B12 Flashcards
Vasodilation
If body temperature is too high
Blood vessels supplying capillaries dilate(widen)
Bloods closer to skin so more heat can be lost by radiation
High core= enzyme denatures
Body sweats which evaporates to cool you down
Vasoconstriction
Body temperature drops so blood vessels supplying capillaries constrict moving away from the skin so less heat is lost
Piloerection- hairs stand up trapping air particles acting as an insulator
Shivering- skeletal muscles contract and relax rapidly which needs lots of respiration (exothermic)
Raises temp till shivering stops
What happens to amino acids that cannot be stored in the body
Amino acids form ammonia which is toxic in the liver
Converted into urea which is less toxic
Travels through the bloodstream
Filtered in the kidneys and excreted in your urine
How water is lost:
Via the lungs during exhalation
Via the skin in sweat
Excess water lost via the kidneys in the urine
Kidneys
Filters blood and reabsorbs useful substances
Useful= glucose, some ions, water
Stays= proteins and red blood cells-too large
Filtered out= amino acids, urea, mineral ions, excess water
Role of ADH
Concentrated blood
1) if blood too concentrated with less water
2) pituitary gland secretes more ADH
3) kidney reabsorbs more water in the collecting duct
4) small volume of concentrated urine is produced
Kidney failure symptoms:
Urinating more often
Back pain
Thirsty
Tiredness-anaemia
Diagnosing:
Urine sample
^presence of large proteins
^blood
MRI scanning
Treatment:
Dialysis(artificial membrane) \+suitable for all patients \+ successful -slow short term solution -EXPENSIVE -restricted diet -BUILD UP OF UREA Transplantation: \+cheaper in the long run \+no regular check ups \+low chance of rejection \+NO BUILD UP OF WASTE PRODUCTS -immunosuppressants -infections -SHORTAGE of spare kidneys
