Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Gastrointestinal > liver physiology > Flashcards

liver physiology Flashcards

1
Q

how are vessels organised in the liver

A

in a hexagonal portal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

functions of the liver

A

detoxification, energy storage, immune functions , synthesis of clotting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are lipids

A

Esters of fatty acids and glycerol

Large and diverse naturally occurring organic compounds that are insoluble in water
Variety of structure and functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how are lipids stored

A

adipocytes, hepatocytes,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

lipid functions

A

energy reserve, hormone metabolism

Structural part of cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

lipid transport?

A

Lipids are often transported as TGs or FAs bound to Albumin or within lipoproteins
TGs cannot diffuse through cell membrane
FA are released through lipases to facilitate transport into the cells
In the cell FA are re-esterified to TG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

fatty acid uptake and regulation

A

Diffusion through the lipid bilayer of the cell membrane

Facilitated transport
Increases if increased substrate (↑supply) or increase in receptor molecules (↑ demand)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

transporter systems of fatty acids

A

induction to increased expression may result in increased uptake of FA in the hepatocytes)
FAT - fatty acid translocase
FATP - FA transport polypeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what do lipoproteins consists of?

A

core of tg’s and cholestrol esters and a surface monolayer of phospholipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

where is iron absorbed and stored

A

duodenum made

Stored in liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what transports iron around the body

A

transferrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

ferritin?

A

A blood protein that contains iron

Large spherical protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where is ferritin found

A

Ferritin found in the cytoplasm of cells but can also be found in the serum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

xenobiotics

A

foreign substances with no nutritional value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how can xenobiotics damage cells

A

dna damage, react with o2 to make free radicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

function of phase1 biotransformation of xenophobes

A

to add or expose functional groups- OH, COOH, NH2 and SH to make the xenophobe more hydrophilic to be excreted from kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

where are cytochrome p450 found

A

present in smooth er

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Function of cytochrome p450 in phase 1 reactions

A

Uses cytochrome p450 reductive to transfer electrons to nadph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

outline phase 1 reactions

A

oxidation, hydrolysis and reduction
addition of an oh group to make it more polar
with cytochrome p450

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

POSITIVE NITROGEN BALANCE

A

). If the intake of nitrogen is greater than the excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

NEGATIVE nitrogen BALANCE

A

, if excretion greater than intake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

