Summary The excretory system grade 11 Life Science (B&W printable version)
9 views 1 purchase
Course
Life Sciences
Institution
11th Grade
This summary contains study notes on the following topics for grade 11 Life science: excretion in humans, excretory organs, metabolic wastes and their origins, structure of the urinary system, structure and functions of the kidneys, homeostatic control, and diseases that affect the kidneys.
EXCRETION IN HUMANS
• Metabolic wastes → diffuses from cells via tissue fluid into blood.
• Metabolic waste in blood → to various excretory organs →removes waste from
bloodstream & excreted out of the body.
EXCRETORY ORGANS
LUNGS:
Excretes CO2, water vapour, & heat
KIDNEYS & BLADDER:
• Excretes urine.
• Urine: excess water, mineral salts, nitrates (urea, uric acid, creatine).
• Urea: transports via blood to kidneys + excreted in urine.
• Gall pigments: end up in small intestine as bile salts in faeces.
SKIN:
• Sweats via sweat glands
• Sweat: excess water, salt, small amount of urea
Metabolic wastes and their origins
• CO2 → product of cellular respiration
• Excess water → product of cellular respiration & ingestion of fluids + food
• Urea → formed through deamination of excess amino acids in liver.
• Uric acid → end product of metabolism of nucleic acid.
• Creatine → formed in cells by creatine phosphates.
• Gall pigments → formed during breakdown of haemoglobin in liver
, STRUCTURE
• Consists of the two kidneys, two ureters, bladder, & urethra
• 2 types of blood vessels, renal arteries & veins
• 2 kidneys → in abdominal cavity, either sides of spinal column, just underneath
diaphragm.
• Kidneys receive oxygenated blood, rich in metabolic wastes, through renal
artery.
• O2 -rich blood → transported away from kidneys through renal veins once
filtered from all the metabolic wastes.
• 2 thin tubules, the ureters, each connect separately to bladder.
• Bladder → thin-walled, muscular sac that temporarily stores urine.
• Urethra → tube that transports urine from bladder to external environment.
• Sphincter → at base of bladder, controls flow of urine to urethra.
STRUCTURE OF THE KIDNEYS
EXTERNAL STRUCTURE
• Kidneys → dark red, bean-shaped organ, concave side towards spinal column.
• Indent in middle of concave side, called the hilum (renal port), where renal artery
enters kidney & where renal vein + ureter exits kidney.
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 or Stuvia-credit 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 emmagriesel. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.76. You're not tied to anything after your purchase.
