FINAL EXAM: Unit 1 Flashcards
what is osmotic equilibrium?
fluid concentration equal in ICF & ECF
what is chemical disequilibrium?
ECF high in Na+, Cl-, Ca2+
ICF high in K+, anions
what is electrical disequilibrium?
ECF positively charged
ICF negatively charged
what is osmosis?
movement of water across a MB
-in response to a gradient
what is osmolarity?
number of particles per liter
-looking at combined total of NP & P
what is isosmotic?
same number of particles
what is hyperosmotic?
ECF is higher (outside)
what is hypoosmotic?
ICF is higher (cell)
what is tonicity?
comparing solution to cell volume
-look only at NP solutes!!
what is hypotonic?
cell swells, gains H2O
-ICF high
what is hypertonic?
cell shrinks, loses H2O
-ECF high
what is isotonic?
no gain or loss of H2O
what are penetrating solutes?
UREA
-freely diffuse across MB
-no water movement
what are nonpenetrating solute?
NaCl, GLUCOSE
-trapped by the MB
-needs water to move it
when ICF NP is bigger than ECF NP, water moves ____
water move INTO cell
-direction goes towards the higher amount
what is a conductor?
ions move freely through
-water
what is an insulator?
ion movement stopped
-phospholipid bilayer
how does the Na+/K+ pump impact RMP?
3 Na+ OUT, 2 K+ IN
-makes ECF more positive, ICF more negative
how does the K+ leak channel impact RMP?
K+ OUT (tonic control)
-makes ECF more positive, ICF more negative
how do anions impact RMP?
makes ICF more negative
what does depolarization do to RMP?
makes ICF more positive
-opening Na+ channels, removing K+ leak channels
what does hyperpolarization do to RMP?
makes ICF more negative
-opening Cl- or K+ channels
what does repolarization do to RMP?
returns RMP back to ~70mV
what type of cell secretes insulin? what is the process of it?
beta cells when glucose is HIGH
-ATP -> close K+ channels -> open Ca2+ channels
-exocytosis (release) of insulin
what is the mOsm of the ICF?
always 300mOsm NP!!!
osmolarity ____ predict tonicity
does not predict
is the cell more permeable to K+ or Na+?
K+
what is the generic response to a stimulus?
stimulus -> sensor -> input -> int. center -> output -> target
what is homeostasis?
range
-when disrupted it compensates for change
what is negative feedback?
response opposes / decreases initial stimulus
-brings toward homeostasis
what is positive feedback?
response enhances / increases initial stimulus
-brings away from homeostasis
what is feedforward control?
starts response prior to stimulus (smell, sight)
what is circadian rhythm?
repeatable & predictable day & night cycles (temp)
what is acclimatization?
adapting to the environments (altitude)
what are three types of local communication?
gap junctions
contact-dependent signal
paracrine & autocrine
how do gap junctions work?
direct connection through cytoplasm
-connexion proteins close & open junction
how do contact-dependent signals work?
ligand & receptor
how do paracrines & autocrines work?
paracrine: release from cell
autocrine: release from itself
what are two ways of long-distance communication?
endocrine glands
neurons
how do endocrine glands work for communication?
secrete hormones into the blood
how do neurons work for communication?
secrete neurocrines
-NT, neuromodulator, neurohormone
what is the generic signal pathway?
- signal molecule, 1st messenger (ligand, extracellular signal)
- recep. protein, transducer (receptor, converts extra to intra)
- intracell signal molecule, 2nd messenger (activates pathway)
- target proteins (modifies, phosphorylation)
- response
describe lipophilic / hydrophobic signal molecules
lipid loving, water fearing
-diffuses easily into cell
-binds intracellular receptor
-alters gene expression
-SLOW
describe lipophobic / hydrophilic signal molecules
lipid fearing, water loving
-binds receptor on surface of cell
-RAPID
what are the four types of signal pathways?
receptor / ion channels
GPCR
receptor enzymes
integrin receptor
how does the receptor / ion channel work?
ligand binds receptor
-opens/closes ion channel
-depolarization or hyperpolarization
-RAPID
-EX: muscle contraction
how does the cAMP pathway work? (GPCR)
- ligand binds GPCR
- G-protein activates
- adenyly cyclase activates
- increases cAMP
- activates protein kinase A
- phosphorylation cascade
how does the phospholipase C pathway work? (GPCR)
- ligand binds GPCR
- activates PLC
- activates DAG & IP3
- DAG activates protein kinase C
- IP3 releases Ca2+ stores
how does the receptor enzyme work?
two parts
-receptor region (extracellular
-enzymatic region (intracelluar)
how does the tyrosine kinase pathway work? (receptor enzyme)
- ligand binds extracellular region
- activates intracellular region
- activates tyrosine kinase
- phosphorylation cascade
how does the integrin receptor work?
-receptor spreads across entire MB
-connects to cytoskeleton through an anchor protein
-extracellular matrix interacts with intracellular components
-antibodies, clotting factors
how does nitric oxide (NO) modify signal pathways?
smooth muscle relaxation
-vasodilation
-neuromodulator
-LOCAL, SHORT ACTING
how does carbon monoxide (CO) modify signal pathways?
vasodilation
how does hydrogen sulfide (H2S) modify signal pathways?
vasodilator
how do eicasanoids modify signal pathways?
lipid soluble
how are eicasanoids synthesized?
