1. Parts of the The Digestive System

2. Anatomical Terms

3. Anatomy Terminology Medial- towards the midline of the body
Lateral- away from the midline of the body
Anterior (ventral)- front of the body
Posterior (dorsal)- back of the body
Superior (cranial)- toward the head
Inferior (caudal) – away from the head
Proximal- in proximity to or closer to
Distal- distant from or further away from

5. Pathway of Food: A) Mouth (oral cavity)
Hard palate- bony anterior portion of the roof of the mouth
Soft palate- entirely muscular posterior part of the roof of the mouth

6. Tonsils- protection against disease
Salivary glands- has an enzyme that are involved in chemical digestion

7. B) Teeth
- used to break down (masticate) food

8. C) Pharynx
- portion of the digestive tract between the mouth and the esophagus
Serves as a passageway for food and also air on its way to the trachea

11. D) Esophagus
-muscular tube passing from the pharynx through the thoracic cavity into the abdominal cavity to the stomach

12. Usually collapses until it receives bolus
Peristalsis- rhythmic contraction that pushes food along the digestive tract
Sphincter is located between the esophagus and the stomach to prevent acidic content from coming up

14. Heartburn/indigestions/acid reflux- when stomach contents enter the esophagus

15. E. Stomach “Gastric”
Muscular sac that mixes food with digestive juices to form chyme which enters the small intestine
Length- 25 cm
Rugae- deep folds in the wall of the stomach
Protein digestion begins
Mechanical and chemical digestion

17. Gastric glands secrete gastric juices:
Enzymes and HCl
Stomach empties in 2-6 hours
Chyme enters small intestine via a sphincter
Mucous- help protect the lining of the stomach wall

18. Ulcer- open sore in the wall of the stomach caused by the break down of tissue.

19. F) Small intestine
Named for its small diameter
Absorb nutrients
6 m in length
Bile (from the liver) and pancreatic juices (from the pancreas) are emptied into the small intestine

20. Bile emulsifies fats
Pancreatic juices- aid in digestion and neutralize acidic content coming from the stomach
The small intestine has a huge surface area- tennis court

21. G) Large intestine
Function- absorb water, salts and vitamins
Parts include: cecum, appendix, colon (ascending, transverse and descending) and rectum

23. When feces are forced into the rectum by peristalsis a defecation reflex occurs
Stretching of intestinal wall sends a message to the spinal cord. Shortly after the rectal walls contract and the anal sphincter relaxes.

24. Defecation is a way in which the body maintains homeostasis
Feces are ¾ water and ¼ solids- include bacteria and indigestible remains
Polyps
Constipation and diarrhea
Diarrhea can be caused by nervous stimulation or infection

25. When a person is constipated, the feces are dry and hard
Water and fiber will help!

26. Assignment
Choose 10 structures/processes that have been presented about the digestive system
For each structure write “who/what am I?” questions-
I am a process that helps move food along the digestive tract by rhythmic contractions....
I am ______________________________