Digestive System Day 3 Digestive System Parts: Esophagus and Stomach

2. Esophagus (gullet: gula=throat in latin) To eat To carry (gullet: gula=throat in latin) Connects pharynx to stomach https://www.youtube.com/watch?v=3XG3pwR7pzs https://www.youtube.com/watch?v=DmtbNKRkhwY

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

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

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)

3. Stomach Function: mixes, churns, and breaks down food (washing machine) pH – 1-4 (ranges depending on amount of food present) https://www.youtube.com/watch?v=-U5JyODRVng pH of small intestines is about 8

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)

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 https://www.youtube.com/watch?v=-U5JyODRVng

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

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

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

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