Digestive System Overview Quiz

Digestive System Overview

• The digestive system comprises the digestive tract (or alimentary canal) and associated glands
• The digestive tract includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine
• Digestive glands include salivary glands, liver, gall bladder, and pancreas

Alimentary Canal

• The alimentary canal is a hollow tube that's open at both ends
• It's a muscular tube

1- Mouth (Oral Cavity)

• The mouth is a mucus membrane-lined cavity.
• Lips protect the anterior opening.
• Cheeks form lateral walls.
• Palate forms the roof.
• Tongue is attached to the floor of the mouth.

2- The Pharynx

• The oral cavity leads to the oropharynx
• The oropharynx continues as the laryngopharynx, leading to the esophagus

3- Esophagus

• A 25 cm long muscular tube
• Begins at the end of the pharynx and ends at the stomach
• Has cervical, thoracic, and short abdominal parts
• Carries ingested food from the pharynx to the stomach via peristalsis

4- The Stomach

• Starts at the cardiac opening and ends at the pyloric opening
• Subdivided into cardia, fundus, body, antrum, and pyloric canal

5- The Small Intestine

• The longest part of the alimentary canal (6 meters)
• Composed of three parts: duodenum, jejunum, and ileum
• Starts at the pylorus and ends at the ileocecal junction
• Receives secretions from the bile duct and pancreatic ducts
• Primary site of food absorption
• Has increased surface area due to villi and microvilli
• Plicae circularis are folds in the mucosa and submucosa
• Peyer's patches are lymphoid nodules in the distal parts of the small intestine
• Duodenum's function is the digestion of food particles, aided by bile from the liver and pancreatic enzymes

6- The Large Intestine

• Larger in diameter but shorter than the small intestine
• Starts at the ileocecal junction and ends at the anal canal
• Parts include cecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anal canal
• Absorbs water and electrolytes
• Stores digestion residues and eliminates them as feces

Accessory Organs

• Contribute to food breakdown (digestion), but are not part of the alimentary tract
• Includes Tongue, Teeth, Salivary Glands, Liver, Gall Bladder, and Pancreas

Tongue

• A mass of skeletal muscles covered by mucous membrane
• Located in the oral cavity and oropharynx

Teeth

• Deciduous teeth (childhood): 20
• Permanent teeth: 32

Salivary Glands

• Three pairs (parotid, sublingual, submandibular)
• Their ducts open into the oral cavity

Pancreas

• A soft, pinkish triangular gland in the posterior abdominal wall
• Produces digestive enzymes (secreted into the duodenum)
• Endocrine gland, secreting insulin and glucagon
• Surrounded by the duodenum
• Divided into head, neck, body, and tail

Liver

• Largest gland in the body
• Located under the diaphragm, to the right side
• Involved in many metabolic functions
• Digestive function is via bile secretion, delivered through biliary ducts to the duodenum
• Divided into lobes (right, left, caudate, quadrate)

Gall Bladder

• Small, thin-walled green sac
• Right and left hepatic ducts merge to form the common hepatic duct
• Common hepatic duct joins the cystic duct to form the common bile duct
• Common bile duct opens into the duodenum

Peritoneum

• Largest serous membrane in the body
• Parietal peritoneum lines the abdominal walls
• Visceral peritoneum covers the organs
• Peritoneal cavity is the space between visceral and parietal peritoneum, containing peritoneal fluid.
• Ascites is fluid accumulation in the peritoneal cavity

Peritoneal Folds

• Major folds include greater omentum, falciform ligament, lesser omentum, mesentery, and mesocolon, among others

Test your knowledge on the digestive system with this overview quiz. Explore the structure and function of the alimentary canal and associated glands through questions about the mouth, pharynx, esophagus, and other components. It's a great way to reinforce your understanding of human anatomy!