Digestive System

Question 1

Functions of Digestive System

Answer 1

The mechanical and chemical breakdown of food and the absorption of nutrients. Excretion of waste.
Consists of alimentary canal and accessory organs
Mucosa - protects tissues and carries on absorption
Submucosa - glands, blood vessels, nerves
Muscular Layer - smooth muscle, pushes food (PERISTALSIS)
Serosa - lubricates surfaces

Question 2

Two types of bowel movements

Answer 2

Mixing Movements:
mix food with digestive juices

Propelling Movements:
called peristalsis; pushes food down the tube

Question 3

Mouth

Answer 3

Mouth - begins digestion by chewing and mixing with saliva
Palate - forms roof of oral cavity (hard and soft)
Uvula - back of the mouth

Question 4

Tongue

Answer 4

Tongue - moves food, connects to floor of mouth via frenulum

Question 5

Amylase

Answer 5

Amylase - enzyme breaks down starch into sugars

Mucus cells also produce mucus for lubrication during swallowing

Question 6

Esophagus

Answer 6

The muscular tube that carries food and liquids from your mouth to the stomach.

Question 7

Four regions of the stomach

Answer 7

There are four main regions in the stomach: the cardia, fundus, body, and pylorus.
The cardia (or cardiac region) is the point where the esophagus connects to the stomach and through which food passes into the stomach.
Located inferior to the diaphragm, above and to the left of the cardia, is the dome-shaped fundus.
Below the fundus is the body, the main part of the stomach.
The funnel-shaped pylorus connects the stomach to the duodenum. The wider end of the funnel, the pyloric antrum, connects to the body of the stomach.

Question 8

Pyloric canal

Answer 8

The narrower end is called the pyloric canal, which connects to the duodenum.

Question 9

Pyloric sphincter

Answer 9

The smooth muscle pyloric sphincter is located at this latter point of connection and controls stomach emptying.
In the absence of food, the stomach deflates inward, and its mucosa and submucosa fall into a large fold called a ruga.

Question 10

Stomach lining

Answer 10

Mucus prevents stomach from digesting itself, small openings called gastric pits contain glands
Glands secrete gastric juices to breakdown food

Question 11

Pepsin

Answer 11

Pepsin - most important digestive enzyme for breaking down food

Question 12

Mechanical Digestion

Answer 12

Mechanical - Food being broken down in smaller pieces (ex: chewing and churning of the stomach)

Question 13

Chemical Digestion

Answer 13

Chemical - Substances in our digestive organs are released that change food particles into particles that are chemically different (ex: acids and bases)

Question 14

Chyme

Answer 14

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.

Question 15

Small Intestine

Answer 15

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.

Question 16

Duodenum

Answer 16

The shortest region is the 25.4-cm (10-in) duodenum, which begins at the pyloric sphincter. Just past the pyloric sphincter, it bends posteriorly behind the peritoneum, becoming retroperitoneal, and then makes a C-shaped curve around the head of the pancreas before ascending anteriorly again to return to the peritoneal cavity and join the jejunum.

Question 17

Jejunum

Answer 17

The jejunum is about 0.9 meters (3 feet) long (in life) and runs from the duodenum to the ileum. Jejunum means “empty” in Latin and supposedly was so named by the ancient Greeks who noticed it was always empty at death. No clear line exists between the jejunum and the final segment of the small intestine, the ileum.

Question 18

Ileum

Answer 18

The ileum is the longest part of the small intestine, measuring about 1.8 meters (6 feet) in length. It is thicker, more vascular, and has more developed mucosal folds than the jejunum. The jejunum and ileum are tethered to the posterior abdominal wall by the mesentery. The large intestine frames these three parts of the small intestine.

Question 19

Large Intestine

Answer 19

The large intestine is subdivided into four main regions: the cecum, the colon, the rectum, and the anus. The ileocecal valve, located at the opening between the ileum and the large intestine, controls the flow of chyme from the small intestine to the large intestine.

Question 20

Cecum

Answer 20

Cecum - start of large intestine, has an attached appendix

Question 21

Colon

Answer 21

Colon - 4 sections 
Ascending
Transverse
Descending
Sigmoid

Question 22

Rectum

Answer 22

Rectum – stores waste before it is expelled from the body

Question 23

Anus

Answer 23

Anus - muscular sphincter which controls the exit of waste

Question 24

Function of Large Intestine

Answer 24

Secretes mucus, reabsorbs water, contains bacteria to aid in digestion
Mass Movements (defecation) - removes undigested food
The main job is: Water Reabsorption

Question 25

Bristol Stool Chart

Answer 25

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

Question 26

Liver

Answer 26

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. The liver lies inferior to the diaphragm in the right upper quadrant of the abdominal cavity and receives protection from the surrounding ribs.

Question 27

Gallbladder

Answer 27

The gallbladder stores and concentrates bile, releasing it when it is needed by the small intestine.

Question 28

Pancreas

Answer 28

The pancreas is responsible for secretion of digestive enzymes and bicarbonate