Sec 32.4: Excretory System

Question 1

What is the excretory system?

Answer 1

It is the body system that eliminates nonsolid wastes through sweat, urine, and exhalation to help maintain homeostasis in the body

Question 2

What are the waste products of the excretory system?

Answer 2

Toxic materials, excess water, salts, CO2, urea, minerals and vitamins

Question 3

What are the main organs of the excretory system?

Answer 3

Skin, lungs, kidneys, ureters, urinary bladder, and urethra

Question 4

What is the function of the lungs in the excretory system?

Answer 4

They remove CO2 and water vapor through exhalation

Question 5

What is the function of the skin in the excretory system?

Answer 5

Sweat glands release excess water and salts to cool the body to maintain stable internal temperature

Question 6

What are kidneys?

Answer 6

They are organs that eliminate wastes through filtration of the blood

Question 7

How much of the blood supply passes through your kidneys?

Answer 7

1/4 of your blood supply every minute

Question 8

What do kidneys look like? where are they located?

Answer 8

They are bean-shaped organs the size of a fist, located on the left and right sides of the lower back.

Question 9

Where is blood returned after filtration?

Answer 9

To the circulatory system (duh)

Question 10

What is the medulla?

Answer 10

The inner layer of the kidney

Question 11

What is the cortex?

Answer 11

The outer layer of the kidney (packed with nephrons)

Question 12

What are nephrons?

Answer 12

They are the individual filtering unit of the kidney. There are 1 million nephrons per kidney

Question 13

Where does the blood enter and exit in the kidney?

Answer 13

Large volume of blood enters through the renal artery and exits through the renal vein.

Question 14

What is the function of nephron controlled by?

Answer 14

By how much water, salts, & other materials are concentrated in the blood.

Question 15

What helps regulate kidney function?

Answer 15

Hormones released in response to concentrations of water, salts, and other materials in the blood

Question 16

What are the kidney’s three basic functions?

Answer 16

1. Remove waste products from the blood, such as wastes from digestion and cell respiration
2. Help to maintain electrolyte, pH, and fluid balances in the body
3. Release hormones that help to keep bones healthy, produce red blood cells, and regulate blood pressure

Question 17

What is the glomerulus?

Answer 17

It is a tangled ball of capillaries which supplies blood to each nephron. It is tucked into a cup-shaped structure called Bowman’s capsule

Question 18

What is urea?

Answer 18

It is a waste product produced by breakdown of proteins

Question 19

What is the ureter?

Answer 19

It is a tube that carries urine from each kidney to the bladder

Question 20

What is the urinary bladder?

Answer 20

It is a saclike organ that can store up to half a liter (over 2 cups) of urine at one time

Question 21

What is urethra?

Answer 21

It is the tube that releases urine

Question 22

How do nephrons filter the blood and produce urine?

Answer 22

Filtration, Reabsorption, and Excretion

Question 23

Describe the process of filtration

Answer 23

Blood enters kidney -> flows into arterioles -> moves into glomerulus of each nephron -> small molecules diffuse out of capillaries and into the Bowman’s capsule (forming the filtrate) -> blood cells, plasma, proteins, platelets stay in the blood because they are too big.

Question 24

What is filtrate?

Answer 24

It consists of the small materials that diffuse into Bowman’s capsule such as water, electrolytes, amino acids, glucose, and urea

Question 25

Describe the process of reabsorption

Answer 25

1% of filtrate is excreted as urine, and the other 99% is reabsorbed into the capillaries and returns to the blood

Question 26

What does the reabsorption of H2O and Na+ do?

Answer 26

It helps maintain fluid balance

Question 27

Why is reabsorption important?

Answer 27

Because it ensures nutrients are made available to the body

Question 28

What is urine?

Answer 28

It is made up of water, salts, urea, and other materials that remain in the filtrate after reabsorption, and includes ions such as potassium and hydrogen.

Question 29

Why is the removal of ions such as potassium and hydrogen important?

Answer 29

Because their removal maintains homeostasis by keeping blood pH within normal limits

Question 30

What is the loop of Henle?

Answer 30

It is where water is removed one final time to reduce the volume of urine

Question 31

Describe the process of Excretion

Answer 31

Filtrate moves out of Bowman’s capsule into loop of Henle, where water is reabsorbed one final time, and then remaining urine flows into a collecting duct that leads to the ureter -> urinary bladder

Question 32

What happens when the bladder is full?

Answer 32

Bladder wall nerves send signals to the brain to get the urge to urinate

Question 33

What is the importance of urine testing?

Answer 33

It determines whether a person is abusing drugs and what types, because drugs are broken down n he liver, filtered by the kidneys, and excreted in the urine

Question 34

What does urine sample containing sugar, protein, or blood mean?

Answer 34

That there is possible nephron damage by an infection or injury

Question 35

What are the possible causes of renal failure (kidney failure/damage)? What do they do?

Answer 35

Diabetes, high blood pressure, low blood pressure. They damage the capillary walls in the glomerulus and make them more porous, causing too many substances to pass through walls, so nephrons lose their ability to filter the blood

Question 36

What are the treatments for kidney failure?

Answer 36

Transplants and dialysis

Question 37

What is dialysis?

Answer 37

It is a treatment in which a patient’s blood is cleaned and chemically balanced through a mechanical process, and then returned to the patient’s body.

Question 38

What must happen before and after a transplant?

Answer 38

Tissue must be similar enough that the recipient’s body will accept the new kidney, and recipient must take drugs that suppress the immune system for the rest of their life to guard against the possibility of the body rejecting the organ