Physiology - Everything! Flashcards
What are the three most important tumor suppressor genes?
RB, p53 & APC
What is the equation for the equilibrium constant Keq?
Keq = kf/kr = [C][D]/[A][B]
What is the normal pH of blood?
7.28-7.44
What is the normal pH of cytosol?
6.9
What is the normal pH of urine?
5-8
What is the normal pH of gastric juice?
~2
Which organ controls the excretion & absorption of bicarbonate ions?
Kidney
What is the relative pKa of a strong acid? Strong base?
Lower pKa indicates stronger acid. Higher pKa is stronger base.
What are some examples of medically important weak bases?
Amphetamines, procainamide, nortriptylene, local anesthetics
What enzyme does H. pylori use to create a neutral pH environment in the gut?
Urease
What is the Henderson-Hasselbalch equation?
pH = pKa + log([proton acceptor]/[proton donor])
When does pH equal pKa?
When an acid or base is 50% deprotonated and 50% protonated
When pH»_space; pKa, about what fraction of the acid or base is deprotonated?
> 99%
When pH «_space;pKa, about what fraction of the acid or base is deprotonated?
<1%
How does bicarbonate act as a buffer of extracellular pH?
Bicarbonate binds protons in ECF to form carbonic acid. Another reaction release water molecules and carbon dioxide is left which gets exhaled by lungs.
What is the normal concentration of bicarbonate?
24 mM
Which enzyme catalyzes the second reaction of the bicarbonate buffer system?
Carbonic anhydrase
What is the normal partial pressure of dissolved CO2 in blood?
40mmHg
When calculating pH of ECF using HH equation, what value of pKa is used?
6.1
What is the normal pH of blood?
7.4
What is “Cushing’s triad?”
Hypertension, bradycardia, aginal respirations
What does Cushing’s triad indicate?
Cerebral edema
What are the later signs of cerebral edema due to treatment of DKA?
Cushing’s triad + fixed dilated pupils due to compression of nerve
