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.