Question 1

What is the ability that makes kangaroo rats one of the best in the world among animals?

Accepted Answer

Kangaroo rats have the ability to produce incredibly concentrated urine, which allows them to conserve water and survive in arid environments.

Question 2

Which substance is typically found in urine at the highest concentration?

Accepted Answer

Urea, a byproduct of protein metabolism, is typically found in the highest concentration in urine compared to other substances listed.

Question 3

Which statement about the kidneys is false?

Accepted Answer

Creatinine is a waste product formed from the normal breakdown of muscle tissue, not a direct product of lipid metabolism.

Question 4

Which of the following would not be found in urine produced by healthy kidneys?

Accepted Answer

Proteins are typically not found in the urine produced by healthy kidneys because they are too large to pass through the glomerular filtration barrier. Their presence in urine can indicate kidney damage or disease.

Question 5

After the kidneys, the _______ contribute(s) most to filtration.

Accepted Answer

The heart contributes to filtration by pumping blood, which creates the pressure necessary for the kidneys to filter blood.

Question 6

Podocytes are found in the

Accepted Answer

The answer of Podocytes are found in the
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Question 7

A molecule greater than _______ kilodaltons cannot pass through the nephrons.

Accepted Answer

Molecules larger than 12.5 kilodaltons are generally too large to pass through the filtration barrier of the nephron in the kidneys.

Question 8

Which statement about amphibian nephrons is false?

Accepted Answer

Amphibians do not have loops of Henle in their nephrons; this structure is characteristic of mammalian kidneys and is involved in concentrating urine.

Question 9

Filtration slits are found in

Accepted Answer

The answer of Filtration slits are found in
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Question 10

Glomerular filtration rate in vertebrates is defined as the rate of _______ of an animal's kidney tubules.

Accepted Answer

Glomerular filtration rate (GFR) refers to the rate at which primary urine is formed by all the kidney tubules (glomeruli) in an animal. It is a measure of kidney function.

Question 11

If the blood pressure in the glomerular capillary is +5 kPa, the colloid osmotic pressure is -2.5 kPa, and the capsular fluid hydrostatic pressure is -2 kPa, then the filtration pressure is _______ kPa.

Accepted Answer

The answer of If the blood pressure in the glomerular...

Question 12

If the filtration pressure is +7 kPa, the colloid osmotic pressure is -3 kPa, and the capsular fluid hydrostatic pressure is -2 kPa, then the blood pressure in the glomerular capillaries is _______ kPa.

Accepted Answer

The net filtration pressure is calculated as blood pressure in glomerular capillaries - (colloid osmotic pressure + capsular fluid hydrostatic pressure). Rearranging gives blood pressure = filtration pressure + colloid osmotic pressure + capsular fluid hydrostatic pressure = 7 + 3 + 2 = 12 kPa.

Question 13

If the blood pressure in the glomerular capillary is +10 kPa, the filtration pressure is +6 kPa, and the capsular fluid hydrostatic pressure is -2 kPa, then the colloid osmotic pressure is _______ kPa.

Accepted Answer

The colloid osmotic pressure is -2 kPa. This is because the filtration pressure is +6 kPa, the capsular fluid hydrostatic pressure is -2 kPa, and the blood pressure in the glomerular capillary is +10 kPa. The colloid osmotic pressure is the only pressure that is not given, so it must be calculated. The colloid osmotic pressure is equal to the filtration pressure minus the capsular fluid hydrostatic pressure. Therefore, the colloid osmotic pressure is +6 kPa - (-2 kPa) = -2 kPa.

Question 14

If the blood pressure in the glomerular capillary is +14 kPa, the filtration pressure is +8 kPa, and the colloid osmotic pressure is -4 kPa, then the capsular fluid hydrostatic pressure is _______ kPa.

Accepted Answer

The answer of If the blood pressure in the glomerular...

Question 15

The _______ system(s) effect(s) the change in flow resistance in the glomerular blood pressure.

Accepted Answer

The nervous and endocrine systems both play roles in regulating glomerular blood pressure by affecting the resistance in blood flow. The nervous system can influence it through neural signals, while the endocrine system can do so through hormones like angiotensin.

Question 16

Which of the following is found in primary urine but not in definitive urine of a healthy human?

Accepted Answer

In a healthy human, glucose is reabsorbed completely in the proximal tubule of the nephron, so it is present in primary urine but not in definitive urine.

Question 17

Which of the following is the best description of active solute secretion?

Accepted Answer

Active solute secretion often involves using energy to create a concentration gradient for one solute, which then allows another solute to passively cross the membrane, a process known as secondary active transport.

Question 18

In amphibians, the first part of the nephron is

Accepted Answer

Bowman's capsule is the first part of the nephron where blood filtration begins in amphibians, as well as in other vertebrates.

Question 19

The last part of the nephron in amphibians is

Accepted Answer

The collecting duct is the last part of the nephron in amphibians, where urine is collected before it is transported to the bladder.

Question 20

The filtered fluid that forms in the nephrons will first empty into the

Accepted Answer

The filtered fluid, or urine, first empties from the nephrons into the ureter, which then transports it to the bladder.

Quiz 29: Kidneys and Excretion With Notes on Nitrogen Excretion