ap psych m9-15 test 3 10/23/23

phrenology

phrenology

studying bumps on the skull; once believed to reveal mental abilities and character traits

localization of function

various brain regions have particular functions

biological psychologists

links between biological activity and psychological events

neurons

nerve cells

dendrite fibers

receive info and conduct it toward the cell body/soma

axon fiber

sends info through terminal branches to other neurons or muscles/glands - long

myelin sheath

layer of fatty tissue that insulates and speeds up impulses; degenerates in multiple sclerosis

multiple sclerosis

degeneration of myelin sheath, slower communication to muscles

neurons transmit messages when

stimulated by sensory signals or chemical signals from neighboring neurons; response coordinated by the nucleus

action potential

a brief electrical charge that travels down the axon and leads to synaptic activity

node of Ranvier

what the action potential "jumps on" between myelin

potential

separation of charge, "potential" to do work

voltage-gated channels

when V approches -55 mV, they open and allow Na+ in; when V approaches +30 mV, they open and allow rush of K+ out

depolarization

Na+ ions move in, increasing V

repolarization

K+ ions move out, decreasing V

graded potential

voltage moving towards and away from threshold, but not reaching it

resting potential

typically -70 mV, fluid inside axon's membrane has more K+, less Na+ and Cl-

leak channels

allow some K+ to move out, charge becomes more positive outside for a greater difference

Na+/K+ pump

keeping up with the leaking, requires ATP

refractory period

neuron pumps the Na+ ions back outside, recharging it back to -70 mV so it can fire again

excitatory signals

those that push the neuron closer to an action potential

inhibitory signals

those that pull the neuron further from an action potential

if excitatory > inhibitory by a minimum intensity (threshold)

combined signals trigger an action potential

all-or-none response

increasing stimulation above the threshold does not affect intensity; the neuron either fires or doesn't

the higher the frequency of action potentials

the stronger the sensation

we differentiate stimulus intensity by

number of neurons fired and frequency

threshold voltage

-55 mV

synaptic cleft

separation between axon terminal of one neuron and receiving neuron

neurotransmitters

chemical messengers that cross the synaptic cleft and bind to receptor sites on the receiving neuron

chemically-gated channels

located on receiving neuron, excited (allow Na+ in) or inhibited (allow K+ out or Cl- in) by neurotransmitter

reuptake

sending neuron reasorbs excess neurotransmitters; can also be destroyed by enzymes

acetylcholine

learning and memory, messenger at every junction between motor neurons and skeletal muscles, paralysis if blocked

dopamine

influences movement, learning, attention, and emotion; oversupply linked to schizophrenia, undersupply linked to termors and decreased mobility in Parkinson's disease

serotonin

affects mood, hunger, sleep, and arousal; undersupply linked to depression

noradrenaline

helps control alertness and arousal; undersupply can depress mood

GABA (gamma-aminobutryic acid)

major inhibitory neurotransmitter; undersupply linked to seizures, tremors, and insomnia

glutamate

major excitatory neurotransmitter involved in memory; oversupply can overstimulate the brain, producing migraines or seizures

opiate receptors

respond to morphine and naturally-produced endorphins

agonist molecules

similar to neurotransmitters and can bind to their receptors to mimic effects

antagonist molecules

block a neurotransmitter's receptor and prevent its effect

nervous system

allows our body to take in info from around the world and its tissues, to make decisions, and to send back info and orders to its tissues

central nervous system

brain and spinal cord; body's decision maker

peripheral nervous system

gathers info and transmits CNS decisions to other body parts

nerves

electrical cable formed of bundles of axons, link CNS with body's sensory receptors, muscles, and glands

sensory neurons

carry messages from body's tissues and sensory receptors inward to brain and spinal cord for processing

motor neurons

carry instructions from CNS to muscles and glands

motor neurons found in

cardiac muscles, skeletal muscles, smooth muscles, and endocrine glands

interneurons

brain's internal communication system, process info between sensory input and motor output

somatic nervous system

within peripheral; enables voluntary control of our skeletal muscles

autonomic nervous system

within peripheral; controls our glands and internal organs’ muscles, usually operates autonomously

sympathetic nervous system

within autonomic; arouses and expends energy (e.g. higher heartbeat and BP, slower digestion, sweating)

parasympathetic nervous system

within autonomic; opposite of sympathetic, conserving energy as it calms you

neural networks

work groups that can have shorter, faster connections, multiple layers and connections to the next layer