gain or lose proteins in positive N balance

A

gaining protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

gain or loose protein in negative N balance

A

lose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

kwashiorkor

A

protein malutrition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
amino acid absorption
The first stage is via a cell surface channel where it is co transported with a sodium ion. Then via the basal membrane is is actively transported into the portal veinous circulation by an ATP consuming process. From there it travels into the liver.
26
difference between essential and non essential amino acids
essential- amino acid that cant be synthesized by the body and must come from diet non - essential- can be synthesised by the body
27
most important hepatic protiein
albumin
28
alpha ketoacid?
removal of amine group from amino acid left with carbon backbone
29
transamination
a chemical reaction that transfers an amino group to a ketoacid to form new amino acids enzyme- aminotransferase
30
what happens to amino acids in the fasting state
stored in muscle as protein, broken down into monomer form of amino acid , to make atp gluconeogenesis
31
glucose alanine cycle
Excess alanine transferred to the liver and converted to pyruvate Pyruvate can be used to produce glucose in gluconeogenesis Glucose enters blood used by muscles Glutamate to ammonium by oxidative deamination dissociates to ammonia , converted to urea
32
why is albumin important
Binding and transport 2. Maintenance of colloid oncotic pressure 3. Free Radicals 4. Anticoagulant effects
33
What causes Albumin to decrease
Decreased synthesis 2. Increased catabolism 3. Increased loss
34
Consequences of decreased Albumin
Decreased colloid oncotic pressure 2. Decreased ligand binding
35
Disease processes associated with | low Albumin
``` Malnutrition Liver disease Renal disease Burns / trauma Sepsis ```
36
why is bile important
Lipid digestion and absorption Cholesterol homeostasis Excretion of lipid soluble xenobiotics / drug metabolites / heavy metals
37
What is bile?
digestive fluid produced by the liver and stored in the gall bladder
38
what does bile formation depend on?
Formation depends on the hepatic SYNTHESIS and cannalicular SECRETION of bile acids (=major organic anion in bile)
39
breakdown product of red blood cells
bilirubin
40
where are bile acids synthesised ?
Synthesised from cholesterol in hepatocytes of the acini
41
what does amphipathic mean
hydrophillic and hydrophobic parts
42
Fat soluble vitamins
A d e k
43
Function of copper and storage
Helps to form rbc | Transported in plasma bound to ceruloplasmin
44
Three types of plasma protein
Albumin | Fibrinogen and globulin
45
Most common plasma protein and function
Albumin Maintains oncotic pressure Binds and transports large hydrophobic molecules
46
Which clotting factors does the liver produce
All but 8
47
Where is iron stored
In the liver as ferritin in kuppfer cells
48
What are microsomes
Fragments with endoplasmic reticulum and ribosomes
49
Define lipophilic
Able to pass through plasma membranes
50
Phase 2 reaction outline
Adding a glucaronic acid group Increase hydrophilicity Done by glucuronosyltransferase
51
What reactions are non microsomal enzymes involved in
All conjugation reactions except glucoronidation
52
What is the role of fad
Accept electrons from nadph
53
Function of complement proteins
Aid in immune response
54
Role of urea cycle
Series of enzymatic reactions | Convert ammonia into urea
55
Where does urea cycle happen
Mitochondria of hepatocytes
56
How does ammonia get into liver mitochondria
Glutamine synthesise Adds ammonia to the amino acid glutamate forming glutamine Once in the liver glutamine hydrolyses the products back into their original form
57
Urea cycle steps
Ammonium and co2 combine to make carbomoyl phosphate This allows ornithine to be converted to citruiline citruiline to arginine Arginine is cleaved by arginase into urea and ornithine and the cycle repeats
58
In what three forms is energy stored in the body
Triglycerides 78% Protein 21% Carbohydrate 1%
59
Where is most body fat stored
Adipocytes
60
Three types of lipoprotein and where they’re formed and function
Hdl liver good cholesterol , removes excess via excretion in bile LDL plasma delivers cholesterol to cells Vldl synthesised in hepatocytes triglyceride delivery from liver to adipocytes
61
Function of lipoprotein
Transport cholesterol through the blood
62
Function of lipoprotein lipase
Hydrolyses triglycerides into 2 fatty acids and one monoglyceride molecule
63
Function of hepatic lipase
``` Found in liver and adrenal cells Converts IDL ( intermediate density lipoprotein ) into LDL thereby packaging it with more triglycerides to be released into the body . ```
64
describe the steps in beta oxidation of fatty acids
- CoA binds to the end of a fatty acid chain: fatty acyl CoA. - ATP -> AMP + 2Pi. - Fatty acyl CoA is a substrate for beta-oxidation. - Acetyl CoA is split off from FA and 2H+ are transferred to coenzymes. - H+ enter OP and another CoA attaches to repeat the cycl
65
Difference between white and brown fats
White few mitochondria , little endoplasmic reticulum , stores energy Brown fat lots of mitochondria , expending energy and heat production
66
Constituents of bile
``` Bile salts Lecithin Hco3- Cholesterol Bile pigments ```
67
How is bile secreted
Secreted under the action of cholecystokinin CCK released in response to increased fatty acid conc in duodenum Gall bladder contracts Bile released into duodenum via sphincter of oddi
68
Where are bile salts reabsorbed and how
In the terminal ileum via portal vein 95%
69
What is bilirubin
Pigment that gives bile it’s yellow colour | By products of haem metabolism
70
Bilirubin metabolism
Hb-> haem and glob in with macrophage Haem —> biliverdin with haem oxidase Biliverdin to bilirubin via biliverdin reductase Unconjugated bilirubin transported to the liver via albumin carrier Glucoronic acid conjugates it via glucoronyl transferase Released in bile via duodenum
71
What is enterohepatic circulation
Movement of bile acid molecules from the liver to the small intestine and back to the liver
72
How is urobilinigen made
Intestinal bacteria in the terminal ileum reduce the cb into urobilinigen
73
Three types of jaundice
Pre hepatic Hepatic Post hepatic

Gastrointestinal (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions