Untitled Flashcards Set

Alimentary Canal

The long tube through which food passes during digestion, including the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.

Lumen

The inside space of a tubular structure such as a blood vessel or an organ like the intestines or esophagus.

Propulsion

The process by which food moves through the digestive tract, including peristalsis and swallowing.

Absorption

The process by which nutrients from digested food are taken up into the bloodstream or lymphatic system, mainly occurring in the small intestine.

Bolus

A soft mass of chewed food mixed with saliva, ready to be swallowed.

Chyme

The semi-liquid mixture of partially digested food and digestive juices found in the stomach and small intestine.

Peristalsis

The wave-like muscular contractions that propel food through the digestive tract.

Segmentation

A type of movement in the intestines that mixes food with digestive enzymes without moving it along the digestive tract.

Mastication

The process of chewing food, which breaks it down into smaller pieces to facilitate digestion.

Chemical Digestion

The breakdown of food through enzymatic reactions, converting food into absorbable nutrients.

Salivary Amylase

An enzyme in saliva that begins the breakdown of carbohydrates (starches) into simpler sugars.

Pancreatic Amylase

An enzyme secreted by the pancreas that continues the digestion of carbohydrates in the small intestine.

Lipases

Enzymes that break down fats (lipids) into fatty acids and glycerol.

Pepsin

An enzyme found in the stomach that begins the digestion of proteins into smaller peptides.

Trypsin

A pancreatic enzyme that further breaks down proteins into peptides and amino acids in the small intestine.

Lactase

An enzyme that breaks down lactose (milk sugar) into glucose and galactose.

Maltase

An enzyme that breaks down maltose (a sugar) into two glucose molecules.

Sucrase

An enzyme that breaks down sucrose (table sugar) into glucose and fructose.

Dipeptidases

Enzymes that break down dipeptides (two amino acids linked together) into individual amino acids.

Mechanical Digestion

The physical breakdown of food, such as chewing and churning, that helps in digestion.

Gastric Glands

Glands in the stomach that secrete gastric juices, including hydrochloric acid (HCl) and digestive enzymes.

Gastric Pits

Indentations in the stomach lining that contain gastric glands.

Mucous Cells

Cells in the stomach lining that secrete mucus to protect the stomach lining from the acidic environment.

Regenerative Cells

Cells in the stomach lining that produce new cells to replace those that are worn out or damaged.

Enteroendocrine Cells

Cells in the digestive tract that secrete hormones to regulate digestion (e.g., gastrin).

Intrinsic Factor

A glycoprotein produced by parietal cells in the stomach that is essential for the absorption of vitamin B12 in the small intestine.

HCl (Hydrochloric Acid)

A strong acid secreted by parietal cells in the stomach that helps in the digestion of food and kills harmful bacteria.

Chief Cells

Cells in the stomach that secrete pepsinogen, an inactive form of pepsin, which is activated by HCl.

Parietal Cells

Cells in the stomach that secrete hydrochloric acid (HCl) and intrinsic factor.

Brush Border

The microvilli-covered surface of the small intestine that increases surface area for nutrient absorption.

Microvilli

Tiny hair-like projections on the surface of epithelial cells in the small intestine that increase surface area for absorption.

Villus (Villi)

Finger-like projections of the mucosa in the small intestine that contain capillaries and lacteals for nutrient absorption.

Circular Folds

Permanent folds in the lining of the small intestine that increase surface area and slow down the passage of food for more efficient absorption.

Bile Salts

Compounds in bile that help in the emulsification of fats, breaking them into smaller droplets for easier digestion.

Emulsification

The process by which bile salts break down large fat droplets into smaller ones, increasing the surface area for lipases to act on.

Bicarbonate Ions

Ions secreted by the pancreas into the small intestine that neutralize stomach acid and create a favorable pH for digestive enzymes.

Micelle

A tiny, spherical arrangement of bile salts and lipids that helps transport lipids to the intestinal cells for absorption.

Chylomicron

A lipoprotein particle that transports lipids (fats) absorbed from the intestines to the lymphatic system and bloodstream.

Lacteal

A lymphatic vessel in the villus of the small intestine that absorbs lipids and transports them to the lymphatic system.

Mucosa

The innermost layer of the digestive tract that contains epithelial cells, glands, and lymphatic tissue involved in digestion and absorption.

Submucosa

The layer of connective tissue beneath the mucosa that contains blood vessels, lymphatic vessels, and nerves.

Muscularis Externa

The muscle layer of the digestive tract responsible for peristalsis and segmentation.

Serosa

The outermost layer of the digestive tract, made up of connective tissue and covered by a layer of epithelial cells, providing protection and support.