a2 biology unit f214 module 2: excretion dr. sona arya e – mail: [email protected]
TRANSCRIPT
IN TODAY’S LESSON.... Recap on Liver Histology – how much can you
remember?
Finish off Liver Functions (Detoxification of substances by the Liver)
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Feedback and Reflection on Ecology Test
Exam Re-sits
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Kidney Dissection (Gross structure) R18
Examine sections of Kidney tissue (Histology) and Practice Drawing structures (needed for F216
A2 BIOLOGY UNIT F214:THE LIVER
LAST LESSON...
You learnt about
… Blood Supply to the liver
… Cells of the liver
How much can you remember?
On your white boards......
Which of these vessels supply oxygenated blood to the liver from the heart?
A hepatic artery
B hepatic vein
A
Name the blood vessel that brings blood to the liver from the small intestine?
Hepatic portal vein
What are liver cells called? (correct spelling please!)
Hepatocytes
Name the channels that allow blood to flow pass very close to all the liver cells
Sinusoids
What do Kupffer cells do? (2)
Remove bacteria and break down old red blood cells
The bile duct is connected to the central vein by tubes called......? (correct spelling please!)
Canaliculi
CAN YOU ADD LABELS?
A
B
C
HOME WORK CHECK ….
Up to 100,000 lobules each 1-2 mm in diameter.
Complete the right hand column of the table, found on page 7.
Feature What they are and their function
Hepatocyte
Sinusoid
Bile canaliculus
Kupffer cells
Intralobular vessel
/ Branch of hepatic vein
HOME WORK - EXAM PRACTICE
Practice questions on the exam objectives:
Describe with the aid of diagrams and photographs, the histology and gross structure of the liver for your exam?
Extension : Exam Qs /Activities in Excretion Booklet
LIVER FUNCTIONS
FUNCTIONS OF THE LIVER
http://www.nottingham.ac.uk/nursing/sonet/rlos/bioproc/liverphysiology/7.html
Protein Metabolism includes
i) deamination and
ii) urea production via the ornithine cycle (in cytosol and mitochondria)
See page 8 Excretion booklet and page 40 in the textbook
EXAM OBJECTIVES
Describe the formation of urea in the liver, including an outline of the ornithine cycle
TASKS PG 40 OF BOOKLET
Explain why deamination of excess amino acids is needed and what the process is
… Include all equations
Ornithine Cycle to produce safer urea. Draw and learn the cycle, and explain why it is necessary
… Include all equations
20 min
DEAMINATION – KEY POINTS
Amino acids contain nitrogen in their amino group
Excess amino acids have their amino group removed forming ammonia and organic acid (keto acid) - this process is called deamination
The keto acid can be respired to give ATP or converted to carbohydrates and fats
ORNITHINE CYCLE
Ammonia is too toxic for mammals to excrete directly, so is combined with CO2 in the ornithine cycle to create safer urea
Urea released into the blood
Kidneys remove urea as urine
EXAM OBJECTIVES
Describe the roles of the liver in detoxification
DETOXIFICATION IN THE LIVER CAN BE OF INTERNALLY OR EXTERNALLY GAINED SUBSTANCES SUCH AS…..
What is keydefinition?
DRUGS
http://www.youtube.com/watch?v=mEFPdNv2Ddk
(Drugs make you ugly)
If alcohol was discovered today, it would be classified as a class A drug.
http://www.youtube.com/watch?v=1a687tDtwyk
TOXINS CAN BE RENDERED HARMLESS IN THE LIVER BY… (PAGE 11 – INCLUDE HYDROGEN PEROXIDE)
Oxidation
Reduction
Methylation - replacing an H with a CH3.
Combination with a harmless molecule.
DETOXIFICATION OF ALCOHOL
Alcohol (ethanol)
TASK ---- 10 MIN USING PAGE 41 TEXTBOOK Draw the flow diagram to show
Detoxification of Alcohol and add the name of the enzymes to the diagram (learn the names)
Describe the role of NAD and fatty acids in the development of a “fatty liver” (homework check)
STRETCH AND CHALLENGE
Research and Summarise information as a leaflet on liver disorders to show your understanding of liver functions
Choose one disorder from:
Gallstone
Jaundice (new born)
Hepatitis
Cirrhosis
… Liver Histology and Symptoms
… Hand in next week/email me
PLENARY – EXAM PRACTICE
Practice Exam Qs on Liver Functions
Less than 15 min
Extension:Using your text books, page 41, answer the questions on page 12 of your booklet and /or exam Qs on pg 17 as extension/homework
ANSWERS
Word Document
ACADEMIC TUTORIAL
AS Exam Re-sits
MPG Sheets
Ecology Test (Reflections)
JAN EXAM RE-SITS
A2 students re-sitting F211 and F212 can collect re-sit forms from 21st September.
Anyone re-sitting F213 should enter their re-sit in March although we will be starting these soon
COL D (Mon) and COL G
The deadline for submitting re-sit forms is Thursday 18th October at 4.00 pm.
ECOLOGY TEST RESULTS
Compare to your MPG
You will need to do a SELF –Analysis on how you did
See back of test for objectives and what you think you need to do to improve
Well Done to those who achieved their MPGs!
I will collect your tests back in today and return next lesson
Everyone below MPG/Grade U needs to do re-do test
AFTER BREAK
Kidney Dissection and Training for F216
On Friday
Group will be split in two
One half use Ground floor LRC and do Independent study task on:
Kidney Failure (pages 50-51 textbook)
Complete pages 31-35 of booklet
Then swap after break (do F216)