Digestive System Anatomy & Physiology

These flashcards cover essential concepts related to the anatomy, physiology, and function of the digestive system, preparing the student for exam review.

What is the primary function of the digestive system?

To process food, extract nutrients, and eliminate residue.

What are the five stages of digestion?

Ingestion, digestion, absorption, compaction, and defecation.

What distinguishes mechanical digestion from chemical digestion?

Mechanical digestion involves physical breakdown of food, while chemical digestion involves enzymatic reactions that break macromolecules into monomers.

What are the major products of chemical digestion for polysaccharides, proteins, fats, and nucleic acids?

Polysaccharides into monosaccharides; proteins into amino acids; fats into monoglycerides and fatty acids; nucleic acids into nucleotides.

List the regions of the digestive tract.

Mouth, pharynx, esophagus, stomach, small intestine, and large intestine.

What are the accessory organs of the digestive system?

Teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

What are the layers of the digestive tract?

Mucosa, submucosa, muscularis externa, and serosa.

What is the function of the enteric plexus?

It regulates digestive tract motility, secretion, and blood flow, functioning largely independently of the central nervous system.

What is the role of the mesentery in the digestive system?

It connects the stomach and intestines to the abdominal wall, allowing for freedom of movement and passage of blood vessels and nerves.

How is gastric secretion regulated?

Through neural, hormonal, and paracrine mechanisms, including reflex arcs and the action of digestive hormones.

What are the components of saliva?

Water, mucus, electrolytes, lysozyme, immunoglobulin A, salivary amylase, and lingual lipase.

What is the composition and function of bile?

Bile contains minerals, cholesterol, neutral fats, phospholipids, bile pigments, and bile acids; it is essential for fat digestion.

What is the importance of intrinsic factor in the stomach?

It is essential for the absorption of vitamin B12 in the small intestine.

Describe the progression of swallowing phases.

Oral phase (voluntary), pharyngeal phase (involuntary), and esophageal phase (peristalsis).

What are chylomicrons and their function?

Chylomicrons are lipoprotein particles made of triglycerides and proteins; they transport absorbed lipids from the intestine to the lymphatic system.

What role do intestinal microbes play in digestion?

They help digest cellulose and synthesize vitamins B and K.

What triggers the defecation reflex?

Stretching of the rectum stimulates two reflexes, intrinsic and parasympathetic, leading to contraction of the rectum and relaxation of the internal anal sphincter.