Physiology Flashcards
What mm comprises the upper esophageal sphincter?
cricopharyngeus
T/F: chewing is essential for digestion
False: it just increases the surface area of the food
in which region of the stomach are parietal and chief cells located?
Body or corpus
What hormone, released in response to low pH, inhibits gastric emptying by decreasing antral contractions, increases constriction of the pyloric sphincter, and also increases bicarb secretions from the pancreas?
Secretin
In which regin of the stomach are G cells located?
Antrum (they secrete gastrin: G for gastrin)
How long is the transit time through the large intestine?
3-4 days
How long is the transit time through the small intestine?
2-4 hours
What hormone causes contractions of smooth mm, regulates interdigestive motility, and prepares the intestine for the next meal?
Motilin
What is the main function of HCL in the stomach
converts pepsinogen into pepsin
What hormone increases the intestinal secretions of electrolytes and H20, relaxes smooth mm, dilates peripheral blood vessels, and inhibits gastric secretions?
Vasoactive intestinal peptide (VIP)
What gland produces 20% of salivary secretions and contributes to almost all of the amylase secretions
Parotid gland (serous secretions)
What hormone causes contractions of the gallbladder, augments the action of secretin to produce an alkaline pancreatic juice, inhibits gastric emptying, and increases constriction of the pyloric sphincter?
Cholecystokinin (CCK)
What are the 4 functions of saliva?
- Provdies antibacterial action
- lubricates
- begins carb digestion
- begins fat digestion
What is composed of skeletal mm, innervated by the pudendal nerve, and in a voluntary constant state of contraction that relaxes for defecation?
External anal sphincter
What hormone is stimulated by glucose and fat in the duodenum, inhibits gastric secretions and motility, and stimulates insulin secretion?
Gastrin inhibitory peptide (GIP)
Which portion of the autonomic nervous system regulates salivary flow?
parasympathetic portion
a pH less than 4.5 stimulates the release of what hormone?
Secretin (it inhibits acid secretion)
what is composed of smooth mm, innervated by pelvic splanchnics and hypogastric nerves, and involuntary?
internal anal sphincter
What gland produces 70% of total salivary secretion?
submandibular gland (produces both mucous and serous secretions)
what is the tonicity of pancreatic juice?
isotonic
what organism is associated with gastric ulcers?
h pylori
what is the only gastric secretion required to sustain life?
intrinsic factor (IF)
what 3 structures increase the surface area of the GI tract?
- plicae circularis (x3)
- villi (x30)
- microvilli (x600)
what hormone is the primary regulator of HCO3 secretion from the pancreas
secretin
what cells of the GI tract secrete mucus
goblet cels
what are the five F’s associated with gallstones?
- fat
- forty
- female
- familial
- fertile
lactose intolerance is caused by a lack of what enzyme
lactase
what are the 3 end products of amylase digestion?
- maltose
- maltotetrose
- alpha limit dextrans (alpha-1,6 binding)
what percentage of bile acids are excreted daily?
5% (95% reabsorbed via enterohepatic circulation)
which glands of the upper duodenum secrete a bicarb-rich solution?
brunner’s glands
what is the major route for excretion of cholesterol?
bile
what hormone potentiates the effect of secretin?
CCK
what is the major phospholipid in bile?
lecithin
what is the rate-limiting step in the formation of bile acids?
7a-hydroxylase
what 2 aa are conjugated to bile acids to increase h20 solubility?
- glycine
2. taurine
what is absorbed in the gallbladder to concentrate bile?
water
if a substance is removed from circulation by an organ, is its arteriovenous (AV) difference positive or negative?
positive AV difference
in laminar flow, which area has the fastest flow?
the center of the tube
what are 4 ways to get an increased pump function of the heart?
- exercise
- increase HR
- increase arterial pressure
- increase contractility
what system has an increased pressure, decreased resistance, increased flow, increased compliance, and blood volume that is proportional to flow?
pulmonary circuit
what 2 organs have local metabolites as the main determinant of blood flow?
- brain (cerebral circulation)
- GI tract (after a meal)
all other organs are under neural control
what are the 3 sympathetic effects on the pacemaker cells of the heart?
- increase the slope of prepotential
- take less time to reach threshold
- increase the rate of firing
what are the 3 parasympathetic effects on the pacemaker cells of the heart?
- hyperpolarize the cells by increasing K+ conductance
- take longer to reach threshold
- decrease the rate of firing
what are the 2 major causes of arterial pressure?
- contraction of the heart
2. hydrostatic pressure
what causes an increase in cardiac performance with no increase in preload?
contractility (inotropic)
change in what intracellular ion causes a change in contractility?
calcium
what are the 2 main circulations with extrinsic regulation that are most affected by nervous reflexes?
