The Renal System Quiz

Study Notes

Primary Functions of the Kidneys

Main role is to filter blood and reclaim most water and solutes for the body.
Kidneys also produce hormones but this is secondary to their filtering capacity.

Urinary Structures

Ureter carries urine from the kidneys to the bladder.
Urethra dispels urine from the bladder to the outside.

Anatomy of the Kidney

Kidneys are bean-shaped and approximately the size of a fist (around 11 cm long).
Located behind the peritoneum on the posterior abdominal wall.

Internal Anatomy of the Kidney

Medulla contains cone-shaped structures known as renal pyramids.
Renal pelvis functions to drain urine from the kidney into the ureter.

Nephron

The nephron is the kidney's structural and functional unit.
Renal corpuscle within the nephron is responsible for the filtration of plasma.
85% of nephrons in the kidneys are classified as cortical nephrons.
Renal tubules handle reabsorption and secretion processes.

Hormonal Functions of the Kidneys

Erythropoietin, produced by the kidneys, stimulates the formation of red blood cells (hemopoiesis).
Average Glomerular Filtration Rate (GFR) is about 125 ml/min.
Calcitriol, a hormone, aids in calcium reabsorption in the kidneys.

Micturition Reflex

Stretch receptors in the bladder wall are activated by urine filling the bladder.
The pons and cerebrum increase conscious awareness of the need to urinate.
External urethral sphincter is controlled by skeletal muscle, allowing voluntary control over urination.

Glomerular Filtration Rate

High GFR can lead to loss of beneficial substances due to rapid fluid passage through nephrons.
GFR is kept constant through autoregulation via the juxtaglomerular apparatus.

Tubular Reabsorption

Around 99.5% of the nephron filtrate is reabsorbed back into the body.
Proximal convoluted tubule (PCT) is primarily responsible for reabsorption operations.
ADH (antidiuretic hormone) regulates water reabsorption in the distal convoluted tubule (DCT).

Tubular Secretion

The distal convoluted tubule (DCT) is most active in the secretion process.
Secretion of H+ ions helps to control blood pH in the nephron.

Loop of Henle

The Loop of Henle establishes a salt gradient in the medulla, crucial for concentrating urine.
Juxtamedullary nephrons feature long Loops of Henle facilitating this gradient.

Juxtaglomerular Apparatus (JGA)

Juxtaglomerular cells monitor blood pressure, playing a key role in renal regulation.
Macula densa cells detect changes in filtrate flow, adjusting nephron function accordingly.

Collecting Duct

Aldosterone controls Na+ reabsorption in the collecting duct, influencing blood pressure and volume.
Collecting ducts empty urine into papillary ducts, leading toward the urinary bladder.

Miscellaneous Functions

The renal capsule surrounds and protects the kidneys, providing vital structural support.

Description

Test your knowledge on the renal system with this quiz covering the anatomy and functions of the kidneys. From the primary roles of the kidneys to the structures involved in urine transport, challenge your understanding of this vital organ system.