MCAT- behavioral sciences

Parasympathetic

* REST AND DIGEST conserve energy, acetylcholine, digestion and exocrine secretion
* Constrict pupils
* Stimulates saliva
* Constricts bronchi
* Slows heartbeat
* Stimulates peristalsis and secretion
* Stimulates bile release
* Contracts bladder

Sympathetic

* FIGHT OR FLIGHT- stress
* Dilates pupils
* Inhibits salvation
* Relaxes bronchi
* Accelerates heartbeat
* Stimulates sweating
* Inhibits peristalsis and secretion
* Stimulates glucose production and release
* Recreation of adrenaline and noradrenaline
* Inhibits bladder contraction
* Stimulates orgasm

Meninges: 3 layers

* Dura mater- outer layer connective tissue connected to skull
* Arachnoid matter- middle layer fibrous weblike
* Pia matter- inner layer directly connected to brain

\-absorb cerebrospinal fluid that nourishes brain and spinal cord, provides cushion

Forebrain- prosencephalon

* greatest influence on human behavior
* Divides to form telencephalon: cerebral cortex, basal ganglia, limbic system and diencephalon: thalamus hypothalamus posterior pituitary gland and pineal gland

Cerebral cortex

* perception, cognition, behavior processes

Basal ganglia

* movement

limbic system

emotion and memory

thalamus

sensory relay

* Sorts and transmit them to appropriate areas of cerebral cortex

hypothalamus

* our main functions: defending, fighting, flighting, sexual function
* Homeostatic functions
* Metabolism, temp, water balance
* Some endocrine function
* Emotional experiences during high arousal aggressive and sexual states
* When any functions are out of balance it detects problem signals body to correct

Midbrain- mesencephalon

receives sensory and motor info from rest of body, involuntary reflex responses

* Inferior (sensory info from auditory) and superior colliculi (sensory info from visual)- sensorimotor reflexes

Hindbrain-Rhombencephalon

* balance motor coordination breathing digestion arousal sleeping waking: vital functions
* divides to form myelencaphalon: medulla oblongata and mentencephalon: pons and cerebellum

Cerebellum

refined motor movements, posture balance coordinates body movements

medulla oblongata

herat, vital relfexes

reticular formation

arousal and alertness

pons

communication within brain, breathing : sensory and motor pathways btwn cortex and medulla

Lateral hypothalamus: LH

Lacks Hunger- triggers eating and drinking

Ventromedial hypothalamus: VMH:

Very Much Hungry- provides signal to stop eating - brain lesions lead to obesity

Anterior hypothalamus-

sexual behavior sleep body temp

Posterior pituitary

release for hypothalamic hormones: antidiuretic hormone (vasopressin) and oxytocin

pineal gland

biological rhythms- secrets melatonin- directs signals from retinal for coordination with sunlight

Basal ganglia

muscle movement, receive info from cortex and relay info to brain and spinal cord via extrapyramidal motor system

* Parkinson's- destruction of portions of basal ganglia

extrapyramidal motor system

gathers info about body position and carries info to CNS but does not education directly through motor neurons

Limbic system: main function and primary components

emotion and memory

septal nuclei

amygdala

hippocampus

anterior cingulate cortex

anterior cingulate cortex

* connects with frontal and parietal lobes
* Higher order cognitive processes- regulation of impulse control and decision making
* Plays role in emotion and motivation

septal nuclei

* pleasure centers - association between these nuclei and addictive behavior

amygdala

* defensive and aggressive behaviors
* When damages: decrease in aggression and fear reaction
* Lesions result in submissive and hypersexual states

hippocampus

* memory and learning
* form long term memories and redistribute remote memories to cerebral cortex
* Communicates w other portions of limbic system through long projections: fornix
* Anterograde amnesia- cant form new long term memories but memory for events that occurred before brain injury is intact
* Retrograde amnesia- memory loss of events before brain injury

frontal lobe:

* prefrontal cortex: association area
* supervising and directing operations of other brain regions
* Regulate attention and alertness
* Wake up or relax
* Supervises processes with perception memory emotion impulse control
* Projection areas: perceptual and motor tasks
* Primary motor cortex - precentral gyrus : imitate voluntary motor movements by sending neural impulses toward muscles
* Motor homunculus
* Brocas area- speech production - only found in one hemisphere

parietal lobe

* somatosensory cortex
* Homunculus

occipital lobe

visual cortex

learning and motor control

temporal lobe

auditory cortex

* Wernikes area- language perception and comprehension
* Memory processing emotion and language

Corpus callosum

connects and shares info between two cerebral hemispheres

Anterior pituitary gland releases what hormones

hormones that regulates actives of endocrine glands

* Endorphins, FHS LH ACTH TSH GH prolactin

posterior pituitary gland releases what hormones

ADH and oxytocin

undersupply of serotonin leads to whereas oversupply leads to

undersupply- depression

oversupply-mania

norepinephrine: low levels associated with

high levels associated with

low-depression

high-anxiety and mania

* GABA

inhibitory postsynaptic potentials- stabilizing neural activity- hyper polarization

* Glycine

inhibitory in CNS increases chloride into neuron- hyper polarizes

* Glutamate

excitatory

dopamine imbalances leads to

affects basal ganglia functions

* schizophrenia-delusions hallucinations and agitation associate w too much dopamine or oversensitivity to dopamine, parkinsons- loss of dopaminergic neurons= tremors jerky movements

Epinephrine norepinephrine and dopamine:

* catecholamines- experience of emotions
* Epinephrine (adrenaline) and norepinephrine (noradrenaline)- alertness and wakefulness fight or flight

Acetylcholine

* efferent limb of somatic nervous and parasympathetic: acts as inhibitory and excitatory

