Question 1

Considering the arrangement of blood vessels in the vertebrate kidney bringing blood to and from the glomerulus, a(n) _______ in the diameter of the _______ could result in an increased rate of filtration.

Accepted Answer

The afferent arteriole is the vessel that brings blood into the glomerulus, and an increase in its diameter would increase the rate of blood flow into the glomerulus, resulting in an increased rate of filtration. A decrease in the diameter of the afferent arteriole would have the opposite effect, decreasing the rate of filtration. Changes in the diameter of the efferent arteriole or peritubular capillaries would not have as direct an effect on filtration, and the renal venule carries blood away from the kidney and does not directly affect filtration.

Question 2

With respect to osmoregulation, marine bony fishes do not

Accepted Answer

The answer of With respect to osmoregulation, marine bony fishes...

Question 3

Which feature does not characterize reptiles?

Accepted Answer

Retaining urea to raise the osmolarity of extracellular fluid is a characteristic of birds and mammals, not reptiles. Reptiles excrete uric acid to limit water loss.

Question 4

During urine formation in the vertebrate kidney, the processes of filtration and tubular secretion are similar in that both

Accepted Answer

Filtration and tubular secretion both involve the movement of substances from the blood into the filtrate. Filtration occurs as blood pressure forces water and solutes out of the blood and into the filtrate in the Bowman's capsule, while tubular secretion involves the active or passive transfer of substances from the blood into the tubular fluid along the nephron, allowing the body to excrete certain substances at rates higher than would occur with filtration alone.

Question 5

Once pathogenic bacteria have infected the urethra (in the urinary tract), they can move directly to the

Accepted Answer

Pathogenic bacteria can travel from the urethra to the urinary bladder through the short urethra, but it is less likely for them to reach the ureter, proximal convoluted tubule, kidney or collecting duct.

Question 6

Which of these substance(s) would you expect to find in a urine specimen collected from a healthy person?

Accepted Answer

Urine from a healthy person should contain water. Glucose would only be present if there is high blood sugar or diabetes. Red blood cells would indicate bleeding or injury to the urinary tract. Large molecules should be filtered out by the kidneys and not present in urine. Amino acids may be present in trace amounts but not typically detected in a routine urine test.

Question 7

Which structures do not play a role in renal filtration?

Accepted Answer

Collecting ducts do not play a direct role in renal filtration.

Question 8

Refer to the figure showing the vertebrate nephron.  Based on the figure, which statement is false?

Accepted Answer

Proteins and red blood cells are not normally present in the fluid that is filtered through the nephron (point 2), so it is not possible for them to be present in the fluid at point 5. Therefore, they cannot be reabsorbed later, and this statement is false. The other statements are true based on the figure.

Question 9

Which adaptation is not one of the water conservation adaptations of amphibians living in dry environments?

Accepted Answer

The answer of Which adaptation is not one of the...

Question 10

Considering the arrangement of blood vessels in the vertebrate kidney bringing blood to and from the glomerulus, a(n) _______ in the diameter of the _______ could result in a decreased rate of filtration.

Accepted Answer

The answer of Considering the arrangement of blood vessels in...

Question 11

Blood enters the glomerulus by way of the

Accepted Answer

Blood enters the glomerulus via the afferent arteriole, which then branches out to form the glomerular capillaries.

Question 12

Which feature is not one of the adaptations that allows reptiles to live in terrestrial environments where water must be conserved?

Accepted Answer

Excretion of salts is not specifically an adaptation for conserving water in terrestrial environments for reptiles. While reptiles do have mechanisms to deal with salt balance, the key adaptations that enable them to conserve water in terrestrial environments include scaly skin to reduce water loss, excretion of uric acid which requires less water to eliminate waste, shelled eggs that prevent desiccation of the embryo, and internal fertilization to ensure successful reproduction without the need for an aquatic environment.

Question 13

The presence of _______ in a person's urine sample might suggest problems with glomerular filtration.

Accepted Answer

Red blood cells in the urine sample might suggest problems with glomerular filtration.

Question 14

In the vertebrate kidney, the process of filtration from the capillaries into Bowman's capsule is driven by

Accepted Answer

Filtration in the vertebrate kidney is driven by arterial blood pressure. Blood entering the glomerulus through the afferent arteriole has a higher pressure than the fluid in Bowman's capsule, which creates a pressure gradient that drives filtration of water and solutes through the capillary walls and into the capsule. This process is known as ultrafiltration.

Question 15

Refer to the figure showing the vertebrate nephron.  Based on the figure, which statement is false?

Accepted Answer

Blood pressure in the glomerulus (point 2) is actually high, as it is necessary for filtration to occur. Therefore, statement E is false.

Question 16

While studying histological sections of a mammalian kidney, you come across a slide labeled "inner medulla." Which structure might you see on this slide?

Accepted Answer

The Loop of Henle is part of the renal tubule and extends into the inner medulla of the kidney. It plays a crucial role in the process of urine concentration, making it the most likely structure to be seen on a slide labeled "inner medulla."

Question 17

Regarding renal clearance in humans, foreign substances such as drugs would most likely be

Accepted Answer

Foreign substances such as drugs are typically secreted into the renal tubule during renal clearance, as this is the process by which the body eliminates them from circulation. Reabsorption at Bowman's capsule or the glomerulus would lead to these substances being returned to circulation, whereas reabsorption into the filtrate would not provide effective elimination. Secretion into the blood would also not be effective in eliminating these substances from the body.

Question 18

Which structure plays an increasing role in urination as toddlers develop?

Accepted Answer

As toddlers develop, they begin to gain control over their external urinary sphincter, which is a skeletal muscle located at the base of the urethra. This muscle helps to regulate the release of urine from the urinary bladder, and its increasing control is what allows toddlers to begin potty training and achieve continence. The other structures listed (ureter, urethra, urinary bladder) also play important roles in the urinary system, but do not undergo as significant changes during toddler development with regards to urination.

Question 19

Marine bony fishes acquire salt when they feed.They handle this salt load by

Accepted Answer

Marine bony fishes manage their salt load primarily by excreting ions through their gills and by limiting the absorption of certain ions from their gut. This helps them maintain osmotic balance in the high-salinity marine environment.

Question 20

Which substance would be reabsorbed in the smallest amounts by the renal tubule?

Accepted Answer

Of the given options, urea is the only one that is not essential for bodily function and is not actively reabsorbed by the renal tubule. Water is actively reabsorbed to maintain proper hydration levels, glucose is actively reabsorbed to provide energy, sodium ions are actively reabsorbed to maintain proper electrolyte balance, and amino acids are actively reabsorbed for protein synthesis.

Quiz 51: Salt and Water Balance and Nitrogen Excretion

Considering the arrangement of blood vessels in the vertebrate kidney bringing blood to and from the glomerulus, a(n) _ in the diameter of the _ could result in an increased rate of filtration.