neuroscience

nerves

bundle of neurons (individual cells)

what are the two divisions of the nervous system

central & periphery

central nervous system

consists of the brain & spinal cord in the vertebral column; all nerves encased in bone/very well protected, so not as regenerative if hurt

what happens if we hurt spinal cord

lose connection with some part of the body

cerebral fluid

liquid in and around the brain; makes brain float, very tender & malleable

why is the fact that there's no sensory neurons in the brain significant?

we don't feel anything. could hit head, think you're ok, and then wake up dead; we don't feel brain bleeding & swelling, brain seeping into vertebrae (all rare but deadly outcomes)

brain paralysis

no oxygen going into brain; one sided stroke... creepy smiling thing

spinal cord paralysis

brain can still send messages, but it stops at a certain point in nerves

peripheral nervous system

any sort of nerve that serves the body outside the CNS (limbs & organs); more susceptible to injury bc not encased in bone, more regenerative

2 parts of peripheral nervous system

somatic & autonomic

somatic nervous system

takes in sensory info and directs voluntary actions; sends info to brain; controls movement of skeletal muscles

4 skin senses

skin & tissues packed with touch receptors for hot, cold, pressure, pain

autonomic nervous system

controls internal organs; runs on it's own & directs involuntary actions like breathing and heart beating but can be consciously overriden to a certain extent bc it always wins(manual breathing)

sympathetic nervous system (subsection of autonomic)

our body's response to emergencies (fight or flight); honed in evolution

five actions to prepare for flight or fight

sweat, increase heart rate, increase respiration rate, dilate pupils, slow digestion (bc it's energy extensive)

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy; reverses sympathetic

relationship between endocrine & nervous system

they work together; nervous sends neurotransmitters, endocrine secretes hormones carried in the bloodstream

pituitary gland

master gland; not a brain structure, but lives in the neighborhood & is controlled by hypothalamus; controls growth, hunger, many hormones like thyroid/ovaries

when does pituitary gland function

exclusively during deep sleep; explains why hormone levels highest in the morning and kids growing in sleep

early brain research

all we could know was from dead brains; phineas gage (1848)

Electrostimulation

adding electricity speeds up firing of the brain, stimulates neurons

lesion

tissue destruction to see effects of destroying healthy cells (not done on humans)

Electroencephalogram (EEG)

records brain waves through electrodes on scalp during sleep; printout

structural neuroimaging techniques

shows what the brain looks like; CT scan & MRI

functional neuroimaging techniques

shows what the brain is doing; PET, fMRI

CAT/CT scan

computerized axial tomography, one step above x-ray bc it shows bones AND soft tissue; big donut that spins around; can be used anywhere in body

MRI

magnetic resonance imaging; one step above CT, more detailed soft tissue & fluid filled areas; takes longer; strong magnet

PET scan

positron emission tomography; shows brain activity using radioactive glucose (injected or consumed)

fMRI

functional MRI; uses slightly magnetic property of blood to reveal blood flow in brain (exclusively)

hemispheric specialization

The control of distinct neurological functions by the right and left hemispheres of the brain.

left brain

logical thought, problem solving, reasoning, analysis, language, grammar, measurement, algebra, right side of the body control, linear thinking

right brain

nonverbal, artistic, musical, creative, imagination, emotional perception, spatial orientation, geometry, shapes, patterns, estimation, facial recognition, left side control

the idea that you can be more right or left brained is...

pseudoscience; they work together

contralateral

left brain controls right side of the body and vice versa

corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them; most white structure

cerebral cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center

split brain procedure

performed to limit number & severity of epileptic seizures; sperry & gazzaniga research led to discovery that language is localized on left side of the brain; things seen through left eye received but can't be verbalized bc right hemisphere is non verbal

how does our cerebral cortex separate us from lower animals?

wrinkles allow for more surface area to be housed in a smaller brain, resulting in superior processing power; other animals have flat ones

lobes in the hemispheres

frontal, parietal, temporal, occipital; separated by fissures (longer & deeper folds)

frontal lobe

associated with prefrontal cortex, motor cortex, broca's area

functions of the prefrontal cortex

higher level executive functions like problem solving, planning, decision making, self control, attention & focus; doesn't fully develop until 25; phineas gage injured this

motor cortex

generate signals to make the body move voluntarily; contralateral; space on it not equivalent to size of the limb, space is proportional to how precisely a body part can be moved

broca's area

only in left hemisphere; allows for physical movements required for speech; coordinates lips, tongue, jaw, soft palette

damage to broca's area

causes aphasia (language difficulty) where people are unable to speak intelligibly

parietal lobe

left: math, spatial reasoning; right: shapes, estimation, facial recognition; also includes the sensory cortex

sensory cortex

receives incoming messages from sense of touch ONLY; space on sensory cortex is proportional to how sensitive a body part feels; contralateral

