100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
excretion topic summary £5.49
Add to cart
Quickly navigate to
Preview
  2.  
  3. OCR
  4.  
  5. Biology
  6.  
  7. A2 Unit F214 - Communication, Homeostasis and Energy

Summary

excretion topic summary
 0 purchase
  • Institution
  • OCR

a brief summary of excretion : excretory organs, liver and kidney structure, kidney transplant, kidney failure, pregnancy testing, anabolic steroid testing. diagrams for structure of liver and kidney bullet points to summarise sequence of events in excretion key words highlighted for better r...

[Show more]

Preview 3 out of 17  pages

Document information

  • January 4, 2024
  • 17
  • 2023/2024
  • Summary

Subjects

Written for

All documents for this subject (31)

Seller

avatar-seller
erikakumar

Reviews received

Content preview

EXCRETION
BIOLOGY
___


Notes

Removal of metabolic waste

Kidneys, liver + lungs remove toxic products of metabolism from blood

- Kidneys control water potential of blood + excrete waste in urine
- Liver excretes waste products via bile into small intestine, then it’s removed in
faeces, and metabolises ingested toxins
- Lungs excrete CO2

2 main excretory products :

1. CO2: product of aerobic respiration

Build-up: reduce oxygen transport by blood by causing oxyhaemoglobin to
dissociate with oxygen & combining with haemoglobin to form
carbaminohaemoglobin

= respiratory acidosis: blood pH falls below 7.35 = homeostatic mechanisms
removing CO2 don’t function properly

2. Excess amino acids undergo deamination, removing their amine group

Amino acid + oxygen → keto acid + ammonia

Keto acid used in respiration / stored as carbohydrate or fat

Ammonia water soluble and toxic = converted to urea in Ornithine cycle

, 3. Bile pigments from breakdown of haemoglobin from old red blood cells in liver,
excreted in bile into small intestine via gall bladder + bile duct


LIVER
● Hepatic artery : oxygenated blood from aorta
● Hepatic vein : carries blood away from liver to vena cava
● Hepatic portal vein : blood rich in nutrients from small intestine

Cylindrical lobule: rows of hepatocytes (liver cells can divide + replicate) with :

- Mitochondria : produce lot of ATP =active
- Golgi apparatus: making , modifying + packaging lots of proteins
● Centre: central vein (branch of hepatic vein)
● Blood from hep artery + hep portal vein flows btw rows of hepatocytes towards
central vein in sinusoids (channels) that increase oxygen content of blood from
hep portal vein
● Hepatocytes take up what required from blood = shed their products into it
● Btw rows canaliculi (channels) receive bile secreted from hepatocytes + connect
up with bile ducts at edge of lobule
● Bile emulsifies lipids, stored temporarily in gall bladder b4 periodic release into
small intestine
● Kupffer cells (macrophages) attached to walls of sinusoids that destroy old
erythrocytes + remove bacteria & foreign particles from blood

, Stained with haemotoxylin + eosin


FUNCTIONS

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

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

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

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 erikakumar. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £5.49. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

69988 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 15 years now

Start selling
£5.49
  • (0)
Add to cart
Added