Physiology Flashcards
1
Q
where does ivabradine act and what are it’s common uses?
A
SA Node → blocks funny current → decreases HR
- idiopathic sinus tach
- systolic HF when BB don’t reduce HR
2
Q
how does hyperkalemia look on the EKG?
A
“increases repolarization”
- sharp-spiked T waves
- short QT
3
Q
how does hypokalemia look on the EKG?
A
“decreases repolarization rate”
- U waves
- prolonged QT
4
Q
how does hypercalcemia look on the EKG?
A
decreased QT
5
Q
how does hypocalcemia look on the EKG?
A
increased QT
6
Q
what are the 3 key differences in cardiac vs skeletal muscle physiology?
A
cardiac:
- extracellular Ca+ is involved
- magnitude of SR Ca+ released can be altered → increase in contractility
- 2 mechanisms to remove Ca+ from the cytosol (SERCA + Na/Ca Exchanger)
7
Q
what are the causes of an elevated osmolar gap?
A
ethanol
methanol
ethylene glycol
acetone
mannitol
8
Q
normal lung volumes and capacities:
Vt, IRV, ERV, RV
IC, FRC, VC, TLC
A
Vt: 0.5 L
IRV: 3.5 L
ERV: 1.5 L
RV: 1.2 L
IC: 4 L
FRC: 2.7 L
VC: 5.5 L
TLC: 6.7 L
9
Q
Normal value for PBS (hydrostatic pressure in the bowman space)
A
8 mmHg
10
Q
Normal value for PGC (hp in the glom capillary)
A
45 mmHg
11
Q
Normal value for πGC (oncotic pressure in the glomerular capillary)
A
24 mmHg
12
Q
Normal value for πBS (oncotic pressure in the bowman space)
A
0 mmHg
13
Q
Normal GFR
A
120 ml/min or 180 L/day
14
Q
formula for filtration fraction
A
FF = GFR / RPF
15
Q
formula for net transport rate or mass balance
A
filtered load - excretion rate
(GFR x Px) - (V x Ux)
16
Q
clearance formula
A
Clearance of X = ER/Px = (V x Ux)/Px
17
Q
Tm for glucose
A
375 mg/min
18
Q
formula to estimate RPF from RBF
A
RPF = RBF (1-Hct)
19
Q
what is the net transport of inulin
A
no tubular modification
what is filtered is excreted
(no reabsorption, no secretion)
20
Q
what is the net transport of manitol
A
no tubular modification
what is filtered is excreted
(no reabsorption, no secretion)
21
Q
what is the net transport of bicarbonate?
A
fully reabsorbed
22
Q
what is the net transport of PAH
A
freely filtered + secreted until TM
23
Q
what is the net transport of creatinine
A
freely filtered + secreted until TM
(very little is secreted the TM is very low)
serves as a marker of GFR
24
Q
what is the net transport of urea
A
partially reabsorbed
25
most common cause of apneustic breathing
lesions to the caudal pons
26
most common cause of cheyene-stokes breathing
congestive heart failure
midbrain lesions
27
common clinical uses for hyperbaric chamber?
- carbon monoxide poisoning
- compromised tissue grafts
- gas gangrene
(clostridium perfringens, staph aureus, vibrio vulnificus)
28
formula for free water clearance
Clearance = V - (UosmxV/Posm)
29
expected ↑HCO3 in respiratory acidosis (↑CO2)
1 : 0.1
30
expected ↓HCO3 in respiratory alkalosis (↓CO2)
1 : 0.2
31
calculate adequate compensation for respiratory acidosis
32
calculate adequate compensation for respiratory alkalosis
33
calculate adequate compensation for metabolic acidosis
winter's formula
34
calculate adequate compensation for metabolic alkalosis
"summer's formula"
35
causes of metab acidosis with HIGH ANION GAP
36
causes of metab acidosis with NORMAL anion gap
37
effects of Fanconi
defect in proximal tubule
* metabolic acidosis
* hypophosphatemia
* hypokalemia
38
effects of bartter syndrome
defect in thick ascending limb
* hypercalciuria
* secondary aldosteronism
* metabolic alkalosis
* hypokalemia
39
effects of gitelman syndrome
defect in distal tubule
* hypocalciuria
* hypercalcemia
* metabolic alkalosis
* hypokalemia
* hypomagnesemia
40
effects of liddle syndrome
gain of function in ENaCs
* hypertention
* hypokalemia
* metabolic alkalosis
* low aldosterone
41
effects of SAME
cortisol actives mineralocorticoid receptors / hereditary deficiency (cortisol in mineralocorticoid receptor)
high aldosterone effects:
* metabolic alkalosis
* hypokalemia
* hypertention
**low serum aldosterone**
42
causes of HYPERkalemia
43
pathologies associated with MEN 1
Pancreatic endocrine tumors
Parathyroid adenomas
Pituitary tumors
(3Ps)
44
pathologies associated with MEN 2A
Medullary thyroid cancer
Pheocromocytoma
Parathyroid adenomas/hyperplasia
(2P's)
45
pathologies associated with MEN 2B
Medullary thyroid cancer
Pheocromocytoma
Mucosal neuromas
(1P)
46
wide slitting of S2
pathophysiology + causes
abnormal delay in the closure of S2
anything that causes a delay in RV emptying:
pulm stenosis, RBBB
47
fixed splitting of S2
pathophysiology + causes
equal splitting in inspiration and expiration
ASD!!!!
