LG 2.2 Human Digestive System (PART 1) Flashcards
Ingestion and the initial steps of digestion happen in the _____?
Mouth or Oral Cavity
It plays a major role in mechanically tearing food into smaller pieces.
Teeth
They have ducts that open in to the oral cavity and secrete saliva which moistens the food for easier swallowing.
Salivary Glands
Saliva is composed of ___. ___. ___. and ___.
mucus - protects the mouth from abrasion and from drying out.
enzymes - breakdown starch and glycogen into smaller polysaccharides or disaccharides.
electrolytes - maintain the saliva within a certain range of pH only.
antibacterial enzymes - destroys microorganisms.
It helps form a food bolus, the mass of food that has been chewed and mixed with the saliva.
Tongue
It is the part of the throat behind the mouth and it leads to two passageways namely: trachea and esophagus.
Pharynx
The act of swallowing has three phases namely:
Oral Phase, Pharyngeal phase, and esophageal phase respectively.
The act of swallowing where it includes the closing of vocal folds and the movement of the larynx upward.
Pharyngeal Phase
The act of swallowing in which the formation of food bolus and the movement of it toward the back of the mouth with the help of the tongue.
Oral Phase
The esophagus has two sphincters namely:
Upper Esophageal Sphincter, and Lower Esophageal Sphincter
It is a hollow muscular organ found just beneath the diaphragm, and is the widest and most flexible part of the digestive tract.
Stomach
Inside the stomach are many folds that increase the surface area. What is it called?
Rugae
The pulpy acidic fluid which passes from the stomach to the small intestine, consisting of gastric juices and partly digested food.
Chyme
The gastric glands of the stomach have 3 types of cells namely:
Mucous Cells, Parietal Cells, Chief Cells
These cells of the gastric glands are responsible for actively pumping hydrogen ions into the lumen of the stomach.
Parietal Cells
