Renal System: Functions and Morphology

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main function of cortical nephrons?

Absorption of sodium (correct)

Formation of urine

Regulation of blood pressure

Filtration of blood

What percentage of nephrons are juxtamedullary nephrons?

30%

14% (correct)

10%

20%

What is the function of the glomerulus?

To absorb sodium from the filtrate

To regulate blood pressure

To filter waste from the blood (correct)

To form urine

What is the structure that encloses the glomerulus?

Bowman's capsule Signup and view all the answers

What is the rate of blood flow to the kidneys?

1200 ml/min Signup and view all the answers

What is peculiar about the renal circulation?

Very high blood supply Signup and view all the answers

What is the term for the thin segment of the loop of Henle?

Thin segment Signup and view all the answers

What is the main function of the proximal convoluted tubule?

Reabsorption of useful substances Signup and view all the answers

What is the primary function of the kidneys in regulating the body's electrolyte balance?

To maintain a balance between intake and output of water and electrolytes Signup and view all the answers

Which of the following waste products is excreted by the kidneys?

Urea Signup and view all the answers

What is the name of the hormone produced by the kidneys that stimulates the production of red blood cells?

Erythropoietin Signup and view all the answers

What is the term for the process of removing waste products from the body?

Excretion Signup and view all the answers

What is the main function of cortical nephrons?

To form urine Signup and view all the answers

Which of the following organs is responsible for excreting carbon dioxide?

Lungs Signup and view all the answers

What is the role of the kidneys in regulating blood pressure?

To maintain a stable blood pressure Signup and view all the answers

What is the purpose of the nephron, the structural and functional unit of the kidney?

To form urine Signup and view all the answers

What is the main function of the efferent arteriole in the nephron?

To break into the peritubular capillary network around the tubules of cortical nephrons Signup and view all the answers

What is the characteristic of blood flow through the vasa recta?

It is sluggish and has a low pressure Signup and view all the answers

What is the main function of the afferent arteriole in the nephron?

To provide a short, straight branch of the interlobular artery Signup and view all the answers

What is the purpose of autoregulation in the kidneys?

To maintain a constant renal blood flow despite changes in blood pressure Signup and view all the answers

What is the pressure in the glomerular capillary bed?

60 mmHg Signup and view all the answers

What is the function of the distal convoluted tubules?

To open into initial arched collecting ducts Signup and view all the answers

What is the name of the ducts that open into the papilla of minor calyces?

Papillary ducts Signup and view all the answers

What is the percentage of blood flow through the vasa recta?

1-2% Signup and view all the answers

Study Notes

Role of the Kidneys in the Body

Regulate the volume and composition of the ECF by maintaining a balance between intake and output of water and electrolytes in the body.
Excrete and eliminate waste products of metabolism, such as urea, creatinine, and uric acids, as well as various toxins like drugs and food additives.
Act as endocrine glands, producing hormones like erythropoietin and renin.
Play a dominant role in the long-term and short-term regulation of arterial blood pressure.
Contribute to acid-base regulation along with the respiratory system.
Synthesize glucose from amino acids and other precursors.

Excretion

Defined as the removal of waste products from the body.
Organs involved in excretion:
- Kidneys: excrete water and water-soluble waste products.
- Lungs: excrete carbon dioxide, water vapor, and other volatile substances.
- Skin: excretes water and salts mainly in the form of sweat.
- Gastrointestinal tract: excretes undigested food.

Structure of Nephron

Nephron is a structural and functional unit of the kidney.
Each nephron is capable of forming urine.
Two types of nephrons:
- Cortical nephrons (86%): glomeruli are present near the surface of the kidneys; main function is absorption of sodium.
- Juxtamedullary nephrons (14%): glomeruli lie at the junction of cortex and medulla; main function is to increase concentration of medullary interstitial fluid.
Two major parts of a nephron:
- Glomerulus: a tuft of capillaries that connect afferent arteriole with an efferent arteriole.
- Renal tubule: consists of three parts - proximal convoluted tubule, loop of Henle, and distal convoluted tubule.

Blood Flow to Kidneys

Rate of blood flow to kidneys: 1200 ml/min.
Peculiarities of renal circulation:
- Very high blood supply (21% of cardiac output).
- Two sets of capillaries: glomerular capillaries and peritubular capillaries.
- Glomerular capillary bed has a high hydrostatic pressure (60 mmHg) due to a smaller diameter of the efferent arteriole compared to the afferent arteriole.
- Peritubular capillary bed is a low-pressure bed (13 mmHg).
- Vasa recta (loop-shaped vessels) in juxtamedullary nephrons receive only 1-2% of blood flow, which is very sluggish.
- Renal blood flow shows remarkable constancy in the face of blood pressure changes due to autoregulation.
The kidneys regulate the hydrostatic pressure in both capillary beds by adjusting resistance of the afferent and efferent arterioles.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the functions of the kidney, morphology of the typical nephron, and the concept of clearance. It also explores the role of the kidneys in regulating the body's ECF volume and composition.