- cutaneous circulation
2. resting skeletal mm
what is the third heart sound caused by?
ventricular filling (heard during diastole)
what is the fourth heart sound caused by?
atrial contraction (heard during diastole)
if a substance is put into circulation by an organ, is its arteriovenous difference positive or negative?
negative
What is the baroreceptor response to an increase in BP?
increase afferent activity of CN IX and CN X to decrease HR (parasympathetic)
what is a perfusion-limited situation
when alveolar and capillary blood equilibrate for a substance
which region of the lungs has a low perfusion pressure and a high resistance so that there is little blood flow?
apex
what fluid is monitored directly by central chemoreceptors
cerebrospinal fluid (H+:CO2)
On a pressure-volume loop, what is seen with: aortic regurgitation?
increase in stroke volume
On a pressure-volume loop, what is seen with: aortic stenosis?
increase in afterload, decrease in stroke volume, increase in peak tension
On a pressure-volume loop, what is seen with: increase contractility
increase in SV by decreasing the end-systolic volume
On a pressure-volume loop, what is seen with: heart failure?
increase in end-systolic volume, decrease in afterload, decrease in peak tension, increase in peak tension
What 2 compensatory mechanisms occur to reverse hypoxia at high altitutdes?
- increase in EPO
2. increase in 2,3-BPG,also called 2,3 diphosphoglcerate (increase in glycolysis)
what would you give to neutralize the excess base in an alkalotic patient?
NH4Cl (strong acid can lyse RBCs)
What would you give to neutralize the excess acid in an acidotic patient?
NaCO2 (CO2 eliminated by lungs)
what is a diffusion-limited situation?
when alveolar gas and capillary blood attempt to equilibrate but do NOT (ie CO2)
what must occur in order for PaCO2 to remain constant when there is an increase in the body’s metabolism?
need to increase alveolar ventilation (if not hypercapnia would result)
what enzyem is needed for conversion of testosterone to estradiol?
aromatase
what 2 anions compete with iodine for the iodine pump in the thyroid gland?
- percholorate
2. thiocyanate
what enzyme is associated with isteoblastic activity?
alkaline phosphatase
what form of plasma calcium is the physiologically active form and is regulated within narrow limits?
free calcium (ionized)
which 3 factors cause the release of epinephrine from the adrenal medulla?
- exercise
- emergencies (stress)
- exposure to cold
(the 3 Es)
what phase of the female cycle ALWAYS lasts for the same number of days (14 days in most women)?
luteal phase
what serves as a marker for 24 hour GH secretion?
plasma insulinlike growth factor type 1 (IGF-1) levels
what 3 things inhibit the secretion of glucagon?
- insulin
- somatostatin
- hyperglycemia
which 3 organs or structures have gluconeogenic capabilities?
- liver
- kidney
- GI epithelium
which type of diabetes is more likely to lead to ketoacidosis?
type I (insulin-dependent diabetes mellitus)
excess bone demineralization and remodeling can be detected by checking urine levels of what substance?
hydroxyproline (breakdown product of collagen)
what 2 things cause 1a-hydroxylase activity to increase?
- PTH
2. a decrease in PO4 levels
what type of membrane is permeable to water and small solutes?
selectively permeable membrane
what is the movement of ions in an electrical field known as ?
conductance
what 2 components of a body of water cannot be measured and need to be calculated?
ICF (water minus ECF)
2. interstitial fluid (ISF) - ESF-plasma volume
what phase of an action potential has the greatest rate of Na+ flux?
phase 0
which phase of an action potential requires energy?
phase 4 (via the Na+/K+ pump)
what type of mm is assoc with one T tubule and 2 cisternae (triad)?
skeletal mm
what is the region of an axon where no myelin is found
nodes of ranvier
what type(s) of mm contain the thin filament troponin
skeletal and cardiac mm
where are ADH and oxytocin produced?
the supraoptic and paraventricular nuclei of the hypothalamus
what is the only hormone to INCREASE with a DECREASE in pituitary function
prolactin
which enzyme converts cholesterol to pregnenolone?
desmolase - rate limiting step in steroid hormone synthesis
what are the 4 “stress” hormones?
- GH
- gulcagon
- cortisol
- epinephrine
pro-opiomelanocortin (POMC) is cleaved into what 2 substances?
- ACTH (adrenocorticotrophic hormone)
2. -lipotropins (melanotropins and endorphins)
what are the 6 substances that promote the secretion of insulin?
- glucose
- aa (arginine)
- GIP (gastrin inhibitory peptide)
- glucagon
- B-agonists
- ACh
what is the thin filament that has the attachment site for the cross-bridges and also activates adenosine triphosphatease (ATPase)?
actin
what types of muscle have a sarcomere?
skeletal mm and cardiac mm
where is the action potential generated on a neuron?
axon hillock
what is the name for the load that the mm is working aginst during stimulation?
afterload
what type of contraction has an active tension when the length is shortened?
isotonic contraction
what type of mm has high creatinine phosphokinase (CPK), high ATPase activity, and no myoglobin; is anaerobic; and is for short-term use?
white mm (fast)
what type of mm uses calmodulin
smooth mm
what thick filament has cross-bridges and ATPase activity?
myosin
what causes actin-myosin cross-bridge dissociation?
binding of ATP
what is used as an index of cortisol secretions?
urine 17-OH steroids
What would be the 2 major consequences if the zona fasciculata and the zona reticularis were removed?
