GI

Question 1

What is an accessary organ and name some

Answer 1

Organs which affect but are not physically part of the digestive tract. Salivary glands, Liver, Pancreas and gall bladder

Question 2

Name the parts of the GI tract

Answer 2

Oral cavity, Pharynx, Oesophagus, Stomach, small intestine, large intestine, rectum/anus

Question 3

What is the role of the mucosa layer in the GI Tract

Answer 3

Lumen, mucosa contains epithelial cells which secrete mucus for lubrication of the tract

Question 4

what is the role of the submucosa layer

Answer 4

contains connective tissue which contains blood vessels, lymph vessels and nerves

Question 5

what is the structure layer of the muscularis around the GI tract

Answer 5

smooth muscle split into two layers, inside layer is circular with the outside moving longitudinal

Question 6

what is the role of the Serosa layer

Answer 6

connective tissue which secretes serous fluid which lubricates the outside of the tract

Question 7

What holds the tongue to the floor of the mouth

Answer 7

Lingual Frenulum

Question 8

What are the three sections of the pharynx

Answer 8

Nasopharynx (not used in GI) Ciliated
Oropharynx (stratified epithelial cells which secrete mucus)
Laryngopharynx (stratified epithelial cells which secrete mucus)

Question 9

Describe the Oesophogus, it geometric proportions and where it passes through the diaphragm

Answer 9

Long muscular tube 2cm wide. Passes through the Diaphragm through the Oesophageal Hiatus at T10. still stratified epitheliam

Question 10

Describe the stomach, include th names o the sphincters, its location in the abdomen & it overall shape and internal structure

Answer 10

Entrance point is called the Cardia. Inferior to diaphragm. J-shape in the upper left abdominal quadrant. Cardiac and Pyloric Sphincters. Contains Rugae folds which allows the stomach to fold

Question 11

Describe the stomach lining, include the structure of the cell layers

Answer 11

Differs in the mucosa layer, now a single layer of columnar cells, form tube-like pits which form glands.

Question 12

In the glands in the stomach lining what are the 5 types of epithelial cells

Answer 12

Surface mucous cells, mucous neck cells, Parietiel cells (Hydrocholric acid), chiefs cells(Enzymes) and Endocrine cells (hormones)

Question 13

Describe the 3 muscle layers surrounding the stomach

Answer 13

Outer - longitudinal
Middle - Circular
Inner oblique
This allows the stomach to more easily digest food

Question 14

What is the peritoneum and what are it’s roles

Answer 14

Continuous sheet of serous membrane.
Visceral peritoneum- covers abdominal organs
Parietal… lines abdominal and pelvic cavities
peritoneal cavity - space between the two types

Question 15

What does Intraperitoneal and Retroperitoneal refer to

Answer 15

Intraperitoneal - inside the peritoneum (organ is surrounded by serosa
Retroperitoneal - Behind the peritoneum (Organ is surrounded by advantisia) Because it needs to be anchored to something in the cavity.

Question 16

Mesenteries peritoneum are sheets of connective tissue which do what?

Answer 16

stop the organs from moving around and provide a good medium to provide a good blood supply to the organs

Question 17

What are the 3 subdivisions in the small intestine

Answer 17

Duodenum (30cm)
Jejunum (2.5m)(Completely peritonised)
ileum (3.5m)Completely peritonised
90% of nutrient absorption occurs here

Question 18

What does the Duodenum do in the small intestine

Answer 18

Extends from the Pyloric sphincter to the jejunum
C-shaped structure adjascent to the head of the pancreas
Short superior part which lies in the peritoneal lining. Has extra mucus glands called Brunner glands that secrete alkaline mucus to neutralise the stuff coming out the stomach.

Question 19

How do the epithelial cells change throughout the course of the small intestine

Answer 19

Mucosa and submucosa fold to increase the surface area The further along the intestine you move the more folds there are.

Question 20

In the Villi in the small intestine what are the 4 types of cells

Answer 20

Absorpative, Goblet, Grannular, Endocrine. Absorpative and goblet cells can migrate over the villi surface.

