1. Digestive System
Day 3
Digestive System Parts:
Esophagus and Stomach

2. 2. Esophagus (gullet: gula=throat in latin)
To eat
To carry
(gullet: gula=throat in latin)
Connects pharynx to stomach

3. 2. Esophagus Muscular Sphincters Upper: push food downward
Lower: prevents stomach acid back flow
Peristalsis: continued contraction and relation of muscles

4. 2. Esophagus https://www.youtube.com/watch?v=3XG3pwR7pzs

5. Create a stomach Materials: Copy paper Scissors Ruler Colors String
Create an actual size stomach
Materials:
Copy paper
Scissors
Ruler
Colors
String
Find out:
Width of the stomach
Length of the stomach
Length of the lesser curvature
Length of the greater curvature
Length of the esophagus
(create with string)

6. 3. Stomach
Function: mixes, churns, and breaks down food (washing machine)
pH – 1-4 (ranges depending on amount of food present)
pH of small intestines is about 8

7. 3. Stomach A.Cardiac region (cardia): secretes mucous to
give to the esophagus to help protect it from stomach acid
(Stomach pH 1-4; esophagus pH >4)

8. B. Fundus : secretes acids and enzymes for break down of food
3. Stomach
B. Fundus : secretes acids and enzymes for break down of food
C. Body:
mixes and churns food and secretes acids and enzymes

9. D. Pylorus: secretes hormone gastrin which triggers HCl to be released
3. Stomach
D. Pylorus: secretes hormone gastrin which triggers HCl to be released
E. Pyloric sphincter : ring of muscle that determines when chyme (broken down food) goes into the small intestine

10. 3. Stomach
F. Rugae: folds of muscle inside stomach, stretch out when stomach is full (increase surface area inside stomach)

11. Gastric Juices: Pepsin – HCl (hydrochloric acid)- Mucus – Gastrin –
3. Stomach
Gastric Juices:
Pepsin –
HCl (hydrochloric acid)-
Mucus –
Gastrin –
Intrinsic factor –
B12 – DNA synthesis and RBC production

12. 3. Stomach Gastric Juices:
Pepsin – speed up the breaks down of proteins (catalyst)
HCl (hydrochloric acid)– pH 2; breaks down food; antimicrobial (kills bacteria)
Mucus – protects wall from acidic chyme and pepsin
Gastrin – hormone that regulates stomach secretions and movement
Intrinsic factor –takes vitamin B12 off of proteins (meat, fish, poultry, eggs) and absorbs it
B12 – DNA synthesis and RBC production