histology of accessory glands

Question 1

salivary gland functions

Answer 1

tasting, digesting and swallowing food

produce 700-1100ml of saliva each day

Question 2

secretory potion arrangement

Answer 2

tubules and acini

Question 3

three cell types on salivary glands + functions

Answer 3

serous cells- secrete proteins and polysaccharides

mucous cells- secrete mucous

myoepithelial basket cells- several long processes that envelop the acinus and contract to expel secretions

Question 4

explain duct arrangement

Answer 4

highly branched ducts formed of

intercalated to striated to intralobular to interlobular to lobar to principle terminal

Question 5

function of terminal ducts

Answer 5

deliver saliva to oral caity

Question 6

two types of salivary gland

Answer 6

major and minor salivary glands

Question 7

three types of major salivary gland

Answer 7

parotid, sublingual and submandibular

Question 8

parotid size and secretion

Answer 8

largest gland

produces 30% of saliva

serous secretion with high levels of amylase

Question 9

sublingual size and secretion

Answer 9

very small gland

5% of saliva

mainly composed of mucus and serous cells

Question 10

submandibular size and secretion

Answer 10

produces 60% saliva and serious cells predominate

Question 11

acinar and duct cell functions

Answer 11

acinar- responsible for volume of saliva

duct- responsible for composition

Question 12

explain sympathetic control of secretion

Answer 12

superior cervical ganglion, release of noradrenaline, decreases production of saliva, increased protein

Question 13

explain parasympathetic control of secretion

Answer 13

innervation due to facial and glossopharyngeal nerve

afferent fibres in the mouth detect changes to food in mouth- travel to the medulla

parasympathetic fibres release acetylcholine onto muscarinic receptors

increase secretion from acinar cells

duct cells increase bicarbonate secretion

contraction of myoepithelium

Question 14

two component of pancreas + function

Answer 14

exocrine- secretes enzymes

endocrine - secretes hormones

Question 15

explain endocrine structure

Answer 15

islets of Langerhans comprise 1-2% of the volume

consist of beta, alpha, delta and pancreatic polypeptide cells

Question 16

pancreatic polypeptide fucntion

Answer 16

inhibits acinar endocrine secretion

Question 17

explain exocrine structure

Answer 17

clusters of cells

duct cells penetrate into central regions of acini called centroacinar cells

Question 18

where do the ducts open into?

Answer 18

the common bile duct, and empty into the major papilla duct (ampulla of vater)

Question 19

what is present in both salivary and pancreatic acinar cells?

Answer 19

zymogen granules

Question 20

zymogen granule function

Answer 20

specialised storage granules of proteases, that allow for release

Question 21

what is the largest gland within the body?

Answer 21

liver

Question 22

how much blood perfuses the liver per minute?

Answer 22

1.5 litres

Question 23

liver major functions

Answer 23

recycling, waste disposal

Question 24

how is the liver represented?

Answer 24

polygonal aggregation of cells that are arranged in irregular radial cords of cells interrupted by strands of supporting tissues that contain vascular and biliary passages

Question 25

main cell type in liver

Answer 25

hepatocytes

Question 26

classic liver lobule structure

Answer 26

central vein, peripheral portal triads set at angles to the polygons hepatocytes radiating from central vein separated by vascular sinusoids

Question 27

sinusoid definition

Answer 27

low pressure vascular channels that receive blood from hepatic arteries and the hepatic portal vein at the peripheries of the lobules and then bring them towards the central vein liver capillary

Question 28

hepatic lobule definition

Answer 28

building block of the liver contains a central vein, portal triad, hepatocytes in linear cords and a capillary network

Question 29

what is present in the portal triad?

Answer 29

hepatic artery, portal vein, bile ductule, lymphatic vessels and branch of vagus nerve

Question 30

portal triad shape

Answer 30

triangle, connecting three central veins

Question 31

two important features of liver sinusoids

Answer 31

Kuppfer cells and space of Disse

Question 32

explain structure and function of space of Disse

Answer 32

space between a sinusoid and the hepatocyte contains blood plasma microvilli of hepatocytes extend here so that they can absorb molecules from blood

Question 33

structure of sinusoid

Answer 33

discontinuous basement membrane and fenestrated endothelium allows for easy exchange

Question 34

kupffer cell location

Answer 34

within sinusoids

Question 35

kupffer cell function

Answer 35

specialised macrophages clear bacteria break down red blood cells, split haemoglobin

Question 36

kupffer cells are an example of

Answer 36

mononuclear phagocyte systems

Question 37

bile duct definition

Answer 37

tiny intracellular spaces flanked by tight junctions that form small conduits around hepatocytes produce bile continually

Question 38

bile function

Answer 38

emulsify fats and facilitate their absorption

Question 39

what is bile?

Answer 39

breakdown products of worn out red blood cells

Question 40

biliary tract definition

Answer 40

liver, gall bladder and bile ducts

Question 41

gall bladder function

Answer 41

reservoir for bile concentrates bile adds mucus to bile

Question 42

when does the gall bladder secrete bile?

Answer 42

discharges its contents in response to the entry of fatty foods into the duodenum

Question 43

histology of gall bladder

Answer 43

folded mucosa or simple columnar epithelial cells fibrovascualr lamina propria deep muscularis external layer of supporting tissue with elastic fibres outer serosa

Question 44

what is the gall bladder epithelium resistant to?

Answer 44

bile

Question 45

common disorder of the biliary system

Answer 45

gallstones

Question 46

explain gall stones

Answer 46

excessive accumulation of cholesterol in the bile excess sterol may crystallise and calcify into a stone painless unless they are located in the neck where they may obstruct outflow and cause inflammation