Digestive system Flashcards
What are the components of the digestive system?
mouth, pharynx, oesophagus, stomach, small intestines, large intestines and anus.
What accessory organs does the D.S have?
salivary glands, teeth, liver, gallbladder and pancreas.
What is the function of the D.S
- Physical and chemical breakdown of food
● Absorption of nutrients
● Elimination of waste
What is the alimentary canal?
-Continuous hollow tube
-Approximately 30 ft long in cadavers
-Food is always considered external
-Tissues similar along length of canal with slight modifications to aid digestion (mechanical/chemical)
-Goes all the way through the body
What are the two layers of muscle in the alimentary canal?
Two layers of mostly smooth (involuntary) muscle: —Inner circular layer and Outer longitudinal layer –
what is peristalsis and what causes it?
The mixing and pushing of contents along, and waves of contraction causes this.
What acts as valves in the alimentary canal?
-Sphincters of thickened circular muscle at points to act as valves.
What is the purpose of the mouth/pharynx?
starts the process of chemical and mechanical digestion. Mixing food with enzymes and making food swallowable.
What are the mouths/ oral cavity boundaries?
Anteriorly – lips, posteriorly – oropharyngeal isthmus, laterally – cheeks / buccal surfaces (buccinators muscle), Superiorly – palate (hard/soft), Inferiorly - tongue and floor
What is the floor of the mouth?
Formed by mylohyoid and geniohyoid muscles (mandible to hyoid). U-shaped diaphragm. Supports tongue
What is the hard palate of the mouth?
Anterior 2⁄3. Made of Maxilla and palatine bones.
what is the soft palate of the mouth?
Posterior 1⁄3. Mobile muscular fold. Uvula – fold of muscle; saliva, speech, gag reflex
What is the tongue and its function?
Accessory organ. Functions in mastication (mechanical breakdown of chewing), swallowing, speech and taste. Base attached to hyoid bone and to floor by lingual frenulum. Skeletal muscle fibres (intrinsic and extrinsic).
what does mastication mean?
(mechanical breakdown of chewing),
whats the function of teeth?
Accessory organ. Functions in mastication and speech