Flashcards in Physiology Deck (16):
Describe BRCA 1
protein which aids in dsDNA break repair; acts as a tumor suppressor--a mutation in it may cause lack of repressor function and can cause breast cancer
protein which pumps CL and bicarb; important for movement of water--mutation in BOTH alleles can lead to thickened mucous, resp infections, pancreas--malnutrition and diabetes
familial early onset alzheimer's disease (30-60 years of age); single-gene mutation can cause it-->amyloid precursor protein (presenilin 1 or 2)
what is LOAD?
late onset alz disease, after 60yrs; combination of factors contributes to the onset, progression and severity; genetics is a 60-80% risk factor; APOE is a risk factor-->involved in the synth of apolipoprotein E,, which is a cholesterol carrier to the brain; there are several alleles, one of which is protective; APOE e4 is present in 40% of all LOAD cases, is the risk factor allele.
what do unicellular organisms requir?
Information store (DNA/RNA)
Energy & substrate uptake
--Makes energy extraction more efficient, but not required
Growth & repair mechs
Volume (solute) control
Border between internal and external environment
equation for mass balance?
Total amount (or load) of Substance X
= intake + production – excretion – metabolism
what are the body's options for output?
excretion--lungs, urine, feces, etc
metabolism-->metabolize to a different substance
what is clearance?
the rate at which a substance disappears from the body
mass flow definition and equation
Defined as the rate of intake, production or output of x
Mass flow = concentration x volume flow
amount/min = amount/vol x vol/min
how is body temp regulated?
hypothalamus is the control centre for body temp--it's at 37.1 C; if the body deviates from this, hypothal activates corrective mechs
Output methods for fluids?
kidneys, lungs, feces, sweat, skin
what is transcellular fluid, and give examples?
Specialized type of extracellular fluid counting for another 1 – 2 liters. The composition of this fluid differs and can be completely different from the main compartments.
-Digestive system cavity
total body water in L, and the % or L of the fluid compartments?
60L in total; 40L is ICF; 12L is interstitial fluid; 3L is plasma
The most important difference between plasma and interstitial fluid is the higher concentration of proteins in the plasma
ECF contains large amount of sodium and chloride
Reasonably high bicarbonate
But only small amounts of potassium, calcium, magnesium and phosphate
All carefully regulated mainly by the kidney
what molecules can pass through the lipid membrane without carriers?
O2, CO2, and other small, nonpolar molecues; some H2O molecules