Unit 2 psych

Central Nervous System

Central Nervous System

brain and spinal cord, body's decision maker

Peripheral Nervous System

includes somatic and autonomic nervous systems; the sensory and motor neurons that connect the central nervous system to the rest of the body

Somatic Nervous System

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

Autonomic Nervous System

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

Sympathetic Nervous System

mobilizing its energy and prepares body for action in stressful situations; fight or flight; releases adrenaline, increases heart rate

Parasympathetic Nervous System

relaxes and calms you down, rest and digest

Sensory Neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord; messages come from outside —> into body —> to brain

Interneurons

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

Motor Neurons

Carry outgoing information from the brain and spinal cord to the muscles and glands; messages sent —> out

neuron

individual nerve cells in nervous systems that recieve, integrate, and transmit info

dendrite

parts of a neuron that receives info

Soma (cell body)

contains the nucleus and much of cells normal organs

axon and axon terminals

A long, thin fiber that carries electrical impulses away from the neuron's cell body; The branches at the end of an axon transmit signals to other neurons or target cells.

myelin sheath

Insulating material encasing the fibers some axons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next; damage leads to multiple sclerosis

nodes of ranvier

gaps in the myelin sheath

Reuptake

neurotransmitters are absorbed back into the neuron after they’ve been released; Descending neuron fires NT → goes through receptor site and ions enter → gets reabsorbed by ascending neuron

depolarization

The process during the action potential when Na+ is rushing into the cell causing the interior to become more positive; negatively charged neuron becomes positive

action potential

a neural impulse; a brief electrical charge that travels down an axon (+40mV)

threshold

the level of stimulation required to trigger a neural impulse (-55mV)

all-or-nothing principle

a neuron's reaction of either firing or not firing; all action potentials are the same strength; if the neuron fires, it will always fire at the same intensity. 100% each time

refractory period

recharging phase; when a neuron, after firing, cannot generate another action potential; momentarily drops below -70mV then returns to resting state

acetylcholine (ACh)

excitatory; enables muscle (motor) action, learning, and memory; Excess —> muscle cramps, confusion agitation; Lack —> memory problems, Alzheimer’s, muscle weakness; ACH being inhibited —> myasthenia gravis

dopamine

inhibitory; influences movement, learning, attention, emotion, reward systems; Excess —> hallucinations, impulsivity, schizophrenia; Lack —> Depression, Parkinson’s (tremors, slow movement)

serotonin

inhibitory; Affects mood, hunger, sleep, and arousal; created by sun; Excess —> agitation, rapid heart rate; Lack —> Depression, anxiety, sleep issues

norepinephrine

excitatory; helps control alertness and arousal, fight or flight state (sympathetic nervous system activation); Excess —> anxiety, high blood pressure, hyperactivity, (mania phase for bpd); Lack —> depression, low energy, poor focus

GABA

major inhibitory neurotransmitter; stops messages; Excess —> drowsiness, cognitive impairment; Lack —> anxiety, insomnia, seizures, Huntington’s disease

Glutamate

Excitatory neurotransmitter; involved in memory, thinking, learning; opposite of GABA; Excess —> neuron damage, anxiety, hyperactivity; Lack —> cognitive decline, learning issues

Endorphins

inhibitory; pain control and to pleasure; brain’s natural aspirin; drugs like morphine/opioids mimic this; Excess —> euphoria, reduced pain sensitivity (addiction); Lack —> Depression, increased pain sensitivity

agonist

mimics the action of a NT; increase effect of neurotransmitter; ex: meth mimics action of dopamine

antagonist

opposes / blocks the action (connections) of a NT; slow down effects

The Brainstem

responsible for automatic survival functions; connects cerebrum to spinal cord and cerebellum

Medulla

in the hindbrain, (brainstem), attaches to the spinal cord, controls unconscious functions; blood pressure, respiration, heart rate; if damaged —> likely dying / close to death

