B12(Homeostasis In Action) Flashcards
If the body temperature is too high ..
-blood vessels dilate(vasodilation)
-sweat is produced from the sweat glands
-which causes a transfer of energy from the skin to the environment
If your body temperature is too low
-blood vessels constrict(vasoconstriction)
-Sweating stops reducing the transfer of energy to the environment
-Skeletal muscles contract(shiver) and the exothermic reactions of respiration needed for muscle contraction raise the temperature
Why does carbon dioxide need to be removed from the body
-This needs to be removed from our bodies because it dissolves and forms a weak acid called Carbonic Acid
-We exhale it through our lung using our alveoli
-The weak acids will cause enzymes to denature
Why does urea need to be removed from the body
-Protein-> amino acids-> ammonia + other molecules-> urea
-urea is poisonous so it needs to be removed from the body
-this process is called deamination because it is the removal of the amine groups from the amino acids
-the other molecules get used to make other molecules such as glucose for respiration
What are the processes in the kidney
-ultrafiltration
-selective reabsorption
-Excretion
What is ultrafiltration
-small molecules are removed from the blood into the kidney tubules( glucose,mineral ions,urea,water)
-Large molecules like proteins stay in the blood
What is selective reabsorption
-useful substances are reabsorbed from the tubules back into the blood by diffusion
-glucose mineral ions and some water is absorbed
What is excretion
-excess water, ions,and urea pass along the ureter to the bladder as urine
What is dialysis
-A kidney dialysis machine provides an artificial kidney for the sufferers of kidney failure
How does a dialysis machine works
-the persons blood flows alongside a selectively permeable barrier, surround by dialysis fluid
-it’s permeable to things like ions and waste substances but not big molecules like proteins
-The dialysis fluid has the same concentration of dissolved ions and glucose as healthy blood
-this means that useful dissolved ions and glucose won’t be lost from the blood during dialysis
-only waste substances and excess ions and water diffuse across the barrier
-dialysis may cause blood clots and infections
The donor kidney can be rejected by …
-the patients immune system, the foreign antigens on the donor kidney are attacked by the patients antibodies
