Digestive System

Question 1

What are the layers of the alimentary canal?

Answer 1

Mucosa, submucosa, muscularis (inner and outer), serosa

Question 2

What is the movement of food within the GI tract called?

Answer 2

Peristalsis

Question 3

What are the accessory organs within the digestive system?

Answer 3

The liver, gallbladder, pancreas.

Question 4

The mucosa is made up of _______

Answer 4

Epithelial cells

Question 5

The submucosa is made up of ________

Answer 5

Underlying tissue (containing glands, blood vessels, nerves)

Question 6

The muscularis is made up of _______

Answer 6

An inner and outer muscle layer (a third internal layer within the stomach)

Question 7

What 2 layers does the serosa form?

Answer 7

Visceral peritoneum and periental peritoneum (with serous fluid between)

Question 8

What enzyme does saliva contain?

Answer 8

Salivary amylase

Question 9

What does salivary amylase do in the mouth?

Answer 9

Assists with the initial digestion of carbohydrates - converts some to disaccharides.

Question 10

The glands on the mucosa secrete ________

Answer 10

Mucus (lubricant..helps with the movement inside the GI tract) and digestive enzymes (breakdown products from lumen)

Question 11

The mixture of food and saliva is called ______

Answer 11

Bolus

Question 12

Name the 3 pairs of salivatory glands

Answer 12

Parotid glands, submandibular glands, sublingual glands

Question 13

Name and describe the 3 stages of swallowing.

Answer 13

Oral stage - voluntary muscles (tongue and cheeks) push bolus to pharynx)
Pharyngeal stage - involuntary pharynx muscles propel bolus into oesophagus.
Oesophageal stage - bolus moves by peristalsis into the stomach.

Question 14

What allows food into the stomach?

Answer 14

Lower oesophageal sphincter

Question 15

_____ are small pores in the lining of the thick stomach mucous membrane.

Answer 15

Gastric Pits

Question 16

What are the 3 types of secretory glands in the gastric glands and what do they secrete?

Answer 16

Mucous cells - mucus

Chief cells- pepsinogen (inactive digestive enzyme) Parietal cells - hydrochloric acid and intrinsic factor

Question 17

What is the purpose of hydrochloric acid?

Answer 17

Activates pepsinogen, converting it to pepsin, allowing it to convert proteins into polypeptides.

Question 18

_____ is the name of the liquid released from the stomach into the small intestine

Answer 18

Chyme

Question 19

The pyloric canal leads to the ______________ which controls gastric emptying.

Answer 19

Pyloric sphincter

Question 20

______ and ______ stimulate the secretion of gastric glands

Answer 20

acetylcholine and gastrin

Question 21

Taste, smell, food entering stomach cause SYMPATHETIC/PARASYMPATHETIC stimulation by the _________, which releases acetylcholine.

Answer 21

parasympathetic , vagus nerve

Question 22

What is the function of the hormone gastrin? (2)

Answer 22

Stimulates gastric glands and increases mitosis in the mucosa - replaces damaged cells to protect outer layers.

Question 23

Chyme entering the small intestine causes _____ impulses to _______ gastric secretion.

Answer 23

Sympathetic, inhibit.

Question 24

Chyme stimulates the intestinal wall to release _______, which …..

Answer 24

Cholecystokinin

decreases gastric motility ( stomach emptying, intestine filling).

Question 25

What is the exocrine function of the pancreas?

Answer 25

Release pancreatic juice

Question 26

Which cells release pancreatic juice?

Answer 26

Pancreatic acinar cells

Question 27

Where does pancreatic juice enter the duodenum?

Answer 27

At the duodenum papilla (surrounded by the sphincter of oddi/hepatopancreatic sphincter)

Question 28

The entry of pancreatic juice into the duodenum is regulated by ________

Answer 28

The hepatopancreatic sphincter/sphincter of oddi

Question 29

What are the enzymes within pancreatic juice and what do they breakdown?

Answer 29

Pancreatic amylase - polysaccharides to disaccharides Pancreatic Lipase - fats to fatty acids and glycerol Nucleases - digest DNA and RNA Trypsin, chemotrypsin, carboxypeptidase - proteins, polypeptides, peptides to amino acids.

