Module 18: The Urinary System

Question 1

Hilum

Answer 1

Notch near the center of the concave border of the kidney Where the ureter leaves the kidney and where blood vessels, nerves, and lymph vessels enter and leave the kidney

Question 2

Renal pyramids

Answer 2

Triangular structures that look striated (striped) due to straight renal tubules and blood vessels

Question 3

Glomerulus

Answer 3

Network of capillaries
Surrounded by the Bowman’s capsule
Blood is filtered from the glomerulus and enters the Bowman’s capsule

Question 4

Bowman’s capsule

Answer 4

Double-walled structure that surrounds the glomerulus
Receives filtered blood (called filtrate) from the glomerulus and delivers it to the renal tubule
Contains a fluid (derived from plasma, rich in solutes, free of proteins) that is the raw material of urine

Question 5

Renal tubule

Answer 5

Site of urine formation through 2 processes called reabsorption and secretion

Question 6

Afferent arteriole

Answer 6

Renal artery branches into smaller blood vessels that merge as the afferent arteriole
Forms glomerulus

Question 7

Efferent arterioles

Answer 7

Form peritubular capillaries

Question 8

Basic processes of urine formation

Answer 8

Glomerular filtration
Tubular reabsorption
Tubular secretion

Question 9

Glomerular filtration

Answer 9

Small substances are filtrated through hydrostatic pressure, no energy needed
Large molecules are NOT filtrated (e.g., blood cells and large proteins)

Question 10

Tubular reabsorption

Answer 10

Occurs mostly in the proximal convoluted tubule

Question 11

Aldosterone

Answer 11

Released by the adrenal glands
Helps to regulate fluid balance
Stimulates the distal tubules to reabsorb Na+ ions and
water, and to excrete K+ ions

Question 12

Atrial natriuretic peptide

Answer 12

Inhibits the reabsorption of Na+ and water, decreasing blood volume and blood pressure
Relaxes glomerular mesangial cells which increases capillary surface area, increasing GFR

Question 13

Renin

Answer 13

Enzyme secreted by the juxtaglomerular apparatus (located in the afferent arterioles)
Circulates in the bloodstream where it is indirectly involved with the control of blood pressure
Leads to the formation angiotensin I which is converted into angiotensin II by angiotensin-converting enzyme

Question 14

Erythropoietin

Answer 14

Secreted in response to low oxygen in arterial blood

Transported in the blood stream to bone marrow

Question 15

Micturition

Answer 15

Urination

The detrusor muscle of the bladder contracts as do the muscles of the pelvic floor and abdominal wall

Question 16

Angiotensin I

Answer 16

Converted to angiotensin II by angiotensin-converting enzyme

Question 17

Angiotensin II

Answer 17

Raises blood pressure by exerting a powerful constrictor effect on the arterioles