Anatomy & Physiology II

1. Anatomy & Physiology II BIOS 2320 Instructor: Mrs. Sarah Jeffers

2. Introduction • Syllabus • Typical schedule with resources • Student email • Helpful websites: • http://faculty.mccneb.edu/sajeffers • http://www.quia.com/pages/sjeffers53/bios2320 • www.mhhe.com/saladin5 • “Student edition” link

3. Unit I: MetabolismDigestive System Part I Chapter 21

4. Metabolism Cardiopulmonary system • multiple changes in the molecules of the food we eat. • Digestive System: • primary purpose – to break food down into forms that can be used by the body and to absorb them so they can be distributed to the tissues. O2 and CO2 Digestive system Cardio- vascular system Nutrients Tissue cells Urinary system Wastes

5. Digestive Processes • Motility • Secretion • Membrane transport

6. Digestive Functions • Ingestion • Digestion • Mechanical • Chemical • Absorption • Compaction • Defecation

7. Stages of Digestion • Mechanical digestion • Chemical digestion • a. enzymes • series of hydrolysis reactions that break macromolecules into their monomers (residues) • Results: • Monosaccharides, amino acids, glycerol, fatty acids, and nucleotides • Vitamins, minerals, cholesterol, & water are absorbed.

8. Anatomical Subdivisions of Digestive System • Digestive tract • (Alimentary canal) • 30 foot long tube • GI tract • Accessory organs • salivary glands, teeth, tongue, liver, gallbladder, pancreas Mouth Oral cavity, teeth, tongue Pharynx Esophagus Accessory Organs Salivary glands Liver Stomach Gallbladder Pancreas Small intestine Large intestine Anus

9. Tissue Layers • Mucosa • Submucosa • Muscularis Externa • Serosa/Adventitia Components of the Mucosa Circular Folds stratified squamous epithelium or simple columnar epithelium Villi Lamina propria Muscularis mucosae Artery and vein Lymphatic vessel Mucosa Submucosa Muscularis Externa Circular layer Submucosal plexus Longitudinal layer Serosa Myenteric plexus

10. Mouth/Oral Cavity/Buccal Cavity • Functions: • Ingestion • Taste • Mechanical digestion • Chemical digestion • Swallowing • Speech • Respiration • Stratified Squamous • Skeletal Muscle Upper lip Labial frenulum Vestibule Hard palate and friction ridges Palatopharyngeal arch Soft palate Palatine tonsil Uvula Tongue Salivary glands: Sublingual Submandibular Lower lip

11. Boundaries of the Oral Cavity Superior Boundary Hard palate Soft palate Pharyngeal tonsil Nasal cavity Anterior and Lateral Boundary Labium, or lip Posterior Boundary Cheek Uvula Palatine tonsil Body of the tongue Root of the tongue Lingual tonsil Inferior Boundary The geniohyoid and mylohyoid muscles supporting the floor of the mouth

12. Dentition • Deciduous (20) by 3 years; Permenant (32) between 6 and 25 years • Types of teeth: • Incisors • Canines/ Cuspids • Premolars and molars/ Bicuspids

13. Salivary Glands • Small intrinsic glands found dispersed amid oral tissues, lips, cheeks and tongue - secrete at constant rate • 3 pairs extrinsic glands connected to oral cavity by ducts • Parotid • Submandibular • Sublingual Sublingual Parotid Submandibular Salivary gland duct Mucous cells Serous cells Submandibular salivary gland LM x 600

14. Saliva • Hypotonic solution of 99.5% water + solutes • Salivary amylase: begin starch digestion • Lingual lipase: fat digestion in stomach • Mucus: bind food together into bolus • Lysozyme: inhibit bacteria • Immunoglobin A: inhibit bacteria • Electrolytes (Na, K, Cl, phosphate, bicarbonate) • pH 6.8 - 7

15. Pharynx • Muscular funnel 13 cm long • Skeletal muscle • deep layer – • superficial layer - • Superior • middle • inferior (UES) • Stratified squamous Vomer Pharynx: Nasopharynx Oropharynx Laryngopharynx

16. Esophagus • Straight muscular tube 25-30 cm long • Extends from pharynx to cardiac stomach passing through esophageal hiatus in diaphragm • Cardiac orifice • Lower esophageal sphincter (LES)

17. Why do you think acid causes such problems for people when acid is actually a natural product found in the digestive system? i.e. How does the stomach tolerate such acidity?

18. Healthy Mucosa and Peptic Ulcer Helicobacter pylori

19. Stomach • Mechanically breaks up food, liquifies food • chyme • Does not absorb significant amount of nutrients • absorbs aspirin and some lipid-soluble drugs

20. Gross Anatomy of Stomach Esophagus Lesser omentum Lesser curvature Fundus • Volume: 50ml – 4L • Four regions • Muscular sac Diaphragm Esophagus Anterior surface Stomach Regions Spleen Liver Cardiac Layers of the Muscularis Externa Fundus The Pylorus Cardiac Body Longitudinal layer Lesser curvature Body Circular layer Pylorus Pyloric sphincter Oblique layer Greater curvature Rugae Duodenum Greater curvature Greater omentum

21. Unique Features of Stomach Wall • Mucosa • simple columnar glandular epithelium • Rugae / gastric pits • Muscularis externae: 3 layers

22. Gastric Secretions • HCl • Gastric glands contain carbonic anhydrase (CAH) • Functions: • Activates pepsin and lingual lipase • Breaks up connective tissues and plant cell walls • Converts iron to a usable form (Fe2+) • Destroys ingested bacteria and pathogens

23. Gastric Secretions 2. Pepsin - • pepsinogen (inactive) + HCl pepsin (active) • Chief cells 3. Gastric Lipase • Digests fats • Chief cells 4. Intrinsic factor • Essential for vitamin B12 absorption • RBC production (lack causes pernicious anemia) • Parietal cells

24. Chemical Secretions • 5. Chemical Messengers • Many produced by G-cells • Ex.) gastrin, serotonin, histamine, somatostatin • hormones • paracrine secretions • Gut-brain peptides