Excretory System in the Human Flashcards
What is excretion?
Excretion is the removal of waste products of metabolism from the body.
How does the excretory system play a role in homeostasis?
The excretory system plays a role in homeostasis: (i) by maintaining the composition of an organism’s fluids, including fluid balance and chemistry. (ii) by preventing the accumulation of poisonous wastes which might interfere with metabolism.
What is homeostasis?
Homeostasis is the maintenance of a constant internal environment within the body.
What are the main waste products of homeostasis
The main waste products are water, carbon dioxide and nitrogenous (nitrogen-containing) wastes.
What happens to wastes which go into the liver and what are they called? What wastes are produced?
In the liver, excess amino acids are split into a carbohydrate and urea.
What wastes do the lungs remove?
The lungs remove carbon dioxide and water.
What wastes do the sweat glands excrete?
The sweat glands excrete water and some salts.
What do the kidneys remove?
The kidneys remove most of the rest, including the urea.
What does the urinary system consist of? (basic)
The kidneys, the bladder and some ducts (tubes).
Draw the urinary system
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What are all the parts of the urinary system?
Diaphragm, Aorta, Vena Cava, Adrenal gland, Renal artery, Kidney, Renal vein, Ureter, Bladder, Urethra, Sphincter (controls the release of urine)
What does a section through the kidney show?
A section through the kidney shows an outer darker region (cortex) and a lighter inner zone (medulla).
Draw a diagram of the kidney.
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What are all the parts of the kidney?
Tubule, Pyramid, Collecting duct, Cortex, Medulla, Renal vein, Renal artery, Pelvis, Ureter
How do the kidneys work?
The kidneys work by filtering the blood and then absorbing back what the body needs to keep. The wastes are allowed pass to the bladder, for storage and release.
What happens as urine is produced?
As urine is produced, it flows into the renal pelvis, then into the ureter, to the bladder
What are two main words to describe what the kidneys do?
Filtration and Reabsorption
How does filtration happen in the kidney?
In the outer cortex, small molecules like glucose, amino acids, water, urea and salts filter out of the blood into narrow tubules
How does reabsorption happen in the kidney?
Blood vessels reabsorb back useful nutrients from the tubules. Urea, excess salts and water, are allowed to continue down the tubule and on to the bladder.
What is secretion?
Secretion is the production and release of chemicals from cells.
Where are some substances secreted from and where are they secreted into?
Some substances, especially potassium and hydrogen ions, are secreted from the blood into the tubule in the cortex region.
What happens when the blood becomes too acidic?
When the blood becomes too acidic, hydrogen ions are secreted into the urine.
How do the kidneys control blood pH?
By controlling the hydrogen ion concentration in the blood, the kidneys control blood pH.
From where is water lost from the body?
Lungs, skin, intestines and kidneys
Do we have control over the amount of water lost each day from the lungs, skin or intestines?
We have no control over the amount of water lost each day from the lungs, skin or intestines.
What organs control water in the body and what is this called?
So the kidneys are the water control (osmoregulatory) organs of the body - conserving or eliminating water as the body requires.