Flashcards in Physiology Deck (34):
What is osmolarity?
Concentration of osmotically active particles present in a solution
Hos is osmolarity calculated?
No. active particles * molar concentration
What is tonicity?
The effect a solution has on cell volume
Concentrated, less fluid, cell shrinkage
More water, cell lysis
Which is bigger ICF or ECF
What makes up the ECF
Most interstitial fluid but also plasma and negligible amounts of transcellular fluid and lymph
Name 5 methods of fluid loss in the body
Skin, lungs, sweat faeces and urine
Which type of nephron is more abundant?
What is the main difference between the two types of nephron?
Juxtamedullary has a longer loop of Henle and has the vasa recta
In which structure is the glomerulus?
Which cells make up the inner layer of Bowman's capsule?
What are the three filtration barriers?
Glomerular capillary endothelium
Slit processes of podocytes
What are the four forces which comprise net filtration pressure?
Glomerular capillary BP and Bowman's capsule oncotic pressure are out
Bowman's capsule hydrostatic pressure and capillary oncotic pressure are in
Rate at which protein-free plasma is filtered from the glomeruli into Bowman's capsule per unit time
What is the normal GFR
How is GFR extrinsically controlled?
(+BP = +GFR)
How is GFR intrinsically controlled?
Tubuloglomerular feedback mechanism and myogenic mechanisms
What is the myogenic mechanisms?
If smooth muscle is stretched in increased pressure, arteriole constricts
What is the tubuloglomerular feedback mechanism?
+GFR means more NaCl flows through the tubule casing constriction of arteriole
What is the role of the macula densa?
To sense NaCl content of tubular fluid
Which pressure will kidney stones increase and how does it affect GFR?
The Bowman's capsule fluid pressure
Which pressure which diarrhoea increase?
Bowman's capsule oncotic pressure
What effect does sever burns have on GFR?
What is plasma clearance?
A measure of how effectively the kidneys can clean blood
What is inulin clearance equal to?
How can RPF be measured
Using PAH as this is freely filtered and not reabsorbed
What is RPF
Renal plasma flow, 650ml/min
Name 5 substances normally reabsorbed in the prox tubule
Sugar, AAs, phosphate, sulphate and lactate
Name 7 substances which are secreted in the prox tubule
H+, hippurates, neurotransmitters, bile, uric acid, drugs and toxins
Define primary active transport
Energy required to move a substrate against its concentration gradient (Na)
Define secondary active transport
The carrier molecule is transported coupled to another ion (usually Na)