Digestive System Flashcards
What are the functions of the digestive system (6x)
- Ingestion
- Mechanical digestion and propulsion
- Chemical digestion
- Secretion (water, acid, enzyme, hormones, buffer and salts)
- Absorption
- Defecation
What does the digestive system consist of?
the digestive tract (gastrointestinal (GI) tract) and various accessory organs.
What are the accessory organs of the digestive system? (6x)
Teeth, Tongue, Salivary Glands, Liver, Gallbladder, Pancreas
What are the major organs of the digestive tract? (6x)
Oral Cavity, Pharynx, Esophagus, Stomach, Small Intestine, Large Intestine
What is the peritoneum?
Peritoneum is membrane that lines our abdominal wall and cover most of the organs
What is mesentery?
The mesentery is a fold of membrane that attaches the intestine to the abdominal wall.
What does mesentery proper support?
The mesentery proper supports all but first 25 cm of the small intestine and provides stability and limited movement.
What does the greater omentum contain?
Greater omentum contains adipose tissue and provides padding for the anterior and lateral portions of the abdomen
What is lesser omentum?
Lesser omentum stabilizes the position of the stomach and provides an access route for blood vessels and other structures entering or leaving the liver.
What is mesocolon?
Mesocolon a mesentery associated with a portion of the large intestine.
What increases the surface area of the mucosa of the small intestine
Circular fold and intestinal villi increase the surface area of the mucosa of the small intestine.
What is Lamina Propria (in relation to the digestive system)?
Lamina propria is layer of areolar tissue that contains blood vessels, sensory nerve endings, lymphatic vessels, smooth muscle cells and lymphatic tissue.
What is Muscularis mucosae?
is a narrow sheet of smooth muscle and elastic fibers.
What is submucosa?
Submucosa is a layer of dense irregular connective tissue that binds the mucosa to the muscular layer.
What is submucosal neural plexus?
Submucosal neural plexus is a network of intrinsic nerve fibers and scattered neurons. The submucosal plexus lies along the inner border of the muscularis externa (muscularis).
What is the myenteric plexus?
Myenteric plexus is a network of parasympathetic ganglia, sensory neurons, interneurons, and sympathetic postganglionic fibers.
What is Serosa in relation to the digestive tract?
Serosa covers the muscularis externa along most portions of the digestive tract inside the peritoneal cavity
What does segmentation mean in relation to the digestive system?
Most areas of the small intestine and some portions of the large intestine undergo cycles of contraction that churn and fragment the bolus, mixing the contents with intestinal secretions.
What does Peristalsis contain?
Peristalsis consists of waves of muscular contractions that move a bolus, or soft rounded ball of digestive contents, along the length of the digestive tract
What is Peristalsis?
Peristalsis is the waves of muscular contraction that propel the contents of the digestive tract.
How does the digestive system move material? (4 steps)
- Initial Stage
- Contraction of circular muscles behind bolus
- Contraction of longitudinal muscles ahead of bolus
- A wave of contraction in circular muscle layer forces bolus forward
What controls digestive function? (3x)
- Local Factors
- Neural Control Mechanism
- Hormonal Control Mechanism
What are the local factors that control digestive functions?
pH, volume or chemical composition
What are the neural control mechanisms that control digestive functions?
Sensory receptors in the wall, motor neuron control smooth muscle contraction.
What are the hormonal control mechanisms that control digestive functions?
Digestive hormones (produced by enteroendocrine cells) can enhance or diminish the sensitivity of the smooth muscle cells to neural commands
What are the functions of the oral cavity? (4x)
(1) sensory analysis of food before swallowing;
(2) mechanical digestion through the actions of the teeth, tongue, and palatal surfaces;
(3) lubrication by mixing with mucus and saliva;
(4) limited chemical digestion of carbohydrates and lipids.
What is Gingiva?
The ridge of oral mucosa that surrounds the base of a tooth
What is vestibule in relation to the oral cavity?
Vestibule, The space between the cheeks or lips and the teeth
What is the oral cavity lined with?
oral mucosa.
What is the oral mucosa?
(stratified squamous epithelium).
Where is Uvula located?
located at the posterior margin of the soft palate.
How is the dangling process of the Ulva helpful?
The dangling process that aids in keeping food out of the nasopharynx
What does the Palatoglossal arch do?
This extends from the soft palate to the pharyngeal wall.
What is the function of the tongue? (4x)
(1) mechanical digestion by compression, abrasion, and distortion;
(2) manipulation to assist in chewing and to prepare food for swallowing;
(3) sensory analysis by touch, temperature, and taste receptors
(4) secretion of mucins and the enzyme lingual lipase.
How does the pulp cavity receive blood vessels and nerves?
The pulp cavity receives blood vessels and nerves through the root canal.
What is pulp cavity?
The part of a tooth that contains blood vessels and nerves
What is Enamel?
cover the crown of a tooth
What is Dentin?
The bulk of each tooth consists of a mineralized matrix similar to that of bone.
What is Gingival sulcus?
A shallow groove called the gingival sulcus surrounds the neck of each tooth
What does the Periodontal ligament do?
Each tooth is held in the alveolar socket by this ligament
What are the 4 types of Teeth?
- Incisor
- Canine
- Premolar
- Molar
What are Incisor teeth and its function?
Blade-shaped teeth that function in cutting or clipping
What are Canine and its function?
or cuspids, are conical with a single, pointed cusp. the canines are used for tearing or slashing.
What are Premolar teeth and its function?
or bicuspids, have flattened crowns with two prominent rounded cusps. They crush, mash, and grind.
What are Molar teeth and its function?
Teeth with flattened crowns and prominent ridges that are adapted for crushing and grinding.