Thalamus (forebrain)

primary relay station for all senses except smell; neural messages —> this —> cerebral cortex; handles incoming and outgoing signals; damage—>synesthesia (tasting words); also associated with memory and emotion, like hearing a song and associating a memory with it

Reticular Activating System / Formation - RAS

central core of the brainstem; oversees alertness, arousal (heightened body systems), and attention processes; if damaged —> coma

Cerebellum (hindbrain)

back of the brainstem; coordination of movement, sense of equilibrium, balance

amygdala (limbic system)(forebrain)

involved in memory and emotion, particularly fear and anger; warns us when somethings wrong or scary; messages go faster to this than to prefrontal cortex

hypothalamus (limbic system)(forebrain)

regulator of biological needs (homeostasis), links endocrine system via the pituitary gland to brain, 4 biological drives: food, fight, flight, fornication

hippocampus (limbic system)(forebrain)

Memories are processed / formed through this part and then sent to various parts of cerebral cortex and stored as long term memory

cerebral cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center; higher brain functions (occipital, parietal, temporal, frontal lobe)

glial cells (nervous system)

support, nourish, and protect neurons; ex-schwann cells; gluey substance that speeds up process, helps repair damaged axons

frontal lobe (Cerebral Cortex)

planning, reasoning, working memory, paying attention, solving problems, and performing movements; contains broca’s area, motor cortex, prefrontal cortex

motor cortex (frontal lobe)

an area at the rear of the frontal lobes that controls voluntary movements

broca's area (frontal lobe)

in left frontal lobe, deals with speech production

Parietal Lobe (Cerebral Cortex)

Deals with sensory perception → how brains interprets what we are sensing; Visual and spatial relations; handles somatosensory info, receives info about temperature, pressure, texture, and pain; contains somatosensory cortex

Somatosensory Cortex (parietal lobe)

area at the front of the parietal lobes that registers and processes body touch and movement sensations; messages being recieved

Wernicke's area

in left temporal lobe, deals with speech interpretation / language comprehension

Occipital lobe (Cerebral Cortex)

Primary visual cortex; Receives and processes visual information

Visual Cortex (occipital lobe)

conscious processing of sights

Temporal lobe (Cerebral Cortex)

hearing and balance; memory, smell, motivation, emotion; recognizing faces (right hemisphere); contains auditory cortex, Wernicke’s area

Auditory Cortex (temporal lobe)

the area of the temporal lobe responsible for processing sound information

Association Areas

involved in higher mental functions such as learning, remembering, thinking, and speaking; an area of the cerebral cortex that functions in linking and coordinating the sensory and motor areas and relating the info the past experiences

Plasticity

ability of the brain to modify its structure/function following changes within the body or in the external environment, brain’s ability to rewire itself after damage

Neurogenesis

the formation of new neurons

Corpus Callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them

Split Brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them; Researcher Roger Sperry discovered brain specialization for the right and left through SAIL while Michael Gazzinga did a study on patients that have undergone split-brain surgery and revealed brain lateralization of functions

Left Hemisphere Functions

speech and language (Wernicke’s and Broca’s area), sequential processing, analytic thought, logic, science, math; contralateral representation

Right Hemisphere Functions

Spatial functions, patterns, visual configurations, color discrimination, musical functions, contralateral representation

adrenal glands

inner part helps trigger the fight or flight response; secretes epinephrine in times of stress

heredity

genetic transmission of traits and characteristics from parents to their offspring

Endocrine System

glands that secrete chemicals into the bloodstream that help control bodily functioning (in charge of the adrenaline effect)

Hormones (Endocrine System)

chemical messengers; travel through body much slower than neurotransmitters; regulate many physical and behavioral functions

Pituitary Gland (In Hypothalamus)

master gland of entire endocrine system; Stress, growth, reproduction; Signals other glands of the endocrine system to secrete hormones

Resting Potential

neuron is at rest (-70mV) and capable of generating action potential; if resting potential rises above threshold (-55mV), an action potential starts to travel from cell body down axon

Broca’s Aphasia

can’t produce speech

Wernicke’s Aphasia

can’t comprehend language

Hindbrain

contains medulla and cerebellum

Forebrain

Cerebral cortex, limbic system

midbrain

contains an area integrating sensory processes (vision and hearing), dopamine center of the brain

Limbic System (forebrain)

behavioral and emotional responses; associated with emotion and motivation; under cerebral cortex, above brainstem

EEG

Electroencephalograph; measures brain waves/electrical activity; seen a lot in sleep studies; measures brain activity

PET Scan

radioactive glucose to see functioning of the brain or where is activity occuring in the brain

MRI

magnets/radio waves to see structure of the soft tissue

fMRI

measures brain activity by detecting associated changes in blood flow, shows structure and function; mix of mri and pet

genetic predisposition

to be susceptible to it or more likely to encounter it due to inherited genes

evolutionary perspective

based on Charles Darwin's theory of natural selection

eugenics

the selection of desired heritable characteristics in order to improve future generations, typically in reference to humans

twin, family, adoption studies

observe nature vs nurture. ex. minnesota twins study

reflex arc

neurological and sensory mechanism that controls a reflex, an immediate response to a particular stimulus, message sent to spine 

neural transmission

neuron firing

multiple sclerosis

caused by demyelination; ranges from fatigue to inability to walk, disease in which the body’s immune system can affect nerves in central nervous system

Myasthenia gravis

neurological disorder where one can’t contract their muscles; ACH is being inhibited

Excitatory neurotransmitters

tell second neuron to keep action potential going

Inhibitory neurotransmitters

not firing, stop action potential and stop message

substance P

deals with body’s pain perception; transmission of pain signals to the brain

adrenaline

energy; alertness and physical readiness; secreted by adrenal glands

leptin

energy balance by inhibiting hunger; secreted by fat cells; can affect mood and emotions, motivations related to eating behaviors; more leptin = less hungry; long term regulation of body weight

ghrelin

hunger hormone; produced in stomach and will signal brain to stimulate appetite; more ghrelin = more hungry

melatonin

sleep hormone; secreted based on darkness; sense light —> melatonin go down

oxytocin

love hormone; released in response to forms of social interaction and bonding; ex: childbirth or breastfeeding

psychoactive drugs

Chemicals that change the chemistry of the brain, altering perception and mental process through: chemical - blood/brain barrier, mental set - you get what you expect, environment - get more drunk at higher elevations

reuptake inhibitors

prevent a neurotransmitter from being reabsorbed by presynaptic axons

stimulant

euphoric feeling; ex: caffeine, nicotine, MDMA (ecstasy), PCP, cocaine, phetamines (meth), amphetamines (adderall); love = 150 units of dopamine, meth = 1250 units

depressants

slow down heart rate; ex: Alcohol, barbiturates, tranquilizers, anti-anxiety, valium; develop withdrawal symptoms

hallucinogens

change perception of reality, sensory (visual, auditory, tactile) hallucinations, loss of identity (dissociation); ex: (psychedelics) LSD, Mescaline (Peyote), mushrooms, marijuana; Tend to stay in system longer than other types of drugs

opiates

Agonists for endorphins (mimic) —> Reduce levels of GABA = slows down release of dopamine; Powerful painkillers and mood elevators; Drowsiness and euphoria due to artificially increasing dopamine levels; ex: Opium, morphine, heroin, methadone, codeine, oxycontin; highly physically addictive

tolerance

Diminished effect of the drug with the same dosage; Reverse —> Less of the drug to get the same type of effect, Ex. hallucinogens (Don’t leave the body’s system)

addiction

dependence; Psychological - crave the feeling / effect of the drug; Physiological - without the drug → physical withdrawals

withdrawal

Pain or discomfort from the lack of the chemical

executive functioning

the mental processes that enable us to plan, focus attention, remember instructions, and juggle multiple tasks successfully

prefrontal cortex

large portion of the frontal lobe; deals with personality, abstract thought, emotion, behavior, broca’s area