Question

No plagiarizing please

”1. Explain the digestion that occurs in the oral cavity.”

”2. What is the function of the liver in digestion? ”

”3. What role does the gallbladder play in digestion? ”

4. Why is the orientation of the muscle of the stomach wall important? How does this contribute to its function?

Answer 1

a) Digestion in the oral cavity:

The process of mechanically and enzymatically breaking down food into substances for absorption into the bloodstream is called digestion. Food contains three macronutrients that require digestion before they can be absorbed: fats, carbohydrates, and proteins. Through the process of digestion, these macronutrients are broken down into molecules that can traverse the intestinal epithelium and enter the bloodstream for use in the body. It involves two processes:   mechanical digestion and chemical digestion. Mechanical digestion involves physically breaking down food substances into smaller particles to more efficiently undergo chemical digestion. The role of chemical digestion is to further degrade the molecular structure of the ingested compounds by digestive enzymes into a form that is absorbable into the bloodstream.

Mechanical digestion in the oral cavity consists of grinding of food into smaller pieces by the teeth; a process called mastication.

During chewing as food mixes with saliva produced by the salivary glands, the chemical process of digestion begins. Saliva contains mucus that moistens food and buffers the pH of the food. Saliva also contains lysozyme which has antibacterial action. It also contains an enzyme called salivary amylase that begins the process of converting starches in the food into a disaccharide called maltose. Another enzyme called lipase is produced by cells in the tongue to break down fats. The chewing and wetting action provided by the teeth and saliva prepare the food into a mass called the bolus for swallowing.