Digestive - 2

Question 1

What is the function of the oesophagus?

Answer 1

Transports food from the mouth to the stomach

Protects against abrasive fragments of food

Question 2

What is a unique feature of the oesophagus epithelium? What is this features function

Answer 2

Has multi-layered thick stratified squamous epithelium that act as sacrificial cells for protection

Question 3

What is a unique feature of the oesophagus external muscle layer? What is this features function

Answer 3

The top third of the oesophagus contains skeletal muscle to allow for rapid and voluntary control of swallowing

Question 4

What is a unique feature of the oesophagus serosa? What is this features function

Answer 4

Most of the length of the oesophagus is not inside a body cavity so it is instead covered with a fibrous adventitia (outer layer that connects oesophagus to trachea and surrounding) until it is in the abdomen and covered in serosa

Question 5

What is the primary function of the stomach?

Answer 5

Storage

Question 6

What are some of the secondary functions of the stomach?

Answer 6

Secretion of acid, enzymes and mucus

Digestion of proteins

Absorption of water and ions

Transport

Question 7

Label the diagram

Answer 7

Question 8

What are the cardia and pylorus mostly made of?

Answer 8

Mucous glands

Question 9

What is the function of the funds and body?

Answer 9

Secrete acid, enzymes and mucus

Question 10

Label cell types in the diagram and explain their function

Answer 10

Question 11

What is an issues that parietal cells have due to their function (i.e. production HCl)? How is this overcome?

Answer 11

They secrete acid (HCl) which could kill them

They secrete H+ and Cl- into the lumen which then forms HCl outside the cell

Question 12

Other than acid do parietal cells secrete? What is its function and why is it important?

Answer 12

It also secretes intrinsic factor which is essential for B12 absorption which is essential for red blood cell synthesis

Question 13

What is an issue that chief cells have with function (i.e. secreting pepsin)? How is this mitigated

Answer 13

Pepsin breaks down proteins and if it is released in its active form inside the cell then it will break down the cell. This is overcome as the pepsin is only active in acidic environments which is in the gastric pit, away from the gastric glands where the chief cells reside

Question 14

What is the process called when a cell digests itself (i.e. chief cells releasing pepsin instead of pepsinogen)?

Answer 14

Autodigestion

Question 15

What happens to the surface mucous cells over time?

Answer 15

They get disintegrated by the acid and enzymes

Question 16

What happens if the surface mucous cells don’t provide protection?

Answer 16

Ulcers

Question 17

Gastrin cells are endocrine and chief cells are exocrine, what does this mean?

Answer 17

Gastrin cells release hormones that go directly into the blood

Chief cell release their hormones onto the surface of tissue

Question 18

What stimulates gastrin cells? Why?

Answer 18

Eating food/water etc. to get all the cells in the stomach to perform the functions faster because of the dilution of the acid

Question 19

What is the function of bile?

Answer 19

It emulsifies large lipid globules into smaller ones to increase the surface are for digestion

Question 20

What are the functional cells of the liver? What can they do?

Answer 20

Hepatocytes can perform more than 500 different metabolic functions including (know 3):

glycogen/glucose storage and release

red blood cell recycling

bile synthesis and secretion

toxin removal

Question 21

What does each hepatocyte require to function?

Answer 21

Access to nutrient rich blood from the intestine

Access to oxygenated blood

Access to bile ducts (that drain to gall bladder FYI)

Question 22

Label the hepatocyte

Answer 22

Question 23

How does the bile that is produced by the hepatocyte exit the liver?

Answer 23

It travels via the bile canaliculus (and doesn’t leak because of tight junctions FYI)

Question 24

What do the endothelial cells on the hepatocytes do? What special features allows this?

Answer 24

They filter out large particles (i.e. proteins, red blood cells…)

They are fenestrated (i.e. have holes in them)

Question 25

Label the diagram of different types of vessels going into/out of the liver and what they do

Answer 25

Question 26

What is the movement of blood and the nutrients (and specify the function of the blood) in the liver?

Answer 26

Nutrient rich (but deoxygenated blood from the hepatic portal vein) blood from the small intestine and oxygenated blood (from the systemic circuit) transport nutrients from the outside of the tubule structure to the central vein

Question 27

What is the movement of bile from the liver?

Answer 27

From the hepatocytes through bile ducts that link up to tributary of bile duct (i.e. shared duct) to gall bladder (for storage)

Question 28

What is the sinusoid?

Answer 28

It is the blood vessel that runs though the hepatocytes to the central vein