Digestion Lecture Flashcards

Flashcards for review of human digestion lecture.

Incisors

Nip food into small pieces

Canine teeth

Effective for piercing food which allows it to be torn.

Premolar (ie., bicuspid) teeth

Surface which helps grind food into smaller particles

Molars

The broadest of the teeth and perform the bulk of the crushing activity which is important for chewing hard foods

Saliva production

Glands associated with the oral cavity which includes the parotid, sublingual and submandibular glands

Parotid glands

Comprised of mainly serosal cells which secrete a fluid that includes salivary amylase which functions to digest starch molecules into smaller disaccharides.

Sublingual glands

Located just beneath the tongue and secrete a mucus-rich secretion that functions to lubricate the food bolus in order to promote swallowing.

Submandibular glands

Located along the margins of the mandible produce a mix of serous and mucus-rich fluid which also includes salivary amylase.

Peristalsis

Wave-like actions that helps propel the food along the digestive tract

Cardiac sphincter

When it fails to close, the esophageal tissue is exposed to gastric juices containing hydrochloric acid and pepsin which can damage this tissue.

Parietal cells

Located within the gastric pit produce hydrochloric acid which lowers the stomach pH to nearly 1.

Chief cells

Located within the gastric pits secrete the proenzyme pepsinogen which is converted by acid into its active form, pepsin, which cleaves proteins into smaller peptide residues.

Fundus

Upper region of the stomach which bulges toward the lungs

Body of the stomach

Middle majority of the stomach organ

Pylorus region

Lower region of the stomach which is situated nearest to the small intestines

Chyme

Passes from the stomach into the small intestine through the pyloric sphincter.

Duodenum

First segment of the small intestine which is the site where the pancreas and gallbladder empty their secretions.

Pancreatic

Secretions serve to neutralize the acidic chyme, while also providing key enzymes that further hydrolyze food molecules, including lipase, chymotrypsin and pancreatic amylase.

Gallbladder

Secretes bile which promotes the emulsification of fat molecules thereby making them more easily absorbed within the lower parts of the intestine

Liver

Site of synthesis for bile which is delivered to the gallbladder for storage and delivery.

Hepatocyte

Major cell of the liver which is organized into groups within the hexagonally shaped hepatic lobule.

Jejunum

Segment of the small intestine which makes up approximately 40% of the small intestine length, and where the majority of the absorption activities of the intestine takes place.

Ileum

Last segment of the small intestine which empties into the large intestine (colon) via the ileocecal valve.

Large intestine

Segments include the: (a) ascending colon; (b) transverse colon; (c) descending colon; (d) sigmoid colon; and, (e) the rectum.

Colon

As residue from digestion navigates this passageway, water and electrolytes are reabsorbed by the body which helps compact the feces in a form suitable for defecation.

Amylase

Produced in two distinctive areas along the digestive tract: the salivary glands of the mouth and the pancreas.

Pepsin

An enzyme produced by chief cells within the stomach that functions to breakdown proteins into smaller peptide subunits.