U8

Question 1

Define excretion

Answer 1

The process of removing metabolic wastes from the body

Question 2

What are the 5 organs that are part of the excretory system?

Answer 2

1. The kidneys 2. the large intestine 3. the lungs 4. the liver 5. skin

Question 3

What does the skin excrete?

Answer 3

water, salt and urea

Question 4

Under what circumstances does the skin produce an increased amount of waste?

Answer 4

During renal/kidney failure

Question 5

Where does the yellow pigment in urine come from?

Answer 5

Breakdown of heme from old blood cell hemoglobin by the liver being deposited in the blood, later removed by the kidneys

Question 6

What 2 things does expiration by the lungs remove?

Answer 6

co2 and water

Question 7

What do the epithelial cells of the intestine excrete? Where is this excreted to?

Answer 7

certain salts such as iron and calcium. cavity of the large intestine directly becoming part of the feces

Question 8

What are the 2 ways water enters the body?

Answer 8

1. Drink water 2. Absorbed from food eaten

Question 9

What are the 6 ways water leaves the body?

Answer 9

1. urination 2. perspiration 3. exhalation 4. Tears 5. Defecation 6. Expectorating/ plegm

Question 10

What are the 4 structures in the urinary system and what are their functions?

Answer 10

1. Kidney = produce urine 2. Ureters = kidney to bladder transport 3. Bladder = storage of urine 4. urethra = elimination of urine

Question 11

What are the 3 regions of the kidney shown in a slice?

Answer 11

1. Renal cortex = outer granulated region 2. renal medula = striated or lined layer 3. lower cavity = renal pelvis where urine collects

Question 12

Where is the kidney located in the abdomen?

Answer 12

lower dorsal portion

Question 13

Where does the blood filtered by the kidney come from?

Answer 13

the renal arteries

Question 14

How many nephrons in each kidney?

Answer 14

1M

Question 15

What 3 parts are contained in the cortex (outer) of a kidney?

Answer 15

1. Bowman’s capsule 2. Proximal convoluted tubule 3. Distal convoluted tubule

Question 16

What key structure does the medulla of the kidney contain?

Answer 16

the loop of henle

Question 17

What does the renal artery carry and what is its function?

Answer 17

blood with high concentration of urea. brings blood to be cleaned

Question 18

What does the renal vein carry and what is its function?

Answer 18

blood with low urea and high glucose concentration. return ‘clean’ blood to the body

Question 19

What are the 2 capillary regions in the nephron?

Answer 19

1. the glomerulus 2. the peritubular capillary network

Question 20

What are the 5 steps of urine formation?

Answer 20

1. pressure filtration 2. selective re-absorption 3. re-absorption of water 4. tubular excretion 5. excretion of urine

Question 21

What are the 2 key events happen during the first step of urine formation; pressure filtration?

Answer 21

1. blood enters glomerus 2. bp forces water, nutrients, & wastes out of glomerus into the bowman’s capsule (large organic materials stay in blood)»_space; filtrate is mostly composed of urea from ammonia produced by liver

Question 22

What components are found in filtrate in bowman’s capsule?

Answer 22

water, nutrients, urea and salt

Question 23

What are the 2 key events that happen during step 2 of urination formation; selective reabsorption?

Answer 23

1. In the proximal convulated tubule, ATP used to selectively reabsorb nutrients (glucose, amino acids, vitamins, minerals, salt & water into pertibular capillary network 2. bicarbonate reabsorbed; lower pH more re-absorption

Question 24

What are the key events that happen during step 3 of urine formation; water re-absorption?

Answer 24

1. cells of ascending loop of henle, pumps Na+ out of nephron into medulla, K+ in and Cl- follows Na+ 2. Water follows the Na2+ and Cl- via osmosis 2. water is then reabsorbed all along the nephron 3. urine concentrated

Question 25

What does the distal side of the loop of henle contain?

Answer 25

wastes and little nutrience

Question 26

What controls rate of water absorption?

Answer 26

hormones

Question 27

What are the key events that happen during step 4 of urine formation; tubular excretion?

Answer 27

1. At the distal convulated tubule H+ ions, hitsamine, penecillin, creatin and ammonia are secreted into the tubule

Question 28

How is the pH of blood maintained?

Answer 28

By tubular excretion regulating the concentration of H+ filtered out vs left in the blood

Question 29

Where is urine stored?

Answer 29

renal pelvis

Question 30

What kind of feedback loop is ADH's control of the re-absorption of water?

Answer 30

negative feedback loop

Question 31

What effect does ADH create when its released?

Answer 31

Increases permeability of the distal convoluted tubule + collecting duct >> more water is reabsorbed >> urine concentration increased >> blood volume increased

Question 32

What is urea?

Answer 32

the waste product from deaminiation aka waste product in the metabolism of proteins

Question 33

How does alcohol affect ADH?

Answer 33

It sends a false message to the hypothalamus that there is too much water in the blood >> ADH is then inhibited >> water isn't reabsorbed >> lower concentration and higher volume of urine

Question 34

What does Aldosterone regulate?

Answer 34

Level of sodium in the blood

Question 35

What happens if sodium is too low in the blood?

Answer 35

Aldosterone released >> more sodium reabsorbed from the ascending limb of the loop of henle into the renal medulla

Question 36

What happens if sodium is too high in the blood?

Answer 36

Aldosterone inhibited

Question 37

Why is too much sodium in the blood bad?

Answer 37

Pertibular capillary network in the medulla is hypertonic to the nephron >> more water is reabsorbed by descending arm of loop of henle, the distal tubule and collecting duct

Question 38

What control aldosterone?

Answer 38

the adrenal cortex