The Kidney and Excretion

Question 1

1 . blood enters the kidneys through

Answer 1

the renal artery

Question 2

2 . blood passes through capillaires in the

Answer 2

cortex

Question 3

3 . as the blood passes throughthe capillaries, subtances are?

Answer 3

filtered out into long tubules that surround the capillaries (ultrafiltration)

Question 4

4 . useful substances are reabsorbed back from the tubules in?

Answer 4

medulla and cortex (selective reabsorption)

Question 5

5 . what happens to remaining unwanted substances

Answer 5

pass alon thr tubules along the ureter to the bladder where theyre expelled as urine

Question 6

6 . the filtered blood passes through

Answer 6

the renal vein

Question 7

ULTRAFILTRATION

what are nephrons

Answer 7

long tubules along with a bundle of capillaries where the blood is filtered

Question 8

ULTRAFILTRATION

1 . blood from the renal artery enters

Answer 8

smalller arterioles in the cortex

Question 9

ULTRAFILTRATION

2 . each arteriole splits into a structure called

Answer 9

a glomerulus

Question 10

ULTRAFILTRATION

3 . ultrafiltration takes place in the glomerulus which is?

Answer 10

(bundle of capillaries looped inside a hollow ball called bowman’s capsule)

Question 11

ULTRAFILTRATION

4 . what are affarent and efferent aretioles?

Answer 11

afferent: takes blood into each glomerulus
efferent: takes the filtered blood away from the glomerulus

Question 12

ULTRAFILTRATION

5 . why is the blood in the glomerulus under high pressure?

Answer 12

efferent arteriole is smaller in diameter than the afferent arteriole

Question 13

ULTRAFILTRATION

6 . the high pressure in the glomerulus leads to what

Answer 13

forces liquid and small molecules in the blood out of the capillary and into the Bowman’s capsule.

Question 14

ULTRAFILTRATION

7 . how many layers does the liquid pass through to get into the bowmans capsule and enter the nephron tubule

Answer 14

3

Question 15

ULTRAFILTRATION

8 . what cant pass through the basement membrane?

Answer 15

large proteins - so they stay in the blood.

Question 16

ULTRAFILTRATION

9 . the filtrate passes along the nephron and what happens during this

Answer 16

useful substances are reabsorbed

Question 17

ULTRAFILTRATION

10 . finally the filrare flows through

Answer 17

the collecting duct andpasses out of the kidney along the ureter.

Question 18

SELECTIVE REABSORPTION

1 . selective reabsorption takes place as

Answer 18

the filtrate floes along the proximal convulated tubule through the loop of henle and along the distal convulated tubule.

Question 19

SELECTIVE REABSORPTION

2 . useful substances leave the tubules of the nephrons and enter?

Answer 19

the capillary network wrapped around them.

Question 20

SELECTIVE REABSORPTION

3 . the epithelium of the PCT wall has what to provide a large surface area?

Answer 20

microvili

Question 21

SELECTIVE REABSORPTION

4 . useful solutes like what is absorbed along the PTC

Answer 21

glucose, amino acids, vitamin and some salts through diffusion and active transport.

Question 22

SELECTIVE REABSORPTION

5 . what else is absorbed by diffusion

Answer 22

some urea

Question 23

SELECTIVE REABSORPTION

6 . water enters the blood by osmosis - why?

Answer 23

the WP of the blood is lower than that of the filtrate. it is hen reabsorbed from the lop of hene , DCT and collecting ducts.

Question 24

SELECTIVE REABSORPTION

the filtrate that remains is?

Answer 24

urine which passes along the ureter to the bladder.

Question 25

# URINE is usually made up of?

Answer 25

water dissolve salts urea hormones excess vitamins

Question 26

# URINE doesnt usually contain

Answer 26

proteins and blood cells (too big to leave) glucose, amino acids and viteamis (theyre actively reabsorbed as theyre needed by the body)

Question 27

# EXAMINING NEPHRONS - CORTEX the bundle of capillaries on the kidney tissue is

Answer 27

the glomerulus

Question 28

# EXAMINING NEPHRONS - CORTEX the white area aroud the glomerulus is

Answer 28

the bowman's capsule

Question 29

# EXAMINING NEPHRONS - CORTEX small white circular areas (surrounded by squamous epithelial cells -purple blobs are the nuclei of them)

Answer 29

are the PCTs and the DCTs

Question 30

# EXAMINING NEPHRONS - MEDULLA the white areas are

Answer 30

the loops of henle

Question 31

# EXAMINING NEPHRONS - MEDULLA the loops of henle are surrounded by

Answer 31

capillaries where thered dots represent the. red blood cells.