Question 30

What is the function of bicarbonate ions within the pancreatic juice?

Answer 30

Provide an alkaline environment - for best enzyme action and to neutralise acid chyme entering the duodenum.

Question 31

The entry of chyme to the duodenum triggers the _____ to release secretin.

Answer 31

mucosa

Question 32

Pancreatic juice secretion is regulated by _____ and _____.

Answer 32

Secretin and Cholecystokinin

Question 33

Bile is secreted in the _____ and stored in the _____

Answer 33

liver , gallbladder

Question 34

What causes the gallbladder to contract and the secretion of bile and pancreatic juice into the duodenum?

Answer 34

Cholecystokinin

Question 35

What are the functions of bile? (2)

Answer 35

Emulsifies fats in the small intestine. Enables absorption of fatty acids and cholesterol. (also facilitates the excretion of bilirubin)

Question 36

Name the 3 sections which make up the small intestine.

Answer 36

Duodenum, jejunem, ileum

Question 37

What controls entry into the large intestine?

Answer 37

Illeocaecal valve (prevents backflow into ileum)

Question 38

The ______ is a double layer of peritoneal membrane

Answer 38

Mesentry

Question 39

What are the functions of the mesentry?

Answer 39

Supports the jejunem and ileum | Supports blood vessels, nerves and lymphatics

Question 40

The ________________ is a double fold of the peritoneum that drapes over the stomach, transverse colon and small intestine.

Answer 40

The greater omentum

Question 41

_____ are projections from the mucosa within the small intestine

Answer 41

Intestinal villa

Question 42

what is the function of intestinal villa?

Answer 42

Better absorption - push into lumen contents to increase surface area and carry the nutrients away from the small intestine

Question 43

Intestinal villa are lined with __________ cells

Answer 43

columnar epithelial

Question 44

The connective tissue core of the intestinal villa contain ______ and a ________.

Answer 44

Blood capillaries | lacteal (a lymphatic capillary)

Question 45

______ sit at the base between villi.

Answer 45

Intestinal glands

Question 46

______ secrete mucus throughout the small intestine.

Answer 46

Goblet cells

Question 47

What do intestinal glands secrete and what is the purpose?

Answer 47

Watery fluid - brings products for digestion to villi surface,

Question 48

_____ (smaller than intestinal villi) of the cells carry ________ to complete the final phase before absorption into the villus.

Answer 48

Microvilli, digestive enzymes

Question 49

What are the digestive enzymes of the microvilli and what do they breakdown?

Answer 49

Peptidase - peptides to amino acids Sucrase, maltase, lactase - disaccharides to monosaccharides Intestinal lipase - fats to fatty acids and glycerol

Question 50

What are the 4 methods of absorption of nutrients through the small intestine?

Answer 50

Diffusion, facilitated diffusion, active transport, osmosis

Question 51

Monosaccharides are transported into ______ by ______

Answer 51

capillaries | facilitated diffusion or active transport

Question 52

Amino acids are transported into ______ by _______

Answer 52

active transport

Question 53

Fatty acids and glycerol are transported into _______ by _______.

Answer 53

epithelial cells , diffusion

Question 54

What are fatty acids and glycerol converted into within epithelial cells and why?

Answer 54

Chylomicrons (tryglycerides surrounded by water soluble proteins) Allows them to enter lacteals where they are transported along lymphatic vessels to thoracic duct - water soluble so dont clog them

Question 55

Electrolytes are transported by ______ and ______

Answer 55

diffusion and active transport

Question 56

Water is transported by ______

Answer 56

osmosis

Question 57

Name the sections of the large intestine

Answer 57

Caecum Colon ( ascending, transverse, descending) Rectum Anal canal (internal sphincter-involuntary smooth muscle, external sphincter-voluntary skeletal muscle)

Question 58

_____ is not regular in the large intestine - only 4-6 times daily

Answer 58

peristalsis

Question 59

Does the large intestine have villi?

Answer 59

Nooooooooo

Question 60

____ are pouch like folds within the large intestine

Answer 60

Haustra

Question 61

The large intestine involves only some reabsorption of _____ and ______

Answer 61

water and electrolytes

Question 62

Faecal matter is forced from the ______ colon into the ______

Answer 62

sigmoid , rectum