211 Midterm 2 Flashcards
Whitten Effect
pheromones in male urine trigger synchronous estrous cycles
Lee-Boot Effect
without the presence of male urine, estrous cycles slow down
Vandenburgh Effect
earlier onset of puberty in females when housed with uncastrated males
Bruce Effect
unfamiliar male scent triggers female termination of pregnancy
Hypertonic solution
higher concentration of solute outside the cell = cell shrinks as water leaves the cell = thirst
Hypotonic solution
lower concentration of solute outside the cell = cell expands as water enters
3 pathways of light
photoreceptor cells - bipolar cells - retinal ganglion cells (AP starts here) - lateral geniculate nucleus of the thalamus - area V1 (primary visual cortex) - visual association cortex (dorsal = where or ventral = what)
from the retina - midbrain (superior colliculi)
retina - hypothalamus (sleep-wake cycles)
which receptors do bipolar cells express?
ON cell: inhibitory metabotropic receptors (inhibited by the release of glutamate by photoreceptors in the dark)
OFF cell: excitatory ionotropic receptors (excited by the release of glutamate by photoreceptors in the dark)
suprachiasmatic nucleus
internal clock
ventromedial nucleus of the hypothalamus (VNH)
sexual behaviour in females
medial preoptic area of the hypothalamus (mPOA)
sexual behaviour in males
medial amygdala
sexual arousal (low frequency GABA stimulation) and aggression (high frequency GABA stimulation) in both males and females + social disinhibition (glutamate stimulation)
pathway of sound
pinna - ear canal - tympanic membrane - ossicles - oval window - cochlea - organ of Corti - cochlear nerve - cochlear nuclei in the medulla - crosses over - inferior colliculi - medial geniculate nucleus of the thalamus - primary auditory cortex - auditory association cortex (posterior (parietal): where and anterior (frontal/temporal): what)
Wave frequencies
Beta: awake and aroused (12-30Hz)
Alpha: awake and relaxed (8-12Hz)
Theta: stage 1 sleep/drowsy (4-8Hz)
Delta: stage 3 sleep (<4Hz)
desynchronized EEG = REM
ventral lateral preoptic area (vlPOA)
associated with drowsiness and sleep
flip-flop circuit with arousal system (Ach, histamine, 5-HT, NE) - reciprocal inhibition
MALE signaling cascade
XY - SRY gene - testes - anti-Mullerian hormone (defeminization) - androgens (masculinizing = internal (testosterone) and external (dihydrotestosterone) male genitalia)
FEMALE signaling cascade
XX - ovaries - lack of anti-Mullerian hormone = no defeminization - absence of androgens = Wolffian system withers away - female genitalia
Turner syndrome
X0: develops as female, but infertile
Swyer syndrome
XY with a faulty SRY gene: develops as female, infertile
insufficient androgen signaling
Mullerian system withers away as usual = defeminization
Wolffian system and external genitalia don’t develop (insufficient masculinization) - people develop female genitalia
lack of anti-Mullerian hormone
no defeminization, but masculinization occurs as usual = both male and female internal sex organs, but only male external genitalia
puberty signaling cascade
hypothalamus releases kisspeptin - activates gonadotropin-releasing hormone (GNRh) - activates pituitary which releases gonadotropin into the blood - ovaries release estradiol
congenital adrenal hyperplasia
excessive release of androgens in females at birth = masculinization = likely that they will identify as men and be attracted to women
nucleus accumbens in the ventral forebrain
setting priorities and motivational processes (associated with drug addiction and falling in love) - involves oxytocin, vasopressin, serotonin, and dopamine signaling)
central nucleus of the amygdala
fear responses (conditioned and innate)
ventromedial prefrontal cortex (vmPFC)
extinguishing conditioned fear responses, emotional regulation, suppressing emotional outbursts - inhibitory influence on the amygdala (damage = childlike behaviour)
signals in fasting phase
pancreas releases glucagon = liver and muscles convert glycogen back into glucose to be used as energy in the brain and triglycerides back into fatty acids to be used in the body
signals after having eaten
pancreas released insulin = liver and muscle cells store glucose as glycogen and fats as adipose tissue (body and brain can use glucose)
signals that make you hungry
ghrelin from an empty duodenum and stomach
low-leptin signals (lipoprivation) = stimulates AGRP neurons and inhibits POMC neurons = PVN neurons don’t fire enough = intense hunger
hypoglycemia (low blood sugar)
signals that decrease hunger
CCK, PYY, GLP-1 released in proportion to calories ingested = feeling full (anticipatory)
liver signals sufficient glucose and fatty acids in the blood
pancreas releases insulin = satiety
leptin signals sufficient amounts of fat available (high leptin levels = sensitive to short-term satiety signals)
leptin stimulates POMC neurons and inhibits AGRP neurons = PVN neurons fire correctly
paraventricular nucleus of the hypothalamus (PVN)
oxytocin neurons involved in a low-leptin feeding emergency (don’t fire enough - intense hunger - Prader-Willis syndrome)
arcuate nucleus of the hypothalamus (ARC)
contain AGRP and POMC neurons which project to the PVN
narcolepsy
associated with the loss of orexin neurons (so losing a positive influence on the arousal system): sleep paralysis, cataplexy (intrusion of REM-like states)
orexin neurons
promote wakefulness, connections to a flip-flop circuit that determines which stage of sleep you’re in (REM-on/REM-off), hunger = orexin stimulation, satiation = orexin inhibition
Merkel’s disks
simple touch
Meissner’s corpuscles
light localized touch, only found in glabrous skin (fingertips), information travels to the brain via the dorsal column ipsalaterally until the medulla
Pacinian corpuscles
vibrations
Ruffini corpuscles
kinesthetic information, where your body is in space
Free nerve endings
pain and temperature, not localized information (travels to the brain via the spinothalamic tract contralaterally)
