12.7.2 Human Excretion: Urinary System Structure

Question 1

Human Excretion: Urinary System Structure

Answer 1

• The excretory system functions in the disposal of metabolic wastes and in maintaining a proper fluid balance in the body.
• The kidneys, a major component of the excretory system, are located on the dorsal body wall and function in the filtration of blood to produce urine.
• Filtrate leaves the kidney, travels down the ureter, into the bladder, and exits the body through the urethra.
• The kidney consists of many small filtration units called nephrons. A human kidney consists of approximately one million nephrons. A single nephron consists of a long tubule and associated capillaries.

Question 2

excretory system

Answer 2

• The kidneys are the urine-producing organs of the
  excretory system that are located along the dorsal body wall. The renal artery delivers blood to the kidneys, where it is filtered, and the renal vein removes blood from the kidneys, where it will eventually return to the heart. Urine then travels from the kidneys down the ureters and to the urinary bladder, where it is stored until urination.

Question 3

kidney

Answer 3

• The kidney consists of many, small functional units called nephrons that take part in the filtration of blood. Each nephron consists of a long tubule (in which filtrate is formed) and the blood vessels that are associated with the tubule.

Question 4

tubules and vessels of nephron

Answer 4

• The diagram to the left shows a closer view of the tubules and vessels of a nephron. Blood travels into the
  afferent arteriole and enters the glomerulus, a ball of
  capillaries that serves as a site of blood filtration (shown in the upper left portion of the diagram). Blood leaves the glomerulus through the efferent arteriole. Filtrate from the blood enters Bowman’s capsule, which is the cup-shaped, terminal end of the tubule that surrounds the glomerulus. The filtrate then travels through the tubules of the nephron and into the collecting duct, eventually forming urine.

Question 5

Which of the following describes the correct path of blood moving through the vessels surrounding a nephron?

Answer 5

• afferent arteriole, glomerulus, efferent arteriole, vein

Question 6

The filtration unit of the kidney is the

Answer 6

• nephron

Question 7

All of the following statements about the kidneys are true except:

Answer 7

• They are well protected by the rib cage

Question 8

Complete the following analogy:

Lung : pulmonary :: kidney : ?

Answer 8

• renal

Question 9

Three tubes (or types of tubes) connect to each kidney. Which does not represent a “tube” that is directly connected to a kidney?

Answer 9

• urethra

Question 10

All of the following statements about kidney structure are true except:

Answer 10

• Nephrons are found only in the renal medulla.

Question 11

The kidneys remove waste products from __________ and produce __________.

Answer 11

• blood, urine

Question 12

Nephrons are found in the

Answer 12

• medulla

- cortex