Question 32

# KIDNEY DISSECTION what equipment is needed?

Answer 32

scalpel, apron, lab gloves

Question 33

# KIDNEY DISSECTION - external 4 steps?

Answer 33

1 - identify renal capsule 2 - find cortex 3 - identify tubes in the indented part as renal vein, artery and ureter (artery walls are thicker than the vein) 4 - draw a sketch and label

Question 33

# KIDNEY DISSECTION - internal 5 steps

Answer 33

1 - cut the kidney in half lengthways and split it open 2 - identify cortex (light) and medulla (dark) 3 - identify renal pyramids in the medulla (contains loop of henle and collecting duct) 4 - identify the renal pelvis which connects to the ureter 5 - draw a sketch and label

Question 33

# CONTROLLING WATER POTENTIAL if the water potential of the blood is too low...

Answer 33

more water is reabsorbed by osmosis into the blood from the tubules of the nephrons so urine is more concentrated and less water is lost during excretion

Question 34

# CONTROLLING WATER POTENTIAL if the water potential of the blood is too high...

Answer 34

less water is reabsorbed to the body by osmisis into the blood from the tubules of the nephrons so urine is more dilute and more water is lost during excretion.

Question 35

# CONTROLLING WATER POTENTIAL regulation of the water potential of the blood takes place in the...

Answer 35

middle and last parts of the nephron (loop of henle, distal CT and the collecting duct.)

Question 36

# CONTROLLING WATER POTENTIAL the volume of water reabsorbed is controlled by?

Answer 36

hormones - ADH

Question 37

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE the loop of henle is made up of 2 limbs which help set up the countercurrent multiplier mechanim: what are they

Answer 37

descending limb ascending limb

Question 38

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE 1 - what happens near the top of the ascending limb?

Answer 38

Na+ AND Cl- ions are actively pumped out into the medulla - the ascending limb ins impermeable to water so this creates a low water potential in the medulla

Question 39

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE 2 - because there is a lower water potential in the medulla than in the descending limb, water....

Answer 39

moves out of the descening limb into the medulla by osmosis, making the filtrate more concenrared since the limb is unpermeanle to ions. water in the blood is also reabsorbed into the blood.

Question 40

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE 3 - what happens near the bottom of the ascending limb?

Answer 40

Na+ AND Cl- ions diffuse out into the meddulla, further lowering the water potential in the medullla

Question 41

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE 4 - the 3 stages massively increase the ion concentration in the medulla, which does what?

Answer 41

lowers the water potential and causes water to move out of the collecting duct by osmosis - water is reabsorbed again by the capillary network into the blood.

Question 42

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE the volume of water reabsorbed from the collecting duct into the capillary is controlled by

Answer 42

the changing permeability of the collecting duct

Question 43

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE longer the loop of henle

Answer 43

the more water can be reabsorbed from the filtrate

Question 44

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE longer the ascending limb

Answer 44

more ions are actively pumped out into the medulla

Question 45

# CONTROLLING WATER POTENTIAL - LOOP OF HENLE when ions are pumped out into the medulla it creates a lower water potential in the medulla which means

Answer 45

water moves out of the nephron and collecting duct into the capillaries, giving a very concentrated urine.

Question 46

# CONTROLLING WATER POTENTIAL monitored by cells called osmoreceptors, located

Answer 46

in the hypothalamus

Question 47

# CONTROLLING WATER POTENTIAL when the osmoreceptors are stimulated bt low water potential in the blood, what happens?

Answer 47

jypothalamus sends nerve impulses to the posterior pituitary flandd which releases ADJH into the blood.

Question 48

# CONTROLLING WATER POTENTIAL effect of ADH on the collecting duct and DCT?

Answer 48

makes their walls more permeable to water so more water is reabsorbed from them into the meddulla and the blood ny osmosis producing a small amount of concentrated urine.

