digestive system

Question 1

what are the layers of the alimentary canal

Answer 1

mucosa, submucosa, muscularis externa, serosa/adventitia

Question 2

what is in the upper vs the lower alimentary canal?

Answer 2

upper: oral cavity/pharynx, esophagus, stomach
lower: small intestine, large intestine, rectum, anal canal

Question 3

what is the primary site of mechanical digestion?

Answer 3

the upper alimentary canal

Question 4

what is the primary function of the lower alimentary canal?

Answer 4

food and water absorption and elimination of waste

Question 5

what are the borders of the oral cavity?

Answer 5

the lips protect the opening, the cheeks form the lateral walls, the palate is the roof

Question 6

what is the hard palate composed of?

Answer 6

palatine and maxillae bones

Question 7

briefly describe teeth in the oral cavity

Answer 7

we have 32 teeth embedded in maxillae and mandible that consist of a crown, a neck, and a root. They are made of dentin covered by enamel

Question 8

briefly describe the tongue in the oral cavity

Answer 8

it is composed of four intrinsic muscles and attaches to the hyoid, mandible, styloid process, and pharynx. it is supported largely by the mylohyoid muscle and the lingual frenulum secures it at the midline. it is innervated by two cranial nerves.

Question 9

what are the two main types of tonsils?

Answer 9

palatine (lymphoid tissue at the posterior of the mouth) and lingual (base of the tongue)

Question 10

what are the three types of salivary glands?

Answer 10

parotid (serous and contains amylase), submandibular (mucin and serous), sublingual (mucin)

Question 11

what are the muscles of mastication?

Answer 11

temporalis, superficial/deep masseters, medial pterygoid, lateral pterygoid

Question 12

briefly describe the pharynx

Answer 12

it is a bi-layered wall of skeletal muscle that helps create peristaltic contractions. It consists of the nasopharynx, oropharynx, and laryngopharynx

Question 13

briefly describe the esophagus

Answer 13

extends from the pharynx to the gastroesophageal sphincter at the stomach

Question 14

briefly describe the regions of the stomach

Answer 14

• surrounded by mesentery, divided into lesser and greater omentum
• fundus: superior and lateral to caria
• cardia: surrounds the cardiac sphincter
• body: largest portion and mid portion of the stomach
• pyloric antrum: chyme waits here
• pyloric canal: chyme moves through here to the sphincter
• pyloric sphincter: valve that releases chyme into the small intestine

Question 15

the stomach is ___ to the liver

Answer 15

posterior

Question 16

what are the parts of the small intestine

Answer 16

• duodenum: first and smallest portion that receives chyme from the stomach. Lies in a retroperitoneal position
• jejunum: occupies umbilical region of the abdominal cavity
• illeum: longest portion largely in the hypogastric region

Question 17

what are peyers patches

Answer 17

lymph tissue in the submucosa of the small intestine

Question 18

what are the regions of the large intestine

Answer 18

cecum: first region that receives undigested food from the small intestine
colon: ascending, transverse, descending, sigmoid
rectum: holds feces
anal canal: excretes feces

Question 19

what produces bile? What stores bile?

Answer 19

the liver produces it, the gall bladder stores it

Question 20

what is the function of hepatic portal circulation

Answer 20

to gather absorbed nutrients from metabolic processes

Question 21

what is the hepatic portal vein

Answer 21

carries blood from GI tract, gall bladder, pancreas, and spleen to the liver

Question 22

what are the hepatic veins

Answer 22

drains blood from the liver into the inferior vena cava

Question 23

what is the splenic vein

Answer 23

drains blood from the spleen

Question 24

what are the superior and inferior mesenteric veins

Answer 24

drain blood from the small and large intestines