A comprehensive summary of the kidney, specifically tailored for Grade 11 IEB students. It provides an in-depth yet concise overview of the structure and function of the kidney, covering key concepts such as filtration, reabsorption, and urine formation. The summary includes diagrams for visual lea...
The excretory system • Water, salt, small amount of urea are released
*Define excretion and the position and as sweat from sweat gland
• Regulates body temp.
function of the main excretory organs.
*secretion- release of useful substances*
1. Excretion- removal of waste products from the
4. Gut/ Colon:
body (water, CO2 and nitrogenous waste from
metabolic reactions) • Bile and Cholestrol from liver go into small
2. Products are excreted because if accumulated, intestine and then exctrete from colon as
becomes toxic to body, and disrupt homeostasis. faeces.
• Little mucus and bacteria also excreted
Liver:
*defaecation/ egestion- removal of undigested
Not excretory organ, but waste products form in liver. and un absorbed food material.*
Nitrogenous waste:
*macrostructure of urinary system
• Urea: formed from excess amino acids broken
into ammonia then into urea through deamination.
and main functions.
Main nitrogenous waste from kidneys Urinary system- reg volume and concentration of body
• Uric acid: formed from breakdown of nucleic fluids and regs homeostasis
acids
• Creatinine: in skeletal muscle cells formed from
creatine phosphate.
Non- nitrogenous waste:
• Toxins and drugs: painkillers and nicotine
• Alcohol: can cause permanent damage to livers
(cirrhosis)
Other excr. products formed in liver:
• Bile products: from breakdown of red blood cells 1. Inferior vena cava- carries purified
• Cholesterol: from breakdown of bile salts deoxygenated blood back to heart
2. Kidney- filters nitrogenous waste out of blood
Excretory Organs:
(excretory function) regs water and salts balance
1. Kidney: (osmoregulatory function)
• Excretes all non and nitrogenous from liver 3. Aorta- carries oxygenated blood with nitro waste
2. Lungs: to all over the body
• CO2 is released from cellular resp. 4. Ureter- carries urine to bladder.
3. Skin: 5. Bladder- stores urine
6. Urethra- Carries urine out of body
, 7. Renal Artery- Carries oxy and nitro waste to 6. Renal pelvis- urine drains from calyces into
kidney. upper ureter
8. Adrenal gland- Secretes aldosterone (regs salt
concentration in the body)
9. Renal Vein- carries purified blood to inferior *Micro structure
vena cava
1. Kidney made of million of small tubular units-
*macrostructure of the kidney- label nephron (in cortex and medulla)- Form
structural unit of kidney because it makes up
and description.
most of the kidney
Where are they found? 2. Nephron removes waste from blood, therefore
form functional unit of kidney
1. 2 kidneys found in abdominal cavity
2. on either side of the vertebral column Nephron:
3. kept in place by connective tissue (peritoneum)
Each tubule is made of:
and the large renal vessels
1. Renal corpuscle found in renal cortex+ made of:
what do they look like externally?
• Bowmans Capsule- Cshaped
1. Bean shaped
• Glomerulus- Cluster of capillaries
2. Inner border facing vertebral column is concave-
(increases surface area)
hilum
2. Renal Tubule found in cortex and Medulla,
3. Surrounded by 3 layers;
Made of:
• Tough fibrous renal capsule covers kidney
• Proximal convoluted tubule
surface- prevents infections
• Loop of henle
• Middle layer- adipose tissue , hold in place and
• Distal convoluted tubule
cushions from impact
Nephron usually lead to collecting duct, 12 nephrons
• Outer layer of fibrous connective tissue (renal
share same collecting ducts. Collecting ducts form
fascia) anchors kidney.
pyramids
*see macrostructure diagram*
How is kidney supplied w/ blood?
Functions: - Renal artery enters kidney at hilum and spread
1. Renal capsule- protects kidney + prevents through medulla to cortex. Carries nitro waste
infection blood
2. Cortex- reddish area made of renal corpuscles - Renal vein carries purified (less nitro waste)
3. Medulla- reddish brown area made up of 8-12 deoxygenated from kidney to inferior vena cava
cone shaped pyramids
4. Pyramid- made up of collecting ducts
5. Calyx- short duct collects urine from collecting
ducts
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 EFT, 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 this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller damitadevsheel. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R199,33. You're not tied to anything after your purchase.
