Unit 2 AP Psych 75-119

Biological psychology

The scientific study of the links between biological and psychological processes

neuron

a specialized cell transmitting nerve impulses that consists of a cell body, dendrites, axon, and terminal branches of the axon.

dendrites

branching extensions at the cell body. Receive messages from other neurons.

axon

long single extension of a neuron, covered with myelin sheath to insulate and speed up messages through neurons.

myelin sheath

covers the axon of some neurons and helps speed neural impulses

action potential

the actual action of the message being sent

refractory period

a period of inactivity after a neuron has fired

threshold

The amount of stimulation or neurotransmitters required to register that a message needs to be sent

all-or-none response

the neuron either fires or it doesn't; there is no in between

synapse

A junction where information is transmitted from one neuron to the next.

neurotransmitters

Chemicals released from the sending neuron that travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing it to generate an action potential.

reuptake

excess neurotransmitters in the synapse are reabsorbed into the sending neurons through the process of reuptake.

endorphins

A group of hormones secreted within the brain and nervous system and having a number of physiological functions which activate the body's opiate receptors.

agonist

mimics neurotransmitters, opening receptor site

antagonist

blocks neurotransmitter from opening receptor site

nervous system

the network of nerve cells and fibers that transmits nerve impulses between parts of the body to produce different functions

central nervous system

Controls most functions of the body and mind. It consists of two parts: the brain and the spinal cord.

peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body

nerves

a bundle of fibers that receives and sends messages between the body and the brain

sensory neurons

carry impulses from the sense organs to the spinal cord and brain

motor neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands to commit certain functions

interneurons

neurons that are found exclusively in the central nervous system

somatic nervous system

The division of the peripheral nervous system that controls the body's skeletal muscles

autonomic nervous system

part of the PNS that controls the glands and other muscles, such as the heart

sympathetic nervous system

division of the ANS that arouses the body, mobilizing its energy in stressful situations (fight or flight)

parasympathetic nervous system

division of the ANS that calms the body, conserving its energy (rest and digest)

reflex

A simple, automatic, inborn 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

chemicals synthesized by the endocrine glands that are secreted in the bloodstream. They affect the brain and many other tissues of the body

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 "master gland" which releases hormones that influence growth and its secretions also influence the release of hormones by other endocrine glands.

lesion

tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue

EEG

electroencephalogram; an amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp

CT scan

computed tomography scan (x-ray images in cross-sectional view)

PET scan

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, uses strong magnets and radio waves to form images of body

fMRI

functional MRI

brainstem

The oldest part and central core of the brain, responsible for automatic survival functions.

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

reticular formation

a nerve network in the brainstem that plays an important role in controlling arousal

cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance

limbic system

neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.

amygdala

Involved in memory and emotion, particularly fear and aggression.

hypothalamus

a neural structure lying below the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion