Unit 1: Brain

Nature vs. Nurture

name for a controversy over relative contributions that genes or experience is responsible the development of psychological traits and behaviors

Epigenetics

environment can trigger or block genetic expression

Twin studies

research utilizing twins to assess the relative contributions of heredity and environment

central nervous system

in brain and spinal cord, body's decision maker

peripheral nervous system

contains sensory and motor neurons that connects CNS to the rest of the body and gathers information and transmitts CNS decisions to other body parts

somatic nervous system

division of PNS that controls body's skeletal muscles (voluntary movement)

autonomic nervous system

division of the PNS that controls glands and muscles of internal organs (involuntary muscles)

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy (increases heart rate, bp, blood sugar, slows digestion and body temp)

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy (slows heart rate, increases stomach activity)

Neurons

a nerve cell; the basic building block of the nervous system

Reflex arc

neuro circuit involved in reflux automatic response to sensory stimulus)

Pain arc

neuro circuit involved during pain reflex action

Sensory neurons

neurons that carry incoming information from the body's tissues and sensory receptors to the brain and spinal cord

Motor neurons

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 process info between the sensory inputs and motor outputs

all or nothing principle

a neuron's reaction of either firing (with a full-strength response) or not firing.

Action potential

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

Depolarization

the inner surface of the membrane becomes less neg in relation to the outer surface

refractory period

A brief period after a neuron has fired (cannot generate another action potential in this state)

Resting period

electric potential of a neuron when it's nonexcited

Reuptake

a neurotransmitter's reabsorption by the sending neuron

multiple sclerosis

disease of the CNS characterized by the inflammation and scarring of myelin sheath nerves, which disrupts neural transmission

myasthena gravis

autoimmune disorder where the body produces antibodies against acetylcholine receptors, causing faulty transmission of nerve impulses

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

excitatory neurotransmitters

exert a facilitatory effect on postsynaptic neurons be depolarizing them causing greater likelihood of action potential

Inhibitory neurotransmitters

hyperpolarizes postsynaptic neurons causing a smaller likelihood of action potential

Hormones

substance secreted into bloodstream by endocrine gland to regulate processes in distant target organs and tissues

Agonist

a molecule that increases a neurotransmitter's action

Antagonist

a molecule that inhibits or blocks a neurotransmitter's action

Reuptake inhibitors

a substance that interferes with the reabsorption of neurotransmitters by the presynaptic neurons that released them.

Psychoactive drugs

Any drug that has significant effects on psychological processes (thinking, perception, and emotion)

Stimulants

any agent that has significant effect on psychological processes

Depressants

any agent that can diminish a function of activity of body system or organ

Hallucinogens

substance capable of producing sensory effect or altering it

Opioids

mimics a natural substance

Brainstem

central core of the brain, responsible for automatic survival functions

Medulla

controls heartbeat and breathing

Cerebellum

processes sensory input and coordinates movement output and balance and nonverbal learning/memory

Cerebral cortex

outer layer of brain that has tissue folded in on itself and is responsible for thinking, learning and memory

Brain hemispheres

half of the cerebrum and contains left and right hemispheres which work laterally with the body

limbic system

group of brain nuclei that form a network involved in automatic and visceral processes like controlling emotions

Thalamus

the brain's sensory switchboard, processes and transmits sensory info

Hypothalamus

homeostasis regulator (hunger, thirst, body temp, sleep and mood)

Pituitary gland

produces and secretes hormones

Amygdala

controls fear, anger and the fight or flight response

Hippocampus

processes new memories for permanent storage

Corpus callosum

connects the cerebral hemispheres making it the principal connection between the two sides

occipital lobe

receives info from the visual fields, recognizing line angles, shapes etc

Frontal lobe

involved in speaking and muscle movements and in making plans and judgements

Temporal lobe

processes sound and faces, recognizes features and arrangement

Parietal lobe

receives sensory input for touch and body position

Specialization of right hemisphere

greater responsibility for spatial awareness and controls left side of body

Specialization of left hemisphere

greater responsibility for speech and controls right side of body

Broca's area

controls motor functions involved in speech production

Wernicke's area

comprehends words and speech

Brain plasticity

the brain's ability to change, especially during childhood, by reorganizing past damage or by building new pathways based on experience

EEG

measures brainwaves

fMRI

shows detailed structure and activity