Digestive system
Sponsored Links
This presentation is the property of its rightful owner.
1 / 46

Digestive System PowerPoint PPT Presentation


  • 39 Views
  • Uploaded on
  • Presentation posted in: General

Digestive System. AKA. G-I Tract Alimentary Canal. Overview. Consists of Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus About 30’ in length Accessory Organs Teeth, tongue, gall bladder, salivary glands, liver and pancreas

Download Presentation

Digestive System

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Digestive System


AKA

  • G-I Tract

  • Alimentary Canal


Overview

  • Consists of

  • Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus

  • About 30’ in length

  • Accessory Organs

    • Teeth, tongue, gall bladder, salivary glands, liver and pancreas

    • Glands secrete saliva, bile and enzymes


GI System


Process Includes

  • Ingestion

  • Mechanical – chewing, churning

  • Propulsion – swallowing and peristalsis

  • Chemical – breakdown via enzymes

  • Absorption – transport of end products into blood

  • Defecation – elimination as feces


GI Process


Peritoneum and cavity

  • Parietal peritoneum surrounds cavity, lines body wall

  • Visceral surrounds organ

  • Serous membrane allows organs to glide/expand

  • Retroperitoneal refers to organs in the dorsal region

  • Peritonitis = inflammation of peritoneum

  • Perforation = infection


Peritoneum


Regions


Mesentery

  • Double layer of peritoneum, holds organs in place

  • Omentums - protection

  • Lesser = fatty skin, superficial near the stomach

  • Greater = deeper, made of connective tissue, significant fat

  • Three layers of fascia – Skin, Fascia, mesentary


Messentery


Messentary


Omentum


Histology

  • Smooth muscle - peristalsis

  • Glands with ducts

  • Nerves, arteries and veins


Histology


MouthPoint of Origin

  • Oral cavity

  • Tongue

  • Soft and hard palate

  • Uvula

  • Oropharynx

  • Epiglottis

  • Larynx/pharynx

  • Esophagus


Mouth Anatomy


Mouth Anatomy


Salivary glands

  • Produce saliva, a mixture of water, ions, mucous, and enzymes

  • Dissolve food

  • Wets food to help bind it to become a bolus

  • Neutralizes acids, helps growth of beneficial bacteria

  • Intrinsic –in tongue, palate, lips and cheeks

  • Extrinsic = outside mouth

    • Parotids

    • Submandibular

    • Sublingual


Salivary Glands


Pharynx

  • Oso

  • Laryngopharynx

  • Lined with epithelial cells for protection


Pharynx


Esophagus

  • Muscular tube

  • Propels swallowed food to stomach

  • Passes through diaphragm (esophageal hiatus) into abdomen

  • Join the stomach at cardiac orifice

  • Cardiac sphincter prevents reflux or regurgitation of acid


Esophagus


Esophagus


Stomach

  • Food churned into chyme; a paste

  • Secretes pepsin – a protein digesting enzyme and HCl

  • Waters, electrolytes, some drugs absorbed through stomach

  • Anatomy

    • Cardiac orifice, fundus, lesser and greater curvature, pylorus

    • Rugae = numerous longitudinal folds of mucosa which flatten as stomach fills, allows expand


Stomach


Stomach


Small Intestine

  • Longest part of alimentary canal

  • Most enzymes involved in small intestine come from pancreas

  • Three divisions

    • Duodenum – 5%

    • Jejunum – 40%

    • Ileum – almost 50%


Duodenum

  • Receives digestive enzymes from pancreas

  • Bile from gall bladder and liver

  • Almost all nutrients are absorbed in small intestine

  • Large surface area, great length


Small Intestine


Small Intestine


Gall Bladder

  • Cystic duct

  • Bile duct – empties into small cystic duct

  • Secrete bile for duodenum digestion

  • Bile – Right and Left hepatic ducts to common cystic duct to Gall bladder for storage

  • From GB to bile duct to duodenum


Pancreas

  • Exocrine gland – produces most enzymes for digestion in small intestine

  • Endocrine function = produce hormones that regulate levels of sugar in the blood

  • Main pancreatic duct


Gall Bladder and Pancreas


Large Intestine

  • Most material has been digested by the time it reaches LI

  • 12-24 hours in large bowel

  • Little breakdown

  • Performs some absorption, especially water

  • Components

    • Ascending colon

    • Transverse colon

    • Descending colon

    • Sigmoid to rectum and anus


Large Intestine


Cecum and appendix

  • Cecum is a small sac (blind pouch)

  • Valve prevents a back up of fecal matter to ileum

  • Appendix

    • Lymph tissue neutralizes bacteria

  • Diverticulosus – a small outward herniation of colon, especially sigmoid

  • Diverticulitis – infection with leaks into peritoneal cavity may lead to peritonitis


Anal Canal

  • ANS balance between defecation or not

  • PNS = increase movement

  • SNS = decrease

  • Voluntary control via external sphincter muscles


Anal Canal


Defecation


Liver

  • Largest gland in the body (1.4 kg – 3 lbs.)

  • Produces bile

  • Stored in GB

  • Emulsifies fats

  • Involved in metabolism

  • Diaphramatic and visceral surface

  • Right and left lobes

  • Porta hepatis = major vessels and nerves

  • Right and left hepatic ducts, common bile, common


Liver


Liver


Liver


Study Points

  • Know the components of GI Tract

  • Know the peritoneum

  • Understand smooth muscle control

  • Know the various ducts and how they connect to specific organs

  • Understand the role of the stomach v. small intestine v. large intestine


  • Login