1.8 Excretory System (PPT) Flashcards
What is metabolism?
All the biochemical reactions carried out by living things
Examples include aerobic respiration and photosynthesis.
What is excretion?
Removal of metabolic waste products
Metabolic waste includes carbon dioxide and urea.
What is considered metabolic waste?
Carbon dioxide and urea
Faeces is not considered ‘waste’ as it is not produced by metabolic reactions.
What is the function of the excretory system?
Responsible for the removal of nitrogen-containing waste from the blood
Includes urea and uric acid.
What does urine contain?
Excess water, salt, urea, and uric acid
What are the main organs of excretion?
Kidneys
The kidneys filter blood and remove unwanted waste materials.
What is the primary function of the kidneys?
Filter blood and remove unwanted waste materials containing nitrogen
What are the two distinct regions of kidney tissue?
Cortex and medulla
What is a nephron?
The structural and functional unit of the kidneys
Each kidney contains around 1 million nephrons.
What does the glomerulus do?
A ball of capillaries that allows for filtration of blood
What is the liquid that passes into the Bowman’s capsule called?
Glomerular filtrate
What are the components of glomerular filtrate?
Water, salts, glucose, urea, vitamins, and amino acids
What is reabsorption in the nephron?
Process where small molecules essential for the organism are reabsorbed into the capillaries
Where does reabsorption of water, glucose, and amino acids primarily occur?
Proximal tubule
What is the role of the Loop of Henle?
Reabsorption of water and salts
What does the distal tubule regulate?
Reabsorbs calcium, sodium, and chloride, and regulates blood pH
What is the collecting duct’s role?
Collects remaining unwanted waste and drains it into the bladder to be excreted
What are the two processes that nephron uses to regulate blood composition?
Filtration and reabsorption
What is osmoregulation?
Maintaining correct balance of salt and water in the blood
Where is the main site of osmoregulation?
Collecting duct in the kidney
What hormone controls the reabsorption of water?
ADH (Anti-diuretic hormone)
What happens when ADH is present?
Collecting duct becomes permeable to water, allowing reabsorption
What is the consequence of dehydration on ADH levels?
More ADH is released, increasing water reabsorption
What is dialysis?
Artificially performs the function of the kidney
What is kidney transplant?
Involves removing the diseased kidney and replacing it with a healthy one
