Biological Basis of Psychology (Unit 2, Part 1)

Neuron

transmits and receives information from all over the body; there are over 100 billion in the brain; is the smallest unit in the nervous system

Dendrites

look like leafless tree branches; receive messages from terminal buttons

Axon

the shaft that transfers the electrical message across the neuron

Cell body

the cell’s (neuron’s) life-support center

Myelin sheath

covers the axon and helps transfer messages efficiently; looks like a sausage link

Glial cells

nourish and protect the neuron

Terminal buttons

transfer the neurotransmitters from the axon terminals to the dendrites of another neuron

Synapse

created by the terminal button of one neuron, the synaptic gap, and the dendrite of another neuron

Synaptic gap

the space between the terminal button of one neuron and the dendrite of another

Postsynaptic neuron

the neuron that transfers the neurotransmitters to another neuron

Presynaptic neuron

the neuron that receives the neurotransmitters from another neuron

Neural Transmission

The process of transferring information between neurons via neurotransmitters

All-or-none law

law that states a neuron must fire all the way through or not at all

Graded potential

shifting of positive and negative ions only in one part of a neuron so it won’t fire

Resting potential

when there is an electrical charge all across the neuron; the outside is positive and the inside is negative

Polarization

when the neuron is at rest; is the same as resting potential

Action potential

when the positive ions on the outside rush into the neuron and the negative ions rush out

Depolarization

when the neuron fires; is the same as action potential

Threshold

the level an electrical impulse must exceed for a neuron to fire

Absolute Refractory period

immediately after firing, the neuron cannot fire again; lasts a few thousandths of a second

Relative Refractory period

neuron can fire only if the incoming message is stronger than normal

Reuptake

when the sending neuron reabsorbs the neurotransmitters that were sent

Neurotransmitters

endogenous chemicals that allow neurons to communicate with each other throughout the body

Inhibitory neurotransmitter

inhibits the next neuron from firing

Excitatory neurotransmitter

excite the next cell into firing

Endorphins

inhibit the transmission of pain messages; the body’s natural morphine; oversupply of opiates reduces the body’s natural production

Serotonin

Chemical that regulates mood, sleep, hunger, and arousal; also called the “happy chemical;” low levels is associated with depression and anxiety

Dopamine

controls voluntary movements, learning, attention and emotions; is the body’s “reward” neurotransmitter; oversupply can lead to schizophrenia; undersupply can lead to Parkinson’s disease with decreased mobility and tremors

Acetylcholine (ACh)

regulation of muscle action, attention, learning, and memory; producing neurons deteriorate with Alzheimer’s disease

Norepinephrine

Chemical that controls alertness and arousal; is released during the flight or fight response; undersupply can depress mood

Glutamate

widely distributed excitatory neurotransmitter; involved in memory; is the energy source for neurons; oversupply is linked with migraines and seizures

GABA

widely distributed inhibitory neurotransmitter; contributes to the regulation of anxiety, sleep, and arousal; undersupply is linked with seizures, tremors, and insomnia

Substance P

Chemical responsible for the regulation of pain transmission; is released in response to injury

Multiple sclerosis

autoimmune disorder causing immune system to attack the myelin sheath; characterized by numbness, speech impairment, and motor coordination issues

Myasthenia Gravis

autoimmune disorder causing weakness of voluntary muscles; destroys the connection between muscles and neurons

Psychoactive Drugs

substances that, when taken in or administered into one's system, affect mental processes, e.g. perception, consciousness, cognition or mood and emotions

Agonist

psychoactive drug that increases a neurotransmitter’s action

Antagonist

psychoactive drug that blocks a neurotransmitter’s action

Reuptake Inhibitor

psychoactive drug that blocks reabsorption of a neurotransmitter by a presynaptic neuron

Nervous system

the body's complex communication network, made of nerves and nerve cells (neurons), that transmits signals between the brain, spinal cord, and the rest of the body to control thought, movement, sensation, and involuntary bodily functions

Central Nervous System (CNS)

nervous system made up of the brain and spinal cord

Peripheral Nervous System

the part of your nervous system that lies outside your brain and spinal cord; made up of the somatic and autonomic systems

Somatic nervous system

the division of the peripheral nervous system responsible for processing sensory information and controlling voluntary movements

Autonomic nervous system

part of the peripheral nervous system that controls involuntary bodily functions like heart rate, digestion, and breathing; also controls the “fight or flight” response

Sympathetic nervous system

arouses the body; engages the “fight, flight, or freeze” response

Parasympathetic nervous system

calms the body

Nerves

bundled axons on many neurons connecting the CNS with the muscles, glands, and sense organs

