Upper Gi tract structure and function Flashcards

1
Q

Give 2 reasons why we chew

A

to prolong taste

defend against respiratory failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In what 2 ways is chewing controlled?

A

Somatic nerves innervate skeletal muscle voluntarily

Reflex - pressure of food on parts of the mouth initiating mechanoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many pairs of glands secrete saliva and what are they?

A

3 - submandibular, parotid and sublingual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the major component of saliva?

A

water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What 2 substances found in saliva mix to form mucus?

A

mucins and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are mucins?

A

Major protein component in saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What else is found in saliva?

A

alpha amylase to form maltose
electrolytes for pH balance
Lysozyme to kill bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Are salivary glands endocrine or exocrine?

A

exocrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 types of alveoli found in salivary glands?

A

mucous, serous and mixed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What nervous system is stimulatory for saliva production?

A

both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What nerves control parasympathetic innervation of saliva production and what saliva is produced?

A

glossopharyngeal (4) and facial (7) cranial nerves

profuse, watery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What nerves control sympathetic innervation of saliva production and what saliva is produced?

A

adrenoreceptors (alpha1 - high mucus and beta 2 - high amylase) - low volume and viscous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What reflex is due to food being in the mouth on saliva production?

A

chemoreceptors and mechanoreceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What kind of epithelium line the mucosa of the oesophagus?

A

non keratinising stratified squamous epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain the muscles in the muscularis externa in the oesophagus (smooth, skeletal)

A

smooth in the lower 2/3 and skeletal above to help with swallowing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does the upper and lower oesophageal sphincters control?

A

upper - prevent regurgitation into the airway

lower - control entry into the duodenum

17
Q

What are the 3 stages of getting food to the stomach?

A

oral, pharyngeal and oesophageal

18
Q

What is the oral phase monitored by?

A

voluntary as bolus is put to the back of the mouth by the tongue

19
Q

What muscles contract and how to help with swallowing?

A

pharyngeal muscles coordinated by medulla swallowing centre

20
Q

What closes off the nasopharynx?

A

soft palette

21
Q

What closes off the larynx?

A

epiglottis

22
Q

What does the UOS contracting prevent?

23
Q

How long and by what means does the bolus get from oesophagus to stomach?

A

10 seconds

peristaltic wave

24
Q

What causes the relaxation of the stomach?

A

As the LOS relaxes and the food enters

vagal reflex relaxes smooth muscle of fundus and body

25
How does the stomach not change in pressure when going from a volume of 50ml to 1500ml?
Gastric rugae unfold
26
What are some functions of the stomach?
temporary store, dissolve food and digestion, control small intestine delivery, sterilisation and produce intrinsic factor
27
Why is intrinsic factor produced from the stomach important?
Important for vitamin B12 absorption
28
Explain the difference between muscle found at the top and bottom of the stomach
stretchy smooth muscle at the top and thick powerful muscle at the bottom to break down larger molecules
29
What is the additional layer found in the muscularis externa in the stomach? What does this allow?
oblique | like wringing a cloth
30
Where is the cardicac region of the stomach close to?
The heart
31
Where is the antrum of the stomach?
Basically the pyloric region
32
What layers is the rugae present in the stomach?
mucosa and submucosa
33
What are present in the lumen of the stomach?
mucus cells with gastric pit invaginations feeding into gastric glands
34
What are the 3 types of gastric glands?
chief, parietal and mucus neck cells