Chapter 19: Urinary System

which blood vessel supplies blood to the kidney?

Renal artery

What are the filtration units of the kidney?

Nephrons

What is the hilum?

A concave notch on the medial side of the kidney through which structures such as blood vessels, the ureters, and nerves enter and leave the organ

What structures make up a renal corpuscle?

The glomerulus & Bowman's capsule

Identify the four regions of the renal tubule, beginning with the region closest to the renal corpuscle.

Proximal convoluted tubule, loop of Henle (which consists of a descending limb and an ascending limb), distal convoluted tubule, and collecting duct.

Where are renal corpuscles located?

Renal cortex

What is the first step in the creation of urine?

Water and small solutes filter out of the blood inside the glomerulus and into the surrounding space of Bowman's capsule.

What prevents calcium, iron, and thyroid hormone from filtering out of the blood in the glomerulus?

Most of these substances are bound to plasma proteins, which are too large to pass through the pores of the glomerulus.

How does hypertension cause kidney damage?

High blood pressure can cause glomerular capillaries to burst, resulting in scarring. Hypertension also causes atherosclerosis, which reduces blood flow to the kidneys and causes further damage.

Nerves enter the kidney at the hilum. What is their role in urine formation?

The mainly sympathetic fibers adjust the diameter of the afferent and efferent arterioles to control the flow of blood, and therefore blood pressure, inside the glomerulus.

What effect does aldosterone have on the renal system and on blood pressure?

Aldosterone causes the distal convoluted tubule to retain sodium, which leads to increased retention of water. This causes blood volume to increase and blood pressure rises.

Where are most of the water, electrolytes, and nutrients reabsorbed?

Proximal convoluted tubule.

What occurs in the distal convoluted tubule and collecting ducts?

Variable amounts of water and salts are reabsorbed; specialized cells also reabsorb potassium and secrete hydrogen to aid acid-base balance.

Many diuretics block the tubular reabsorption of sodium. How does this affect urine volume & blood pressure?

Blocking the reabsorption of sodium also blocks the reabsorption of water. This leads to increased urine output, decreased blood volume, and lower blood pressure.

How does the antidiuretic hormone (ADH) affect the kidneys?

ADH causes the cells of the distal and collecting tubules to become more permeable to water. Water flows out of the tubule and into the interstitial fluid, causing urine volume to decrease.

What is the muscular wall of the bladder called?

Detrusor muscle

Infections commonly attack which area of the bladder?

The trigone: the triangular-shaped area formed by the two ureters and the urethra.

Filtration unit of the kidney

Nephron

Outer region of the kidney

Renal cortex

Inner region of the kidney

Renal medulla

Cuplike area that collects urine

Calyx

Cluster of capillaries inside the nephron

Glomerulus

Two layers of epithelial cells surrounding glomerulus

Bowman's capsule

Portion of the nephron where glomerular filtrate is processed, with some chemicals being removed and others added

Renal tubule

Portion of nephron that filters blood

Renal corpuscle

The cluster of capillaries in the nephron is the:

glomerulus

The location where blood vessels, nerves, and the ureter enter and leave the kidney is the:

hilum

The portion of the nephron in charge of making urine is the:

renal tubule

Most sodium is reabsorbed from the glomerular filtrate in the:

proximal convoluted tubule

Which of the following substances should never be found in urine?

glucose

The hormone aldosterone:

causes the distal convoluted tubule to reabsorb more sodium, which leads to water retention and a rise in blood pressure

Many diuretics work by blocking tubular reabsorption of:

Sodium

In women, the _______ is shorter than in men, which contributes to the higher incidence of urinary tract infections in women.

urethra (not ureter)

Urination occurs when:

the bladder contracts and the external urethral sphincter relaxes

A triangular-shaped smooth area on the floor of the bladder is called the:

trigone

What is the purpose of lithotripsy?

disintegrate a kidney stone