- circulatory failure
2. inability to mobilize energy stores
how many carbonds do androgens have?
androgens are 19-carbon steroids
how many carbons do estrogens have?
estrogens are 19-carbon steroids (removal of 1 carbon from an androgen = an estrogen)
the level of what hormone tends to decrease with stress
insulin
on what 2 occasions are cortisol-releasing hormone (CRH) secretions elevated?
- Early morning
2. during stress
what is an inhibitory interneuron known as?
Renshaw neuron
what is the summation of mechanical stimuli known as?
tetany
what is the thin filament that binds to calcium?
troponin
what determines the max velocity of shortening mm?
the muscle’s ATPase activity
what type of mm has end plates?
skeletal mm
what type of contraction has an active tension, but the overall length of the contraction does not change and no work is done?
isometric contraction
what thin filament covers the attachment site in resting mm so that the cross-bridges are unavailable for binding?
tropomyosin
what is the load on a mm in the relaxed state known as?
preload
total tension - reload = what?
active tension (contraction)
what types of mm are uninuclear?
cardiac and smooth mm
in a contractile mm, what is the source of the calcium?
sarcoplasmic reticulum (the source is NOT extracellular)
what is the max force of a contraction determined by?
the number of motor units activated during the contraction
what types of mm have T tubules assoc with them?
cardiac and skeletal mm
what type of mm has myoglobin, low CPK, and low ATPase activity; is aerobic; and is used for long-term use?
red mm (slow-twitch mm)
what event signifies the first day of the menstrual cycle?
the first day of bleeding
what hormone is essential for induction of ovulation and formation of the corpus luteum?
LH
how many days before the first day of bleeding is ovulation?
14 days in most women (remember; the luteal phase is always constant)
what is required to maintain lactation?
suckling (stimulates oxytocin secretion)
what hormone , in high levels, blocks milk production?
estrogen
what hormone is necessary for maintenance of the corpus luteum for the first 3 months of pregnancy?
hCG from the trophoblast.
Up to how many hours after ejaculation are sperm able to fertilize the egg?
72 hours
what hormone induces myometrial contraction and causes milk let-down
oxytocin
what hormone is necessary for the maintenance of the uterine endometrium from the 4th month of pregnancy on?
progesterone (estrogen is needed for progesterone to be effective)
how long after ovulation does fertilization occur?
8-25 hours
what hormone thins cervical mucus, stimulates LH receptors on granulosa cells, elicits the LH surge, and increases proliferation of the uterine mucosal layers?
estradiol
what hormone is secreted by the placenta late in pregnancy, stimulates mammary growth during pregnancy, mobilizes energy stores from the mother so that hte fetus can use them and has an aa sequence like GH
Human chorionic somatomammotropin (hCS) or human placental lactogen (hPL)
what hormone causes an increase in the production of milk?
prolactin
what is the force necessary to collapse the lung known as?
lung recoil
for what hormone do Leydig cells have receptors?
LH
what vitamin needs thyroid hormone for conversion to its active form?
Vit A
What is the tonicity of fluid that leaves the loop of Henle?
Hypotonic
what enzyme converts androgens to estrogens?
aromatase
what does excess production of TSH cause?
goiter
what type of cell reabsorbs bone?
osteoclast
Blast makes
clasts take
what is the major form of androgen secreted from the adrenal gland?
Dehydroepiandrosterone (DHEA)
what cells of the GU system produces testosterone in males?
Leydig cells
What type of urine does ADH cause to be excreted?
hypertonic urine (bc of the water reabsorption in the collecting duct
what is the term for the volume of plasma removed from a substance per unit time?
clearance
what is the most potent male sex steroid?
dihydrotestosterone
what 2 substances stimulate sertoli cells?
follicle-stimulating hormone (FSH) and testosterone
at which 3 sites in the body is T4 converted to T3?
- Liver
- Kidney
- Pituitary gland (via 5’-deiodinase enzyme)
the fresh air being delivered to the respiratory zone per minute is known as what?
Alveolar ventilation (the first 150ml is not included)
What region of the lungs gets very little ventilation?
Apex
Where does polyuria orginate if the patient is dehydrated and has electrolyte deficiencies?
before the collecting duct (there is no electrolyte disturbance in the collecting duct)
what substance is free filtered but partially reabsorbed by passive mechanisms?
urea
what hormone promotes mobilization of energy stores, enhances the capacity of glucagon and catecholamines, and increases the capacity to withstand stress?
cortisol
what is used as an index of androgen secretion?
urine 17-ketosteroids
what are the pituitary hormones associated with: thyrotropin releasing hormone (TRH)?
