MT M 6.2 Anatomy and Physiology Review

Question 1

alimentary canal

Answer 1

The gastrointestinal tract is also referred to as the alimentary canal. This is a continuous tube that is formed from the mouth to the anus, and it contains the main organs and accessory organs of the GI tract. It can be 30 feet long in an adult. This term, alimentary canal, comes from the Latin word alimentarius, which means nourishment.

Question 2

mouth

Answer 2

The mouth is where food enters the digestive system.

Question 3

oral cavity

Answer 3

The mouth is also called the oral cavity. The roof of the oral cavity is formed by the soft and hard palates, the sides are formed by the cheeks, and the tongue forms the floor. The lips create the opening to the oral cavity. Within the mouth, the teeth are embedded in the gingivae on the roof and floor. Salivary ducts under the tongue and on either side of the cheeks secrete saliva from the sublingual and submandibular salivary glands and parotid glands to help moisten the food and lubricate it.

Question 4

tongue

Answer 4

The tongue is a muscle that is covered with a mucus membrane. The anterior part of the tongue is free-moving, which helps to move food throughout the mouth for chewing. The posterior part of the tongue is fixed within the mouth, and it functions to initiate swallowing. On the surface of the tongue are papillae and taste buds. There are five different types of tastes: sweet, sour, salt, bitter, and umami.

Question 5

Teeth

Answer 5

Teeth are used to crush and chew food. 32 permanent teeth.

Question 6

incisors

teeth

Answer 6

Incisors and canines are used for biting into food, as they have a sharp cutting edge.

Question 7

canines

teeth

Answer 7

Incisors and canines are used for biting into food, as they have a sharp cutting edge.

Question 8

premolars

teeth

Answer 8

The premolars and molars are used for crushing food, as the crown of the tooth is broad.

Question 9

molars

teeth

Answer 9

The premolars and molars are used for crushing food, as the crown of the tooth is broad.

Question 10

As the teeth chew

Answer 10

As the teeth chew and break down food, the food mixes with saliva that contains digestive enzymes. A bolus of food is formed, which is then moved to the back of the oral cavity by the tongue and swallowed.

Question 11

pharynx

Answer 11

The pharynx was discussed in Module 5 as a part of the respiratory system. It is also a part of the digestive system, as food moves through two sections of the pharynx, the oropharynx and laryngopharynx, and into the esophagus

Question 12

nasopharynx

Answer 12

The nasopharynx is located superiorly to the soft palate.

Question 13

esophagus

Answer 13

The esophagus is a tube that extends from the pharynx to the stomach. It is made of several layers of muscle that contract in a coordinated way to move the food bolus and liquid from the pharynx to the stomach. The epiglottis can be seen closing the entrance to the trachea, which prevents food and liquids from entering the lungs.

Question 13

lower esophageal sphincter

cardiac sphincter

Answer 13

At the bottom of the esophagus is the lower esophageal sphincter, which is also called the cardiac sphincter.

Question 14

sphincter

Answer 14

A sphincter is a muscle that encircles a tube, and when it contracts, it causes the tube to close. When the lower esophageal sphincter contracts, the entry into the stomach is closed. This prevents stomach contents, which are very acidic, from regurgitating up from the stomach back into the esophagus.

Question 14

fundus

stomach

Answer 14

the fundus is the upper part,

Question 15

stomach

Answer 15

The stomach is a sac that is made of muscle and can distend as the stomach fills with food. The stomach has three parts:

Question 16

body

stomach

Answer 16

the body is the main part

Question 17

antrum

stomach

Answer 17

the lower part is the antrum.

Question 18

rugae

Answer 18

The digestive juices are made by glands located in the rugae, which are folds within the walls of the stomach that allow the stomach to expand as it fills with food. These juices are highly acidic and contain enzymes and hormones that break down the food.

Question 18

chemical digestion,

Answer 18

This is called chemical digestion, and this process converts the food into a liquid state, called chyme, that can be absorbed by the body.

Question 19

Mechanical digestion

Answer 19

Mechanical digestion occurs as the muscles in the walls of the stomach contract. This action churns and mixes the food with the digestive juices contained within the stomach.

Question 20

pyloric sphincter

Answer 20

This sphincter contracts in intervals to slowly release a small amount of chyme into the small intestine.

