Lecture 12: Digestive system Flashcards
The upper and lower digestive tracts make up what
the alimentary canal
What are the 4 parts of the upper digestive tract
- mouth
- pharynx
- esophagus
- stomach
What are the 3 parts of the lower digestive tract
- small intestine (duodenum, jejunum, lleum)
- large intestine (cecum, colon, rectum)
- anus
What are the 7 accessory organs of the digestive system
- salivary glands (parotid, submandibular, sublingual)
- tongue
- teeth
- liver
- gallbladder
- pancreas
- appendix
What are the 6 main functions of the digestive ssytem
- ingestion
- mechanical breakdown
- propulsion
- digestion
- absorption
- defecation
what parts of the digestive system are involved in mechanical breakdown of food
- mouth = chewing
- stomach = churning
- small intestine = segmentation
Where does propulsion occur and how
- oropharynx = swallowing
- Peristalsis in esophagus, stomach, small intestine, large intestine
What are the 4 structural layers of the alimentary canal
- Mucosa
- Submucosa
- Muscularis Externa
- Serosa or adventitia
What makes up the mucosa layer of alimentary canal
membrane lining cavities that open to the exterior
- mucous epithelium (mouth, esophagus, anal canal)
- Lamina propria
- muscularis mucosae
What makes up the submucosa layer of alimentary canal
- gland in submucosa
- duct from gland
What makes up the muscularis layer of alimentary canal
- circular muscle layer
- longitudinal muscle layer
What makes up the serosa layer of alimentary canal
- connective tissue layer
- peritoneum / Mesothelium
What are the roles of the mucosa layer of the alimentary canal
- secretion (mucus, enzymes, hormone)
- absorption (nutrients)
- protection (infectious diseases)
What are the roles of the submucosa layer of the alimentary canal
- contains loose ct, blood & lymphatic vessels, neural fibers
- submucosal plexus (part of ENS)
- stomach (has lots of elastic fibers so it regains form after distention)
Where is the voluntary / skeletal muscles of the muscularis externa found
-mouth pharynx, superior part of esophagus, external sphincter (valve) of anus
Where is the internal / smooth muscle of the muscularis externa found
rest of tube
the serosa layer interfaces with what
the peritoneum (visceral/ parietal)
The mouth is a structure of what cavity
oral or buccal
describe the lips of mouth
covered externally by skin and internally by mucous membrane
Describe cheeks of mouth
- lateral boudaries, continuous w/ the lips and lined by mucous membrane
- formed in large part by the buccinator muscle covered by adipose tissue
- contain mucous-secreting glands
Describe the hard palate of the mouth
-consists of portions of 4 bones : 2 maxillae and 2 palatines
Describe the soft palate of the moutth
- forms the partition btw the mouth and nasopharynx and is made of muscle arranged in an arch
- suspended from the midpoint of the posterior border of the arch is the uvula
What is the tongue
solid mass of skeletal muscle covered by a mucous membrane; extremely maneuverable
What are the 3 parts of the tongue
- root
- tip
- body