Digestive System Functions

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Questions and Answers

What is the main function of the jejunum?

Site for mechanical digestion

Site for digestion and absorption (correct)

Secretion of hormones

Transportation of food through the GI tract

Which type of muscle is responsible for the internal anal sphincter?

Striated muscle

Skeletal muscle

Cardiac muscle

Smooth muscle (correct)

What is the characteristic of the large intestine in terms of movement?

Segmental movement

Pendular movement

Rapid movement

Sluggish movement (correct)

What is the term for the finger-like projections in the lining of the small intestine?

Villi Signup and view all the answers

What is the function of the taenia coli?

To produce haustration Signup and view all the answers

What type of muscle is present in the middle third of the stomach?

A mixture of skeletal and smooth muscle Signup and view all the answers

What is the primary function of the duct cells in the GI tract?

Production of digestive secretions Signup and view all the answers

Which type of motility involves short peristaltic contractions that propel the contents to the ileocecal valve?

Segmentation Signup and view all the answers

What is the primary function of the muscularis layer in the GI tract?

Mixing and propulsion of food Signup and view all the answers

Which of the following is NOT a type of motility in the small intestine?

Deglutition Signup and view all the answers

What is the primary function of the exocrine gland cells in the GI tract?

Production of digestive enzymes Signup and view all the answers

Which nervous system regulates the GI tract functions indirectly?

Central nervous system Signup and view all the answers

What is the primary function of the mucosa layer in the GI tract?

Absorption of nutrients Signup and view all the answers

Which type of motility is initiated by the stomach?

Gastrocolic reflex Signup and view all the answers

What is the primary function of mixing movements in the digestive tract?

To mix food with digestive enzymes and facilitate absorption Signup and view all the answers

What is the main difference between exocrine and endocrine secretions in the digestive system?

Exocrine secretions include digestive enzymes, while endocrine secretions include hormones Signup and view all the answers

What is the functions of the Muscularis layer in the digestive tract?

To mix and move food through the digestive tract Signup and view all the answers

What are the four main layers of the GI tract?

Mucosa, Submucosa, Muscularis, Serosa Signup and view all the answers

What is the primary function of the propulsive movement in the digestive tract?

To push food forward through the digestive tract at varying speeds Signup and view all the answers

Which of the following hormones is involved in regulating the GI system?

All of the above Signup and view all the answers

What is the primary function of the Mucosa layer in the digestive tract?

To form the mucous lining of the digestive tract Signup and view all the answers

What is the role of the sympathetic and parasympathetic nervous systems in the digestive tract?

To control the contraction and relaxation of the Muscularis layer Signup and view all the answers

Study Notes

Digestive Process

Digestion is done by enzymatic hydrolysis.
Absorption involves the passage of small absorbable units into blood and lymph.
Storage and elimination involve the temporary storage of undigested food and its elimination in feces.

Basic Structure and Functions of the GI Tract

The GI tract has layers: mucosa, submucosa, muscularis, and serosa.
The source of digestive secretion is from exocrine gland cells and duct cells.
Motility refers to the movement of food through the GI tract.

Motility

Motility involves the muscular contraction that mixes and moves forward the contents of the GI tract.
There are two types of motility: propulsive and mixing movements.
Propulsive movements propel the contents forward through the digestive tract at varying speeds.
Mixing movements mix food with digestive enzymes and facilitate absorption.

Secretion

Secretion includes both exocrine and endocrine secretions.
Exocrine secretion involves the release of digestive enzymes and fluids into the lumen.
Endocrine secretion involves the release of hormones that help regulate the GI system.

Digestion

Digestion is the biochemical breakdown of large food particles into simple absorbable units.
Digestion occurs in the stomach and small intestine.

Stomach and Small Intestine

The stomach is a J-shaped sac-like chamber that empties into the duodenum.
The stomach is the most distensible part of the GI tract.
The small intestine is a coiled tube of about 6m long and 3cm diameter.
The small intestine is the main site for digestion and absorption.
The small intestine has divisions: duodenum, jejunum, and ileum.

Large Intestine

The large intestine extends from the ileocecal junction to the anus.
The large intestine consists of the cecum, colon, rectum, and anal canal.
Movements in the large intestine are sluggish, taking 18-24 hours.
The large intestine has modifications such as the presence of Peyer's patches or lymph nodules.

Cecum, Colon, Rectum, and Anal Canal

The cecum is a blind sac with a vermiform appendix attached.
The colon has ascending, transverse, descending, and sigmoid parts.
The rectum is a straight muscular tube.
The anal canal has an internal anal sphincter (smooth muscle) and an external anal sphincter (skeletal muscle).