Summary The excretory system Gr 11 IEB & DBE notes
20 views 1 purchase
Module
Life Sciences
Institution
11th Grade
Detailed notes of Gr 12 excretory system section.
Including:
Functions of excretion
Main excretory organs
Urinary system
Function of kidneys
Structure and function of nephrons
Process of ultrafiltration
Process of reabsorption
Tubular excretion and ph control
Formation of urine ...
, Excretory System
Function of excretion Homeostasis
Excretion: removal of metabolic waste, vital in homeostasis, Process of keeping balance in body. Important
for survival. Oxygen & digested food are
maintenance of constant internal environment.
absorbed/carried by blood to cells, used in cell
Egestion: removal of undigested substance, not products respiration/other metabolic processes.
of metabolism, never inside cells.
Metabolism
Secretion: release of useful substances produced by cells The chemical processes occurring in living organism. Provide
energy & products for growth/maintenance. Also produce
for important functions, (digestive juices, hormones & milk) waste products (CO2) & nitrogenous waste (urea, uric acid
& ammonia). Metabolic waste products build up in cells,
Waste products not removed changes composition of tissue fluid become toxic & eventually stop metabolic processes. Need
efficient waste disposal systems.
surrounding cells/cell cytoplasm
Change pH, temperature & water potential of cells disrupt metabolism, death of cells/organism
Organ Excretory product Origin of this product
Lungs CO2, water vapour Product of cellular respiration
Skin(sweat glands) Mineral salts, little urea, water Extracted from blood
Deamination of excess amino acids, break down
Liver Urea, bile pigment of haemoglobin
Gut Bile pigment, excess mineral salt From liver, haemoglobin breakdown
Deamination of excess amino acids in liver
Kidneys Urea, mineral salts Excess taken in with food
Role of the main excretory organs
Major organs: lungs, kidneys & skin. Liver & alimentary play minor role
Lungs excrete CO2 as waste product of cellular respiration, transported to lungs from cells
via circulatory system, also excrete water vapour & heat.
Kidneys & bladder form urinary system. Removes waste material from
bloodstream, regulates amount of water salts. Kidneys produce urine, liquid:
water & nitrogenous waste products (urea, uric acid, creatinine & ammonia)
Skin, Sweat is salty fluid secreted by sweat glands in skin. Skin excretes small
amount of urea, water & salts. As sweat evaporates, heat is lost from body.
Liver breaks down extra amino acids in bloodstream into glucose & urea. Urea
carried in bloodstream to kidneys, excreted in urine, breaks down haemoglobin to bile
pigments, carried in bile to duodenum of alimentary canal.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller erinswanepoel. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £4.77. You're not tied to anything after your purchase.