Question 20

chyme

Answer 20

chemical digestion, and this process converts the food into a liquid state, called chyme, that can be absorbed by the body. The chyme moves out of the stomach through the pyloric sphincter.

Question 21

villi

small intestine

Answer 21

The small intestinal wall is made up of villi, which are tiny projections from the mucus membrane surface of the small intestine. These villi increase the surface area of the small intestine dramatically so that there can be more area for absorption. As the food is digested into individual nutrients, carbohydrates, proteins, and fats, it is absorbed into the bloodstream through the villi and sent to the cells of the body.

Question 22

small intestine

Answer 22

The small intestine starts at the pyloric sphincter and extends to the entrance of the large intestine at the ileocecal sphincter. It is very long, 21 feet in an adult, and its function is to continue the chemical digestion of food through mixing the chyme with digestive enzymes from the liver and pancreas and to facilitate the absorption of nutrients from the food into the bloodstream.

Question 23

duodenum

The small intestine has three parts:

Answer 23

The duodenum is the first 12 inches of the small intestine,

Question 24

ileum

The small intestine has three parts:

Answer 24

The ileum is the last 12 inches before the large intestine.

Question 25

jejunum

The small intestine has three parts:

Answer 25

the jejunum is the middle portion of the small intestine

Question 26

large intestine

Answer 26

The large intestine starts at the ileocecal valve at the end of the ileum of the small intestine and extends to the anus. It is five feet long and is called the large intestine because the tube is 2 ½ inches in diameter. In contrast, the diameter of the small intestine is 1 inch. The large intestine is formed from the cecum, colon, rectum, and anal canal. The appendix is connected to the cecum. The large intestine completes digestion as the remaining water in the chyme is absorbed into the body. The waste products of digestion remain in the large intestine. It is compacted into feces or stool and then expelled from the body. Defecation is the process of removing stool from the anal canal.

Question 27

accessory organs of the digestive

Answer 27

The accessory organs of the digestive tract are not actually part of the alimentary canal; however, they contribute to the digestive process and are connected to the alimentary canal via ducts. The accessory organs of the digestive system are the salivary glands, the liver, the pancreas, and the gallbladder.

Question 28

salivary glands

accessory organs of the digestive tract

Answer 28

There are four salivary glands that secrete saliva into the mouth. There are two parotid glands, located on either side of the mouth below the ear, the submandibular gland located in the floor of the mouth, and the sublingual gland located below the tongue. These glands are connected to the oral cavity via ducts. They secrete saliva at the sight, smell, taste, or thought of food. Saliva is largely water, but it also contains digestive enzymes that begin to break down carbohydrates within the mouth.

Question 29

liver

accessory organs of the digestive tract

Answer 29

The liver is a large organ in the abdominal cavity that is important in the metabolism of nutrients for the body.

Question 30

Metabolism

accessory organs of the digestive tract

Answer 30

Metabolism is the process of chemically and physically breaking down tissues and creating different tissues that are needed for the body. Carbohydrates are converted from glucose to glycogen for storage until it is needed by the cells of the body. Proteins are stored, broken down, and formed within the liver. Fats are also stored within the liver, processed, and released into the bloodstream. The liver stores several vitamins and iron. It also detoxifies the blood and removes various drugs and alcohol.

Question 31

The liver produces bile

accessory organs of the digestive tract

Answer 31

The liver produces bile, which is a digestive juice that is involved in fat metabolism.

Question 32

gallbladder

accessory organs of the digestive tract

Answer 32

The gallbladder is connected to the hepatic duct via the cystic duct. The gallbladder functions to store and concentrate bile for later use.

Question 32

hepatic duct

The liver produces bile

Answer 32

Bile leaves the liver through the hepatic duct, which travels to the small intestine.

Question 33

common bile duct

gallbladder

Answer 33

Bile leaves the liver through the hepatic duct, gallbladder is connected to the hepatic duct via the cystic duct. After these two ducts come together, the duct is referred to as the common bile duct, as it travels to the small intestine to release the digestive juices.

Question 34

pancreas

accessory organs of the digestive tract

Answer 34

The pancreas is a large gland that is behind the stomach. It produces the hormones insulin and glucagon, which are crucial for maintaining the levels of glucose in the blood. Digestive enzymes are created in the pancreas and secreted into the small intestine through the pancreatic duct.

Question 34

biliary tree

Answer 34

The ducts that travel from the liver to the intestine can be referred to as the biliary tree.