TSH
what are the pituitary hormones associated with: cortisol-releasing hormone (CRH)?
Adrenocorticotrophic hormone (ACTH)
what are the pituitary hormones associated with: Gonadotropin releasing hormone (GnRH)?
Luteinizing hormone (LH) follicle-stimulating hormone (FSH)
what are the pituitary hormones associated with: Growth hormone relasing hormone (GH-RH)
GH
what are the pituitary hormones associated with: somatostatin?
inhibits GH secretion
what are the pituitary hormones associated with: prolactin-inhibiting factor (PIF) [dopamine]
inhibits prolactin secretion
Which hormones are released from the: zona glomerulosa?
aldosterone (salt)
Which hormones are released from the: zona fasciculata?
cortisol (sugar)
Which hormones are released from the: zona reticularis?
Androgens (sex)
Which hormones are released from the: medulla?
NE:Epi (1:4)
If the zona glomerulosa were removed from the adrenal gland, what would be seen?
Decrease in Na+ causing a decrease in the ECF volume, leading to a decrease in BP, and eventually to circulatory shock and death
What does subatomospheric pressure (neg) do to the lungs?
causes them to expand (bc of the dec in intrathoracic pressure)
where is the last conducting zone of the lungs?
terminal bronchioles (no gas exchange occurs here)
where is there summation, hyperpolarization of the postsynaptic membrane, an increase in Cl- conductance, and local gradation?
inhibitory postsynaptic potential (IPSP)
which extravascular chemoreceptor detects low NaCl concentrations?
macula densa
What is the major stimulus for cell division in chondroblasts?
insulin-like growth factor-1 (IGF-1)
the total air in and out of the respiratory system per minute is known as what
the total ventilation (minute volume or minute ventilation)
what is the major hormone secreted by the ovarian follicle?
17b-estradiol
what 2 conditions cause ADH to be released?
- Low blood volume
2. elevated plasma volume (high solute concentration)
what cell converts androgens to estrogens? what hormone acts on this cell?
granulosa cell
FSH
what 3 lung volumes cannot be measured with a spirometer?
- residual volume
- TLC
- functional residual capacity
What 2 conditions dec the secretion of aldosterone?
- inc in BP
2. weightlessness
what cell in the female GU system is stimulated by LH and is the site where androgens are produced?
thecal cell
what serves as a marker of endogenous insulin secretions?
c peptide
what do you have when there is a depolarization of the postsynaptic membrane owing to an influx of Na+ resulting in summation and local gradation?
excitatory postsynaptic potential (EPSP)
what are days 15-28 in the female cycle known as?
Luteal phase
what hormone is secreted by the Sertoli cells to dec FSH production?
Inhibin
What hormone regulates osmolarity bc it controls water excretion?
ADH (it causes water reabsorption)
what is the term for the air in the system after maximal inspiration?
TLC
what is a sign of a Sertoli cell tumor in a man?
excess estradiol in the blood
what hormone is responsible for the negative feedback onto LH and FSH of the anterior pituitary and positive feedback onto the granulosa cells?
Estrogen
what is the term for the total dead space of the lungs?
physiologic dead space
the surge of what hormone induces ovulation?
LH
what does positive pressure do to the lungs?
it collapses them
what is the term for the air that can be taken in after normal inspiration?
inspiratory reserved volume (IRV)
what is the first zone of the lungs that is capable of O2 exchange?
respiratory bronchioles (bc they have alveoli)
what is the term for ventilation of underperfused alveoli?
alveolar dead space
what is the temp of the scrotum and how is it maintained?
4 degrees cooler than the body - by a countercurrent heat exchanger in the spermatic cord
what happens to sex steroids, LH, and FSH: if the gonads are removed?
sex steroids decrease
LH inc
FSH inc
what happens to sex steroids, LH, and FSH: in postmenopausal women?
sex steroids dec
LH inc
FSH inc
what happens to sex steroids, LH, and FSH: after the admin of testosterone?
Sex steroids inc
LH dec
nothing happens to FSH
what happens to sex steroids, LH, and FSH: after the admin of inhibin?
Sex steroids - nothing
LH - nothing
FSH - dec
what happens to sex steroids, LH, and FSH: with constant infusion of GnRH
Sex steroids dec
LH dec
FSH dec (needs to be givin pulsatile)
What region of the lungs is incapable of gas exchange?
anatomic dead space
what is the term for the amount of air that can never leave the lungs?
residual volume
if you inc the depth of breathing, what ventilatory parameters can be inc?
total ventilation and alveolar ventilation
If you inc the rate of breathing, what ventilatory parameters can be increased?
total ventilation
what is the term for the air left in the lungs after normal expiration?
functional residual capacity (FRC)
the lung vol from max insiration to max expiration is known as what?
vital capacity (VC)
where is renin produced?
in the juxtaglomerular (JG) cells of the kidney
what phase of the female cycle occurs during days 1-15
follicular phase
what hormone level peaks 1 day before the surge of LH and FSH in the female cycle?
