Chapter 10 - Removal Of Waste

Question 1

What dies excretion mean?

Answer 1

Removal of the wastes of metabolism from the body is called excretion. Several organs in the body are involved either in the processing of wastes or in the excretion of those wastes.

Question 2

What is the equation for deamination?

Answer 2

Amino acid + oxygen = carbohydrate + ammonia

Question 3

What is the equation for the removal of urea?

Answer 3

Energy + carbon dioxide + ammonia = urea + water

Question 4

What is the difference between secretion and an excretion?

Answer 4

A secretion is a substance that is produced by cells, glands or organs. Examples of secretions are hormones, stomach acids bile and wastes.

An excretion is the secretion of wastes.

Question 5

Label each component of the kidney

Answer 5

Renal artery 
Renal vein 
Medulla 
Cortex
Renal pelvis 
Ureter

Question 6

Label each component of a nephron

Answer 6

Renal corpuscle ; glomerulus and glomerular capsule
Afferent arteriole
Efferent arteriole 
Peritubular capillaries 
Proximal convoluted tubule 
Descending limb 
Loop of henle 
Ascending limb 
Distal convoluted tubule 
Collecting duct

Question 7

What are nephrons responsible for?

Answer 7

Removing wastes from the blood and regulating blood composition.

Question 8

What are the three major processes of urine formation?

Answer 8

Glomerular filtration - fluid is forced out of the blood and collected by the glomerular capsule. In a healthy person, the filtrate should consist of water salts, amino acids, glucose,urea and uric acid.

Reabsorption - so that components from the plasma don’t unessasarily leave the body, selective reabsorption takes place to filter the wastes once again. This occurs in the cells that line the renal tubule.

Tubular secretion - tubular secretion adds materials to the filtrate from the blood. It controls the pH of the body.

Question 9

Explain the four components of the relationship between the kidneys and their function

Answer 9

1. The glomerular capsule surrounds the glomerulus to collect the fluid filtered out of the blood capillaries
2. The arteriole leading out of the glomerulus has a smaller diameter than the arteriole leading in. This raises the blood pressure so that more fluid is filtered out of the blood.
3. The tubule has two sets of convolutions and a long loop so that each tubule has a large surface area for reabsorption and secretion.
4. Each kidney has over a million nephrons so the total surface area available for reabsorption and secretion is extremely large.

Question 10

What is dialysis?

Answer 10

Dialysis is the method of removing wastes from the blood when kidney failure occurs. There are two types of ; peritoneal and haemodialysis

Question 11

How does lifestyle affect kidney functions?

Answer 11

Kidney stones - solid crystals that build up inside the kidneys. They usually form when urine becomes toon concentrated and some doctors believe that they form because there is insufficient fluid in the diet.

Kidney failure - when the kidneys are unable to filter the blood.
Things you can do to maintain healthy kidneys ;
- regulate your diet to maintain a healthy weight
- don’t smoke
- drink water instead of drinks containing sugar
- drink alcohol in moderation
- don’t take drugs