48
paradoxical splitting of S2
pathophysiology + causes
delayed aortic valve closure (inspiration: split elimintated, expiration: split is heard)
delay in LV emptying:
aortic stenosis, LBBB
49
what are the 3 effects of ANG II (besides vasoconstriction and aldosterone secretion)?
⊕ ADH release from posterior pituitary
↑ Na reabsorbtion in proximal tubule
↑ thirst
50
what is addison's disease
primary adrenal insufficiency (addison's adrenals are shot)
lack of cortisol, aldosterone, adrenal androgens
51
what is conn syndrome?
primary hyperaldosteronism
52
what is a paraganglioma
extra-adrenal pheochromocytoma
53
what is kussmaul breathing and when does it present?
deep rapid breating in order to compensate for acidosis seen in DKA
54
Sign? What does this indicate?
**stippled epiphysis**
hypothyroidism in children
55
🚩 TSI antibodies
graves disease
56
🚩 TPO antibodies
hashimoto's thyroiditis
57
effect of hypercalcemia on the kidney
nephrogenic diabetes insipidus
| (ADH resistance --\> volume loss)
58
sign? what does this indicate?
osteitis fibrosa cystica
| (hypercalcemia, HIGH PTH)
59
🚩 metacarpal or metatarsal bones missing
pseudohypoparathyroidism
(especially if accompanied by short stature, and mental retardation)
60
acetazolamide
drug type
CA inhibitor
61
what are the respiratory system changes expected with age
↔ TLC
↑ RV ↑ FRC
the rest ↓
(TV ↓ but respirations ↑ so ventilation does not change)
"senile enphysema"
62
what is the expected decline in GFR with age
due to what?
1 mL/min per year after 30
due to glomerulosclerosis (glom destruction and decreased number of glomeruli)
63
what happens to BP and HR during inspiration?
BP decreases (less LV output)
HR increases (low BP decreases vagal flow from the heart and that decreases HR)
64
**hypotonic fluid loss**
* dehydration
* diabetes incipidus
* alcoholism
65
**isotonic fluid gain**
* excess aldosterone
* isotonic fluid infusion (saline)
* isotonic colloid (stays in the vascular space)
66
**isotonic fluid loss**
* diarrhea
* vomiting
* hemhorrage
* loss of isotonic urine
67
**hypertonic fluid loss**
* pathologic adrenal insufficiency
68
**hypotonic fluid gain**
* primary polydipsia
* hypotonic infusion (dextrose in water)
* SIADH (causes retention of water with no solutes)
69
**hypertonic fluid gain**
* salt
* hypertonic infusion (extracell distribution)
* hypertonic manitol infusion
* hyperglicemia
70
McCune-Albright Syndrome
gain-of-function mutation in Gprotein --\> elevades cAMP --\> increased secretion of hormones
* precocius puberty
* poluostotic fibrous dysplasia
* cafe-au-lait sking pigmentation
↓ FSH/LH + ↑ estrogen
71
what substances can be used to calculate volume for the following compartments:
TBW
TBW: urea, tritated water
72
what substances can be used to calculate volume for the following compartments:
ECF
ECF:
innulin, manitol, sucrose, radioactive sodium
73
what substances can be used to calculate volume for the following compartments:
PV
PV:
RISA, evan's blue
74
how to calculate volume using tracers
V = A / C
A (amount of tracer remaining)
C (concentration in given compartment)
75
which are the only postganglionic sympathetic neurons that release Ach?
onto what receptors?