Estradiol
what is the day after the LH surge in the female cycle known as?
ovulation
by what mechanism does chronic constriction keep blood flow through the penis low during non-aroused states?
alpha-adrenergic-mediated constriction
days 1-7 of the female cycle are known as what?
menses
the amount of air that enters or leaves the respiratory system in a single respiratory cycle is known as what?
tidal volume
what part of the autonomic nervous system is responsible for the movement of semen through the vas deferens and related structures?
sympathetic nervous system
which pancreatic cells secret glucagon?
alpha cells
which pancreatic cells secrete somatostatin?
delta cells
what term describes how easily a vessel stretches
complaince (pulse pressure is inversely proportional to compliance)
what is the most compliant artery in the body
aorta
what is the best way to regulate mean arterial pressure?
via total peripheral resistance (TPR)
what is the term for resistance to ventricular outflow?
afterload
what is the main determinant of resistance?
the radius of the vessel (also the viscosity and length)
what is the relationship bw NA+ reabsorption and O2 consumption?
an inc in Na+ causes O2 consumption to inc
what vessels have the greatest cross-sectional area?
capillaries
what is the nontitratable acid that buffers secreted H+ in the kidney buffered as?
NH4+ (ammonium). H2PO4 (dihydrogen phosphate) is the tiratable acid that buffers secreted H+
what are the 5 ways to promote turbulent flow?
- inc velocity
- branching
- narrow orifice
- inc tube diameter
- dec viscosity
What part of the CV system has the lowest drop in pressure?
R atrium
what vessels are the resistance vessels and have the largest drop in pressure?
arterioles
What part of the autonomic nervous systemis the main controller of blood flow when a person is at rest?
sympathetic nervous system
Alpha constricts
beta-2 dilates
what process occurs when hydrostatic pressure exceeds plasma oncotic pressure?
filtration
what vessels have the greatest blood volume?
systemic veins of the lower extremities
what vessels have the smallest total cross-sectional area?
aorta then the vena cava
what is the only way to inc O2 delivery to the myocardium?
inc blood flow
what happens to airway resistance during inspiration?
it decreases
sympathetics dec resistance; parasymp inc resistance
what is the main drive for ventilation?
the PCO2 of systemic circulation
where does depolarization in the heart begin?
from the apex to the base and from the endocardium to the epicardium
where is the greatest venous PO2 in resting tissue
renal circulation
the load on the mm in the relaxed state is known as what?
preload (also the end-diastolic vol [EDV])
what cells of the heart have the highest rate of automaticity?
SA nodal cells
what are the slowest conducting cells of the heart?
AV nodal cells
what is the main control of flow in exercising mm?
vasodilator metabolites
During what phase of the cardiac cycle do coronary vessels receive their blood flow?
diastole
on the venous pressure curve, what do the following waves represent? a wave
Atrial contraction
on the venous pressure curve, what do the following waves represent? C wave
ventricular contraction
on the venous pressure curve, what do the following waves represent? v wave
atrial filling (venous filling) Atrial, Contraction, VEnous
what causes the second heart sound?
aortic closure
Where is the second heart sound on an EKG
T wave
what causes the diastolic interval to decrease?
inc in HR
what happens to cerebral circulation during hypoventilation?
blood flow inc bc PCO2 is increased (the opp occurs during hyperventilation)
what is the main factor affecting PCO2?
alveolar ventilation (hyperventilation dec PaCo2 and vice versa. Body metabolism also affects PaCo2
What are the normal values for: PaO2?
100mmHG
What are the normal values for: PaCO2?
40mmHG
What are the normal values for: PvO2?
40mmHG
What are the normal values for: PvCO2
47mmHG
what are the 2 ways to inc SV?
- inc preload (EDV)
2. dec end-systolic volume (ESV)
what is the mian factor that determines the glomerular filtration rate (GFR)?
hydrostatic pressure
What is the normal value for the GFR?
120ml/min
what happens to pulm blood flow under conditions of low alveolar PO2?
dec in blood flow secondary to vasoconstriction
what is the normal compensatory mech for a state of metabolic alkalosis?
Hypoventilation (resp acidosis)
what anion is excreted in large amounts in the urine in a patient with a compensated alkalosis?
bicarbonate (alkaline urine
which hormone affects the osmolarity?
ADH
What are the sympathetic effects on the kidney?
A dec in GFR and inc in filtration fraction: FF= GFR?RPF
There is a larger dec in RPF than the GFR, resulting in an inc in filtration fraction
what are the effects of angiotensin II on the kidney?
construction of the efferent arterioles
what 4 changes occur with an increase in contractility?
