L23: Alimentary System Overview Flashcards
Where does the alimentary system span?
Mouth to anal canal
What are the two groups of organs in the alimentary system?
- Digestive tract;
- Accessory organs.
What organs does the digestive tract consist of?
- Oral cavity;
- Pharynx;
- Oesophagus;
- Stomach;
- Small intestine;
- Large intestine.
What are the accessory organs?
- Salivary glands;
- Gall bladder;
- Liver;
- Pancreas.
What does the gall bladder do?
Stores bile
Where is bile produced?
Liver
Where does most food digestion occur?
Stomach
Where does most nutrient absorption happen?
Small intestine
Where does most water absorption happen?
Large intestine
What are the 4 layers of the G.I. tract?
- Mucosa;
- Submucosa;
- Muscularis Externa;
- Adventatia.
What are the 2 layers of the mucosa?
- Epithelium;
- Lamina propria (loose connective tissue).
What type of epithelium is in the oral cavity?
Stratified squamous
What is the submucosa?
Dense connective tissue
What are the 2 muscle layers in the muscularis adventitia/propria?
- Circular, inner;
- Longitudinal, outer.
What is the adventitia?
The outermost layer, with larger blood vessels and nerves
What is Barrett’s Oesophagus?
- A change (metaplasia) in epithelium in the oesophagus;
- Stratified squamous to columnar;
- Due to G.O.R.D;
- Risk of dysplasia and therefore cancer.
What are fundic glands?
Found in the fundus and body of the stomach, secrete gastric juices
By what process is food moved along the G.I. tract?
Propulsion by peristalsis
Where are villi found and what is their purpose?
Small intestine, to increase the surface area for nutrient absorption
What do nociceptors detect?
Pain
What do mechanoreceptors detect?
Movement
What do thermoreceptors detect?
Temperature
What do chemoreceptors detect?
Chemicals - smell/taste (gustation)
What are the motor functions of the mouth?
- Breakdown (mastication);
- Swallowing (deglutition);
- Communication.
What is the purpose of salivation?
- Lubrication;
- Protection;
- Digestion.
