Lab Session 22: Digestive Organs Histology & Anatomy of Organs Along the GI-Tract

What is the primary function of the mesenteries in the digestive system?

To route blood vessels, lymphatics, nerves, hold/support organs, and store fat.

What does 'intraperitoneal' refer to in the context of digestive organs?

It refers to organs suspended from the body wall by dorsal mesenteries and held by ventral mesenteries.

What is the function of saliva in the chemical digestion process?

Saliva contains salivary amylase, which breaks bonds in carbohydrates.

What are the primary functions of the hard palate?

Provides a rigid surface for the tongue to push against when chewing and creates friction.

What type of muscle makes up the tongue, and what are its functions?

The tongue is made of skeletal muscle, used for mechanical digestion, mixing saliva, propulsion, and speech.

What layers constitute the general 4-layer structure of the digestive tract?

Mucosa, submucosa, muscularis externa, and serosa.

What is the role of the mucosa in the digestive tract?

Secretion of mucus, enzymes, hormones; absorption of nutrients; protection against pathogens.

What role does the muscularis externa play in the digestive tract?

It is involved in peristalsis (propulsion) and segmentation (mechanical digestion).

How does the structure of the esophagus facilitate peristalsis?

It features a smooth muscle layer that contracts to propulse food towards the stomach.

What occurs during the 'Cephalic Phase' of digestion?

It involves food processing in the oral cavity, including ingestion, mechanical and chemical digestion.

What is the role of the circular layer in the muscularis externa?

It contracts to constrict the lumen’s circumference and helps in food propulsion.

What are the main chemical digestion roles of the stomach?

Primarily for protein digestion and production of lipases for fat breakdown.

What is chyme in the context of digestion?

Chyme is the semi-liquid mixture of partially digested food and gastric juices that exits the stomach.

What is the significance of the intrinsic and extrinsic muscles of the tongue?

Intrinsic muscles shape the tongue, while extrinsic muscles alter its position for swallowing and speech.