3: Salivary and gastric secretion, gastric motility

Question 1

What are the three pairs of major salivary glands?

Answer 1

Parotid glands

Submandibular glands

Sublingual glands

Question 2

Which salivary gland produces thick, viscous mucous?

Answer 2

Sublingual glands

Question 3

What is a functional unit of a salivary gland?

Answer 3

Salivon

Question 4

Salivary glands secrete saliva via a system of ___.

Answer 4

ducts

Question 5

Which type of cell within a salivon produces the saliva before it is secreted through ducts?

Answer 5

Acinus (acinar cell)

Question 6

What are the two types of acinar (excretory) cells found in a salivon?

Answer 6

Serous cells

Mucous cells

Question 7

What enzyme is found in the watery excretions of serous cells?

Answer 7

Alpha amylase

Question 8

What is produced by mucous cells?

Answer 8

Thicker mucous

Question 9

What is the purpose of lysozymes?

Answer 9

Break down the cell walls of bacteria

Question 10

Water and mucus ___ the oral cavity, allowing speech and swallowing.

Answer 10

lubricates

Question 11

Is the oral cavity alkaline or acidic?

Why?

Answer 11

Alkaline

Saliva contains bicarbonate ions

Question 12

Saliva contains high levels of Ca²⁺ - what does this serve to protect?

Answer 12

Tooth enamel

Question 13

The protective aspects of saliva serve to kill ___.

Answer 13

bacteria

Question 14

Alpha amylase from the saliva can continue to digest the food for over ___ minutes.

Answer 14

30

Question 15

What deactivates amylase once it has reached the stomach?

Answer 15

Hydrochloric acid

Question 16

Saliva is produced in a greater volume before emesis - what is emesis?

Answer 16

Vomiting

Question 17

In which cells of a salivary gland does secretion of saliva occur?

In which cells does modification occur?

Answer 17

Acinar cells

Duct cells

Question 18

What is the unconditional salivary reflex?

Answer 18

Secretion of saliva triggered by the presence of food in the mouth

Question 19

Which receptors trigger the unconditional salivary reflex?

Answer 19

Chemoreceptors

Mechanoreceptors

detecting the presence of food and the chemicals in it

Question 20

What is the conditional salivary reflex?

Answer 20

Increase in secretion caused by thinking about, smelling, seeing or hearing about food

Question 21

The conditional salivary reflex is (inherent / learned).

Answer 21

learned

Question 22

Which cranial nerves are involved in saliva secretion?

Answer 22

CN VII and IX

Facial nerve and Glossopharyngeal nerve

Question 23

Which arm of the ANS causes the secretion of a large volume of watery, enzyme-rich saliva?

Answer 23

Parasympathetic

Question 24

When does parasympathetic secretion of saliva occur?

Answer 24

Normal resting conditions

Question 25

Which arm of the ANS causes the secretion of thick, viscous saliva?

Answer 25

**Sympathetic**

Question 26

When does **sympathetic secretion** of saliva occur?

Answer 26

**Times of stress**

Question 27

What is ingested food called once it has been mixed with gastric secretions in the stomach?

Answer 27

**Chyme**

Question 28

In the first 30 minutes after a meal, chyme is moved to the ___ of the stomach by peristalsis.

Answer 28

**antrum**

Question 29

Which sphincter separates the stomach from the duodenum?

Answer 29

**Pyloric sphincter**

Question 30

Gastric mucosa is resistant to ___ but damaged by \_\_\_.

Answer 30

**acid** **bile**

Question 31

Regurgitation of bile through the pyloric sphincter can cause peptic \_\_\_.

Answer 31

**ulcers**

Question 32

Stomach emptying is determined by the __ and __ of the chyme.

Answer 32

**volume** **consistency**

Question 33

Volume and consistency of chyme influence how ___ the stomach becomes after a meal.

Answer 33

**distended**

Question 34

By which two means does the duodenum control when chyme is passed to it from the stomach?

Answer 34

**Neuronal** means **Hormonal** means

Question 35

In which area of the **stomach** are **pyloric** glands found?

Answer 35

**Antrum**

Question 36

**Gastrin** and **somatostatin** are two hormones released by the **pyloric glands** - what do they do?

Answer 36

Gastrin **stimulates** HCl secretion Somatostatin **inhibits** HCl secretion

Question 37

From which **pyloric gland** cell is **gastrin** released? From which **pyloric gland** cell is **somatostatin** released?

Answer 37

**Gastrin** is released from **G cells** (easy enough) **Somatostatin** is released from **D cells** (just because)

Question 38

In which areas of the stomach is **oxyntic mucosa** found?

Answer 38

**Fundus** **Body**

Question 39

Which oxyntic mucosa cells secrete **hydrochloric acid** and **intrinsic factor**?

Answer 39

**Parietal cells**

Question 40

What does **intrinsic factor** do?

Answer 40

**Binds to Vitamin B₁₂ to facilitate its digestion later**

Question 41

What is released by **Chief cells** in the oxyntic mucosa?

Answer 41

**Pepsinogen** (precursor to pepsin which is activated by HCl)

Question 42

Which enzyme is important in the secretion of hydrochloric acid from gastric parietal cells in the oxyntic mucosa?

Answer 42

**Carbonic anhydrase**

Question 43

Which signal molecule is the strongest agonist for hydrogen ion secretion?

Answer 43

**Histamine**

Question 44

What effects do a) PPIs (e.g omeprazole) b) prostaglandins c) muscarinic antagonists d) H₂ antagonists have on the secretion of HCl by parietal cells?

Answer 44

**a) PPIs = DECREASE** **b) Prostaglandins = DECREASE** **c) MUSCARINIC ANTAGONISTS = DECREASE** **d) H2 ANTAGONISTS = DECREASE**

Question 45

What are some classes of drugs which influence acid secretion?

Answer 45

**NSAIDs** like aspirin **Proton-pump inhibitors** - e.g omeprazole **Histamine receptor antagonists** **Muscarinic receptor antagonists**

Question 46

What is a gastric side-effect of **NSAIDs** (e.g aspirin)?

Answer 46

**Peptic ulcers**

Question 47

Why do NSAIDS cause peptic ulcers?

Answer 47

**Impair prostaglandins** (which reduce HCl secretion) **and other mechanisms of mucosal protection** ## Footnote **Allowing digestion of epithelium by HCl and pepsin**

Question 48

Which bacteria is associated with **peptic ulcers**?

Answer 48

***H. pylori***

Question 49

Proton-pump inhibitors **(increase / reduce)** gastric secretion. Give an example of a PPI.

Answer 49

**reduce** ## Footnote **omeprazole**

Question 50

What is an example of a **histamine receptor antagonist** which reduces gastric secretion of HCl?

Answer 50

**Ranitidine**