chapter 10

Question 1

what’s kidney failure? what happens?

Answer 1

• when kidneys can’t excrete waste
• can’t control fluid
• proteins are lost in urine so blood protein levels fall and fluid accumulates in tissue which causes swelling of hands, feet, face

Question 2

how can you maintain healthy kidneys?

Answer 2

• healthy diet
• dont smoke
• drink water
• alcohol in moderation
• dont use performance enhancing drugs

Question 3

what is dialysis? what are the two types?

Answer 3

-method of removing waste from the blood once kidney failure has occurred

+peritoneal= catheter placed through abdomen, waste conc is lower in fluid than blood so it diffuses>fluid drained daily

+haemodialysis= blood passes through artificial kidney or dialysis machine, waste diffuses from blood to fluid>4-5 hrs, 3X a week

Question 4

How does the structure of the kidney suit its function?

Answer 4

• glomerular capsule surrounds the glomerulus to collect the fluid filtered out of the blood capillaries
• arteriole leading out of the glomerulus is thinner than the arteriole leading in so the blood pressure is higher and more fluid is filtered out
• tubule has 2 sets of convolutions and a long loop which gives a large surface area for reabsorption and secretion
• kidney has over a million nephrons to give large surface area for reabsorption and secretion

Question 5

what’s the composition of urine?

Answer 5

• water-96%
• salts-1-2%
• urea-2%

Question 6

What is excretion and what are the organs involved?

Answer 6

• removal of metabolic waste from the body
• lungs=excretes CO2
• liver=processes substances to be excreted, urea produced
• sweat glands=secretes sweat (sweat is salt, urea, lactic acid, water)
• alimentary canal=passes out bile pigments
• kidneys=maintains concentration of body fluids, removes wastes e.g. uric acid/creatinine

Question 7

what is deamination, why does it occur and where does it occur?

Answer 7

• when other energy sources are used up the body metabolises proteins
• amino group NH2 is removed from amino acids with aid of enzymes > converted to ammonia NH3 >then urea which is eliminated in urine
• remaining part of amino acid (carbon/hydrogen) is converted into a carbohydrate

Question 8

why is ammonia so quickly converted to urea?

Answer 8

-extremely soluble and toxic to cells > one drop in blood spreads very quickly throughout body and kills you

Question 9

what’s the 3 main functions of the skin?

Answer 9

• protective covering of the body
• regulates body temp
• secretes sweat

Question 10

what is in sweat??

Answer 10

• water
• salts
• lactic acid
• urea

Question 11

what does the nephron do and how does it work?

Answer 11

• forms urine to remove waste
• filtration=renal corpuscle the fluid is forced out of the blood and collected by the glomerular capsule, high blood pressure means this happens quickly. The plasma contains all contents of the blood except red/white blood cells and plasma proteins
• reabsorption=
• selective reapsorption, sodium, potassium, chloride, bicarbonate ions, glucose
• facultative reabsorption, actively absorbing water as its needed

-secretion= adds materials, potassium, hydrogen, creatinine, drugs and maintains blood PH

Question 12

what are kidney stones?

Answer 12

• solid crystals that build up
• when urine becomes too concentrated-insufficient fluids
• if small they pass put urethra unnoticed
• if large then crystals combine to form stones, they get stuck in the urethra, ureter or bladder and cause intense pain