Digestive System Anatomy and Physiology: Upper GI Tract

Vocabulary flashcards covering the anatomical structures, cranial nerves, glandular secretions, and physiological mechanisms of the upper gastrointestinal tract.

Hypoglossal nerve (Cranial nerve 12)

The cranial nerve that innervates the muscles of the tongue to control movement, facilitating speech and swallowing.

Facial nerve (Cranial nerve 7)

The cranial nerve that transmits taste sensation from the anterior two-thirds of the tongue.

Glossopharyngeal nerve (Cranial nerve 9)

The cranial nerve that conveys taste sensation from the posterior third of the tongue and innervates pharyngeal muscles that facilitate swallowing.

Sublingual glands

The pair of salivary glands located inferior to the tongue that secrete saliva into the lower part of the oral cavity.

Submandibular glands

The pair of salivary glands located directly underneath the mandible that release saliva into the lower oral cavity.

Parotid glands

The large pair of salivary glands situated anterior to the ear and superficial to the masseter muscle that deliver saliva to the upper oral cavity via a duct.

Salivary amylase

The digestive enzyme present in saliva that initiates the chemical breakdown of complex carbohydrates in the mouth.

Oropharynx

The region of the pharynx located directly posterior to the oral cavity that serves as a passageway for swallowed food.

Palatine tonsils

Lymphoid structures located at the posterior aspect of the oral cavity near the palate that contain immune cells to defend against infectious agents.

Uvula

A structure hanging from the soft palate that triggers the gag reflex to prevent choking and elevates during swallowing to block food from entering the nasal cavity.

Bolus

A rounded mass or clump of chewed food mixed with saliva that is swallowed and transported through the pharynx and esophagus.

Esophagus

The muscular passage located posterior to the trachea that transitions from skeletal muscle in its upper section to smooth muscle in its lower section to transport food to the stomach.

Esophageal hiatus

The anatomical opening in the diaphragm through which the esophagus passes to connect with the stomach.

Hiatal hernia

A condition in which a portion of the stomach protrudes upward through the esophageal hiatus of the diaphragm into the chest cavity.

Gastroesophageal sphincter

The muscular ring at the distal junction of the esophagus and stomach (also referred to as the cardiac sphincter) that opens for food passage and closes to prevent gastric acid reflux.

Cardia

The anatomical entry zone of the stomach located immediately adjacent to the gastroesophageal junction near the heart.

Fundus

The dome-shaped upper anatomical region of the stomach positioned superior to the point of esophageal entry.

Rugae

The internal pits, grooves, and folds of the stomach lining formed by the muscularis mucosa that increase surface area to enhance mechanical mixing.

Chyme

The acidic, homogeneous, baby food-like mixture of partially digested food boluses and digestive secretions formed in the stomach.

Pyloric sphincter

The muscular valve located at the distal end of the pylorus that regulates gastric emptying into the duodenum of the small intestine.