- inc slope of action otential
- inc peak left ventricular pressure
- inc rate of relaxation
- dec systolic interval
what fibers f the heart have the lowest intrinsic rate of automaticity?
purkinje fibers
what causes the first heart sound, and when does it occur on an EKG?
mitral valve closure at the QRS complex
what is the main determining factor of filtration fraction?
renal plasma flow (dec flow, inc filtration fraction)
what is the normal osmolarity of the filtrate in the renal tubule?
300mOsm
what prohibts the filtering of protein anions into the renal tubule?
the neg charge on the filtration membrane
what are the fastest conducting fibers in the heart?
purkinje
from which point ot which point does repolarization travel in the hear
from the base to the apex and from the epicardium to the endocardium (opp of depolarization)
what is the major autoregulator of: cerebral circulation
inc in PCO2
what is the major autoregulator of: coronary cirulation
dec in PO2, inc in PCO2 and adenosine
what is the major autoregulator of: exercising skeletal mm
lacatate
what process occurs if the capillary oncotic pressure is greater than the hydrostatic pressure
reabsorption
what area of the circulatory system houses the greatest blood velocity?
aorta
what 2 things happen to cutaneous circulation whtn the symp nervous system is stimulated?
- construction of arterioles to dec blood flow
2. constriction of the venous plexus to dec the blood volume
adenosine in the kidney, dec PO2 in the lungs, and thromboxane A2 (TXA2) have what effect in the circulation?
vasoconstriction
what is the period when higher than normal stimulation is required to induce a second action potential?
relative refractory period
during an AP what is the stimulus for opening the Na_ channels?
depolarization
what substance “affects” the AP
Na+ conductance
what substance “affects the resting membrane potential?
K+ conductance
in which direction do somotically active substances cause wtater to move?
toward them
what are the 3 tracers for total body water?
- urea
- thiourea
- titrated water
whate are the 3 characteristics of an AP
- all or none
- propagated
- non summation
in hwat system is the second greatest blood volume found?
pulm system
what are the 4 ways to inc total peripheral resistance?
1 dec radius
2. inc viscosity
3 inc length
4. dec # of parallel channels
what type of system is high-resistance system with flow equal at all points and where total reistance is the SUM of the indivdiual resistances?
vessels connected in a SERIES
what effect on a blood vessel does each of the following have: histamine, bradykinin, prostaglandins (A2, E2, I2), NO, adenosine, inc in K+ ,H, PCO2, and a dec in Po2
vasodilatory
What are 3 characteristics of a subthreshold potential?
- graded
- summation
- not propagated
what is the depolarization phase of an AP caused by?
na influx
if the ventilation-perfusion ratio is less than 1, what part of the lung is involved and what physiologic process is occurring?
base, bc flow exceeds delivery of O2
hwo do you compensate for metabolic acidosis?
hyperventilate (resp alkalosis)
how many liters of water are there in: total body water?
42L
how many liters of water are there in: ICF?
28L
how many liters of water are there in: ECF?
14L
how many liters of water are there in: ISF?
10.5L
how many liters of water are there in: plasma volume?
3.5 L
what hormone affects fluid volume?
aldosterone (Na+ content determines the vol of the plasma)
the repolarization phase of the AP is caused by what?
K+ efflux (depol opens the gates)
what is the name of the period in which, no matter how strong the stimulus, a second action potential cant be generated?
absolute refractory period
what hormone is necessary to maintain normal thyroid hormone levels?
GH
What region of the lung has the greatest blood flow?
the base
during inspiration which region of the lung receives the greatest level of ventilation: the apex or the base?
base
what is the function of the stretch receptors in the lungs?
to prevent overdistention of the lungs (inhibits inspiration)
where does the inherent rhythm for respiration originate?
in the medullary center of the medulla oblongota
where is the deep breathing center located?
apneustic center in the pons
what type of system is a low-resistance system in which the total resistance is always less than an y individual resistance, and the reciprocal of the total resistance is the sum of the reciprocal resistances?
system connected in parallel
what is happening to the renal arteriole when: inc GFR, inc glomerular pressure, dec RPF, inc FF
constriction of efferent arteriole
what is happening to the renal arteriole when: dec GFR, inc RPF, dec glomerular pressure, dec FF?
dilatation of the efferent arteriole
what is happening to the renal arteriole when: Dec GFR, dec RPF, dec glomerular pressure?
constriction of the afferent arteriole
what is happening to the renal arteriole when: inc GFR, inc RPF, inc glomerular pressure?
dilatation of the afferent arteriole
which region in the lungs gives the vest ventilation-perfusion ratio?
hilium
what causes peripheral chemoreceptors to be stimulated?
A dec in the arterioal PO2, H+ and PCO2 (not the normal drive for ventilation)
what is secreted by the parafollicular C cells of the thyroid?
calcitonin
what is the titrated acid that the secreted H+ is buffered as?
