Digestive System : Functions and Structures Flashcards
Digestion
Physical and chemical breakdown of foods into forms that the cell membranes can absorb and excretion of solid waste products
Alimentary Canal
Tube extending from the mouth to the anus (only sphincter muscles)
Includes : mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anal canal
Accessory organs
Outside of the canal.
Includes : Salivary glands, teeth, tongue, liver, gall bladder, and pancreas
Layers of the Alimentary Canal
(MSMS) Mucosa Submucosa Muscularis Serosa
Mucosa
Inner epithelial lining that protects, lubricates, and contains vili that absorb nutrients
Submucosa
Second connective tissue that contains blood vessels (carry away nutrients), lymphatic vessels, glands, and nerves
Muscularis (Externa/Interna)
Third main layer consisting of the 2 layers of smooth muscle
Submucosa and Muscularis function
Both layers work together to squeeze and shorten the canal in rhythmic movements called peristalsis that promote passage of substances through the canal
Serosa
(Serous membrane) Outermost epithelial layer that protects and secretes serous fluid that lubricates the outer edge of the canal
Accessory Gland Structures
Salivary glands
Liver
Gallbladder
Pancreas
Alimentary Canal Structures
Mouth Pharynx Esophagus Stomach Small Intestine Large Intestine Rectum Anus
Oral Cavity (mouth) Functions
Mastication
Mixes food with saliva - begins begins digestion of starches by the enzyme amylase
Prepares food into a bolus for deglutition
Mastication
Chewing; physical digestion of food
Degutition
Swallowing
Pharynx location
Behind the nasal/oral cavities and larynx. Connects to the esophagus
Pharynx Function
Passage way for substances into the body
Esophagus Structure
Straight, collapsible tube that is lined with mucous cels for lubrication
Esophagus Function
Provides passage from the pharynx to the stomach
Moves food down to stomach by peristalsis
Leads to Caridac (or Cardiaoesophageal) sphincter Muscle
Cardic Sphincter Function
Muscle that controls opening to the stomach
“gatekeeper”
Prevents regurgitation
Stomach Structure
J shaped, pouch like organ with an additional oblique muscular layer (total 3) that continues chemical and physical digestion of food
Rugae
Folds in the inner layer that increase surface area and allow distention
Gastric Glands
3 types of cells that makes gastric juice
- Goblet cells
- Chief cells
- Parietal cells
Goblet cells
Mucous, protective layer of inside
Chief Cells
Secrete pepsinogen (pepsin) digestive enzyme that breaks down proteins into amino acids