Question 49

# CONTROLLING WATER POTENTIAL - dehydration when dehydrated , ADH level

Answer 49

rises because water is lost, so it needs to be increased

Question 50

# CONTROLLING WATER POTENTIAL - dehydration 5 steps of rising ADH

Answer 50

1- water content and water potential of the blood drops 2 - detected by osmoreceptors in hypothalamus 3 - posterior pituitary is stimulated to release more ADH into the blood 4 - more ADH means the DCT and collecting duct are more permeable so more water is reabsorbed 5 - small amount of highly concentrated urine priduced, less water lost

Question 51

# CONTROLLING WATER POTENTIAL - hydrated when hydrated, ADH levels

Answer 51

fall because water content needs to be reduced

Question 52

# CONTROLLING WATER POTENTIAL - hydrated 5 steps of falling ADH

Answer 52

1 - water content of blood rises so WP rises 2 - posterior pituitary detects it 3 - releases less ADH into the blood 4 - the DCT and collecting ducts are less permeable so less water is reabsorbed to the blood. 5 - large amount of dilute urine produced and more water is lost.

Question 53

# KIDNEY FAULIRE what is kidney failure?

Answer 53

when kidneys cant carry out their normal funcyions because they dont work properly

Question 54

# KIDNEY FAULIRE explain 2 causes of kidney failure

Answer 54

kidney infections - cause immflammation of the kidneys which can damage the cells and interferes with filterinf in bownmans capsule or rabsorptuon. high blood pressure - damages glomerili as if pressure gers too high capillaries get damaged meaning large molucules like proteins can ger through the capillary walls and into the urine.

Question 54

# KIDNEY FAULIRE how is kidney failure detected?

Answer 54

measuring glomerual filtration rate - the rate at whcih blood is filtered from the glomerulus into the bowman's capsule

Question 55

# KIDNEY FAULIRE give 4 problems caused by kidney failure

Answer 55

1. waste priducts which would normally be removed build up in the blood 2. fluids accumulate in tissues because the kidney cant remove excess water from the bloood 3. balance of electrolytes in the bodybecomes unbalanced - blood may become too acidic and salt buildup cdasues water retention 4. long term causes anaemia - lack of haemoglobin in the blood

Question 56

# KIDNEY FAULIRE what are the 2 main treatment options for kidney failure?

Answer 56

renal dialysis kidney transplant

Question 57

# KIDNEY FAULIRE what is haemodialysis?

Answer 57

where thr pstient's blood is passes through a dialysis machine - the blood flows on one side of a partially permeable membrane and dialysis fluid flows on the other side - so waste products can diffuse into the dialysisi tubing.

Question 58

# KIDNEY FAULIRE what is peritoneal diaysis?

Answer 58

where dialysis fluid is put through a. tube that oasses from the iutside of a patients abdomen into their abdominal cavity - waste products diffuse across the peritoneum.

Question 59

# KIDNEY FAILURE limitations of peritoneal dialysis

Answer 59

infection no dialysis free days

Question 60

# KIDNEY FAILURE strength of dialysis

Answer 60

keeps person alive until transplant less risky than having a major surgery

Question 61

# KIDNEY FAILURE where do kidney transplants come from?

Answer 61

new kidney has to be from same blood and tissue type, often donated from a living relative

Question 62

# KIDNEY FAILURE advantages and disadvantages of transplant?

Answer 62

cheaper than dialysis patient has to undergo a major operatoon and the immune system may also reject the transplants - immunosuppresant drugs are needed to suppress it.

Question 63

# KIDNEY FAILURE describe the 5 steps involved in a test for pregnancy

Answer 63

1. a stick contains monoconal aantibodies of hCG in the application area bound to a coloured bead. 2. when the urine is applied to the area, any hGC will bind to the antibody on the bead 3. urine will move up the test strip, carrying the beads with it 4. the test strip has immobilised antibodies to hCG 5. if hCG is present, the test strip changes colour as the immobilised antibody binds to any hCG attached to coloured beads.

Question 64

# KIDNEY FAILURE what is gas chromotography?

Answer 64

the urine sample is vapourised and passed through a column containing a polymer. different substances move through the column at different speeds - substances in each urine sample separate out.

Question 65

# KIDNEY FAILURE what is mass specrometry?

Answer 65

once substances have separated out following gas chromatography, they are converted into ions and separated absed on mass and charge. the result is analysed by a computer and compared to known substances.