(postganglionic sympathetic cholinergic neurons)
nerve fibers that innervate **sweat glands**
M3 receptors
76
what changes in volumen & osmolality are expected in:
pregnancy
isotonic fluid gain (retention of both salt and water)
77
oocytes arrests
1. **Prophase I** (until it is "chosen" in the monthly cycle and resumes meosis I to become a secondary oocyte + polar body)
2. **Metaphase II** (until fertalized in to become a mature oocyte and polar body)
78
familial glucocorticoid deficiency
genertic disorder with loss-of-dunction mutation in ACTH receptor gene
79
🚩 hypotention with tachicardia
drop in SVR due to vasodilation
80
🚩 bradicardia with hypertention
baroreflex response to vasoconstrictor
81
what acid base disturbance does a PE cause? why?
dead space --\> large v/q missmatch --\> hypoxemia --\> increases resp drive --\> hyperventilation --\> **resp alkalosis**
82
🚩 holosystolic murmur along lower left sternal border + palpable thrill
(in newborns)
can be associated with failure to thrive and signs of heart failure
VDS
83
neuronal excitability in HYPERcalcemia?
DECREASED
| (Ca block Na channels)
84
neuronal excitability in HYPOcalcemia?
INCREASED
| (Ca blocks Na channels)
85
what is the function of the golgi tendon organ in muscle contraction?
propioceptive:
detects changes in muscle tension and inhibits muscle contraction
(to prevent damage)
86
what is the function of the muscle spindle fibers in muscle contraction?
propioceptive:
detects changes in muscle length and activates muscle contraction
(reflex testing)
87
function of A-delta nerve endings
temperature and pain
88
function of pacinian and ruffini's corpuscles
P (rapid)
R (slow)
touch, proprioception, vibration
innervated my myelinated A-beta fibers
89
what vitamins and minerals are absent in breast milk
vitamin D & K
vitamin K --\> given IM at birth
vitamin D --\> exclusively breast fed must supplement, mixed/formula already contains vitamin D
90
what is the effect of hypoxemia on aldosterone?
INHIBITS
91
function of FGF23
secreted by osteocytes
* downregulates Na/Phosphate transp in PT --\> more excretion of phosphate
* inhibits activation of vitamin D --\> less uptake of phosphosrus in the intestine
LOWERS SERUM PHOSPHORUS (secreted in response to hyperphoshpahtemia)
92
🚩 valvulopathy with bounding femoral and carotid pulses
decrecendo diastolic murmur
head bobbing
aortic regurgitation
93
🚩 fixed splitting of P2
ASD
atrial septal defect
94
light criteria
p/s protein \> 0.5
p/s LDH \> 0.6
pleural LDH \> 2/3 upper limit of normal serum LDH
95
markers of bone resorption
| (osteoclastic activity)
hydroxiproline
telopetides
96
markers of bone mineralization
| (osteoblastic activity)
serum alkiline phosphatase
PINP (N-terminal propeptide of type I collagen)
97
IV fluids of choice for:
volume resuscitation
ISOTONIC
* normal saline (0.9)
* Lactated Ringer
* Albumin (more expensive, not first line)
\*SBP, HRS
98
IV fluids of choice for:
free water deficit
HYPOTONIC
* dextrose 5% in water
* 0.45 saline (half normal)
99
IV fluids of choice for:
maintenance hydration
dextrose 5% in 0.45% saline
100
IV fluids of choice for:
sever symptomaic hyponatremia
HYPERTONIC
* 3% saline
101
🚩 hypocalcemia following blood transfusion
calcium chelation by citrate anticoagulant
seen in high rate transfusions OR low rate with impaired liver function
102
normal ejection fraction
≥50%
103
pulsus paradoxus
seen in?