Sensory (afferent) neurons

carry messages from the sense organs to the CNS

Motor (efferent) neurons

carry motor messages from the CNS to the muscles and glands

Interneurons

Transmit messages between neurons in the nervous system

Reflex Arc

the neural pathway responsible for rapid, involuntary, and protective responses to harmful or surprising stimuli

Endocrine system

set of glands that secrete hormones into the blood stream

Pituitary gland

controls growth, metabolism, and reproduction

Hormones

chemical messengers produced by glands in the endocrine system that regulate various bodily functions; travel slower than neurotransmitters

Adrenaline (hormone)

responsible for quick reactions (fight or flight)

Oxytocin (hormone)

the “love hormone;” plays a role in childbirth and physical attraction

Thyroid gland

affects metabolism

Adrenal gland

secretes adrenaline; helps trigger flight or fight response

Testis

secrete male sex hormones

Ovaries

secrete female sex hormones

Pancreas

regulates blood sugar

Parathyroids

help regulate the level or calcium in the blood

Central core

controls the “automatic” parts of our bodies; also called the brain stem

Medulla

part of the central core that controls breathing, heartrate, and blood pressure

Pons

part of the central core that controls the sleep cycle

Cerebellum

part of the central core that controls balance and coordination of the body’s movements

Reticular formation

part of the central core that controls arousal and attention; if damaged, could result in a coma

Midbrain

part of the central core that registers pain and other sensory information; connects the spinal cord to the brain

Parts of the central core

medulla, pons, cerebellum, reticular formation, and the midbrain

Limbic system

part of the brain that controls learning, motivation, and emotions

Thalamus

the relay station for all senses EXCEPT smell

Amygdala

part of the limbic system that controls self preservation emotions; processes fear and anxiety

Hypothalamus

part of the limbic system that controls sexual desires, hunger, and thirst; also regulates emotions and body temperature

Hippocampus

part of the limbic system that facilitates new memory formation

Parts of the limbic system

thalamus, amygdala, hypothalamus, and hippocampus

Cerebral Cortex

part of the brain that controls higher mental processes

Lobes in the cerebral cortex

frontal lobe, parietal lobe, occipital lobe, and temporal lobe

Frontal lobe

part of the cerebral cortex that is the executive center; controls judgement and decision making; involved in speaking, emotional control, and personality; contains the motor and prefrontal cortex

Parietal lobe

part of the cerebral cortex that receives and processes sensory input for body position and touch; controls spatial abilities; contains the somatosensory cortex

Temporal lobe

part of the cerebral cortex that is responsible for hearing and complex visual tasks; contains the auditory cortex

Occipital lobe

part of the cerebral cortex that is involved in visual processing; contains the visual cortex

Prefrontal cortex

part of the frontal lobe involved in impulse control

Motor cortex

part of the frontal lobe that controls voluntary movements

Somatosensory cortex

processes sensory information from the sensory organs

Auditory cortex

part of the temporal lobe that receives information from the ears

Visual cortex

part of the occipital lobe that receives information from the eyes; if damaged, results in blindsight

Association areas

areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking

Broca’s area

area in the left frontal lobe that controls speech

Wernicke’s area

area in the left temporal lobe that controls language comprehension

Corpus callosum

thick band of nerve fibers that connects the left and right hemispheres; coordinates the activities of the hemispheres

Split brain research

studies that examine the effects of a split brain surgery in which the corpus callosum is severed to reduce major epileptic seizures; examines the difference functions of the left and right hemispheres and how we express those functions

Phineas Gage Case study

study of Phineas Gage and the effects of damaging the frontal lobe; explored changes in personality, emotion expression, and impulsivity

Blindsight

A neurological condition where someone can perceive the location of an object despite being cortically blind; the unconscious brain can perceive an object and its location

Brain/Neural plasticity

the brain’s ability to change due to experiences; the brain’s ability to compensate due to tissue loss from injury or disease

Lesion

the destruction or deterioration of brain cells; can be purposeful or not

EEG (electroencephalogram)

a medical test that measures electrical activity in the brain; measures brain wave activities; can investigate sleep patterns

fMRI (functional magnetic resonance imaging)

a medical imaging technique that measures brain activity by detecting changes in blood flow and oxygenation; detects changes in neural activity such as motor, sensory, and cognitive tasks

Heredity

the passing of genetic traits from parents to offspring, which influences an individual's physical, mental, and behavioral characteristics

Identical (monozygotic) twins

develop from a single fertilized egg that splits in two, creating two genetically identical organisms

Fraternal (dizygotic) twins

develop from separate fertilized eggs; are genetically no closer than ordinary siblings, but share a prenatal environment