Topic 6: Urinary System

Question 1

Urinary System Functions

What are the key regulatory and hormonal functions of the urinary system?

Answer 1

The urinary system regulates ion concentration, blood pH, blood volume, blood pressure, blood osmolarity, produces calcitriol and erythropoietin, supports gluconeogenesis, and excretes metabolic wastes.

These functions are performed primarily by the kidneys.

Includes control of Na⁺, K⁺, Cl⁻, Ca²⁺; pH via H⁺/HCO₃⁻; BP via renin-angiotensin-aldosterone; glucose via gluconeogenesis.

Question 2

Nephron Structures

What is the nephron and what structures does it include?

Answer 2

The nephron is the functional unit of the kidney, consisting of the glomerulus, Bowman’s capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct.

Each kidney has about 1 million nephrons.

Processes blood to form urine through filtration, reabsorption, secretion.

Question 3

Bowman’s Capsule

What is the role of Bowman’s capsule in the nephron?

Answer 3

Bowman’s capsule surrounds the glomerulus and collects filtrate forced out of capillaries by hydrostatic pressure.

This is the first step in urine formation.

Question 4

Glomerulus

What occurs at the glomerulus?

Answer 4

The glomerulus is a tuft of capillaries that filters blood plasma into Bowman’s capsule based on pressure.

Filtration excludes blood cells and large proteins.

Question 5

Tubule Segments

What are the segments of the nephron tubule and their primary roles?

Answer 5

PCT reabsorbs bulk of solutes and water; loop of Henle creates an osmotic gradient; DCT fine-tunes ion content and pH; collecting duct finalizes urine composition.

Each segment has specific transporters and hormone responses.

Question 6

Collecting Duct

What is the function of the collecting duct?

Answer 6

It collects tubular fluid from nephrons, regulates water and ion reabsorption, and delivers urine to the minor calyx.

Influenced by hormones like ADH and aldosterone.

Question 7

Retroperitoneal

What does retroperitoneal mean in regard to kidney anatomy?

Answer 7

It means the kidneys are located behind the peritoneum of the abdominal cavity.

Not suspended within the peritoneal sac.

Question 8

Urinary Tract Organs

What are the major organs of the urinary tract?

Answer 8

Kidneys, ureters, urinary bladder, and urethra.

Ureters move urine to the bladder; bladder stores it; urethra expels it.

Question 9

Trigone

What is the trigone of the urinary bladder?

Answer 9

A triangular smooth area between ureteral and urethral openings that signals bladder fullness.

Remains fixed and less distensible.

Question 10

Kidney Gross Anatomy

What structures make up the internal anatomy of the kidney?

Answer 10

Renal capsule, cortex, medulla, pyramids, columns, papillae, minor and major calyces, renal pelvis, and hilum.

These structures direct filtrate through processing and drainage.

Question 11

Urine Flow Pathway

What is the full pathway of urine from blood to exterior?

Answer 11

Blood → glomerulus → Bowman’s capsule → PCT → loop of Henle → DCT → collecting duct → minor calyx → major calyx → renal pelvis → ureter → bladder → urethra → exterior.

Describes the anatomical and functional sequence of urine formation and excretion.