digestive system Flashcards
what are the layers of the alimentary canal
mucosa, submucosa, muscularis externa, serosa/adventitia
what is in the upper vs the lower alimentary canal?
upper: oral cavity/pharynx, esophagus, stomach
lower: small intestine, large intestine, rectum, anal canal
what is the primary site of mechanical digestion?
the upper alimentary canal
what is the primary function of the lower alimentary canal?
food and water absorption and elimination of waste
what are the borders of the oral cavity?
the lips protect the opening, the cheeks form the lateral walls, the palate is the roof
what is the hard palate composed of?
palatine and maxillae bones
briefly describe teeth in the oral cavity
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
briefly describe the tongue in the oral cavity
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.
what are the two main types of tonsils?
palatine (lymphoid tissue at the posterior of the mouth) and lingual (base of the tongue)
what are the three types of salivary glands?
parotid (serous and contains amylase), submandibular (mucin and serous), sublingual (mucin)
what are the muscles of mastication?
temporalis, superficial/deep masseters, medial pterygoid, lateral pterygoid
briefly describe the pharynx
it is a bi-layered wall of skeletal muscle that helps create peristaltic contractions. It consists of the nasopharynx, oropharynx, and laryngopharynx
briefly describe the esophagus
extends from the pharynx to the gastroesophageal sphincter at the stomach
briefly describe the regions of the stomach
- 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
the stomach is ___ to the liver
posterior
what are the parts of the small intestine
- 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
what are peyers patches
lymph tissue in the submucosa of the small intestine
what are the regions of the large intestine
cecum: first region that receives undigested food from the small intestine
colon: ascending, transverse, descending, sigmoid
rectum: holds feces
anal canal: excretes feces
what produces bile? What stores bile?
the liver produces it, the gall bladder stores it
what is the function of hepatic portal circulation
to gather absorbed nutrients from metabolic processes
what is the hepatic portal vein
carries blood from GI tract, gall bladder, pancreas, and spleen to the liver
what are the hepatic veins
drains blood from the liver into the inferior vena cava
what is the splenic vein
drains blood from the spleen
what are the superior and inferior mesenteric veins
drain blood from the small and large intestines
