Excretion

Question 1

What is Excretion?

Answer 1

A process used to remove waste materials that would be toxic to the body
The excretory system also maintains osmotic balance in the body (ratio of solutes to water)

Question 2

How does the Excretory system work?

Answer 2

Using several cell transport mechanisms, or Mossi, facilitated diffusion, active transport, and concentration gradients

Question 3

What organs are involved in waste removal? LLK

Answer 3

Lungs (to remove carbon dioxide)
Liver (Bile Pigments (from the breakdown of haemoglobin) Lactic Acid (from anaerobic respiration) Urea (from the breakdown of protein)
Kidneys (medications/toxins, Nitrogenous Wastes (from liver, urea, Uris acid, ammonia), Ions & electrolytes)

Question 4

How are unwanted toxins turned into less toxic forms?

Answer 4

They are broken down

Question 5

What is Deamination?

Answer 5

It’s when amino acids that form proteins are broken up so the body can harvest materials for carbohydrates (energy). The body does this when more proteins (amino acids) are consumed than are needed

Question 6

What two substances are byproducts of fat metabolism?

Answer 6

Ammonia

Keto Acid

Question 7

What is Red blood cell recycling?

Answer 7

When the liver breaks apart haemoglobin complexes to recycle iron & make bile
Red blood cells are broken down into Haemoglobin, which breaks into Globins, and Heme.
(Heme turns into Bilirubin,and Bilirubin turns to Bile)

Question 8

How is Alcohol broken down?

Answer 8

When Ethanol is broken into more toxic, then less toxic substances to be excreted

Ethanol —> Acetaldehyde —> Acetate —> CO2 + H2O

Question 9

What is the first stage in the Passage of Pee?

Answer 9

First, blood travels through the Hepatic Artery to the Liver

Question 10

What is the second stage in the Passage of Pee? NUUCHH

Answer 10

The blood picks up NH3, urea, uric acid, CO2, H+, HCO-3

Then it travels to the heart via the Hepatic Vein and the Vena Cava

Question 11

What is the third stage in the Passage of Pee?

Answer 11

The heart (right side) pumps the blood to the lungs which drop off CO2, and pick up O2

Then it travels to the heart via the Pulmonary Veins

Question 12

What is the fourth stage in the Passage of Pee?

Answer 12

The heart (left side) pumps the blood to the Renal Artery via the Aorta

Question 13

What is the fifth stage in the Passage of Pee?

Answer 13

The Kidney receive the blood via the Renal Artery and using its Nephrons, it carries out filtration, reabsorption, and it also secretes stuff

Urine then enters the Renal Pelvis, where it travels to the ureter, then the Bladder (urine storage)

Question 14

What happens in the Nephron?

Answer 14

Substances are removed (tube —> collecting duct) and retained (tubules —> capillaries)

Question 15

What does changing the permeability of channels in the Nephron do?

Answer 15

Modifies H2O absorption or excretion
Modifies Ion (Na+ & Cl-) absorption or secretion
Which will affect blood volume & pressure & urine concentration

Modifies H+ & HCO-3 absorption or secretion
Which will affect blood pH

Question 16

What does the Glomerulus do?

Answer 16

Filtration
Everything (except blood cells & proteins) is pushed out at the glomerulus & collected as filtrate
in the Bowman’s Capsule

Question 17

What happens in the first top loop?

Answer 17

Reabsorption, to keep nutrients & glucose

Question 18

What happens in the second top loop?

Answer 18

Secretion
Move toxins to tubules (urine)
Balance blood pH, secrete H+, (increase pH) or secrete HCO-3 (decrease pH)

Question 19

Nephron Anatomy (in order) (7) GBLDPCR

Answer 19

Glomerulus
Bowman’s Capsule
Loop of Henle
Distal convoluted tubule 
Peritubular Capillaries
Collecting Duct
Renal Pelvis

Question 20

What in the brain regulates water intake?

Answer 20

Osmoreceptors

Question 21

What does your brain release when you’re thirsty?

Answer 21

Antidiuretic Hormone (ADH) —> reabsorption H2O
Aldosterone —> reabsorb Na+/Cl- & H2O

Question 22

Two disorders of the Excretory system

Answer 22

Diabetes
(Melitus, sugar, decreased insulin) = sugary urine
(Insipidus decreased ADH) = high volume of dilute pee

Kidney failure
Breakdown of filtration tissues

Question 23

What are two ways to fix kidney failure?

Answer 23

Dialysis
(Artificial/natural membranes used to filter body fluid)

Kidney Transplant