A&P- Digestive System

What are the 4 layers of the digestive tract? What is the innermost layer?

Mucosa (innermost), Submucosa, Muscularis, Serosa (outermost)

What are the 3 functions of the digestive tract?

1. Digestion

2. Absorption

3. Elimination

What is the organ of mastication?

Teeth

How many deciduous teeth are in a human (baby teeth)?

20

How many permanent teeth are in a human?

32

What are the 2 bones that make up the hard palate?

Palatine and maxillae bones

What 2 organs secrete amylase?

Pancreas + salivary glands

How long is the esophagus?

25 cm/ 10 inches

Does the esophagus lie anterior or posterior to the trachea?

Posterior

What is the function of the esophagus?

Transport the food bolus

What is the digestive tract “tube” called?

Alimentary canal

How long is the mouth to anus?

10 meters/ 33 feet

Ingestion definition

Intake of food

Digestion definition + subcategories

Break down of food: Mechanical - physical breakdown of large chunks into small bits, Chemical- Breaks molecules apart

Motility definition

Moves food along digestive tract

Deglutition definition

Swallowing

Peristalsis definition

Wavelike contractions causing a forward movement

Rhythmic segmentation definition

Mixing movement- forward and backward

Secretion definition

Release of digestive juices that facilitates digestion

Absorption definition

Movement of digested nutrients through the GI mucosa into the cellular level

Elimination definition

Defecation

What is the lingual frenulum?

Attaches tongue to mouth floor

Tongue tied (frenulum too short) called:

Ankyloglossia

Circumvallate papillae of tongue:

V-shape on posterior tongue, each one contains thousands of taste buds

Filiform papillae:

Bumps with tiny thread-like projections, no taste buds

Fungiform papillae:

Found on tip and sides of tongue, contain taste buds

Foliate papillae:

Leaf-shaped, lateral edges of posterior tongue, each one contains 100 taste buds

What are the 3 stages of swallowing?

Oral stage (voluntary), pharyngeal stage, and esophageal stage

What is the cardiac antrum?

Distal 1-2 cm of esophagus below the diaphragm

Upper Esophageal Sphincter (UES)

Helps prevent air from entering esophagus, relaxation= belching

Lower Esophageal Sphincter (LES)

AKA Cardiac sphincter, helps contain the stomach contents

What is the most dilated portion of the GI tract?

Stomach

What is the volume of the stomach?

1-1.5 Liters

What is the cardiac orifice?

Opening between the esophagus and stomach

What is the pyloric orifice?

Opening between the stomach (pylorus) and small intestine

What is the medial border of the stomach called?

Lesser curvature

List the 3 types of secretory cells found in the mucosa of the stomach and what they secrete:

1. Chief cells- secrete digestive enzyme Pepsin

2. Parietal cells- secrete stomach acid (HCl) and intrinsic factor

3. Endocrine cells- secrete Grehlin

What are the mucosal folds in the stomach called?

Gastric rugae

Where does the majority of digestion and absorption take place?

Small intestine