Urine Formation and Nephron Structure

<p>Glomerular filtration (C)</p> Signup and view all the answers

<p>180 L (C)</p> Signup and view all the answers

<p>Osmosis (B)</p> Signup and view all the answers

<p>Amino acids (A), Urea (D)</p> Signup and view all the answers

<p>Impermeable to water and more permeable to solutes (D)</p> Signup and view all the answers

<p>Moves additional wastes from blood into the nephron (A)</p> Signup and view all the answers

<p>It is four times higher (B)</p> Signup and view all the answers

<p>To provide energy for active transport (C)</p> Signup and view all the answers

<p>Via osmosis towards a hypertonic medulla (B)</p> Signup and view all the answers

<p>Plasma proteins (B)</p> Signup and view all the answers

<p>Electrostatic attraction to cations (D)</p> Signup and view all the answers

<p>Tubule reabsorption (C)</p> Signup and view all the answers

<p>To remove water from the nephron and return it to the blood (C)</p> Signup and view all the answers

<p>Actively transporting Na+ out of the filtrate (A)</p> Signup and view all the answers

<p>Increased ion concentration in the filtrate (A)</p> Signup and view all the answers

<p>Distal tubule (D)</p> Signup and view all the answers

<p>Hydrogen ions (H+) (C)</p> Signup and view all the answers

<p>It becomes more concentrated as water is reabsorbed. (A)</p> Signup and view all the answers

<p>Decreased filtrate concentration (D)</p> Signup and view all the answers

<p>Filtrate becomes more concentrated (B)</p> Signup and view all the answers

<p>They passively follow cations. (D)</p> Signup and view all the answers

Urea is a waste product formed in the liver when excess protein is broken down. It is produced by the chemical combination of ammonia, which is toxic, and carbon dioxide.

The removal of the amino group from an amino acid molecule. This process produces ammonia as a byproduct, which is then converted into urea.

The process of filtering blood in the kidneys to create urine. It involves moving water and small dissolved substances from the blood into the nephron, which is the functional unit of the kidney.

The process of reabsorbing useful substances like sodium from the nephron back into the bloodstream. It ensures that the body retains essential nutrients and water.

The process of actively transporting additional waste products from the bloodstream into the nephron. This helps eliminate harmful substances from the body.

The process of removing water from the nephron and returning it to the bloodstream. It plays a crucial role in maintaining fluid balance and blood pressure.

The pathway of blood inside the nephron: Blood flows from the afferent arteriole into the glomerulus, a network of capillaries where filtration occurs, and then out through the efferent arteriole.

The filtrate is very similar to blood plasma, but it lacks large proteins like albumin. This means only small substances like water, salts, glucose, urea, and other waste products are present in the filtrate.

The process where essential solutes and water move from the nephron back into the blood.

A process involving the movement of substances out of the nephron and into the blood.

It acts as a selective filter, reabsorbing essential nutrients and water while excreting waste products.

They provide the energy needed for active transport processes, specifically for moving glucose, amino acids, and sodium ions out of the filtrate.

This is caused by the difference in ion concentration between the filtrate and the blood.

The descending limb is permeable to water and less permeable to ions.

The ascending limb is impermeable to water but more permeable to solutes, specifically Na+.

It helps concentrate urine and conserve water by creating a hypertonic environment in the renal medulla facilitating water reabsorption.

The ascending limb of the Loop of Henle is not permeable to water. This means that water cannot pass out of the nephron into the blood vessels. However, salt (NaCl) is reabsorbed through diffusion in the lower portion and active transport in the upper portion. This helps to maintain the high concentration of salt in the medulla.

The proximal tubule is responsible for the reabsorption of water, nutrients, anions, and cations. These substances are reabsorbed from the filtrate back into the blood vessels.

The thick-walled portion of the ascending limb actively transports Na+ out of the filtrate, replenishing the salt levels in the medulla. This transport is active meaning it requires energy. Anions passively follow cations, moving down their concentration gradients.

The collecting duct extends into the very salty medulla, making it highly permeable to water. This gradient causes osmosis of water out of the nephron and into the capillaries. The filtrate becomes more concentrated as water is reabsorbed.

The transport of ions out of the ascending limb contributes to the high concentration of salt in the medulla.

The distal tubule is responsible for actively transporting Na+ out of the filtrate into the capillaries, depending on the body's needs. Anions passively follow cations. As ions are reabsorbed, the filtrate concentration decreases, triggering water reabsorption via osmosis.

The distal tubule is the main site of tubular secretion, followed by the proximal tubule.