AP Psych Unit 3 modules 9 - 11

Biological psychology

scientific study of the links between biological (genetic, neural, hormonal) and psychological processes

Neuron

a nerve cell, the basic building block (unit) of the nervous system

Dendrites

a neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell body

Axon

the neuron extension that passes messages through its branches to other neurons or muscles or glands

Myelin sheath

a layer of fatty tissue segmentally encasing the axons of some neuron

Action potential

a neural impulse; a brief electrical charge that travels down an axon

Refractory Period

a period of inactivity after a neuron has fired

Threshold

a level of stimulation required to trigger a neural impulse (excitatory versus inhibitory)

All or none response

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

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse

Reuptake

a neurotransmitter’s reabsorption by the sending neuron

Agonist

a molecule that, by binding to a receptor site, stimulates a response

Antagonists

a molecule that, by binding to a receptor site, inhibits or blocks a response

Nervous System

the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

Central Nervous System (CNS)

the brain and spinal cord

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

Nerves

bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs

Sensory neurons

(inbound) neurons that carry incoming information from the sensory receptors to the brain and spinal cord

motor neurons

(outbound) neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

Somatic Nervous System

the division of the peripheral nervous system that controls the body’s skeletal muscles (AKA skeletal nervous system)

Autonomic Nervous System

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (ex. heart). Its sympathetic division arouses; its parasympathetic division calms.

sympathetic nervous system

the division of ANS that arouses the body, mobilizing its energy in stressful situations.

Parasympathetic nervous system

the division of ANS that calms the body, conserving its energy

Reflexes

a simple, autonomic response to a sensory stimulus such as the knee-jerk response

Endocrine system

the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream.

Hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.

Adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress

Pituitary gland

the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands

CT (Computed Tomography) scan

a series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure (AKA CAT scan)

PET (Positron Emission Tomography) scan

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

MRI (Magnetic Resonance Imaging)

a technique that used magnetic fields and radio waves to produce computer-generated images of soft tissue

fMRI (Functional MRI)

a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans

brainstem

the oldest part of central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.

pons

responsible for movement and functions during sleep

Medulla

the base of the brainstem; controls heartbeat and breathing.

Thalamus

the brain’s sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla, All the senses EXCEPT smell

Reticular formation

a nerve network that travels through the brainstem and thalamus and plays an important role in controlling arousal

Cerebellum

the “little brain” at the rear of the brainstem

Limbic System

doughnut-shaped neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres
associated with emotions and drives

Amygdala

two lima-bean sized neural clusters in the limbic system
linked to emotion (aggression and fear)

Hypothalamus

a neural structure lying below (hypo) the thalamus, eating, drinking, emotion and reward