Body Systems: Excretory System (Urine Formation)

Question 1

Urine formation:

Answer 1

-excretion is the process of separating wastes from the body fluids and eliminating them.
-depends on:
1. Filtration: movement of fluid from the blood into the bowman’s capsule.
2. Reabsorption: transfer of essential solutes and water from the nephron back into the blood.
3. Secretion: transport of materials from the blood into the nephron.

Question 2

1. Filtration:

Answer 2

-occurs in the glomerulus: high-pressure filter system.
-depends on 2 factors: permeability of capillaries, and blood pressure.
-moves water and solutes, from the blood plasma into the nephron.
-the filtered fluid is called the filtrate.
-plasma proteins, blood cells and platelets are too large to be filtered and therefore do not enter the bowman’s capsule.

Question 3

2. Reabsorption:

Answer 3

-removes useful substances such as sodium from the filtrate and returns them into the blood for reuse by body systems.
-about 65% of the filtrate that passes through the length of the proximal tubule is reabsorbed and returned to the body.

Question 4

3. Secretion:

Answer 4

-moves wastes from the blood into the filtrate.
-mainly takes place in the distal tubule.

Question 5

Water reabsorption:

Answer 5

-removes water from the filtrate and returns it to the blood for reuse by body systems.
-takes place in the loop of henle.
-(Osmosis).

Question 6

Osmosis:

Answer 6

Where water moves through a high concentration of water to a low concentration of water.

Question 7

Counter current mechanisms (descending loop of henle):

Answer 7

-permeable to water.
-impermeable to salts.
-filtrate becomes more concentrated.

Question 8

Counter current mechanisms (ascending loop of henle):

Answer 8

-permeable to salts.
-actively reabsorbed NaCl (sodium chloride).
-impermeable to water.
-filtrate becomes less concentrated.

Question 9

Loop of henle:

Answer 9

-Creates a large vertical osmotic gradient in medulla.
-from 100 to 1200 mosm/litre.

Question 10

Urine contains:

Answer 10

-substances that have undergone both glomerular filtration, and not being reabsorbed back into blood and tubular secretion.
-urine contains: water, salt, urea, uric acid, minerals.

Question 11

Part of the nephron: glomerulus:

Answer 11

Function: filtration.

Question 12

Part of the nephron: bowman’s capsule:

Answer 12

Function: receives filtrate from glomerulus.

Question 13

Part of the nephron: proximal tubule:

Answer 13

Function:
-reabsorption:
-nutrients and cations (active).
-water and anions (passive).
Secretion:
-H+ ions (active).

Question 14

Part of the nephron: descending loop of henle:

Answer 14

Function: reabsorption of water by osmosis (passive).

Question 15

Part of the nephron: ascending loop of henle:

Answer 15

Function: reabsorption of Na+ ions (active) and Cl- and K+ (passive).

Question 16

Part of the nephron: distal tubule:

Answer 16

Reabsorption:
-Na+ ions (active).
-water and Cl- (passive).
Secretion:
-H+ ions (active).
-K+ (passive).

Question 17

Part of the nephron: collecting duct:

Answer 17

Function: reabsorption of water by osmosis (passive).

Question 18

If you are releasing more H+ ions then it’s because:

Answer 18

Your blood has been acidic.
-H+= acidic.
-OH = basic.

Question 19

More water in terms of concentration:

Answer 19

More diluted and less concentrated.

Question 20

Less water in terms of concentration:

Answer 20

More concentrated.

Question 21

Renal arteries:

Answer 21

Carry blood to the kidney from the abdominal aorta.

Question 22

Renal vein:

Answer 22

Carry blood away from the kidney into the inferior vena cava.

Question 23

Aorta:

Answer 23

Carries blood away from the heart towards the torso and legs.

Question 24

Inferior vena cava:

Answer 24

Carries blood from lower torso and legs to the heart.

Question 25

Kidney:

Answer 25

Removes wastes from the blood, thus producing urine.

Question 26

Ureter:

Answer 26

Carries urine from the kidney to the urinary bladder.

Question 27

Bladder:

Answer 27

Temporarily stores urine.

Question 28

Urethra:

Answer 28

Carries urine from the urinary bladder to the exterior of the body.

Question 29

Blood flow (excretory system):

Answer 29

Renal artery—>afferent arteriole—>glomerulus—>efferent arteriole—>(peri tubule) capillaries—>renal vein.

Question 30

Urine flow (excretory system):%

Answer 30

Renal artery—>afferent arteriole—>glomerulus—>bowman’s capsule—>proximal tubule—>descending loop of henle—>ascending loop of henle—>distal tubule—>collecting duct—>renal pelvis—>ureter—>bladder—>urethra.