PLA2 -> arachidonic acid -> leukotrines & prostanoids
what are the effects of leukotrines & prostanoids?
leukotrines: asthma, allergy
prostanoids: inflammation, pain, NSAIDs inhibit them
what is an agonist?
bind same receptor, mimic same response
-creates competition
what is an antagonist?
bind receptor, blocks activity of ligand
what does down-regulation do?
decreases number of receptors, decreases response
what does desensitization do?
chemically modify receptor
-decreases response QUICKER
what does up-regulation do?
increase number of receptors, increases response
what are three ways to terminate a signal?
enzyme destroys ligand
neighbor cells uptake signal
down-regulation
what is the difference between central and peripheral receptors?
central: brain, special senses
peripheral: everything else
what is the difference between simple and complex reflex pathways?
simple: 1 integrating center, FAST
complex: multiple integrating centers, SLOW
what is are differences b/w neural and endocrine reflex pathways?
neural: specific, electrical & chemical, FAST, short duration, increase frequency (identical in strength)
endocrine: nonspecific, chemical, SLOW, long duration, increase amount, endocrine cell is the [sensor, input, integration center]
what are afferent neurons in a reflex pathway?
send signal to integrating centers
what are efferent neurons in a reflex pathway?
send signal to targets
describe the neural reflex pathway?
receptor
afferent neuron
NS
efferent neuron
muscle, gland, fat
contraction, secretion, metabolism
describe the neuroendocrine reflex?
receptor
afferent neuron
NS
efferent neuron
blood
enzymatic rxns, transport, cell proteins
describe the endocrine reflex?
endocrine system
hormone blood
enzymatic rxns, transport, cell proteins
what are pheromones?
secreted into external environment
what are cytokines?
made on demand, not stored
what is a candidate hormone?
appears to look / act like a hormone but isn’t
describe peptide hormone synthesis
preprohormone -> prohormone (R. ER) -> secretory vesicle
describe transport of peptide hormones (solubility, receptor)
lipophobic / hydrophilic
-no transport protein
-surface receptors
-FAST
describe synthesis of steroid hormones
cholesterol -> secreted on demand -> simple diffusion
-SMOOTH ER
describe transport of steroid hormones (solubility, receptor)
lipophilic / hydrophobic
-transport protein
-intracellular receptors
-SLOW
what are the two types of amine hormones?
catecholamines (NE, E, dopamine, melatonin)
thyroid hormone
describe the synthesis of catecholamines
tyrosine -> secretory vesicle
describe transport of catecholamines hormones (solubility, receptor)
lipophobic / hydrophilic
-no transport protein
-surface receptor
-FAST
describe synthesis of thyroid hormone
tyrosine + iodine -> stored in colloid
describe transport of thyroid hormones (solubility, receptor)
lipophilic / hydrophobic
-transport protein
-intracellular signal
-SLOW
what is a synergistic hormone interaction?
effect of hormones is greater than the sum
what is a permissiveness hormone interaction?
hormone isn’t active until the other hormone is present
what is a antagonistic hormone interaction?
hormone effects oppose eachother
what are trophic hormones? name the 5 major ones from the anterior pituitary
controls secretion of other hormones
-GH, ACTH, TSH, FSH, LH
what is the portal system in the brain?
hypothalamus & anterior pituitary
what is a long-loop feedback pathway?
terminal hormones inhibits hypothalamus & anterior pituitary
what is a short-loop feedback pathway?
anterior pituitary inhibits hypothalamus
what is the thyroid hormone feedback pathway? (check image in notes for full info)
TRH -> TSH -> T3 & T4 (thyroid gland)
what is the cortisol feedback pathway? (check image in notes for full info)
CRH -> ACTH -> cortisol (adrenal cortex)
what is the growth hormone pathway? (check image in notes for full info)
GHRH & GHIH/somatostatin -> GH -> IGFs (liver, other)
pineal gland hormones, targets, and effects
[melatonin]
-> brain -> circadian rhythm
hypothalamus hormones, targets, and effects
[DA, TRH, GHIH, CRH, GnRH, GHRH]
-> ant. pit. -> alter channels
posterior pituitary hormones, targets, and effects
[oxytocin, vasopressin/ADH]
-> breasts, kidney -> milk ejection, water reabsorption
anterior pituitary hormones, targets, and effects
[prolactin] -> breast -> milk production
[GH] -> liver -> growth
[ACTH] -> adrenal cortex -> cortisol release
[TSH] -> thyroid gland -> TH release
[FSH, LH] -> gonads -> egg/sperm release
thyroid gland hormones, targets, and effects
[T3, T4, calcitonin]
-> bone, many -> Ca2+ levels, metabolism
parathyroid hormone hormones, targets, and effects
[PTH]
-> bone, kidney -> plasma Ca2+
pancreas hormones, targets, and effects
[insulin, glucagon, somatostatin]
-> many -> metabolism of glucose
adrenal cortex hormones, targets, and effects
[aldosterone, cortisol, androgens]
-> kidney, many -> Na+/K+ balance, stress, sex
testes hormones, targets, and effects
[androgens, inhibin]
-> many, anterior pit -> sperm production, inhibit FSH
ovaries hormones, targets, and effects
[estrogen, progesterone, inhibin, relaxin]
-> many, ant. pit., uterus -> egg production, inhibit FSH, relax muscles
what is the difference between hypersecretion and hyposecretion?
hyper: too much hormone
hypo: not enough hormone
what is primary endocrine pathology?
last gland is defective
-HYPO: high TRH & TSH, low T3 & T4
-HYPER: low TSH & TSH, high T3 & T4.
what is secondary endocrine pathology?
second gland is defective
-HYPO: high TRH, low TSH, T3 & T4
-HYPER: low TRH, high TSH, T3 & T4
what is tertiary endocrine pathology?
first gland is defective (rare)
-all hormones either high or low
