the kidney

Question 1

where are the kidneys located?

Answer 1

at the back of the abdomens

Question 2

what are the kidney’s two important functions?

Answer 2

• regulate the water content in the blood
• they excrete the toxic waste products of metabolism

Question 3

why is regulating the water content of the blood important for the kidneys?

Answer 3

vital for maintaining blood pressure

Question 4

what is an example of a toxic waste product of metabolism?

Answer 4

urea

Question 5

what substances are in excess of requirement?

Answer 5

salts

Question 6

what are the 3 sections of the kidney?

Answer 6

• cortex
• medulla
• pelvis

Question 7

where is the cortex located?

Answer 7

around the outside and has a lighter colour

Question 8

where is the medulla located?

Answer 8

in the middle- triangular shaped

Question 9

where is the pelvis located?

Answer 9

in the centre- yellowy colour

Question 10

what do nephrons do?

Answer 10

they filter the blood

Question 11

what are nephrons?

Answer 11

tiny structures that filter the blood

Question 12

what are nephrons also known as?

Answer 12

kidney tubules/ renal tubules

Question 13

where do the contents of the nephron drain into?

Answer 13

the renal pelvis

Question 14

where does the urine collect?

Answer 14

in the renal pelvis

Question 15

where does urine flow down into?

Answer 15

the ureter

Question 16

where is urine stored?

Answer 16

in the bladder

Question 17

what is the nephron made up of?

Answer 17

a kidney tubule which has several sections

Question 18

what are the sections that make up the nephron?

Answer 18

• bowman’s capsule
• proximal convoluted tube
• loop of Henle
• distal convoluted tube
• collecting duct

Question 19

what is the glomerulus?

Answer 19

a network of capillaries with a knotted section that sits inside the Bowman’s capsule

Question 20

where is the efferent arteriole?

Answer 20

at the exit of the glomerulus

Question 21

where is the afferent arteriole?

Answer 21

at the entrance of the glomerulus

Question 22

which arteriole has the larger diameter- the efferent or afferent?

Answer 22

the efferent arteriole- smaller
the afferent arteriole- larger

Question 23

what does the difference in sizes in the arterioles do?

Answer 23

creates a build up pressure in the capillaries

Question 24

what does the pressure in the glomerulus do?

Answer 24

• forces small molecules such as urea, glucose, amino, acids and salts out of the capillaries of the glomerulus and into the Bowman’s capsule
• this forms the glomerular filtrate

Question 25

what are some examples of small molecules?

Answer 25

urea, glucose, amino acids and salts

Question 26

what are some examples of larger molecules?

Answer 26

proteins or red blood cells

Question 27

what happens to the large molecules?

Answer 27

they stay in the blood as they are too big to fit across the capillary walls

Question 28

what do the capillaries of the glomerulus have between the cells?

Answer 28

gaps

Question 29

what does the basement membrane do?

Answer 29

controls which molecules can pass into the Bowman’s Capsule

Question 30

how are the cells lining the PCT specialised for movement of molecules?

Answer 30

• have a folded membrane- increase surface area
• many mitochondria- provides ATP for active transport

Question 31

where does the glomerular filtrate travel to?

Answer 31

the PCT

Question 32

what happens to the useful materials in the glomerular filtrate?

Answer 32

• the specialised cells in the walls of the PCT move the useful materials back into the bloodstream
• initially, molecules will move by diffusion but some substances will undergo active transport

Question 33

what is all reabsorbed?

Answer 33

• all of the glucose and amino acids
• some salts
• 80% of the water

Question 34

what is involved in reabsorbing water?

Answer 34

the Loop of Henle and collecting duct

Question 35

what does the Loop of Henle do?

Answer 35

• concentrates the urine by transporting salt into the blood by active transport
• this causes water to diffuse into the blood by osmosis

Question 36

the blood being filtered and key substances being absorbed back into the blood is carried out in what order?

Answer 36

1) ultrafiltration
2) selective reabsorption of glucose
3) reabsorption of water and salts

Question 37

where is water reabsorbed at?

Answer 37

loop of henle & collecting duct

Question 38

where are salts reabsorbed?

Answer 38

loop of henle

Question 39

where is glucose reabsorbed?

Answer 39

PCT

Question 40

where is urea reabsorbed?

Answer 40

it’s not reabsorbed

Question 41

what will your urine be like if you have lost a lot of water through sweating or dehydration?

Answer 41

• concentration
• lower volume of water
• darker, browner colour

Question 42

what hormone does the collecting duct respond to?

Answer 42

ADH

Question 43

what does ADH do to the collecting duct?

Answer 43

makes it more or less permeable- varies how much water is reabsorbed

Question 44

why can the reabsorption of glucose not take place anywhere else in the nephron?

Answer 44

the gates that facilitate the active transport of glucose are only found in the PCT

Question 45

do people with diabetes have low or high blood pressures?

Answer 45

high blood glucose levels as they cannot control them

Question 46

high blood glucose levels means what for the glucose?

Answer 46

• not all the glucose filtered out can be reabsorbed into the PCT
• there is nowhere else for the glucose to be reabsorbed into- it ends up in the urine