H2PO4
what type of dehydration is assoc with hemorrhage, burns, vomiting, and diarrhea?
isotonic dehydration
what is the potential at which concentrations are equal and opp to the electrical forces and also at which there is no net flux of ions across the membrane
EQ potential (Nernst’s equation)
what hydration state is caused by the ingestion of salt water?
hypertonic overhydration
what is the free water clearance if the osmolarity of urine is greater than 300mOsm
neg free water clearance (conc urine)
what is the term for the process of water traveling from a low solute to a high solute concentration
osmosis
what 3 factors inc simple diffusion?
- inc solubility
- inc conc gradient
- dec thickness of membrane
what type of dehydration is assoc with addison’s disease?
hypotonic dehydration
when is GH released?
at night and during puberty
what is protein-mediated transportation down a conc gradient known as?
facilitated transport
what determines the level of alveolar ventilation?
central chemoreceptors (PCO2)
which point in the lungs is involved if the ventilation-perfusion ratio is greater than 1? What is occuring?
Apex/ delivery exceeds the flow
how is CO2 carried in the blood?
As plasma bicarbonate
to what hydrated state can excess ingestion of water or SIADH lead?
hypotonic overhydration
what are the 4 major anabolic hormones?
- insulin
- thyroid hormone
- GH
- sex steroids
What are the 8 insulin-independent tissues?
- CNS
- RBCs
- Renal tubules
- testis
- teeth
6, beta cells
7, liver - intestinal epithelium
what are the growth factors released from the liver called? somatomedins
what state of hydration would you be in if you had edema and if you ingested excess salt
isotonic overhydration
what type of cell lays down bone?osteoblast: blasts make; clasts take
what is the only condition in which giving enriched O2 will not significantly inc PaO2
pulmonary shunt
what is the biologically active form of thyroid hormone?
T3
for how many months can you store thyroid hormone?
203 mo
what is the ratio of T4 to T3
20:1
what type of cell is surrounded by mineralized bone?
osteocyte
what type of dehydration is assoc with excess sweating, dec water intake, fever, alcoholism, lithium salts, excess evaporation, and diaetes insipidus?
hypertonic dehyrdation
during what part of the cardiac cycle do you hear: aortic stenosis?
systole
during what part of the cardiac cycle do you hear: mitral stenosis?
diastole
during what part of the cardiac cycle do you hear: mitral regurg
systole (pan)
during what part of the cardiac cycle do you hear: aortic regurg
diastole
What four factors affec the rate of diffusion
- surface area
- thickness of the membrane
- concentration gradient
- solubility (main factor)
What does a dec in GH in adolescence lead to?
dwarfism
what type of transportation requires ATP and is protein mediated against a concentration gradient
primary active transport
what does an inc in GH in adolescence lead to?
gigantism
what gas has a low driving force but high solubility
CO2
what are 2 causes of diffusion impairment in the lungs?
dec in surface area
2. inc in membrane thickness(palvo2 greater than Pao2)
what is evident in the urinarlysis of a compensated acidotic patient?
low HCO3-excretion (acidotic)
what does angiotensin II do to restore blood pressure
vasoconstrictive
when is systemic venous blood delivered to the L side of the heart without o2 exchange in the alveoli
pulm shunt
what gas has a high driving force and low solubility
o2
in what type of shunt do you see an inc in R atrial, ventricular, and pulm arterial Po2 along with an inc in pulm blood flow?
L to R shunt
what causes Ca+ and PO4 to be reabsorbed from the kidney and Ca+ and PO4 to be absorbed from the GI tract, and also promotes bone synthesis?
vit D3
what does excess secretion of GH in an adult lead to?
acromegaly
the rate at which a substance is filtered into Bowman’s capsule is known as what?
filtered load rate (GFR x plasma concentration)
what part of the nephron has the greatest osmolarity?
tip of the loop of Henle (1200 mOsm)
what region of the nephron does H+/HCO3- exchange occur?
distal tubule
what is the length of systole on a pressure curve?
from beginning of the isovolumic contraction (IVC) to the beginning of the isovolumic relaxation (IVR)
from which point to which point does systole appear on EKG?
QRS to the T wave (S1 to S2)
what are the 3 features of aortic stenosis?
- inc in afterload
- inc in LV pressure
- inc in pressure gradient bw LV and aorta
when is surface tension the greatest in a resp cycle?
at the end of inspiration
what type of transportation requires ATP, can be co- or counter transport, and is proteinmediated transport with a conentration gradient
secondary active transport
What lung pathology is assoc with a dec in FEV1/FVC?
obstructive path
what is the most important factor in describing lung recoil?
surface tension (also fibers of tissue)
what is the free water clearance if the osmolarity of urine is less than 300mOOsm?
positive free water clearance (dilute urine)
what four characteristics are common to all protein-mediated transportation?
- more rapid than diffusion
- zero-order kinetics
- chemical specificity
- competition for carriers
what causes an increase in Na+ and water loss from the kidney by inc GFR, stimualted by stress and high Na+ concentrations
atrial natriuetic factor (ANF) release fromt eh RA
wwhat growth factors are chondrogenic, working on the epiphyseal end plates of bone?
somatomedins (insulin-like growth factor type 1 [IGF-1]
what causes an inc in Ca+ reabsorption from the distal tubule, a dec in PO4 reabsorption from the kidney, and an inc in ca+ and PO4 reabsorption from the GI tract?
