Digestive

Question 1

Label a tooth

Answer 1

enamel - dentin - pulp - cementum - peridontal ligament - root canal - alveolar bone - blood supply

Question 2

What are the three major types of papillae?

Answer 2

filiform, fungiform, vallate/circumvallate

Question 3

describe filiform papillae

Answer 3

• no taste buds
• jagged/saw-tooth/pointy looking

Question 4

describe fungiform papillae

Answer 4

• few tatse buds
• look like budding mushrooms

Question 5

describe vallate/circumvallate papillae

Answer 5

• location of majority of taste buds
• dome shaped deep “moat” surrounding its circumference

Question 6

State the properties of the serous cells of salivary glands

Answer 6

• watery
• enzyme rich
• lysozome
• amylase
• parotid gland

Question 7

State the properties of the mucous cells of the salivary glands

Answer 7

• visocus
• mucus-rich
• lubrication

Question 8

What gross convolutions of the gut tube enchance surface area and thus absorption?

Answer 8

• coiled nature of small intestines
• ascending, trasnverse and descending colon

Question 9

What evaginations of the gut tube enchance surface area and thus absorption?

Answer 9

intestinal villi

Question 10

What invaginations of the gut tube enchance surface area and thus absorption?

Answer 10

• intestinal galnds (aka crypts of Lieberkuhn)
• gastric glands

Question 11

What luminal folds of the gut tube enchance surface area and thus absorption?

Answer 11

• plicae circularis
• gastric rugae

Question 12

indicate the 4 layers of thre GI tract

Answer 12

Serosa, muscularis externa, submucosa, mucosa

Question 13

What layer of the mucosa porduces local movment independent of peristalsis?

Answer 13

muscularis mucosae

Question 14

What is the name of the nerve plexus that innervates the muscularis mucosae?

Answer 14

submucosal nerve plexus

Question 15

How is the muscularis externa arranged for most of the alimentary tract?

Answer 15

inner circular layer, outer longtitudinal layer

Question 16

The visceral peritoneum of the intestines is also known as the?

Answer 16

serosa

Question 17

Digestion begins at?

Answer 17

• mouth
• mechanical and chemical digestion (chewing, enzymes)

Question 18

The epithelium in the oesophagus is unique because ?

Answer 18

It is stratified to protect against abrasion
- When abrasive food passes through the oesophagus the stratified layers can slough off and be digested along with the food

Question 19

The primary function of the stomach is ?

Answer 19

• storage
• can be eaten at a much faster rate than it can be digested or absorbed, so the stomach acts as a storage site for food before it is transported through the pyloric sphincter and into the duodenum.

Question 20

What is stored in the liver?

Answer 20

glycogen

Question 21

What two endocrine secretions does the pancreas release?

Answer 21

insulin and glucagon

Question 22

What is different between thoracic and abdominal oesophagus?

Answer 22

thoracic - adventitia
abdominal - serosa

Question 23

Name another region besides the oesophagus in the alimentary tract that is lined with startifies squamous epithelium

Answer 23

oropharynx - protect passageway from friction caused by the passage of food

Question 24

Label the wall of the digestive tract CCA2

Answer 24

• epithelium being sloughed off
• epithelial germ cells
• structures that supply the mucose with nutrients
• muscularis extera (inner ciruclar)
• muscularis externa (outer longitudinal)
• Myenteric plexus

Question 25

What would be the consequence if the surface mucous cells failed to perform their function?

Answer 25

- destruction of the stomach lining by digestive juices - (Their secretions help protect the stomach lumen from acid and pepsin.)

Question 26

What do parietal cells do?

Answer 26

- secrete HCl which kills microbes and living cells - secreted intrinsic factor

Question 27

What do enteroendocrine cells do?

Answer 27

- release gastrin (which enters the blood as a hormone) 1. stimulates secretion of acid and pepsinogen 2. increases muscular contractions of stomach 3. relaxes pyloric sphyncter

Question 28

What do chief cells do?

Answer 28

- release pepsinogen and gastric lipase - pepsinogen is converted into the protein-splitting enzyme pepsin by acid in the lumen of the gland

Question 29

Why is it important that the parietal cells and chief cells release their products in their inactive/precursor forms?

Answer 29

To prevent auto-digestion It is important that the products from these cells are released in either inactive or precursor forms to prevent damage to the cells which release them (autodigestion)

Question 29

Why is it important that the parietal cells and chief cells release their products in their inactive/precursor forms?

Answer 29

To prevent auto-digestion It is important that the products from these cells are released in either inactive or precursor forms to prevent damage to the cells which release them (autodigestion)

Question 30

Bile is a secretory product of the liver which is stored and concentrated in the gall bladder, before being released via a common duct with the pancreas into the duodenum. Which substance does bile play an important part in the digestion of?

Answer 30

lipids

Question 31

Where does the blood traveling in the larger branch of the hepatic protal vein come from immediately upstream of the liver?

Answer 31

intestinal wall/gut - carries nutrient-rich but deoxygenated blood from the intestinal wall. The proteins, carbohydrates and lipids carried in this blood supply are metabolised in the liver and either released into the blood stream or stored as necessary. The hepatocytes also require oxygenated blood provided by the arterial side of the systemic circuit (via the hepatic artery) in order to get oxygen to provide energy to carry out the metabolic processes that occur within the cell. Therefore, the liver has a dual blood supply.

Question 32

What makes up the portal triad?

Answer 32

bile duct, hepatic artery, hepatic portal vein