glands secrete hormones into the bloodstream

Hormones

Chemical messengers affecting tissues

Adrenal Glands

Pair of endocrine glands sitting above kidney that secrete epinephrine and norepinephrine that arouse body in times of stress

Pituitary gland

Major endocrine gland; influenced by the hypothalamus; regulates growth and other endocrine glands

Lesion

Tissue destruction

EEG

Amplified recording of the waves of electrical activity sweeping across the brain’s surface, measured by electrodes placed on the scalp

MEG

Brain imaging technique measuring magnetic fields from the brain’s natural electrical activity

CT/CAT scan

Uses X-rays taken from different angles and combined by the computer into a composite representation of a slice of the brain’s structure

PET Scan

visual display of brain activity detecting where a radioactive form of glucose goes while the brain performs a given task

MRI

Technique using magnetic fields and radio waves to produce computer-generated images of soft-tissue; show brain anatomy

fMRI

reveals blood flow and brain activity by comparing successive MRI scans; show brain function and structure

Brainstem

oldest and central core of brain; begins where spinal core swells entering the skull; responsible for automatic survival functions; made of medulla and Pons

Medulla

Base of the brainstem; controls heartbeat and breathing

Thalamus

Sensory control center on top of the brainstem; directs messages to sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

Reticular formation

nerve network traveling through brainstem into thalamus and plays an important role in controlling arousal; filters incoming stimuli to thalamus and relays important info to other brain areas

Cerebellum

“Little brain” at the rear of the brainstem'; controls processing sensory input, movement coordination output, balance, and nonverbal learning and memory

Limbic system

Includes amygdala, hypothalamus, and hippocampus; located below cerebral hemispheres associated with emotions and drives

Amygdala

2 lima-sized clusters in limbic system linked to emotions like fear, anger, and aggression

Hypothalamus

Lies below the thalamus; directs several maintenance activities (eating, drinking, body temperature), helps govern endocrine system via pituitary gland, and linked to emotion and reward

Hippocampus

Part of limbic system; helps process/store explicit (conscious) memories of facts and events

Cerebral Cortex

Intricate interconnected neural cells covering the cerebral hemispheres; body’s ultimate control and information-processing center

Left Hemisphere of Brain Controls ___

Right side of body, language (for most people), reasoning, number skills, and scientific skills

Right Hemisphere of brain controls ___

Left side of body, insight, 3-D forms, art, visualization

Neuroplasticity

Brain’s ability to self regulate and change itself

Frontal Lobes

Portion of cerebral cortex lying behind forehead; involved in speaking, muscle movements, and making plans or judgements

Parietal Lobes

Portion of cerebral cortex lying on top-rear end of head; recieves sensory input for touch and body position

Occipital Lobes

portion of cerebral cortex lying at back of head; includes areas receiving info from the visual fields

Temporal Lobes

Portion of cerebral cortex roughly above the ears; includes auditory areas

Motor Cortex

Area of the rear part of frontal lobes controlling involuntary movement

Somatosensory Cortex

Area at front of parietal lobes registering/processing body touch and movement sensations

Association areas

Areas of cerebral cortex not involved in primary motor/sensory function and instead higher mental functions (learning, remembering, thinking, and speaking) found in all 4 lobes

Neurogenesis

Formation of new neurons

Multiple sclerosis

disorder caused by degeneration of myelin sheaths, creating lesions and disrupts signals throughout the rest of the body

Corpus Callosum

Large band of neural fibers connecting 2 brain hemispheres and carrying messages between them

Split brains

condition following surgery that isolates the 2 hemispheres by cutting fibers of Corpus Callosum (mainly) between them

Dual Processing

principle that info is often simultaneously processed on separate concious and unconcious tracks

Blindsight

condition where one can respond/act off of visual stimulus without consciously experiencing it

Parallel processing

Processing many aspects of a problem simultaneously; brain’s natural mode of information processing for many functions

Sequential processing

Processing one aspect of a problem at a time; generally to process new info or solve difficult problems

Heritablitity

proportion of variation among individuals attributable to genes; the heritability of a trait may vary depending on the range of populations and environments studies

Epigenetics

Studies how environmental influences on gene expression occur without DNA Changes

Molecular genetics

subfield of biology studying molecular structure and function of genes

Molecular behavior genetics

studies how structure and function of genes interact with our environment to influence behavior

Pineal Body

Located in the Corpus Callosum; produces melatonin, which helps the body know when to sleep

Thyroid gland

Located in front of the neck; plays an important role in the body’s metabolism

Parathyroid glands

play an important role in regulating body’s calcium balance

Thymus

produces white blood cells to fight infections and destroy abnormal cells

Pancreas

Plays a role in digestion and hormone production of insulin and glucagon, which regulate blood sugar levels

Ovary

Produce female sex hormones like estrogen and progesterone

Testis

Produce male sex hormones like testosterone and sperm

Depolarization

Process of balancing out positive and negative ions in an axon following an action potential

Epinephrine

Also known as adrenaline produced by the adrenal glands in response to stress causing increased heart rate and boosted blood flow to muscles

Broca’s area

Part of the frontal lobe; controls speech production and language processing

Wernicke’s area

Part of Temporal Lobe; involved in understanding spoken and written language