Excretory system

Question 1

functions of the excretory system

Answer 1

• removal of waste
• balance blood pH (7.3)
• maintensnce of water balance

Question 2

components of the excretory system

Answer 2

renal artery, renal veins, kidneys, ureters, bladder, urethra

Question 3

renal artery

Answer 3

delivers blood to the kidneys

Question 4

renal veins

Answer 4

returns filtered blood to the heart

Question 5

kidney

Answer 5

filters blood to remove waste products
- weighs 0.5kg
- hold 25% of the bodies blood at one time
located beneath the digestive organs
- made up of three layers: cortex (outer), Medulla(inner), and renal pelvis (central mass where all veins and tubes connect)

Question 6

ureters

Answer 6

transport waste from the kidneys to the bladder

Question 7

bladder

Answer 7

stores waste(urine) and u lose control once it hits 600ml

Question 8

urethra

Answer 8

removes waste product

Question 9

waste products

Answer 9

• urea (2%)
• uric acid
• creatinine
  (make up 5% of waste)

Question 10

urea

Answer 10

• Amino acids are broken down by liver (deamination) producing ammonia
• Ammonia is extremely toxic (0.005 mg can kill a human)
• Ammonia binds with carbon dioxide and forms urea

Question 11

uric acid

Answer 11

formed bt the breakdown of nucleic acids

Question 12

creatinine

Answer 12

by product of muscle metabolism

Question 13

PH balance

Answer 13

• During cellular respiration excess acids (e.g. citric and lactic acid) build up in the body
• These acids are ionized to produce H+ ions
• The build up of H+ ions lowers the pH of blood
  H+ ions can removed from blood and combined with filtrate urine

Question 14

water balance

Answer 14

• The average adult loses 2 liters of water a day (how much you should consume a day)
  By urine, perspiration and exhalation
• ADH (antidiuretic hormone) helps regulate water by causing the kidneys to increase water reabsorption(out of urine and back into the blood)
• When ADH is released more concentrated urine is produced, conserving body water

Question 15

different stages of dehyrdation

Answer 15

A drop in fluid intake by 1% causes thirst, 5% causes u to collapse or feel dizzy/faint, 10% causes death

Question 16

the nephron

Answer 16

Nephrons are the functional unit of the kidneys
There can be up to one million nephrons in each kidney

Question 17

what makes up a nephron

Answer 17

glomerulus, bowmans capsule, proximal tuble, loop of Henle, Distal tubule, collecting duct

Question 18

golmerulus

Answer 18

cappilary bed where the renal artery and vein attach; this is where the kidney recieves blood

Question 19

bowmans capsule

Answer 19

highest level of filtration, receives waste from glomerulus (backwards c)

Question 20

proximal tube

Answer 20

connects to bowmans capsule to loop of henle
- more filtration

Question 21

loop of henel

Answer 21

reabsorbes water and filters

Question 22

distal tube

Answer 22

connects loop of henel to collecting duct

Question 23

collecting duct

Answer 23

delivers waste to uterer

Question 24

filtration

Answer 24

• Dissolved solutes pass through the walls of the glomerulus into bowmans capsules
• Blood cells, plasma and platelets are too large to move through the walls of the glomerulus same with proteins

Question 25

reabsorption

Answer 25

• The transfer of essential solutes and water from the nephron back into the blood
• On average 600ml of fluid flows through the kidneys every minute but only 120ml is filtered through the nephron
• 119 of the 120 are reabsorbed (1ml urine -120ml filtered by the nephron)
• If reabsorption did not happen u would produce 120ml of urine every minute meaning you would need to drink one liter of water every ten minutes to maintain homeostasis