1. DIGESTIVE PROCESS & KEY TERMS
PART 1

2. ALIMENTARY CANAL

3. ACCESSORY ORGANS

4. The GI tract is a “disassembly” line
PROCESS
The GI tract is a “disassembly” line
Function: Digest food & absorb nutrients
There are 6 steps:
Ingestion
Mechanical digestion
Propulsion
Chemical digestion
Absorption
Defecation

5. SECRETIONS
Always are secreted in response to coming in contact with food
Stretch receptors send signals to medulla & vagus nerve that
triggers release of many chemicals
This cascades a response of other hormones involved in digestion.

6. Digestion Part 2
Alimentary Canal

7. Digestion Terms Mastication-mechanical digestion (chewing)
Deglutition-swallowing a bolus
Bolus-chewed up food mixed with saliva
Peristalsis-moves food through the pharynx to the esophagus in a “squeezing” fashion 1 direction
Chyme-semi-liquid mass of partially digested food that passes from the stomach through the pyloric sphincter into the small intestine
Segmentation-churning of chyme in 2 directions (intestines)
Defecation-elimination of wastes

9. Mouth

10. Mouth Hard Palate Under part of maxilla bone Assists tongue in chewing
Soft Palate
Skeletal muscle
Closes off nasopharynx when swallowing

11. Esophagus

12. Where breakdown of proteins begin & bolus is converted to chyme
Stomach
This is where the breakdown of proteins begin & bolus is converted to chyme

13. Stomach Secretion Cell Types
Mucous Neck Cells: mucus in esophagus & stomach
Parietal Cells: HCl & factors for B12 absorption in small intestine
Chief Cells: pepsinogen- digest proteins & lipase- breaks up fats
Enteroendocrine: gastrin- activates parietal

14. Secretions
Always are secreted in response to coming in contact with food
Stretch receptors send signals to medulla and triggers release of many chemicals
This cascades a response of other hormones involved in digestion.

15. Small Intestine Begins breakdown of lipids
Further breaks down proteins & carbs
Secretions:
Bicarbonate→ neutralizes HCL from stomach,
Lipase→ breaks down fats into fatty acids,
Erepsin→ breaks down proteins into amino acids
Begins breakdown of lipids, Further breaks down proteins & carbs, Secretions:Bicarbonate→ neutralizes HCL from stomach, Lipase→ breaks down fats into fatty acids, Erepsin→ breaks down proteins into amino acids

16. Intestinal Villi Nutrients are absorbed into the bloodstream by villi.
After nutrients have been absorbed here:
Meal remnants, bacteria, mucosal cells, and debris are moved into
the large intestine
Nutrients are absorbed into the bloodstream by villi. After nutrients have been absorbed here:Meal remnants, bacteria, mucosal cells, and debris are moved into the large intestine

17. Large Intestine
Absorbs water, Produces vitamins K & B, Stores undigested food.
Haustral Contractions move food towards exit with help of mucus.
Absorbs water, Produces vitamins K & B, Stores undigested food, Haustral Contractions move food towards exit with help of mucus.

18. Digestion Part 3
Accessory Organs

19. Tongue Functions include: Gripping & repositioning food
Mixing food with saliva
Forming the bolus
Initiation of swallowing
Aids in speech

20. Salivary Glands
Parotid
Submandibular
Sublingual

21. Salivary Glands Produce and secrete saliva that: Cleanses the mouth
Moistens & dissolves food chemicals
Aids in bolus formation

22. Salivary Glands Contains enzymes that break down starch
Average output of saliva a day is…
1000mL-1500mL a day

23. Saliva Secreted from salivary glands
98% water, slightly acidic solution containing
Electrolytes – Na+, K+, Cl–, PO42–, HCO3–
Digestive enzyme – salivary amylase (breaks down carbohydrates into simple sugars)
Electrolytes are important because they are what your cells (especially nerve, heart, muscle) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells.
Salivary amylase breaks starches down into sugars
Mucin→ protein w/ high-water holding capacity, think about MUCINEX…
Lysozyme→ enzyme that breaks down bacteria
Defensins→ attack against bacteria and viruses
IgA→ an antibody
Urea→ aids in the release of nitrogen
Uric Acid→ a chemical created when the body breaks down substances called purines. Purines are found in some foods and drinks, such as liver, anchovies, mackerel, dried beans and peas, beer, and wine.

24. Saliva Proteins – 4 Types Mucin: high water holding capacity protein
Lysozyme: enzyme breaks down bacteria
Defensins: attack against bacteria and viruses
IgA: immune defense (antibody)
Metabolic wastes – urea and uric acid
Electrolytes are important because they are what your cells (especially nerve, heart, muscle) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells.
Salivary amylase breaks starches down into sugars
Mucin→ protein w/ high-water holding capacity, think about MUCINEX…
Lysozyme→ enzyme that breaks down bacteria
Defensins→ attack against bacteria and viruses
IgA→ an antibody
Urea→ aids in the release of nitrogen
Uric Acid→ a chemical created when the body breaks down substances called purines. Purines are found in some foods and drinks, such as liver, anchovies, mackerel, dried beans and peas, beer, and wine.

25. Duodenum and Related Organs

26. Liver The largest gland in the body
Located on right side of abdominal cavity

27. Liver Functions include: Involved in proteins synthesis
Hormone production
Destroys used/old RBC
Produces Bile
Stores Glucagen
Liver

29. Composition of Bile A yellow-green, color
Made of: cholesterol, fats, phospholipids, bile salts, and electrolytes

30. Composition of Bile Bile salts are cholesterol derivatives that:
Emulsify fat→ breaks down large fat globules into smaller droplets
Facilitate absorption of fat and cholesterol

31. The Gallbladder Stores bile made by the liver
Releases bile by 2 ducts into the duodenum after meals

32. Pancreas Secretes pancreatic juice containing digestive enzymes
Produces insulin→ released when sugar levels are too high by taking glucose out of the blood
Produces glucagon→ released when sugar levels are low by adding glucose to the blood