Dominant hemisphere

* usually left- analytic in function- managing details- language logic math

Nondominant hemisphere

* usually right- intuition creativity music spatial processing more sensitive to emotion recognition of others moods due to visual and auditory cues

webers law

* observation that difference thresholds are proportional and computed into a %

signal detection theory

* how internal and external factors influence thresholds
* Trials when signal is presented= noise trials
* Trials where signal is not presented= catch trials
* hit= signal is presented and subject correctly perceives signal
* miss= trial which subject fails to perceive presented signal
* False alarm= subject indicates perceiving a signal even tho it wasn’t presented
* Correct negative= subject correctly identifies no signal was presented

sclera

thick later covering exposed portion of the eye

choroidal vessels

blood vessels between sclera and retina

retina

inner most layer of the eye

contains photoreceptors

cornea

where light first gathers and focuses incoming light

anterior chamber

in front of iris

posterior chamber

in between iris and lens

iris

color part of eye

dilator papillae

opens pupil under sympathetic stimulation - muscle in iris

constrictor papillae

closes pupil under parasympathetic stimulation - muscle in iris

choroid

vascular layer of connective tissue that surrounds and nourishes retina

Ciliary body

produces aqueous humor

Canal of schemm

where the aqueous humor drains

lens

behind the iris- helps to control refraction of light

Amacrine and horizontal cells:

receive input form multiple retinal cells and help to amplify the differences in signals in each bipolar cell

when an object stimulates left eye: crossing over

* object from left stimulates right side of brain Object to the right stimulates temporal fibers and continues to the left side of the brain

when an object stimulates right eye: crossing over

* object to your right stimulates nasal fibers which cross over to the left side through optic chasm

Parvocellular cells

in the LGN: high color spatial resolution, only work with slow moving/stationary objects- low temporal resolution

Magnocellular cells:

LGN: detect motions, high temporal resolution low spatial resolution

* Inputs from periphery of vision

From optic chasm nerve fibers pass

LGN of thalamus then to parietal and temporal lobes to visual cortex in occipital lobe

the ear

* Pinna
* External auditory canal
* Tympanic membrane (eardrum) - vibrates back in forth - speed depends on the frequency
* Higher frequency= higher rat of vibration
* Louder sounds= higher intensity= increased amplitude
* Middle ear: ossicles
* Malleus
* Incus
* Stapes

Middle ear connected to nasal cavity via

* eustachian tube to help equalize pressure between middle ear and environment

Bony labyrinth

hollow region of temporal none containing cochlear vestibule and semicircular canals

endolymph

* potassium rich fluid

Perilymph

transmits vibrations from outside world and cushions inner ear

cochlea

* contains receptors for hearing
* Scale- all three run entire length of cochlea
* Middle: actual hearing organ of Corti: made of hair cells bathed in endolymph
* Tectorial membrane: on top of organ of corti
* basilar membrane: where organ of corgi rests on
* Round window: allows the perilymph to move within cochlea
* Organ of corti does transduction and then sends signals through vestibulocochlear nerve

Inferior colliculus

Involved in startle reflex and helps keep eyes fixed on point while head is turned

seterocilia

cause the swaying of hair cells which opens ion channels - amplify sound

Vestibule

* refers to portion of bony labyrinth that contains utricle and saccule
* Sensitive to linear acceleration used to balance apparatus and determine ones orientation in space

Otoliths

* utricle and saccule contain hair cells which have otoliths that help to resist motion it bends and stimulates underlying hair sells that send signals to brain

semicircular canals

* sensitive to rotational acceleration
* Each end in ampulla where hair cells are located
* Bending is what sends signals to brain

Pacinian corpuscles

* deep pressure and vibration

Meissner corpuscles

respond to light tough

Merkel cells

deep pressure and texture

Ruffini endings

stretch

two point threshold

* minimum distance necessary between two points of stimulation of skin so that points will be felt as two different stimuli

gate theory of pain

depth perception

* Relative size- objects appear closer than they are
* interpositon- when two objects overlap the one in front is closers
* Linear persepctive- convergence of parallel lines at a distance
* Motion parallax- perception that objects closer is seen to move faster when we change field of vision

binocular cues

* involve retinal disparity- slight difference in images projected on two Reinas

associate learning

* the creation of a pairing or sociation between two stimuli or behavior and a response

classical conditioning

* takes advantage of biological responses to create associations between 2 unrelated stimuli

habituation

repeated exposure to the same stimulus causing a decrease in response

dishabituation

* recovery of a response to a stimulus after habituation has occurred=
* It is temporary and always referring to changes in response to the original stimulus

pavlov

* turned a neutral stimulus into a conditioned stimulus and through association caused a conditioned response

experiment with dog

operant conditioning

* examines the ways which consequences of voluntary behaviors change the frequency of those behaviors

positive reinforcement

* increases the frequency of a behavior by adding positive consequences or incentive following the behavior

negative reinforcement

* increases the frequency of behavior but by removing something unpleasant
* example you take an aspirin to reduce a headache so the next time you have a headache you're more likely to take an aspirin

escape learning

* describes the situation where the animal experiences the unpleasant stimulus and in response displays the desired behavior in order to trigger the removal of the stimulus

avoidance learning

when animal displays it as desired behavior in anticipation of the unpleasant stimulus in order to avoid the unpleasant stimulus

positive punishment

* adds an unpleasant consequence in response to behavior to reduce that behavior

negative punishment

removing a stimulus in order to cause reduction of behavior

variable ratio schedules

* reinforce the behavior after varying number of performances but such that the number of performances to receive a reward is constant

fixed interval schedules

* reinforce the first instance of a behavior after a specific time period has elapsed

variable interval schedules

* reinforce the behavior for the first time that behavior is performed after a varying interval of time