Week 1 - Control of Digestive Tract

Question 1

Name the main cranial nerve involved in regulating the digestive system

Answer 1

Vagus Nerve (X) ((10))

Question 2

What does Vagus Nerve X stimulate and supply?

Answer 2

Supplies parasympathetic fibers to most of the GI tract. It stimulates digestive secretions & motility

Question 3

State the autonomic system that stimulates the digestive system

Answer 3

Parasympathetic nervous system

Question 4

Name the two main reflexes that affect motility in the intestines

Answer 4

• Gastroileal reflex

- Gastrocolic reflex

Question 5

State the stimulus for the Gastroileal reflex

Answer 5

• Initiated when the stomach is distended (presence of food in the stomach)

Question 6

State the stimulus for the Gastrocolic reflex

Answer 6

Initiated when the stomach is distended. It stimulates mass peristalsis in the colon to move faeces into the rectum

Question 7

State the effect of the Gastroileal reflex

Answer 7

It intensifies peristalsis in the small intestine so chyme is moved into the caecum.

Question 8

State the effect of the Gastrocolic reflex

Answer 8

Occurs during or after a meal & drives faeces into the rectum.

Question 9

State the location of the Gastroileal reflex

Answer 9

In the stomach, and the junction of the small and large intestines (Caecum)

Question 10

State the location of the Gastrocolic reflex

Answer 10

In the stomach and the colon

Question 11

Describe the defecation reflex using the components of the reflex arc (STIMULUS)

Answer 11

As faeces moves into the rectum it causes distension of rectum, this stimulates stretch receptors in the rectal wall

Question 12

Describe the defecation reflex using the components of the reflex arc (CONTROL CENTRE)

Answer 12

Reflex located in the sacral spinal cord

Question 13

Describe the defecation reflex using the components of the reflex arc (EFFECTORS)

Answer 13

• Lower colon & rectal wall contracts
• Internal anal sphincter relaxes
• External anal sphincter is under voluntary control

Question 14

State 2 situations that impact on the functioning of the defecation reflex

Answer 14

• If there is insufficient bulk or lack of faeces
• Elimination of faeces cannot occur if there is damage to the neurons involved in the reflex arc or nerves that control the external anal sphincter

Question 15

What are the 5 effects of ageing on the digestive system

Answer 15

• Decreased gustation & olfaction impact on the pleasure associated with food
• Altered dental function resulting in decreased biting & chewing
• Decreased secretion of digestive enzymes limits digestive functions
• Decreased motility & loss of smooth muscle tone
• Decreased neural & hormonal control

Question 16

Describe ‘Decreased gustation & olfaction impact on the pleasure associated with food’ in ageing of the digestive system

Answer 16

Many older persons have reduced appetite & require smaller portions due to decreased activity

Question 17

Describe ‘Altered dental function resulting in decreased biting & chewing’ in ageing of the digestive system

Answer 17

• Increased risk of gum disease if unable to attend to oral hygiene
• Poorly fitting dentures

Question 18

Describe ‘Decreased secretion of digestive enzymes limits digestive functions’ in ageing of the digestive system

Answer 18

Inadequately digested food results in decreased nutrition

Question 19

Describe ‘Decreased motility & loss of smooth muscle tone’ in ageing of the digestive system

Answer 19

• May result in delayed passage of chyme & faeces
• Increased risk of constipation (also associated with decreased intake of food & fluids & activity levels)
• May have altered voluntary control of external anal sphincter resulting in faecal incontinence

Question 20

Absorption of nutrients occurs primarily where?

Answer 20

Small intestine

Question 21

Where does digestion begin?

Answer 21

Mouth

Question 22

Where does most carbohydrate digestion take place?

Answer 22

Small intestine

Question 23

Where is the cystic duct attached too?

Answer 23

Gallbladder

Question 24

Where do the ducts of the pancreas and liver connect to the digestive tract?

Answer 24

Duodenum

Question 25

What are the final products of protein digestion?

Answer 25

Amino Acids

Question 26

The finger-like projections of the small intestine that give the mucosa a velvety appearance and greatly increase the surface area are called…

Answer 26

Villi

Question 27

The nerves that control the digestive system are located in which tissue layer of the digestive tract?

Answer 27

Submucosa

Question 28

Where is the pyloric sphincter found?

Answer 28

Between the stomach and duodenum

Question 29

The wave like, rhythmic contractions that move food through the digestive tract are called

Answer 29

Peristalsis

Question 30

The main substance in bile that aids in digestion of triglycerides is…

Answer 30

Bile salts

Question 31

What is part of the digestive system, but are not part of the alimentary canal/digestive tract?

Answer 31

Liver, pancreas, gallbladder

Question 32

What is the space between the parietal and visceral peritoneum called?

Answer 32

Peritoneal cavity

Question 33

True or false; secretion of digestive enzymes is a function of hepatocytes

Answer 33

False

Question 34

What are rugae?

Answer 34

Folds of the mucosa of the stomach

Question 35

Explain how the lining of the stomach is protected from acid

Answer 35

The stomach is lined by a thick coating of bicarbonate-rich mucus to protect the muscle layers from strong stomach acid & protein-digesting enzymes