Question 21

What is the function of the large intestine

Answer 21

Reabsorbing water, Compacts intestinal contents into faeces, Absorbs vitamins. Extends from the ileocecal junction to the anus

Question 22

How does the muscle layer vary in the large intestine

Answer 22

2 layers, outer longitudinal layer forms 3 bands called the teniae coli which gather colons into pouches

Question 23

What are the 4 main sphincters in the GI tract

Answer 23

Oesophageal sphincter, Pyloric sphincter, Ileocaecal valve, Internal anal sphincter

Question 24

What are the 6 main functions of GI secretions

Answer 24

Chemical Digestion, Lubrication, Signalling, protection, Activation of Enzymes, Excretion of waste

Question 25

What do salivary glands secrete and for what purpose

Answer 25

saliva, Lubrication and enzymes which break down carbohydrates

Question 26

What is secreted in the stomach

Answer 26

Acid, pepsin, gastric waste

Question 27

what does the pancreas secrete

Answer 27

exocrine cells secrete buffers and digestive enzymes, endocrine cells secrete hormones

Question 28

Gall bladder secretes what

Answer 28

bile

Question 29

What is the difference between endocrine and exocrine secretions

Answer 29

Exocrine - Produce and secrete substances onto an epithelial surface by a wet DUCT Endocrine - Secrete their products, hormonses, directly into the blood rather than through a duct

Question 30

What are the names of the 3 major salivary glands

Answer 30

paratoid, submanbular, sublingual

Question 31

What is the composition of saliva and what roles to they perform

Answer 31

water, Mucins, electrolytes, antibodies, enzymes. Buffer ions keep pH = 7, keeps mout moist to help speach, helps dissolve chamicals to allow taste

Question 32

Parasympathetic and Sympathetic nerves are involved in the production of saliva what roles do each of the systems play in the production

Answer 32

Parasympathetics - Volume | sympathetic - composition

Question 33

What are the exocrine secretions of the stomach

Answer 33

Gastric juice - Hydrochloric acid, Pepsinogen (enzyme), Intrinsic Factor(needed for absorption of Vb12)e.g. production of RBcells), Mucus (lubrication & is alkaline to protect enzymes from acid)

Question 34

What are the secretions of the parietel cells

Answer 34

secrete intinsic factor, HCL (kills microbes, denatures proteins, activate enzymes e.e Pepsinogen to pepsin)

Question 35

chief cells secrete what into the stomach

Answer 35

pepsinogen, gastric lipase

Question 36

What are the secretions of the pancreas

Answer 36

Endocrine - insulin, glucagon, Somatosatin (inhibit gastrin release to slow food movement out of stomach) Exocrine - pancreatic juice (water, Bicarbonate(neitralise stomach acid), Enzymes)

Question 37

What enzymes are in pancreatic juice

Answer 37

amylase - stacrches Lipase - fats Ribonucleoase - RNA Deoxyribonuleoase - DNA

Question 38

What is the composition of function of bile

Answer 38

pH - 7.6 - 8.6 to neutralise stomach acid. contains bile salts, bilirubin, cholesterol, neutral fats, phospholipids and electrolytes

Question 39

What are the phases of Digestion

Answer 39

Cephalic phase - salivary and gastric nerves are activated Gastric phase - Food enters stomach stimulating stretch receptors. Chemoreceptors in stomach detect increase in pH. Chyme empties into the duodenum. Intestinal Phase.

Question 40

Define absorption

Answer 40

Movement of small molecules through absopative epithelial cells of the mucosa into underling blood or lymphatic vessels. They are then carried to the liver.

Question 41

What form are carbohydrates absorbed

Answer 41

monosaccharides (Glucose, fructose, galactose), then borcken down by enzymes e.g. amylase

Question 42

What are proteins brocken down into

Answer 42

large peptides then into amino acids, peptides & bipeptides

Question 43

Where are electrolytes absorped specifically iron and calcium

Answer 43

small intestine, Duodenum