Physiology CH 15 lecture notes

2,316 views

Published on

Published in: Education, Technology, Business
0 Comments
4 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
2,316
On SlideShare
0
From Embeds
0
Number of Embeds
35
Actions
Shares
0
Downloads
0
Comments
0
Likes
4
Embeds 0
No embeds

No notes for slide

Physiology CH 15 lecture notes

  1. 1. CHAPTER 15: DIGESTION& NUTRITION
  2. 2. Digestion  the breakdown of food into simpler compounds and their absorption 2 Types of Digestion 1. Physical or Mechanical - the breakdown of food from big pieces into smaller pieces 2. Chemical - the breakdown of food into their simplest substance
  3. 3. mouth salivary glands pharynx esophagus stomachliver small intestine gall bladderpancreas large intestine rectum anus
  4. 4. General Characteristics of the Alimentary Canal
  5. 5. 4 Layers 1. Mucosa - innermost layer 2. Submucosa - contains many blood vessels and nerve fibers 3. Muscular Layer - has 2 layers of muscles 4. Serosa - protects underlying tissue and secretes serous fluid
  6. 6. ] submucosa
  7. 7. Mouth - begins the physical digestion (chewing) of food Parts of the Mouth 1. Cheeks 2. Lips 3. Tongue - contains the taste buds - connected to mouth by frenulum 4. Hard palate
  8. 8. 5. Soft palate - a muscular partition that closes off the nasal cavity when swallowing6. Uvula - the little hangy thing in back of the mouth7. Teeth - 20 deciduous - 32 permanent
  9. 9. 4 Types of Teeth 1. Incisors - biting 2. Cuspids (canines) - tearing 3. Bicuspids 4. Molars } - grinding
  10. 10. Parts of a Tooth
  11. 11. Salivary Glands - secretes saliva - moistens food which makes taste possible - cleans the mouth Salivary Secretions - there are 2 types of cells in salivary glands 1. Serous - produces salivary amylase 2. Mucous - produces mucus
  12. 12. 3 Major Salivary Glands 1. Parotid 2. Sublingual 3. Submandibular
  13. 13. Digestion in the Mouth Mastication – chewing of food begins physical digestion - salivary glands release salivary amylase which begins chemical digestion of carbohydrates
  14. 14. Pharynx - involved in the swallowing reflex 3 Parts of the Pharynx 1. Nasopharynx 2. Oropharynx 3. Laryngopharynx - once food moves into the pharynx, the reflex causes the epiglottis to cover the trachea & push the food into the esophagus
  15. 15. Esophagus - 25 cm long, leads into the stomach - begins the process of peristalsis  wave-like motion of muscles to move food
  16. 16. Stomach Functions - begins protein digestion - stores food - completes physical digestion of food 4 Parts of the Stomach 1. Cardiac Region 2. Fundic Region 3. Body 4. Pyloric Region
  17. 17. Gastric Glands4 Types of cells a. mucous cells - produce mucus b. parietal cells - produces HCl - produces Intrinsic factor - helps absorb Vit. B12
  18. 18. c. chief cells - produce pepsinogend. G-cells - produce gastrin
  19. 19. Digestion in the Stomach1. Physical - peristaltic waves pass over the stomach every 15-25 seconds - this wave action blends the food into a soupy substance called chyme2. Chemical - pepsinogen changes into active pepsin in the presence of HCl - breaks proteins down into polypeptides
  20. 20. Gastric Absorption - some water - ions - short fatty acids - certain drugs (aspirin) - alcohol
  21. 21. Regulation of Gastric Secretions1. Cephalic Phase - when you see, smell, think about, or taste food, the brain tells the gastric glands to produce gastric juices2. Gastric Phase - when food enters the stomach, it expands, gastrin is released - gastrin causes the release of gastric juices from the gastric glands
  22. 22. 3. Intestinal Phase - when chyme enters sm. int., 2 hormones are produced by the intestinal glands, secretin & CCK - secretin decreases gastric secretions and CCK keeps too much food from entering the stomach Gastric secretion movie
  23. 23. Pancreas
  24. 24. 2 Types of Cells 1. Islets of Langerhans - produce insulin & glucagon 2. Pancreatic Cells - secrete pancreatic juices
  25. 25. Pancreatic Juice - is a basic solution to neutralize the chyme - contains the following enzymes - pancreatic amylase - carbs - pancreatic lipase - lipids } - trypsin - chymotrypsin proteins - carboxypeptidase - pancreatic nuclease - nucleic acidsRegulation of Pancreas - secretin & CCK causes the release of pancreatic juices into the sm. int.
  26. 26. Liver Functions - carbohydrate metabolism - lipid metabolism - protein metabolism - removes damaged RBC’s - removes toxins - makes bile
  27. 27. Structure of Liver - 2 lobes - lobes are divided into hepatic lobules - 100,000 – 200,000 Hepatocyte 
  28. 28. Bile - made by hepatocytes Function - emulsifies fat  breaks big fat globules into small fat globules Regulation - constantly made by liver cells - nerve impulse can trigger bile production
  29. 29. Gall Bladder - stores excess bile from the liver - releases bile when CCK is present
  30. 30. Small Intestine
  31. 31. Structure of Sm. Intestine - mucosa forms finger-like projections called villi - each villus contains absorptive cells that have microvilli on them - goblet cells produce mucus - the lacteal is a lymph capillary that involves fatty acid absorption - intestinal glands secrete intestinal juices
  32. 32. Functions of the Small Intestine1. Segmentation mixes chyme with digestive juices, peristalsis moves food through sm. int.2. Completes chemical digestion of food3. Absorbs 90% of all nutrients
  33. 33. Chemical Digestion in the Small Intestine1. Carbohydrates - pancreatic amylase breaks down polysacccharides - sucrase, lactase, & maltase made by the intestinal glands breaks down disaccharides into monosaccharides
  34. 34. 2. Proteins - aminopeptidase and dipeptidase made by the intestinal glands breaks down polypeptides into amino acids3. Lipids - pancreatic lipase splits the fatty acids from the glycerol4. Nucleic Acids - pancreatic nuclease and intestinal nuclease breaks down RNA & DNA into nucleotides
  35. 35. Absorption of Nutrients
  36. 36. Weight Loss Surgeries1. Lab-Band
  37. 37. 2. Vertical Sleeve Gastrectomy
  38. 38. 3. VSG with duodenal switch
  39. 39. 3. Roux-en-Y
  40. 40. Large Intestine Structure
  41. 41. Funtions - absorption of water and electrolytes - contain bacteria that changes waste into a semi-solid and produces some Vit. K - NO DIGESTION OCCURS IN THE LARGE INTESTINE
  42. 42. FECES! - 75% water - bacteria - mucus - undigested food - bile - bile pigments - cellulose (fiber)
  43. 43. Nutrients  carbohydrates  lipids  proteins  vitamins  minerals  trace elementsAdequate diet – provides sufficient energy and nutrients to support optimal growth and to maintain and repair body tissue
  44. 44. Body Figure 15.34MassIndex

×