Physiology Flashcards
3 general types of body extrinsic control mechanisms?
Feedforward, negative feedback and positive feedback
Normal body temperature?
Around 37 degrees
Sites for monitoring body temperature?
Mouth, ear, anus
2 ways the body gains heat + what effect the first example?
Metabolism (hormone modulated) and muscle activity
Main way the body loses heat?
EMR radiation
Features of a negative feedback system?
Sensor + control centre + effector
Part of the brain responsive to cold + warmth?
Posterior hypothalmic centre + anterior hypothalmic centre
Where are thermoreceptors found and where is their control centre?
In the skin and the hypothalamus
Pathway of regulating a fever?
- Macrophages cause prostaglandin production
- Prostaglandins tell hypothalamus to reset target body temperature higher
- Body increases temperature to reach new target
Hypothermic + hyperthermic temperature?
< 35 degrees + > 40 degrees
3 types of transmembrane proteins?
Channels, carriers and pumps
Channel that allows diffusion of water?
Aquaporin
Docking-marker receptor function?
Interact with vesicles during exocytosis and endocytosis
Name for the sugar coat of cell membrane + function?
Glycoclayx and protection + prevents cells from growing over eachother
Primary vs secondary active transport function?
Primary needs direct energy (ATP) vs secondary uses concentration gradient via antiport/symport
2 types of carrier mediated transport?
Active (primary/secondary) and facilitated
Net diffusion = ?
Rate between A and B - rate between B and A
Fick’s law of Diffusion = ?
Rate of diffusion is proportional to the surface area and inversely proportional to the thickness of the membrane
Osmotic gradient?
Concentration of water in a solution
Tonicity?
The effect a solution has on a cell volume
3 types of tonic solution and their effects on cell volume?
Iso = none, hypo = increase and hyper = decrease
Na/K-ATPase summarised function?
Active transporter that moves 3 Na out of cell for 2 K in
Membrane potential Em is mainly determined by?
K gradient/Ek
Ek + ENa + Em?
-90 mV, +60 mV and -70 mV
What side of the cell is more negative?
Inside
Intra/extracellular factors that balance +ve K and Na?
Intracellular anionic/-ve proteins and extracellular Cl
How is Em maintained?
Na/K-ATPase + leak channels
When do Na, Ca and K channels open?
-55, -40 and +10 mV
Normal MAP + minimum MAP needed to perfuse major organs?
70-100 mm Hg + 60 mm Hg
What do alpha, beta and gamma pancreatic cells release?
Glucagon, insulin and somatostatin
Large molecules enter the cell by?
Endocytosis
Small molecule going against concentration gradient travels by + give an example?
Active transport (primary or secondary) + Na/K ATPase
2 types of secondary active transport?
Antiport and symport
