L11- introduction of the liver

Question 1

hoe many lobes in the liver

Answer 1

4

Question 2

3 main liver functions

Answer 2

metabolism - control of synthesis and utilisation of carbohydrates, lipids and proteins
secretory and excretory functions - particularly with respect to synthesis of secretion of bile and detoxification
vascular function- formation of lymph and the hepatic phagocytic system

Question 3

what is the main functional cell of the liver

Answer 3

hepatocytes

Question 4

carbohydrate is the

Answer 4

glucose buffer of the liver- maintains blood glucose over short and long periods of time

Question 5

glycogenesis

Answer 5

glucose stored as glycogen

Question 6

glycogenolysis

Answer 6

glycogen to glucose

Question 7

gluconeogenesis

Answer 7

when no glycogen available, glucose is synthesised from amino acids and non-hexose carbohydrates

Question 8

how is oxidation of fatty acids used to supply energy for other body functions

Answer 8

liver converts products of casrbohydrate metabolism to fatty acids and lipids that can be stored in adipose tissue. also it syntheises large quantities of cholesterol and phospholipids, some is packaged with lipoproteins.

Question 9

protein metabolism

Answer 9

liver synthesises all of the amino acids which dont need to be supplied in diet, deamination of the amino acids occurs and the amine group is conerted into ammonia and then urea (urea non-toxic and excreted in kidneys) transamination could also happen so new amino acids are made.

Question 10

which amino acids which are present in the plasma are not synthesised in the liver

Answer 10

immunoglobulins

Question 11

albumin determines

Answer 11

plasma oncotic pressureg

Question 12

lglobulins are what kind of proteins

Answer 12

transport

Question 13

where is majority of the blood recieved by liver from

Answer 13

hepatic portal vein

Question 14

what is excreted by the kidneys

Answer 14

small water soluble catabolites

Question 15

how are larger catabolites, lipophilic or steroid hormones excreted

Answer 15

taken up by liver, metabolised and excreted in bile

Question 16

transporters on hepatocytes

Answer 16

remove substances from bood, metabolise them and excrete into bile

Question 17

what does bile contain

Answer 17

water, electrolytes, organic molecules, cholesterol, phospholipids, biliruben

Question 18

2 main functions of bile

Answer 18

important for digestion and absorption of fats and fat soluble vitamins

waste products eg biliruben are secreted in bile to be eliminated in faeces

Question 19

where are bile acids synthesised

Answer 19

in hepatocytes from cholesterol

Question 20

bile salts are

Answer 20

conjugated bile acids - conjugated with glycine or taurine - they are aphipathic ( hydrophobic and lipophilic faces)

Question 21

whats the role of bile in digestion

Answer 21

emulsify lipid aggregates ( breaks down fat to droplets that lipases can act on)
solubilise and transport lipids in aqueous environments (carry lipids and solubilise them by forming micelles)

Question 22

bilirubin synthesis

Answer 22

red blood cells are ohagocytosed and haem is converted to biliruben

Question 23

free bilirubin

Answer 23

bilirubin stripped of albumin

Question 24

bilirubin excretion

Answer 24

free bilirubin absorbed by hepatocytes and conjugated with glucuronic acid/ sultanate , conjugated bilirubin can then be secreted into bile and eliminated in faeces

Question 25

exocrine liver function

Answer 25

synthesises and secretes bile salts secretes a bicarbonate rich solution

Question 26

endocrine functions of the liver

Answer 26

secretes IGF1 activates vit D forms T3 from T4 secretes angiotensin metabolises hormone secretes cytokines involved in immune defence

Question 27

organic metabolism of liver

Answer 27

glucose to glycogen glycogen to glucose amino acid to fatty acid synthesise of triglycerols fatty acids to ketones produce urea

Question 28

cholesterol liver metabolism

Answer 28

synthesises cholesterol secretes plamsa cholesterole into bile converts plasma bile into bile salts

Question 29

liver plasma protein function

Answer 29

synthesises and secretes plasma albumin, binding proteins and lipoproteins

Question 30

excretory and degradative functions of liver

Answer 30

secretes bilirubin and bile pigments into bile destroys old erythrocytes

Question 31

liver clotting functions

Answer 31

produces plasma clotting factors ( prothrombin and fibrinogen ) produces bile salts needed for vit K absorption in GIT which is also needed for production of clotting factors

Question 32

acini

Answer 32

grape like clusters of cells which synthesise and secrete digestive enzymes

Question 33

2 main secretions from exocrine pancreas

Answer 33

digestive enzymes- protease/lipase/amylase secreted from acinar cells and reduce all digestible macromolecules into forms that can be absorbed bicarbonate- secreted from epithelial cells in pancreatic ducts- neutralise stomach acid reaching small intestine

Question 34

how much pancreatic function is exocrine

Answer 34

98%

Question 35

how is exocrine secretion controlled

Answer 35

by endocrine and neutral controls

Question 36

most important exocrine secretion stimulus

Answer 36

3 hormones- released by eteric endocrine system: cholecystokinin, secretin, gastrin

Question 37

cholecystokinin

Answer 37

released from duodenum, bind to receptors on acinar cells to secrete enzymes

Question 38

secretin

Answer 38

secreted from proximal small intestine, stimulates duct cells to secrete water and bicarbonate

Question 39

gastrin

Answer 39

secreted by stomach and stimulates pancreatic acinar cells to secrete enzymes

Question 40

innervation of the pancreas

Answer 40

sympathetic fibers from he splanchnic nerves- mainly inhibitory parasympathetic fibers from the vagus nerves- stimulate both exocrine and endocrine secretion

Question 41

how much endocrine pancreas function

Answer 41

2%

Question 42

4 main cell types in the islet of langerhans and what they secrete

Answer 42

alpha- secretes glucagon beta - secrete insulin delta- secrete somatostatin ( stops a and b cells) gamma - secrete pancreatic polypeptide

Question 43

arrangement of alpha xells in islet

Answer 43

around them

Question 44

gallbladder wall composition

Answer 44

mucosa, muscularis externa abd adventitia

Question 45

gallbladder innervation

Answer 45

vagus nerve- parasympathetic innervation Celiac places- sympathetic and sensory innervation

Question 46

bile is secreted in response to

Answer 46

signals which contract the gallbladder smooth muscle and relax the sphincter of oddi ( parasympathetic stimulation )

Question 47

main stimulatior of bile secretion

Answer 47

cholecystokinin

Question 48

gallstones

Answer 48

stones of cholesterol - common - yellow/green pigment stones- small/dark - biliruben

Question 49

innate immunity involvement of liver

Answer 49

production of acute phase proteins nonspecific phagocytosis nonspecific cell killing disposal of waste moleculesa

Question 50

adaptive immunity involvement

Answer 50

deletion of activated t cells induction of tolerance to ingested and self antigens extrathymic proliferation of t cells disposal of waste molecules