learning occurs as

experience strengthens and modifies certain connections in response to feedback

spinal cord

two-way highway connecting the PNS and brain

ascending neural fibers

send sensory info up spinal cord

descending neural fibers

send motor control info back down spinal cord

reflex pathways

composed of a single sensory neuron and a single motor neuron, often communicating through an interneuron—faster response than if info was sent all the way to the brain

endocrine system

has glands that secrete hormones

hormones

chemical messengers that travel through the bloodstream and affect other tissues; can act on the brain; slower and tend to last longer than nerve impulses

adrenal glands

above the kidneys; release adrenaline and noradrenaline which control the fight-or-flight response (increase heart rate, BP, and blood sugar)

pituitary gland

"master gland"; releases growth hormone, oxytocin, triggers sex glands to release sex hormones, triggers adrenal glands to release cortisol

oxytocin

enables birth contractions, milk flow during nursing, orgasm, pair bonding, group cohesion, and social trust

cortisol

released by adrenal glands in a stressful event to increase blood sugar

hypothalamus

brain region that controls the pituitary

thyroid gland

regulates metabolism through thyroxin

parathyroids

helps regulate calcium level in blood

pancreas

insulin and glucagon to regulate blood sugar level

ovary and testis

secrete female and male sex hormones

lesion

using high frequency electrodes to burn away target tissue; similar damage can also be caused by stroke or seizures; provided hyperlocal observations

microelectrodes

can pick up on the messages of individual neurons

electroencephalogram (EEG)

amplified readout of electrical activity waves (i.e. electrical waves caused by a stimulus are kept; other unrelated activity is filtered out)

computed tomography (CT) scan

takes X-ray photos that can reveal brain damage

positron emission tomography (PET) scan

depicts brain activity by showing each brain area's glucose consumption through temporarily radioactive glucose that releases gamma rays

functional MRI

can reveal the brain's functioning as well as structure by comparing MRI scans taken close together to watch blood move into specific brain areas

increasing complexity arises from

new brain systems built on top of the old (e.g. brainstem, thalamus, and cerebellum)

brainstem

oldest and innermost region responsible for automatic survival functions; crossover point for nerves connecting to opposite side of body from brain

medulla

in brainstem; controls heartbeat and breathing

pons

in brainstem; coordinates movements for purposeful tasks

thalamus

pair of egg-shaped structures; sensory control center (except for smell) that receives info and routes it to higher brain regions i.e. cerebral cortex; receives some replies which it directs to medulla and cerebellum

reticular formation

neuron network that extends from the spinal cord up through the thalamus; incoming stimuli from spinal cord is filtered and important info is relayed to other brain areas; also enables arousal, attention, sleep, and awareness to environment

cerebellum

"little brain", enables nonverbal learning and memory, judges time, modulates emotions, discriminates sounds and textures, works with pons to coordinate voluntary movement and balance, one of the first structures to be affected by alcohol

hindbrain region

includes spinal cord, medulla, pons, and cerebellum

midbrain region

roughly below thalamus, integrates different sensory processes, creates dopamine-releasing neurons that project into higher brain areas

hippocampus

processes conscious memories and forms new ones

amygdala

linked to aggression and fear responses, the perception of these emotions, and processing of emotional memories

hypothalamus

controls autonomic nervous system and influences pituitary gland; bodily maintenance through hunger, thirst, and sexual behavior; tunes blood chemistry and incoming orders from other brain parts

4 Fs that the hypothalamus controls

fighting, fleeing, feeding, and fucking

nucleus accumbens

another reward center in front of hypothalamus

limbic system

hippocampus, amygdala, hypothalamus, and nucleus accumbens

forebrain

cerebrum, thalamus, hypothalamus, and pituitary gland

reward deficiency syndrome

occurs in addictive disorders e.g. substance use and binge eating because of malfunctions in natural brain pleasure systems

glial cells

supportive in neuron's function of nervous system communication

astrocytes

glial cell in CNS; support neurons by maintaining chemical concentrations in extracellular space, removes waste, repairs tissue, and contributes to blood-brain barrier by wrapping around capillaries in the vascular foot process

satellite cells

glial cell in PNS; found surrounding sensory and autonomic ganglia to regulate their microenvironment

oligodendrocytes (CNS) and Schwann cells (PNS)

glial cells that insulate axons with myelin sheath

microglial cells

glial cell in CNS; ingest cells and pathogens for immune support

ependymal cells

glial cell in CNS; tightly adherent to each other, filter blood to make cerebrospinal fluid which protects CNS neural structures; found in choroid plexus in brain ventricles

cerebrum

outer covering of gray matter over the hemispheres containing newer neural networks that enable perception, thought, and speech

cerebral cortex

thin surface layer of interconnected neural cells, control and information processing center