What is the inner lining of the GI tract that is a mucous membrane? What layers is it made of?
Mucosa. Epithelium, Lamina propria, and muscularis mucosae.
What is the epithelium? Where is it found?
- Layer of Mucosa. TYPE VARIES!
- Found in the mouth, pharynx, esophagus, and anal canal.
- Stratified squamous epithelium that serves as a protective function.
- Columar epithelium functions in secretion and abs, lines the stomach and the intestines.
What is the lamina propria?
- Layer of mucosa.
- Areolar connective tissue containing many blood vessels and lymphatic vessels.
- Malt-mucus associated lymphatic tissue.
What is the muscularis mucosae?
- Layer of mucosa
- smooth muscle
- creates folds that generate more surface area to increase digestion and abs
What is the submucosa?
- Consists of alveolar connective tissue
- Blood and lymphatic vessels
- Neurons - suubmucosal plexus
What is the muscularis?
- Skeletal and smooth muscle
- Neurons - myenteric plexus (between layers of the muscularis)
- Voluntary swallowing
What is the Serosa?
- Areolar 7 simple squamos epithelium
- Viseral peritoneum
What is peritoneum?
- Parietal peritoneum
- Viseral peritoneum
- Peritoneal cavity
What are the folds of the peritoneum?
- Greater Omentum (adipose tissue)
- Falciform Ligament (liver to the anterior abd wall)
- Lessor Omentum
- Mesentary (small intestine to posterior abd wall)
What regulates the neural innervation of the GI tract?
- "brain of the gut"
- Autonomic nervous system
What is the role of the ENS in the parasympathetic and the sympathetic?
- They are like to the CNS by the extrinsic sympathetic and parasympathetic nerves.
- Sympathetic nerves decrease GI secretions & motility.
- parasympathetic nerves increase GI secretions & motility
What makes of the Enteric division?
- Myenteric plexus
- submucosal plexus
What is the function of the salivary glands?
Rlease saliva to oral cavity
What are the three pairs of the salivary glands?
What is the composition of saliva?
- 95% water
- 0.5% other (ions, mucus, enzymes, immunoglobulins)
- Salivary Amylase = starches
- Salivary Lipase
What controls/stimulates salvation?
It is controlled by the ANS and stimulated by various mechanisms
What are the four main digestive system functions?
What is deglutition?
The movement of food from the mouth inot the stomach is achieved by the act of swallowing
What are the three stages of deglutition?
- Stages of swallowing
What happens during "stages of swallowing" in deglutition?
- mouth to oropharyx
What happens during the Pharyngeal stage of deglutition?
- Deglutition center
- closing of the epiglottis
What happens during the esophageal phase?
Involuntary peristatic concentrations
What is the function of the stomach?
Serves as mixing chamber & storage area for intested food
What increases volume in to stomach?
Rugae allows for increased volume
What are four main groups of the stomach?
What structures are found in the region of the stomach that connects to the duodenum?
- The pylorus
- The pyloric antrum connects to the body of the stomach
- The pyloric canal leads to the duodenum