PTH
if a patient is irritated, excited, and emotionally unstable and has overal symptoms of B-adrenergic stimulation, would you assume that htis patient is hyperthyroidic or hypothyroidic?
hyperthyroidic
what is needed for proper postnatal and perinatal mental growth and also for proper bone ossification and GH secretion?
thyroid hormone
what type of heart block is assoc with slowed conduction through the A node and PR intervals greater than 0.21 sec?
first-degree heart block
what 2 occurences cause an inc in the force of contraction/
- inc in preload
2. inc in contractility by inc intracellular Ca+
what are 3 features of mitral regurg?
- inc in v wave
- inc in preload
- inc in atrial pressure and volume
what is the length of diastole on a pressure curve and where is it on an EKG?
from the beginning of the IVR to the beginning of IVC, and from the T wave to the QRS complex (s2 to S1)
what are the 3 features of mitral stenosis?
- inc in a wave
- dec in LV filling
- inc in AV pressure
what type of heart block is characterized by: progressive lengthening of the P-R interval until there is failure of the impulse to be transmitted?
second-degree heart block, Wenckebach (Mobitz type 1)
what type of heart block is characterized by: constant P-R interval but with occasional failure of conduction, resulting in atrial rate greater than ventricular rate?
second-degree heart block , non-wenckebach (mobitz type II)
what are the 3 functions of surfactant?
- inc compliance
- dec surface tension
- dec probability of pulm edema formation
more neg intrathoracic pressure causes what to happen to systemic venous return and what to the pulm vessels?
promotes systemic venous return into the chest and inc the caliber and vol of the pulm vessels.
what 4 factors cause the oxygen-hb dissoc curve to shift RIGHT?
- inc PCO2
- dec pH
- inc 2,3 BPG
- inc temp
what part of respiration, on a pressure volume curve acts “like the chest wall”?
inspiration (collapse is due to elastic recoil)
“secretion + filtration = excretion” is the transport max (Tm) for what substance?
para-aminohippurate (PAH)
what has happened if the amount filtered and the amount excreted per unit time are the same?
nothing; there has been no tubular modification
what happens to each of the following parameters in an obstructive vs restrictive lung problem: lung recoil?
obs: dec
rest: inc
what happens to each of the following parameters in an obstructive vs restrictive lung problem: FRC?
obs: inc
rest: dec
what happens to each of the following parameters in an obstructive vs restrictive lung problem: TLC?
obs: inc
rest: dec
what happens to each of the following parameters in an obstructive vs restrictive lung problem: FVC?
obs: dec
rest: dec
what happens to each of the following parameters in an obstructive vs restrictive lung problem:FEV1?
obs: dec
rest: dec
what happens to each of the following parameters in an obstructive vs restrictive lung problem: peak flow?
obs: dec
rest: inc
what happens to each of the following parameters in an obstructive vs restrictive lung problem: RV
obs: inc
rest: dec
what hormone inc reabsorption of Na+ by the principal cells and promotes excretion of H and K+ by the intercalated cells of the kidney?
alodsterone
what 3 situations cause the RAAS to fire?
- dec in BP in afferent arteriole
- low Na+ levels at the macula densa
- b1-symp nervous system imput
what pathology is assoc with low ACTH levels and high levels of cortisol?
Cushing’s syndrome (adrenal)
when do you see low urine flow, high urine osmolarity, high ECF vol, low ECF osmolarity (low Na+), high ICF vol, and low ICF osmolarity?
SIADH (water retention)
what is the term for the process in which excretion is less than the filtered load?
net positive reabsorption (glucose, Na+, urea)
what has happened when everything that is filtered is reabsorbed until the carriers are saturated and the excess is excreted int he urine?
the transport maximum has been reached (Tm glucose = 37g mg/min)
what 4 factors cause aldosterone to be released?
- conversion of angiotesnin I to angiotensin II
- hyperkalemia
- hyponatrimea
- dec in blood volume
what disease state includes buffalo hump, moon facies, hyperglycemia, hyperlipidemia, HTN, hypokalemia, osteoporosis, and thinning of the hair?
Cushings
What condition involes high urine flow, low urine osmolarity, low ECF vol, high ECF osmolarity, low ICF vol and high ICF osmolarity?
Diabetes insipidus (lose water)
whcih condition involves elevated ACTH and cortisol levels?
cushings (pituitary tumor)
which condition involves high ACTH, low cortisol, high ADH, elevated renin levels, hypotension, and low body hair?
addison’s disease (primary adrenal insufficiency)
what process has taken place in the kidney when excretion is greater than the filtered load?
net neg secretion (PAH, creatinine)
