Anatomy stomach/Intestins Flashcards
Small intestine Unique features
Transverse folds, called circular folds or plicae circulares, are the major gross feature of the intestinal lining
Intestinal villi are smaller finger like projections covered with simple columnar epithelium that have microvilli on their apical surface
What are the parts of the digestive tract?
Digestive tract = a muscular tube for the most part, includes: Oral cavity Pharynx Esophagus Stomach Small intestine Large intestine
Accessory organs include:
Teeth
Tongue
Glands: salivary glands, liver, gall bladder, and pancreas
What are the functions of the digestive system?
Ingestion Mechanical processing Digestion Secretion Absorption Excretion
Peritoneum:
visceral and parietal layers line the organs and walls of the abdominopelvic cavity
They reduce friction
Mesenteries:
suspensive ligaments or serous membranes that connect to the two peritoneal layers to stabilize the position of organs and provide routes for blood vessels, lymphatics and nerves.
Hold organs together
What are the mesenteris?
Lesser omentum – stomach
Falciform ligament – liver
Greater omentum – adipose tissue for padding (beer belly)
Mesentery proper – small intestine
Transverse and sigmoid mesocolons – large intestine
What does retro-peritoneal mean?
Name something that is retro-peritoneal
Not found in the peritoneal lineing. retroperitoneal organs are covered in adventitia
Asending and descending colon
What structures do all histology in the GI tract share?
Mucosa
Submucosa
muscularis
Adventitia
Which layers are part of the mucosa?
epithelium, lamina propria, muscularis mucosae
Which layors are part of the submucosa?
loose connective tissue containing vessels, lymphatics and nerves
Which layors are part of the muscularis externa
(Its made of two thin layors of smooth mucle).
Inner circular layer
Outer longitudinal layer
What layers are part of the Aventitia?
What type of epithilium does it have?
outermost layer of connective tissue
simple squamous epithelium called the mesothelium
The Epithelium in the digestive system is determined by what?
varies depending on mechanical stresses of passing food:
What parts of the digestive system have Stratified Squamous epithilium?
Simple columnar?
Stratified squamous in oral cavity, pharynx, esophagus
Simple columnar in stomach and small/large intestine
What is included as part of the oral cavity?
Includes such organs as: Lips Tongue Teeth Salivary glands
What are the functions of the oral cavity?
Ingestion Sensory reception Mechanical processing Lubrication digestion
What type of epithilium is Oral Mucosa?
Where is it kernalized?
Stratified squamous epithilium.
on the tongue and hard palate
What are the glands of the oral cavity?
Parotid, sublingual, sub-mandibular
- What does the parotid gland produce?
- Submandibular gland?
- Sublinqual gland?
- Serous secretion and amylase to start digestion
- Secrete mucins, and amylase
- Mucouse secretion for buffer and lubricant
- Saliva is what percent water?
2. What else is in saliva?
- 99.4%
2. Na, Cl, HCO3, buffers, glycoproteins (mucins) enzymes (amylase, lysozyme), antibodies and waste products
What are the functions of saliva?
(note Neuronal control via salivatory nuclei in medulla
stimulated by CN V or taste buds which stimulate CN VII, IX and X
Parasympathetic stimulation increases output)
Lubricate oral surfaces, Moisten food, Dissolve chemicals to stimulate taste buds, Start digestion of carbohydrates, pH buffering, Bacterial control
What are the tonsillar tissues in the pharynx?
Where are they located?
Lingual tonsil
Palatine tonsils
Pharyngeal tonsil
pharynx
What are the pharyngeal constrictor muscles?
Crocopharyngeus
Inferior pharyngeal constrictor
Middle pharyngeal constrictor
Superior pharyngeal constrictor
What are the phases of swallowing?
What happens during them?
Buccal phase – compression and propulsion toward oropharynx
Pharyngeal phase – elevation of larynx
Epiglottis guards opening to trachea
Uvula and soft palate block opening to nasopharynx
Esophageal phase – contraction of pharyngeal constrictors and peristalsis along esophagus
Stomach entrance – approaching bolus triggers relaxation of lower esophageal (cardiac) sphincter
What is perisalsis?
Peristalsis is different from segmentation that occurs in small and large intestine
Wavelike sequential contraction
Which cranial nerves provide sensory information to salivatory nuclei
5,7,9,10
How many permanent teeth in the normal adult?
32
What are the steps in peristalsis
Steps
1. circular muscles behind bolus contract
- longitudnal mucles ahead of bolus contract(appear to open)
3 contraction in circular muscle forces bolus forward.
