Digestive System Flashcards
Functions of Digestive System
Mechanical and chemical breakdown of food and the absorption of nutrients
Excretion of waste
Two types of bowel movements
Mixing Movements:
mix food with digestive juices
Propelling Movements:
called peristalsis; pushes food down the tube
Mouth
begins digestion by chewing and mixing with saliva
Tongue
moves food, connects to floor of mouth via frenulum
Amylase
enzyme breaks down starch into sugars
Esophagus
The muscular tube that carries food and liquids from your mouth to the stomach.
Four regions of the stomach
cardia, fundus, body, pylorus
Pyloric canal
The narrower end is called the pyloric canal, which connects to the duodenum
Pyloric sphincter
The smooth muscle pyloric sphincter is located at this latter point of connection and controls stomach emptying
Stomach lining
Mucus prevents stomach from digesting itself, small openings called gastric pits contain glands
Glands secrete gastric juices to breakdown food
Pepsin
most important digestive enzyme for breaking down food
Mechanical Digestion
Food being broken down in smaller pieces (ex: chewing and churning of the stomach)
Chemical Digestion
Substances in our digestive organs are released that change food particles into particles that are chemically different (ex: acids and bases)
Chyme
Chyme is the semi-fluid mass of partly digested food that is expelled by a person’s stomach, through the pyloric valve, into the duodenum.
Small Intestine
Chyme released from the stomach enters the small intestine, which is the primary digestive organ in the body. Not only is this where most digestion occurs, it is also where practically all absorption occurs.
Duodenum
The shortest region is the 25.4-cm (10-in) duodenum, which begins at the pyloric sphincter.
Jejunum
The jejunum is about 0.9 meters (3 feet) long (in life) and runs from the duodenum to the ileum
Ileum
The ileum is the longest part of the small intestine, measuring about 1.8 meters (6 feet) in length
Large Intestine
The large intestine is subdivided into four main regions: the cecum, the colon, the rectum, and the anus
Cecum
start of large intestine, has an attached appendix
Colon
4 sections Ascending Transverse Descending Sigmoid
Rectum
stores waste before it is expelled from the body
Anus
muscular sphincter which controls the exit of waste
Function of Large Intestine
Secretes mucus, reabsorbs water, contains bacteria to aid in digestion Mass Movements (defecation) - removes undigested food
Bristol Stool Chart
Diagnostic medical tool designed to classify the form of human feces into seven categories. Type 1 and 2 - Constipation Type 3 and 4 - Normal Type 5 - Lacking Fiber Type 6 - Mild Diarrhea Type 7 - Severe Diarrhea
Liver
The liver is the largest gland in the body, weighing about three pounds in an adult. It is also one of the most important organs. In addition to being an accessory digestive organ, it plays a number of roles in metabolism and regulation
Gallbladder
The gallbladder stores and concentrates bile, releasing it when it is needed by the small intestine.
Pancreas
The pancreas is responsible for secretion of digestive enzymes and bicarbonate