What does serous vs mucus mean and what salivary glands have what?

- Parotid is serous

- submandibuar is some serous, mainly mucus

- sublingual gland is mainly mucus

- serous means that it secretes a fluid that it a lot like plasma (isotonic with it) that has enzymes like alpha amylase.

What's in saliva?

- water, electrolytes, mucus and digestive enzymes (alpha-amylase and a lipase, start digestive process), lysozyme

- IgA

What are islets of Langerhans? What is the endocrine and exocrine parts of the pancreas?

- they are pockets of endocrine cells acattered throughout the pancreas

- the exocrine pancreas is a serous gland, with closely packed acini which drain into a highly branched duct system. The exocrine is made up of acinar cells which secrete digestive enzymes, and the ductal cells which secrete aqueous Na+bicarb solution. This forms like 98% of the gland.

What do acinar vs centroacinar cells do?

Acinar: makes proteases, pancreatic lipase, amylase, genatinase, elastase, ribonuclease... responsible for breakdown of fats, prot and carbs

Centroacinar: they are at the beginning of intercalated ducts, they produce an alkaline fluis (bicarb about 2L/day) to neutralize the acidic chyme.

What hormones control pancreatic secretion?

- secretin stimulates centroacinal and duct cells to secrete bicarb

- CCK and gastrin stimulate acinar cells to secrete enzymes

* vagal stimulation via acetylcholine is a major player

- Enterokinase activates protrypsin to form trypsin which activates prochymotrypsin to form chymotrypsin

- Alpha cells : glucagon

- Beta cells: insulin

- Delta cells: Somatostatin

- G cells: Gastrin

- PP cells: pancreatic polypeptide

What's a Gilsson capsule?

- it's the irregular collagenous CT that surrounds the liver and gives rise to septa separating lobules and lobes

List the components of bile

- bilirubin gluconide, bile acids, salts, cholesterol, phospholipids, ions, IgA and water

*Bilirubin gluconide is a water soluble breakdown product of Hb

Describe very generally the functions of the liver, that beautiful organ.

- production and release of bile (600-1200 ml)

- production and release of plasma proteins (prothrombin, fibrinogen, albumin, factorIII and others I think, lipoproteins)

- aa catabolism and conversion of ammonia to urea

- stores metabolites (glycogen, TGs, vitamins, iron)

- gluconeogenesis (aas and lipids turned into glucose)

- fat metabolism (synthesis and oxidation)

- detoxification (inactivation of various substances like drugs, noxious chemicals, toxins all through oxidation, methylation, and conjugation in the smooth endoplasmic reticulum

- IgA transfer

Why do we care about stellate cells in liver?

- they normally have a function in storage of vit A and they're found in the space of Disse (between the sinusoidal endothelial cell and the hepatocytes).

- they normally contain reticular fibres

- in fibrosis/cirrhosis, there is increased deposition of type I collagen in this space by these cells.

- leads to decreased diffusion across space of Disse and portal hypertension

What the heck are Kupfer cells some kindof cup full of fur?

- they line the sinusoids and are big

- they eat up bacteria and also old erythrocytes and particulate debris from circulation

- breakdown of Hb in these macrophages produces bilirubin, a yellowish hydrophobic and somewhat toxic compound (remember bilirubin also gets made during the breakdown of RBCs in the spleen, and gets transported to the liver via albumin)

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What stimulates gall bladder contraction?

- CCK - released from enteroendocrine cells of the duodenum following ingestion of a meal!