Digestive System #2

Question 1

Saliva
- purpose

Answer 1

purpose is to
- cleanse the mouth
- moisten food to move it down into the pharynx
- help with chemical breakdown

Question 2

Salivary Glands:

Answer 2

1. Parotid: infront of the ears
2. Sublingual: under the tongue
3. Submandibular: under the mandible

Question 3

Composition of Saliva

Answer 3

• 98% water
• contains antibody, lysosomes
• mucus
• salivary amylase (breaks down starch)

Question 4

Pharynx and more
- purpose

Answer 4

• Pharynx: throat
• Uvula: blocks nasal cavity
• Epiglottis: blocks of glottis to prevent food from entering the larynx (prevent choking)

Question 5

Esophagus
- histology

Answer 5

• nonkeratinized stratified squamous; acts as a protective layer
• smooth muscle (under ANS control)

Question 6

What does the stomach produce?

Answer 6

produces hydrochloric acid (kills bacteria) “stomach acid”
-can lead to acid reflux “heart burn” which effects the esophagus

Question 7

Stomach characteristics

Answer 7

• very muscular
• oblique circular longitudinal layers
• has Rugae; which folds and expands
• stomach connects to the esophagus via cardiac sphincter and duodenum via pyloric sphincter
• lots of movement called churning and peristalsis

Question 8

Functions of the Stomach

Answer 8

1. the most vital function is it produces intrinsic factor
2. stores food
3. digestion; chemical + physical (vomiting)
   - ex: vomiting to make it into Chyme
4. produces HCI-acid

Question 9

What is Intrinsic Factor

Answer 9

absorbs vitamin B 12

Question 10

What is Chyme?

Answer 10

liquefied food
- occurs during vomiting

Question 11

Stomach Ulcers

Answer 11

a bacterial infection called H. Pylori
- due to an overuse of Asprin
- causes the protective mucus layer lining of the stomach to erode