Excretory System

Question 1

What is the main job of the excretory system?

Answer 1

It removes nitrogenous waste (urine) from our body.

Question 2

How many liters of blood does the kidney filter each minute?

Answer 2

About 1.25 L.

Question 3

How many liters of blood do we have?

Answer 3

5 L.

Question 4

What are the four main organs in the excretory system and their most basic, summarized functions?

Answer 4

Kidney- filters blood
Ureter- tube from kidney to bladder
Bladder- holding sac for nitrogenous waste
Urethra- where pee/nitrogenous waste exits body

Question 5

Where are the Sphincter muscles located and what is their job? (In excretory system)

Answer 5

At the end of the urethra/mouth of the bladder. They keep the bladder closed or open to allow us to pee or hold it.

Question 6

Why do women who’ve had children sometimes have bladder control issues? What is a treatment for this?

Answer 6

The Sphincter muscles can be damaged by childbirth. Kegel exercises are a way to help improve bladder control.

Question 7

What is a urinary tract infection?

Answer 7

Bacteria can grow in the urethra or bladder and cause an infection. Can be treated with antibiotics.

Question 8

What is a basic overview of how the kidney works?

Answer 8

Blood flows into and out of the kidney, the kidney removes the nitrogenous waste from the blood, and the blood leaves.

Question 9

What is a nephron? Describe how it helps the process.

Answer 9

It is the functional unit of the kidney, the part that does the filtration: The large amount of surface area due to the capillaries and tubes gives many chances for waste to diffuse into the tubules that make up the neurons. Afterwards, the waste goes to the ureter.

Question 10

How many nephrons do we have per kidney?

Answer 10

1 million.

Question 11

What do capillaries do in the filtration process?

Answer 11

It brings the blood for filtration, then the waste goes through the excretory tubule.

Question 12

What are the four main steps in the process that happens within the excretory system?

Answer 12

1. Filtration
2. Reabsorption
3. Secretion
4. Excretion

Question 13

Describe the step of filtration (step 1).

Answer 13

The kidney filters 180 L of water out of our blood each day- lots of water is lost at filtration. Plasma with water, glucose, and minerals is filtered/forced into the excretory tubule.

Question 14

Describe the step of reabsorption.

Answer 14

178 L (out of 180 L) of water is reabsorbed back into our blood to keep us alive and hydrated. Water, solutes, glucose, and amino acids are reabsorbed back into the blood.

Question 15

Describe the step of secretion.

Answer 15

Specialized epithelial cells actively transport ions and drugs into the filtrate (the liquid, before it becomes urine).

Question 16

Describe the step of excretion.

Answer 16

The filtrate is now urine. We pee 2 L a day. At excretion, we remove the products remaining in the excretory tubule (urea and excess water, which form urine).

Question 17

Certain chemicals secreted by the brain affect our kidneys, such as…

Answer 17

ADH (antidiuretic hormone).

Question 18

What is ADH?

Answer 18

Antidiuretic hormone is produced in the hypothalamus and stored in the primary gland. It causes our tubules to reabsorb water and decrease urine to conserve water when we are dehydrated. It helps us maintain homeostasis.

Question 19

What can happen from too much alcohol or caffeine (diuretic) consumption?

Answer 19

Our ADH levels can decrease, less water will be reabsorbed, more urine will be produced, and we can become dehydrated.

Question 20

Kidney stones can form when…

Answer 20

We don’t drink enough water or we don’t use the bathroom often enough. This is often the case with specific jobs.

Question 21

What are kidney stones made of and why are they bad?

Answer 21

They are made of the crystals created by the water and chemicals in our pee. They are bad because they can block the ureter and cause lots of pain.

Question 22

How can kidney stones be treated?

Answer 22

Surgical removal for the bigger ones, also use sound waves to break apart smaller ones.

Question 23

What is kidney disease caused by?

Answer 23

Damage to the nephrons due to drugs, being diabetic, or having high blood pressure.

Question 24

What are two treatments for kidney disease?

Answer 24

Dialysis and peritoneal dialysis.

Question 25

What is dialysis?

Answer 25

An artery is hooked up to an “artificial kidney” which filters the blood.

Question 26

What is peritoneal dialysis?

Answer 26

Dialysate substance is inserted into the abdomen. It causes nitrogenous waste to soak into the abdominal cavity. It is filtered and then goes straight to the bladder.