**↓SBP \> 10 mmHG during INSPIRATION**
Seen in: pea COAT
* Pericarditis
* Croup / COPD
* OSA
* Asthma
* **Tamponade**
104
murmur, seen in
crescendo-decrescendo murmur
AORTIC STENOSIS
105
murmur, seen in
HOLOSYSTOLIC MURMUR
MR, TR, VSD
106
murmur, seen in
late crecendo murmur with **mid systolic click**
MVP
107
murmur, seen in
early diastolic, descrecendo
AORTIC REGURGITATION
108
murmur, seen in
continuous **machine** like murmur
PDA
109
murmur, seen in
delayed rumbling murmur, with opening snap
MITRAL STENOSIS
110
what is the pathophysiology of resistance to thyroid hormone? how do these patients present?
resistance to TH in the hypothalamic-pituitary axis
labs: high T3, T4, TSH (no negative feedback)
clinical: hypo, eu, hyper thyroid
* *goiter**, **ADHD/ADD**
111
what is rT3 derived from?
conversion of T4 into rT3
112
newborns with congenital hypothyroidism present asympotamic due to the placental transfer of what hormone?
T4
113
🚩 newborn with ectopically located, small thyroid gland just above the hyoid
**congenital hypothyroidism**
| (nL or low T4, high TSH)
114
euthyroid sick syndrome
| (cause + labs)
**low T3 syndrome**
transient "hypothyroidism" in an acutely ill patient
pathophysiology: suppresed conversion of T4-T3 as a protective/compensatory mechanism, increased conversion of T4-rT3
labs: early --\> Low T3, nL T4, TSH
late --\> Low T3, T4, TSH
115
why are serum T3 levels normal in primary hypotthyroidism
destruction of thyroid gland leads to decreased production of T4 and T3 but T4 is converted to T3 in the tissues (normal function) therefore we have normal T3, low T4 and because T4 is low we have little negative feedback and high TSH
116
DHT induces the differentiation of which structures?
external male genitalia
* scrotum
* penis
* prostate
117
what is the effect of thyroid hormone on bone
T3 stimulates osteoclasts, increase bone resorption
118
what is the effect of thyroid hormone on lipids?
promotes LDL receptor expression
119
NMDA receptor
under **-70** closed (blocked by **Mg**)
over -70 Mg moves, allows it to to be bound by **aspartate/glutamate** to open the channel
**nonselective cations** (Na, Ca)
120
function of the following nucleus of hte hypothalamus:
lateral nucleus
HUNGER
121
function of the following nucleus of hte hypothalamus:
ventromedual nucleus
SACIETY
122
function of the following nucleus of hte hypothalamus:
anterior nucleus
COOLING
| (parasympathetic)
123
function of the following nucleus of hte hypothalamus:
posterior nucleus
HEATING
| (sympathetic)
124
function of the following nucleus of the hypothalamus:
suparoptice and paraventricular
125
function of the following nucleus of hte hypothalamus:
preoptic nucleus
releases GnRH
thermorregulation, sexual behavior
126
kallmann syndrome
failure of the GnRH producing neurons to migrate from olfactory pit
127
what is the effect of activating M3 receptors?
what's the exception?
PNS receptors --\> increase G couples proteins --\> increase in intracelullar calcium --\> contraction of smooth muscles
exception: vasculature (causes NO mediated dilation)
M3 causes increased synthesis of NO in the endothemlium, diffused into smooth muscle and inhibits contraction by activating MLCP
128
3 histologic changes that occur in the liver with age
increased hepatocyte size
increased poliploidy
accumulation of lipofuscin (brown atrophy)
formation of lipid droplets in setllate cells
129
VIPoma "triad"
pancreatic cholera (secretory diarreah) WDHA syndrome
* Watery Diarrhea
* Hypokalemia
* Achlorydria
130
acid-base disturbance in CKD
high anion gap metabolic acidosis with respiratory compensation
131
refeeding syndrome
acute hypophosphatemia caused by the reintroduction of carbohydrates to amalnourished patient (depleted phosphate levels) which cause the redistribution of phosphate into hepatic and muscle cells for glycolysis.
sx: muscle weakness, arrhythmias, congestive heart failure
132
hungry bone syndrome
increased bone formation after parathyroidectomy as tx of hyperparathyroidism, which causes acute hypophosphatemia and hypocalcemia in the early postoperative period
133
where is magnesium primarily reabsorbed?
thiack ascending loop
134
familia hypocalciuric hypercalcemia
defect in CaSR → no inhibition of Ca reabsorption (NKCC) in the thick ascending loop: hypercalcemia, hypocalciuria
135
electrolyte disturbances that cause nephrogenic DI?
* hyper*calcemia
* hypo*kalemia