plasticity

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

occipital lobe

processes visual information; visual cortex, optic chiasma; breaks down & reassembles visual input into component parts using feature detectors

visual cortex

receives information from optic nerves; contralateral due to optic nerves crossing at the optic chiasma

optic chiasma

the crossing of the optic nerves from the two eyes at the base of the brain

agnosia

visual disruption originating in the brain, usually inability to recognize objects

temporal lobe

allows for comprehension of what is heard; auditory cortex, wernicke's area

auditory cortex

receives sound info from auditory nerves; unlike other senses, hearing is only partially contralateral

wenicke's area

allows us to understand spoken language & differentiate it form other sounds

aphasia in wernicke's area

they can speak fine but can't comprehend speech

agonist medicine

makes cells fire, mimics neurotransmitters; increase the effect of dopamine (for example); will insert itself into receptor site

antagonist medicine

stops cells from firing, blocks neurotransmitters; lessen dopamine (for example); will block receptor site/ sit in site but it's not actually the chemical

neurotransmitters

chemical messengers, they amplify electrical signals between neurons

Acetylcholine (ACh)

controls movement of voluntary muscles, when it reaches a muscle, it contracts; ach also assists in learning & memory

deficit of ACh; excess

Alzheimer's; no existing condition

dopamine

influences how the brain controls movement; also released in rewarding situations; minor mood booster

deficit of dopamine; excess

parkinson's disease (tremors, lack of smooth, controlled movement); schizophrenia

serotonin

affects mood, emotions, sleep, and eating behavior

serotonin deficit; excess

depression, bipolar disorder, ocd anxiety disorders; no naturally existing condition

Norepinephrine

alertness, arousal, concentration

norepinephrine deficit; excess

depression, adhd; anxiety disorders

endorphins

pain control & pleasure; opiates created by the human body on demand in response to exercise or pain; endorphins responsible for runner's high

endorphin deficit; excess

no specific condition but likely to suffer pain, anxiety, sleep difficulties; typically results from addition to opiates (heroine, fentanyl, oxycontin, percocet, vicondin)

Opiod addiction

starts very innocently thru pain medication, body becomes used to it, stops producing natural endorphins, TERRIBLE WITHDRAWAL, could eventually wait it out and body will produce natural endorphins... or just take more opiods.

Gamma-aminobutyric acid (GABA)

inhibitory neurotransmitter, slows down firing of neurons

gaba deficit; excess

insomnia, seizures, tremors; migraines & seizures

gray matter

receives and routes sensory information, used for processing & thinking; covers cerebral cortex & some lower brain structures

white matter

composed mostly of glial cells that support & nourish gray matter; helps move messages around the body

brainstem

most important life sustaining structure; spot where the spinal cord enters the skull; swells, forms medulla & pons; provides such essential functions that loss of these leads to death, "brain dead"

difference in cerebral cortex and lower level structures

CC is used for thinking & processing info, while lower level structures regulate life functions

medulla

controls autonomic functions such as heart rate, blood pressure, breathing

pons

regulates breathing, controls circadian rhythm (sensitive to light), plays a role in generating dreams

pons & sleeping

governs the movement of the eyes during REM (dreaming) sleep, blocks movement messages from the motor cortex during dreaming to keep us from acting out our dreams; explains why we don't toss & turn, just paralysis

REM sleep disorder

not enough dopamine in pons so people act out their dreams

thalamus

sensory switchboard; receives info from all senses except smell & routes it to correct location on cortex

reticular formation/reticular activating system

movement of touch sensation; network of neurons that connect the spinal cord to the thalamus; filters incoming stimuli from spinal cord; controls sleep, wakefulness & alertness

habituation & reticular formation

reduction in response after repeated presentations of a stimulus,; it filters out old or unchanging info; redirects our focus bc if not, we'd be overwhelmed if we were cognizant of every tactile sensation

cerebellum

coordinates voluntary movement, linked to motor cortex; damage does not equal paralysis, just shaky uncoordinated movement.

limbic system

system responsible for primitive motives & most basic emotions; sense of smell; includes amygdala, hypothalamus, pituitary gland, hippocampus

amygdala

two neural clusters; influences fear, aggression, activates fear based responses to threatening stimuli; linked to eyes so all visual info gets evaluated for danger

hypothalamus

aims to keep body at homeostasis by regulating hormones & autonomic nervous system; communicates with pituitary

4 functions of hypothalamus

fahrenheit (temp regulation), fight or flight (directs endocrine system to react), food, sex; hypothalamus gives you rewarding feeling when you when you do any of these things

lateral (left) hypothalamus

let's eat!; evaluates how much time has passed since last ate, how much glucose was last taken in, easy to respond to

ventromedial (right) hypothalamus

slower, detecting fullness, female sex drive found here