digestive system

• The gallbladder stores and releases bile, which helps in the digestion and absorption of fats.
• Pepsinogen is converted to pepsin by HCl, which breaks down proteins in the stomach.
• The stomach is the organ that receives food from the esophagus, mixes it with gastric juices to form chyme, and stores it until it can be further processed by the small intestine.
• Digestion begins in the mouth with chewing and the action of saliva.
• Digestion breaks down food into smaller molecules that can be absorbed by the intestines.
• The liver produces bile, which helps in the digestion and absorption of fats.
• Lipases are enzymes that break down lipids or fats.
• Gastric juice contains hydrochloric acid (HCl), pepsinogen, mucus, and intrinsic factor.
• Salivary amylase starts breaking down carbohydrates into simple sugars.
• Mechanical digestion involves breaking up large pieces of food into smaller ones through mastication (chewing) and peristalsis (muscular contractions).
• the three subdivisions of small intestine are duodenum jejunum and ileum
• the ileum consists of small villi which help in increasing surface area for absorption
• Bile is stored in the gallbladder until needed by the body.
• The liver produces bile to aid in fat digestion.
• the three types of salivary glands are parotid glands, submandibular glands and parotid glands
• the pancreas is located just in front of and behind the stomach
• the functions of saliva are to moisten the mouth cavity, lubricate the food, form a bolus, help in water balance, and cleans the mouth
• the four types of teeth are incisors, canines, premolars and molars
• incisors are used for cutting or biting off pieces of food
• canine teeth are also known as fangs and they tear flesh from meat
• the tongue has taste buds which detect sweetness, sourness, saltiness, and bitterness
• the last molar is known as the wisdom tooth
• the structure of the tooth starts with a hard ivory covering
• underneath the enamel layer there is dentin which makes up most of the tooth
• dentin contains tubules that carry nerve endings to the pulp cavity where blood vessels and nerves enter the root
• the dental formula for humans is 2 incisors, 1 canines, 4 premolars, and 6 molars on both sides of the upper jaw and lower jaw
• cement is another bone like structure covering the root and fixing it in position
• pulp is soft connective tissue contained in central space of the tooth
• teeth are used for biting, chewing, grinding food into smaller pieces so they can be swallowed more easily
• saliva helps break down carbohydrates by amylase
• the two pigments in the bile are the bilirubin and biliverdin
• enzymes in the pancreatic juices are amylase, steapsin, trypsin
• amylase breaks down starch to maltose
• steapsin breaks down fats to fatty acids and glycerol
• trypsin breaks down proteins to peptides
• intestinal juice contains erepsin which converts peptides into amino acids