Chapter 26 Digestive System Flashcards
Functions of the Digestive system
Ingestion
Mixing and propulsion
Digestion
Defecation
Gastrointestinal (GI) tract is a…
Tube through which good pass and where digestion and absorption occur.
The Gastrointestinal tract includes?
Mouth, pharynx, esophagus, stomach, small intestine, large intestine
Accessory organs is a..
Organs that help in digestion but through which food never passes.
Accessory organs include?
Teeth, tongue, salivary glands, liver, gallbladder, and pancreas
Four layers of gastrointestinal (GI) wall?
- Mucosa
- Submucosa
- Muscularis
- Serosa
Mucosa
Inner lining of track, foods due to contractions, lymphatic nodules present
Submucosa
Contains blood and lymph vessels, neurons attached to (ENS)
Muscularis
Thick layer of muscles, smooth and skeletal (swallowing)
Serosa
Outer layer around organs of GI, secrets slippery wet fluid
Formed by cheeks tongue, hard palate, soft palate.
Mouth
During swallowing blocks entry of food or drink to nasal cavity
Uvula
Muscular accessory organ, maneuvers food for chewing, adjust shape for speech and swallowing.
Tongue
Lies at the base of the tongue
Lingual tonsils
Organs of digestion that lie outside the mouth and release their secretions into ducts emptying into oral cavity
Salivary glands
Three pairs of salivary glands
Parotid- largest, anterior
Submandibular- floor of mouth
Sublingual- inferior to tongue
Starts digestion of starch
Salivary amylase
Accessory digestive organs located in bony socket of the mandible and maxillae
Teeth
Chewing or mastication
Mechanical digestion
Salivary amylase (enzyme) breaks down polysaccharides (starch)- maltose and large fragments
Chemical digestion
Muscular tube lined with stratified squamous epithelium that lies posterior to trachea
Esophagus
Upper esophageal sphincter regulates..
Movement of food into esophagus
Lower esophageal regulates…
Movement of food into stomach
Swallowing 3 stages?
Voluntary stage
Pharyngeal stage
Esophageal stage
Swallowing- voluntary stage?
Bolus forced into Oropharynx
Swallowing- pharyngeal stage?
Prevent food from entering nasopharynx and larynx
Swallowing- esophageal stage?
Food pushed through esophagus by process called peristalsis
J- shaped enlargement of GI tract directly below the diaphragm? Mixing chamber holding reservoir.
Stomach
Four regions of stomach?
Cardia- surrounds upper opening
Fundus- superior and to left of cardia
Body- large central portion
Pylorus- lower part leading to pyloric sphincter
Four layers of stomach?
Mucosa
Secretory cells
Muscularis
serous membrane
Food mixed with juice is..
Chyme
Main event of chemical digestion in stomach is the beginning of protein digestion by enzyme called?
Pepsin
Forces small amount of chyme through the partially closed pyloric sphincter into duodenum a process called?
Gastric emptying
Located behind stomach, secretions help digestion, also produces hormone insulin
Pancreas
Clear colorless liquid that consist mostly of water, some salts, sodium bicarbonate, and enzymes
Pancreatic juice
2nd largest organ in the body?
Liver- weighs 1.4 kg
Pear shaped sac that hangs inferiorly from the posterior surface of the liver
Gallbladder
Major functional cells of the liver that perform metabolic, secretory, and endocrine functions.
Hepatocytes
Small ducts between hepatocytes that collect bile
Bile canaliculi
Permeable capillaries with phagocytic kuppfer cells are between cells
Sinsusoids
