NPB101 MT2: APs, CNS, PNS, senses, brain, reproductive system, etc

membrane potential

difference in electrical charges across a cell membrane

equilibrium potential

voltage required to maintain a particular concentration gradient

equilibrium potential of Na

+60 mV

equilibrium potential of K

-90 mV

equilibrium potential of Cl

-70 mV

action potential

excitable cells that produce an electrical signal, all-or-noting, v-gated ch

sodium/potassium pump

maintains resting membrane potential by moving Na and K against their concentration gradient: 2 K+ in and 3 Na+ out

refractory period

cell becomes more positive and another AP cannot occur

central nervous system

brain and spinal cord

peripheral nervous system

efferent/afferent divisions —> autonomic/somatic NS —> sympathetic/parasympathetic

efferent division

information EXITS the brain and tells effectors what to do

afferent division

relays information to brain

somatic NS

motor neurons and skeletal muscles

autonomic NS

sympathetic and parasympathetic NS

sympathetic NS

fight or flight response

parasympathetic NS

rest and digest

basal ganglia

motor planning and initiation of motor movements

thalamus

sensory relay station for motor control

hypothalamus

regulates homeostasis and hormones

brain stem

link beween spinal cord and higher brain regions

cerebellum

motor coordination and fact checking movements

frontal lobe

higher order cognitive functions and motor

parietal lobe

somatosenosory functions

occipital lobe

visual information

temporal lobe

auditory information

photoreceptors

light sensors filled with all disks of rhodopsin proteins that activate with photons

rods

low light photoreceptors

cones

high light/color photoreceptors

what colors are short, medium, and long cones?

short: blue, medium: green, long: red

phototransduction

in the dark: rhodopsin is inactive, cGMP high, ion ch open. light: activates rhodopsin, decreases cGMP, closes Na+ ch and cell is hyperpolarized

pitch

where is sound

volume

how much is sound

sound transduction

vibration of tympanic membrane, vibration of middle ear bones, vibration of oval window, fluid movement in cochlea, vibration of basilar membrane, bending of hair cells, open mechanoreceptors —> graded potential, AP generate in auditory nerve, propagation in auditory cortex

somatosensory system

touch, pain, temperature, proprioception

homunculus

mapping of body parts, the larger the region the more acuity and sensory perception

body parts with high acuity

fingers, toes, face

body parts with low acuity

legs, arms, torso

acuity

density of receptors in receptir field size + lateral inhibition

lateral inhibition

inhibition of adjacent neurons to localize stimuli and sharpen contraction

tonic receptor

type of touch receptor that is slowly adapting and sustains pressure and stretch of skin

phasic receptor

type of touch receptor that is fast adapting, signals changes in pressure on the skins surface, and has an off response

motor neurons

supply skeletal structure to bring about movement

the neuromuscular junction…

chemically links motor neurons and skeletal muscle fibers

what ion triggers release of ACh in NMJ?

Ca2+

what ions flow in and out during NMJ?

Na+ flows in and K+ flows out

spinal reflexes

simple neuromuscular circuits that mediates reflex response to sensory stimuli

stretch reflex

simple reflex circuit that mediates contraction after stretch of homonymous muscle

withdrawal reflex

reflex circuit that mediates removal from painful stimuli

tetanus

toxin that blocks inhibitory NTs leading to stiffness and rigidity

botulism

toxin that blocks excitatory NTs leading to muscle weakness

Parkinson’s disease

destroys dopaminergic nucleus in basal ganglia. difficulty initiating movements, active tremors

multiple sclerosis

demyelination of neurons in the cerebellum. difficulty with precise movements, action tremors.

wernicke’s area

brain area responsible for language comprehension

broca’s area

brain area responsible for speech production

limbic system

system for emotion, motivation, learning, and memory

amygdala

involved in regulation of emotional responses like fear

hippocampus

key for memory formation

Patient H.M.

hippocampus removed and could no longer form long term memory

Phineas Gage

damage to PFC led to deficits in planning, focus, and socially acceptable behaviors

role of the male reproductive system

make and deliver sperm

anti- mullerian hormone

hormone that stops the production of female reproductive parts in males

seamen

fluid containing sperm, testicular fluid, and gland secretions that transports sperm

prostate gland

contracts during secretion to make fluid more permeable to female tract

peenis

structure on male filled with tiny vascular spaces that fill up with blood when aroused and excrete sperm into vag

where does spermatogenesis occur?

sertoli cells

acrosome

enzyme on head of sperm to penetrate the ova

midpiece of sperm

contains a mitochondria that generates energy

tail of sperm

contains microtubules and is key for propulsion and movement

male endocrinology

hypothalamus release GnRH —> pituitary releases FSH and LH —> LH causes leydig cells to release testosterone —> FSH causes sertoli cells to release ABP —> ABP and testosterone bind —> spermatagonia and spermatogenesis

role of female reproductive system

production of ova, reception and transport of sperm, maintenance of developing fetus, birth, nourishing infant

menstral cycle

process in uterus that prepares system for fertilized egg

ovarian cycle

maturation of follicle and egg that drives menstruation (in the ovaries)

in follicular estrogen comes from…

thecal and granulosa cells

in ovulation estrogen comes from…

corpus luteum

follicular phase

hypothalamus release GnRH —> pituitary releases FSH and LH —> FSH leads follicle to secrete estrogen (builds up uterine lining)

ovulation phase

High estrogen levels peak.—>This surge prompts the pituitary gland to release a large amount of LH —>The LH surge forces the ovary to release a mature egg

luteal phase

The follicle transforms into the corpus luteum. —>It begins releasing large amounts of progesterone —> Progesterone further stabilizes the uterine lining for a potential fertilized egg —> If no pregnancy occurs, the corpus luteum breaks down, causing hormone levels to drop —> This drop causes the uterine lining to shed, known as a period

corpus luteum

forms after egg is released in ovulation and releases inhibin, estrogen, and progesterone

cushings syndrome

ACTH secreting tumor —> too much cortisol or androgen secretion (in women masc features and chin hair

congenital adrenal hyperplasia

secreting too little cortisol and lacks negative feedback of ACTH/CRH

graded potential

triggered by a stimulus in dendrites, travel in both directions, only over short distances, can contribute to an AP

impact of low levels of progesterone after ovulation

failure to maintain the uterine lining for implantation

gametes are haploid (not diploid) bc..

meiosis reduces the chromosome so that fertilization restores the diploid state

progesterone

hormone that maintains the uterine lining during pregnancy

where does fertilization typically occur

oviduct (fallopian tube)

impact of blocked release of LH

failure of ovulation and no formation of corpus luteum

absolute refractory period

when another AP cannot be generated due to inactivation of Na+ ch