Biological bases - Unit 5

biological psychologists

scientific study of the links between biological and psychological processes.

neurons

A nerve cell; the basic building block of the nervous system.

soma (cell body)

contains the neuron's nucleus and mitochondria

Node of Ranvier

The unmyelinated section of neuron where the electrochemical process that permits an action potential occurs

Schwann Cell

a specialized glial cell that maintains the myelin sheath

dendrite

A neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body.

axon

A long, thin fiber that transmits signals away from the neuron cell body to other neurons, or to muscles or glands.

myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

multiple sclerosis

communication to muscles slows with eventual loss of muscle control when sheath degenerates

action potential

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

resting potential

The difference in electric charge between the inside and outside of a neuron's cell membrane. positive outside, negative inside

refractory period

a period of inactivity after a neuron has fired

excitatory signal

signals that push a neurons accelerator

inhibitory signal

signals that stop and push the brake

threshold

the level of stimulation required to trigger a neural response

all-or-nothing response

a neurons reaction of either firing with full strength or not firing at all

synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. tiny gap is the synaptic gap

neurotransmitters

chemical messengers that cross the synaptic gaps between neurons, when released by the sending neurons, they travel across the synapse and bind to receptor sites on the receiving neuron, influence neural impulse

vesicle

holds neurotransmitters in the terminal buttons waiting for use

reuptake

a neurotransmitters reabsorption by sending neuron
-ex: sponge reabsorbing water

agonist

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

antagonist

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

curare

an antagonist for ACh - causes paralysis

peyote

an agonist for serotonin - causes euphoria and hallucinations

alcohol

an indirect GABA agonist - causes neurons to slow, causing slowed cognition and motor activity

SSRIs

AKA selective serotonin reuptake inhibitors - traps serotonin in the synapse by blocking its reuptake, causing it to work harder

acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction

A neurotransmitter that enables learning and memory and also triggers muscle contraction

dopamine

influences movement, learning, attention, and emotion

influences movement, learning, attention, and emotion

serotonin

Affects mood, hunger, sleep, and arousal

Affects mood, hunger, sleep, and arousal

norepinephrine

helps control alertness and arousel

helps control alertness and arousel

GABA

A major inhibitory neurotransmitter. Undersupply linked to seizures, tremors, and insomnia

A major inhibitory neurotransmitter. Undersupply linked to seizures, tremors, and insomnia

endorphins

the body's naturally made painkillers - causes dulled pain sensation and mild euphoria upon release (e.g. "Runner's High")

Schizophrenia

A psychotic disorder causes by too much dopamine

Depression

A mood disorder that occurs due to too little serotonin

Parkinson's Disease

A movement disorder characterized by shaking, caused by too little dopamine

Alzheimer's Disease

A memory disorder that occurs in elderly patients, caused by too little ACh

nervous system

the bodes speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous system

central nervous system

the brain and spinal cord

peripheral nervous system

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

sensory neurons (afferent)

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

motor neurons (efferent)

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

reflex

a "short" circuit between afferent, inter-, and efferent neurons that permit rapid responses to aversive stimuli below conscious awareness

somatic nervous system

the division of the peripheral nervous system that controls the bodes skeletal muscles
also called skeletal nervous system

autonomic nervous system

the part of the peripheral nervous system that controls the glands and muscles of the internal organs (heart)

sympathetic nervous system

the division of the autonomic system that arouses the body mobilizing its energy in stressful situations

parasympathetic nervous system

the division of the autonomic nervous system that calms the body conserving its energy

endocrine system

the bodes "slow" chemical communication system
a set of glands that secrete hormones into the blood stream

hormones

chemical messengers that are manufactured by the endocrine glands that travel through the bloodstream and effect other issues

lateral hypothalamus

controls hunger - produces orexin under presence of ghrelin to create the psychological drive to eat

ventromedial hypothalamus

controls satiation - makes you feel full when it detects leptin and glucose by inhibiting the lateral hypothalamus

adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones
-ex: epinephrine, norepinephrine, controls fight or flight response

pituitary gland

the endocrine systems most influential gland
under influence of the hypothalamus
regulates growth and controls other endocrine glands

parathyroids

maintain calcium levels

thyroid

regulates metabolism

testes

produce testosterone to regulate male reproductive drive, aggression, and secondary male sexual characteristics

ovaries

produce estrogen to regulate female reproductive cycle

oxytocin

the cuddle chemical - facilitates social bonding

ghrelin

produced by empty stomachs to tell the hypothalamus you're hungry

electroencephalogram (EEG)

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.

suprachiasmatic nucleus

a region of the hypothalamus that measures levels of light and, when it is day, inhibits the pineal gland

pineal gland

produces melatonin at night in order to order to make you sleepy

Circadian Rhythm

the body's approximately 24 hour cycle of alertness and sleep

computed topography scan (CT)

a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a site of the brains structure

position emission tomography scan (PET)

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task, shows where brain is most active during task

magnetic resonance imaging (MRI)

a technique that uses magnetic fields and radio waves to produce computer generated images of soft tissue, show brain anatomy

functional MRI (FMRI)

a technique for revealing blood flow and therefore, brain activity by comparing MRI scans

medulla

the base of the brainstem

controls heartbeat and breathing

pons

helps coordinate movement and dreaming

thalamus

the brains sensory control center, located on the 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