b12 Flashcards
What monitors and controls body temperature?
Thermoregulatory centre in the brain
How is body temperature detected?
Receptors in thermoregulatory centre measure blood temperature; Receptors in skin send impulses to thermoregulatory centre
What happens if body temperature is too high?
Blood vessels dilate, vasodilation; Sweat glands make sweat
What happens if body temperature is too low?
Blood vessels constrict, vasoconstriction; Sweating stops; Skeletal muscles contract - shivering
How does water leave the body?
Via lungs during exhalation - uncontrolled; Via skin in sweat - uncontrolled; Via kidneys in urine - controlled
How do ions leave the body?
Via skin in sweat - uncontrolled; Via kidneys in urine - controlled
How does urea leave the body?
Via skin in sweat - uncontrolled; Via kidneys in urine - controlled
Why does osmotic balance need to be maintained?
So cells can work efficiently
Where does urea come from?
Excess protein → amino acids → deamination → ammonia → urea
Where is urea produced?
The liver
List the processes that occur in the kidney
Filtration, selective reabsorption and excretion
Which substances are reabsorbed?
Some water and ions; All glucose
Which hormone controls reabsorption of water and where is it made?
ADH - pituitary gland
When is ADH released?
When blood is too concentrated
What effect does ADH have?
Causes more water to be reabsorbed by the tubules
