Science quiz 1

• Digestion is the process wherein the food is broken down into smaller molecules that the body cells can absorb and utilize.
• Ingestion is the process of eating
• Transport of food begins when the food is swallowed
• Excretion is the process of removing waste products from the body
• Feces are the undigested residue or waste products of digestion
• Defecation process wherein feces are expelled from the body through the anus
• Mouth is the anterior opening where food enters
• Anus is the posterior opening where undigested reside called feces exits
• Alimentary tract - mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus
• Accessory organs of digestion - liver, pancreas, salivary, gastric, and intestinal glands
• Mouth or buccal cavity ingests the food
• Teeth breakdown food into smaller pieces
• tongue enables us to taste food, mixes the food with saliva secreted by the ducts of salivary glands
• Salivary glands are located within the mouth, and helps us swallow the partly digested food
• Saliva contains the salivary amylase, also known as ptyalin, the breaks down carbohydrate-rich foods into their simpler equivalents
• Bolus is the ball-shaped mass when the food is chewed and lubricated
• Pharynx or Throat - located posterior to the mouth. It's the common passageway for digestion and respiration
• the swallow reflex raises the flap of the muscles called the epiglottis to cover the opening of the trachea
• Esophagus - muscular tube that conveys food from the pharynx to the stomach
• Peristalsis - a wavelike contraction that begins in the middle portion of the esophagus facilitates the movement of the bolus down the different organs of digestion
• Stomach - a pear-shaped organ that is connected to the distal end of the esophagus
• The gastric glands are composed of cells that secrete materials important in the digestive process -- hydrochloric acid, pepsinogen, and mucus.
• chyme - the action of the stomach changes the bolus into semi-fluid consistency
• small intestine - long, coiled tube that fills the abdomen
• three regions of the small intestine: duodenum, jejunum, and ileum
• The small intestine is considered the organ of complete digestion and absorption because its intestinal glands secrete the final enzymes for digestion
• large intestine/colon - it temporarily stores undigested residue or feces
• three regions of the colon: ascending colon, transverse colon, and descending colon
• Ascending colon - has a blind corner called the caecum that bears the worm-like appendix
• rectum - serves as a warehouse for undigested residue or feces
• anal canal/anus - end part of the rectum that functions as the exit point for the fecal materials
• accessory organs of digestion - are the glands that secrete chemical substances into the organs of digestion
• liver - largest organ in the body
• liver - its function is the secretion of bile which is important in digestion
• Bile - stored and concentrated in the gallbladder
• Gallbladder's two functions: neutralize the acidity of the chyme and to change fat-rich foods into an emulsion, a consistency that will facilitate enzyme action
• pancreas - the large, elongated, and yellowish gland that lies posterior to the stomach.
• enzymes - are protein substances that can initiate or speed us chemical reactions
• 35°c to 40°c - optimum temperature for enzymes to work well in the body
• substrates - substances that are acted upon by enzymes