Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ZA - GI Medicine > Upper GI Tract Structure and Function > Flashcards

Upper GI Tract Structure and Function Flashcards

1
Q

How is voluntary chewing controlled?

A

Somatic nerves control skeletal muscles

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

How is the jaw reflex controlled?

A

Jaw muscles contract and cause the food to press/cause pressure around mouth which is picked up by mechanoreceptors

This inhibits jaw muscles - a safety response

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

What is in saliva?

A 
Water
Alpha-amylase
Mucins
Electrolytes
Lysozyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do mucins do?

A

Mucins + water = mucus. Viscous solution with a lubricant function

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

Why are electrolytes in the saliva?

A

For tonicity/pH regulation

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

What is lysozymes function?

A

Bacteriocidal - cleaves polysaccharide component of bacterial cell wall

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

How is salivation controlled?

A

By ANS - PS and S

PS is by cranial nerves 7 and 9

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

What does PS innervation do?

A

Stimulates a profuse watery secretion

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

What does S innervation do?

A

Stimulates too - but a small amount of viscous saliva with a high mucus and amylase content

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

Describe the reflex control of salivation.

A

Presence of food in mouth activates chemoreceptors/pressure receptors in the walls of mouth and tongue

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

What are the 4 layers of the oesophagus?

A

Mucosa
Submucosa
Muscularis externa
Adventitia

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

What epithelium is in the mucosa?

A

Stratified squamous non-keratinized

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

What type of muscle is in the oesophagus muscularis externa ?

A

Upper 1/3 is skeletal

Lower 2/3 is smooth muscle

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

What are the oesophageal sphincters?

A

Sphincters are the “valves” of the canal and regulate movement in and out of the canal
One at top and bottom
Top one prevent regurgitation

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

What happens if the top sphincter doesn’t work?

A

Pressure builds in stomach and you projectile vomit

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

What are the stages of swallowing?

A 
Oral 
Pharyngeal
As bolus approaches oesophagus
Once food enters oesophagus 
Oesophageal phase
Bolus nearing stomach
17
Q

Describe the oral phase.

A

Bolus is pushed to back of mouth by tongue

18
Q

Describe the pharyngeal phase.

A

Presence of bolus = reflex contractions of pharyngeal muscles - coordinated by the swallowing centre in medulla

Soft palate reflected backward and upward to close off nasopharynx

19
Q

Describe what happens as the bolus gets near the oesophagus?

A

Upper oseophageal sphincter (UOS) relaxes and epiglottis covers opening to larynx (prevents food entering trachea)

20
Q

Describe what happens when food has enters the oesophagus.

A

UOS contracts to prevent a food reflux

21
Q

What happens in the oesophageal phase?

A

Propulsion of bolus to stomach by peristaltic wave sweeps along entire oesophagus
Propelled to stomach in ~10 secs

22
Q

What happens as bolus nears stomach?

A

LOS releaxes

23
Q

What happens once food is in stomach?

A

Stomach prompted to relax by LOS relaxing and presence of food

Vagus PS innervation also = relaxation of smooth thin elastic muscle - this allows stomach to increase size without stretching

24
Q

What is the stomach max volume without changing pressure?

A

1500 ml

25
Q

How an stomach increase size without stretching?

A

The stomach surface is like curtains, all pleated up when contracted

Pleats called rugae

26
Q

Functions of Stomach

A

Temporary store of ingested material
Dissolve food and start digestion
Control delivery of contents to small intestine
Sterilise ingested material
Produce intrinsic factor (Vitamin B12 absorption)

27
Q

What is the layers of the muscularis externa in the stomach?

A

Inner - oblique
Middle - circular
Outer - longitudinal

28
Q

What is the serosa made from of the stomach?

A

CT outer layer

29
Q

What is on the luminal surface of the stomach?

A

Surface mucus cells
Gastric pits
Gastric glands
Mucus neck, parietal and chief cells

ZA - GI Medicine (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions