Digestive System Flashcards

Flashcards for Digestive System Lecture Review

Alimentary canal

Also known as the gastrointestinal tract, consisting of the oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anal canal.

Associated organs of the digestive system

Organs including the tongue, teeth, salivary glands, liver, gall bladder, and pancreas that aid in digestion.

Ingestion

Taking in food or drink through the mouth.

Food Preparation

Chewing and mixing food with saliva to form a soft mass (bolus).

Transport in digestion

Moving food and water through the digestive system.

Storage in digestion

The stomach temporarily holds food, allowing it to mix with digestive juices.

Digestion and Absorption

Breaking down food in the stomach and intestines, and absorbing nutrients into the body.

Secretion

Releasing liquids, salts, hormones, and digestive juices to aid digestion.

Excretion

Getting rid of undigested waste.

Mucosa

The innermost layer of the digestive tract, consisting of the epithelium, lamina propria, and muscularis mucosae.

Submucosa

A layer of dense connective tissue in the digestive tract containing blood vessels, nerves (submucosal plexus), and glands.

Muscularis Externa

Layer of the digestive tract with two layers of muscle (inner circular and outer longitudinal) responsible for peristalsis and segmentation; contains the myenteric plexus.

Serosa/Adventitia

Outermost layer of the digestive tract; serosa for organs in the abdominal cavity, adventitia for those outside it.

Vestibule (oral cavity)

The space located between the lips, cheeks, and teeth.

Oral Cavity Proper

The area enclosed by the teeth, palate, and floor of the mouth.

Keratinized Epithelium (oral cavity)

Found in areas subject to abrasion, such as the gums and the hard palate.

Non-Keratinized Epithelium (oral cavity)

Found in softer areas like the inner cheeks and the floor of the mouth.

Tongue

Muscular organ covered by mucous membrane with specialized structures called papillae. It is involved in tasting, manipulating food, and swallowing.

Teeth

Composed of enamel, dentin, cementum, and pulp. They are anchored in the alveolar bone and are essential for mechanical digestion (chewing).

Salivary Glands

Major glands include the parotid, submandibular, and sublingual glands; they produce saliva, which contains enzymes (like amylase), mucus, and antibacterial compounds.

Hard Palate

Bony anterior part of the roof of the mouth, covered by keratinized epithelium, which provides a surface against which the tongue can press food during chewing.

Soft Palate

Muscular, flexible posterior part of the roof of the mouth, covered by non-keratinized epithelium; it plays a role in swallowing and separating the oral cavity from the nasal cavity.

Floor of the Mouth

Contains the sublingual glands and is lined by non-keratinized epithelium; it supports the tongue and aids in the movement of food.

Fungiform Papillae

Mushroom-shaped papillae scattered across the anterior two-thirds of the tongue, containing taste buds for the sensation of taste.

Foliate Papillae

Leaf-like folds located on the sides of the tongue, mainly in children, containing taste buds, though less prominent in adults.

Circumvallate Papillae

Large and round papillae arranged in a V-shape at the back of the tongue, containing numerous taste buds and important for the taste of bitterness.

Filiform Papillae

Thread-like and conical papillae covering most of the tongue's surface, providing texture and grip for food but not containing taste buds.

Esophagus

A muscular tube that connects the pharynx to the stomach and transports food via peristalsis.

Pharyngoesophageal Sphincter

Also known as the superior esophageal sphincter, it controls the passage of food from the pharynx into the esophagus.

Inferior Esophageal Sphincter

Located at the level of the diaphragm, it prevents stomach contents from refluxing into the esophagus.

Stomach

A muscular organ that stores food, mixes it with gastric juices, and begins the digestion of proteins.

Gastric Pits

Small invaginations in the stomach lining that lead to gastric glands.

Gastric Glands

Located at the base of the gastric pits, these glands are made up of specialized cells that contribute to gastric secretion.

Parietal Cells

Cells in gastric glands that secrete hydrochloric acid (HCl) and intrinsic factor.

Chief Cells

Cells in gastric glands that secrete pepsinogen, the inactive precursor of the enzyme pepsin.

Mucous Cells

Cells that produce mucus that coats and protects the stomach lining.

Pyloric Glands

Located in the pyloric region of the stomach, which connects to the duodenum, the first part of the small intestine.

Small Intestine

A crucial component of the digestive system, primarily responsible for the absorption of nutrients.

Circular folds (plicae circulares)

Permanent ridges in the mucosa and submucosa of the small intestine that enhance nutrient absorption by slowing the passage of food and increasing surface area.

Intestinal villi

Tiny, finger-like projections that line the inner surface of the small intestine, increasing its surface area to enhance nutrient absorption.

Large intestine

The final section of the digestive system, primarily responsible for absorbing water and electrolytes.

Teniae coli

Three distinct bands of the outer longitudinal layer of the muscularis externa in the large intestine that aid in shortening and contracting the colon.

Cecum

First part of the large intestine

Vermiform appendix

Structure similar to the colon but with a higher concentration of lymphoid tissue.

Rectum

Final section of the large intestine and serves as a storage site for feces.

Anal Canal

Has a transitional epithelium to withstand mechanical stress during defecation.