Excretion

Question 1

What is the excretory system?

Answer 1

The body system that deals with the removal of excess, unnecessary materials from the bodily fluids of an organism.

Question 2

What is excretion?

Answer 2

The removal of metabolic wastes from an organism. The main wastes are carbon dioxide, water, urea, ammonia, mineral salts, creatinine, and uric acid, which come from nucleic acid.

Question 3

What is nitrogenous waste?

Answer 3

Urea and ammonia are nitrogenous metabolic wastes. Any waste product that is nitrogen-based.

Question 4

What does the liver do in the excretory system?

Answer 4

It is extremely important for metabolic processes and for the breakdown of proteins and amino acids into urea. The blood byproducts of the liver are filtered out by the kidneys.

Question 5

What do the kidneys do in the excretory system?

Answer 5

These are part of the urinary tract, which makes urine. They filter all of the salts, toxins, and water out of the blood. After they remove all of these waste products from the blood, they return the cleaned blood back into the body. The leftover wastes are made into urine, which is taken out of the body by the urinary tract.

Question 6

What is the renal cortex?

Answer 6

This is the outer layer of the kidney where the nephrons begin. It also creates some hormones.

Question 7

What is the renal medulla?

Answer 7

This regulates the concentration of urine using an osmotic gradient.

Question 8

What is the renal pelvis?

Answer 8

The area at the center of the kidney where urine collects and is funneled into the ureter, which takes it to the bladder.

Question 9

What are the renal arteries?

Answer 9

These are large blood vessels that carry oxygenated blood from the heart to the kidneys to be cleaned. There is one for each of the kidneys.

Question 10

What are the renal veins?

Answer 10

These are large blood vessels that carry filtered blood away from the kidneys and back to the heart, specifically the vena cava. There is one for each kidney.

Question 11

What are the nephrons?

Answer 11

These are located in the kidneys, they process waste products from the urine. They are the functional units of the kidney, and there are about one million of them in each kidney. They include a filter, called a glomerulus, and a tubule that returns needed substances into the blood and removes wastes.

Question 12

What is filtrate in the excretory system?

Answer 12

This is the product that is filtered into the glomerulus. It eventually forms urine once it goes through reabsorption and secretion.

Question 13

What is urine?

Answer 13

A liquid waste created by the kidneys after they filter the blood. It is held by the bladder and removed from the body through the urethra. It consists of water, waste products, salt, electrolytes and urea, which is a nitrogenous metabolic waste made from amino acids.

Question 14

What are the ureters?

Answer 14

The tubes that carry urine from a kidney into the urinary bladder.

Question 15

What is the urinary bladder?

Answer 15

The sac that temporarily stores urine.

Question 16

What is the urethra?

Answer 16

The tube that carries urine from the urinary bladder to the exterior of the body.

Question 17

What are the afferent arterioles?

Answer 17

Blood vessels that carry blood into the glomerulus. They branch off the renal artery.

Question 18

What are the efferent arterioles?

Answer 18

Blood vessels that carry blood out of the glomerulus after it has been flitered and into the rest of the kidney so it can be put back into circulation.

Question 19

What is the glomerulus?

Answer 19

A network of tiny blood vessels that filter the blood, allowing waste products, water, and some other stuff to pass into the nephron’s tubule while retaining the large molecules and blood cells. It is located in Bowman’s Capsule.

Question 20

What is Bowman’s capsule?

Answer 20

A two-walled pouch that surrounds the glomerulus. It works with the glomerulus to filter blood and create urine.

Question 21

What is the peritubular capillary net?

Answer 21

A network of tiny blood vessels that surrounds the renal tubules in the kidneys. They remove waste from the blood and reabsorb nutrients like amino acids, glucose, and minerals.

Question 22

What is the collecting duct?

Answer 22

This is a tubule at the end of the nephron that collects all of the urine formed by the nephron. It collects this urine and transports it into the renal pelvis, where it is drained into the ureters.

Question 23

What is reabsorption?

Answer 23

Most of the water, nutrients and many ions are reabsorbed by the blood in the proximal convoluted tubule and loop of Henle.

Question 24

What is secretion?

Answer 24

Additional substances are actively removed from the blood (H+, drugs, steroids). Fine-tuning of K+ and H+ in the urine to regulate blood pH. This is done in the distal convoluted tubule.

Question 25

What is interstitial fluid?

Answer 25

The fluid that surrounds body cells and tissues. It delivers oxygen and nutrients to cells and removes waste products. It is a pathway for waste to be brought to the kidney.

Question 26

What is filtration in the nephron (steps)?

Answer 26

1. Blood enters through the afferent arteriole. 2. Fluid and solutes from the blood pass through the podocytes into the Bowman’s Capsule. 3. All remaining blood leaves through the efferent arteriole, and the filtrate continues into the renal tubule. 4. The glomerulus moves water through osmosis, and nitrogenous wastes and ammonia through diffusion in the kidneys. 5. Passive transport moves sodium ions, glucose, amino acids, and hydrogen ions across the wall of the nephron into the tubule fluid.

Question 27

What is the loop of Henle?

Answer 27

The Main function is to create and maintain an osmosis gradient to the medulla that enables the collecting ducts to concentrate urine. It reabsorbs substances and helps process urine, it mainly reabsorbs salts and water. It has a descending part, which is thin, and a thin, then thick ascending part.

Question 28

What is the proximal convoluted tubule?

Answer 28

The tube that reabsorbs most filtered substances and excretes the waste products. It comes before the Loop of Henle.

Question 29

What is the distal convoluted tubule?

Answer 29

This is a tube that reabsorbs fluids, electrolytes, and a bunch of other ions. It also secretes potassium. It comes after the Loop of Henle, and helps process urine.

Question 30

What is antidiuretic hormone (ADH)?

Answer 30

This is a regulatory hormone that controls the amount of water the kidneys release, decreasing the amount of urine produced. It does this by increasing the permeability of the collecting duct, meaning more water is absorbed into the bloodstream. By doing this, it controls blood pressure in the body, because the extra water in the blood from this hormone will result in higher blood pressure. Higher levels of ADH mean there will be less urine production and higher blood pressure. Lower levels of ADH will result in higher levels of urine production and lower blood pressure.

Question 31

What is aldosterone?

Answer 31

This is a hormone that regulates sodium reabsorption and potassium excretion. This results in higher concentrated urine, as it has less water content. This helps maintain electrolyte and water balance in the blood. By retaining sodium and water, blood volume is increased and blood pressure is elevated. More aldosterone means higher blood pressure.

Question 32

What is urinalysis?

Answer 32

This is a urine test that checks for signs of blood cells, proteins, pH, osmolality, proteins, urea, creatine and glucose levels. It can diagnose many metabolic or systemic kidney diseases, endocrine disorders, diabetes, pregnancy and drug testing.

Question 33

What is blood pressure in relation to blood volume?

Answer 33

Blood pressure directly relates to blood volume. There is more water in the blood because the more blood there is, the more pressure there is. ADH and aldosterone affect how much water is reabsorbed and returned to the blood. If they reabsorb more water, there will be more blood volume and pressure. If they don’t, you urinate it out, and will have a lower blood volume and therefore lower blood pressure. The glomerulus also works using blood pressure, so if there is not enough blood pressure, then it will not work properly.

Question 34

What is hemodialysis?

Answer 34

This is he act of using a machine to filter the waste and excess fluids and wastes from the blood when the kidneys do not work as they are supposed to. It does the job of the kidneys.