Topic 2 Digestive system

Vocabulary flashcards covering the anatomy, physiological processes, enzymes, transport mechanisms, and common pathologies of the human digestive system.

Mouth

The entry point of the digestive system where teeth perform mechanical digestion and saliva begins chemical digestion.

Esophagus

The structure that transports the bolus (chewed food) from the mouth to the stomach.

Bolus

Chewed food that is transported through the esophagus.

Stomach

An organ that stores food temporarily, mixes it with gastric juices, begins significant protein digestion, and produces chyme.

Chyme

A semi-fluid mass of partially digested food produced by the stomach.

Small Intestine

The main site of digestion and nutrient absorption, which receives digestive enzymes from the pancreas and bile from the liver/gallbladder.

Large Intestine

An organ that absorbs water and minerals, houses gut microbiota, and forms feces.

Peristalsis

Wave-like contractions of smooth muscle that propel food forward through the digestive tract, serving as the major movement in the esophagus.

Segmentation

Mixing contractions that churn food back and forth to increase digestion and absorption without moving food forward.

Sphincters

Muscular valves that regulate food movement, including the upper esophageal, lower esophageal, pyloric, sphincter of Oddi, ileocecal valve, and anal sphincter.

Enzymes

Proteins that act as biological catalysts to speed up chemical reactions and lower activation energy without being consumed.

Hydrolysis

A process where water is used to break large molecules into smaller molecules.

Carbohydrate-Digesting Enzymes

A group of enzymes including Amylase, Sucrase, Lactase, and Maltase.

Protein-Digesting Enzymes

A group of enzymes including Pepsin, Trypsin, and Peptidase.

Lipase

An enzyme responsible for digesting fats.

Passive Diffusion

A method of absorption requiring no energy where nutrients move from high to low concentration.

Facilitated Diffusion

A method of absorption that uses transport proteins but does not require energy.

Active Transport

A method of absorption that requires energy ($ATP$) to move nutrients against concentration gradients.

Endocytosis

A process where a cell engulfs substances into vesicles for transport.

Cardiovascular System Transport

The transport system for amino acids, monosaccharides, water-soluble vitamins, and short/medium-chain fatty acids via the Small Intestine $\rightarrow$ Hepatic Portal Vein $\rightarrow$ Liver $\rightarrow$ Body.

Lymphatic System Transport

The transport system for fat-soluble vitamins (A, D, E, K), long-chain fatty acids, and triglycerides via the Lymphatic System $\rightarrow$ Left Subclavian Vein $\rightarrow$ Bloodstream $\rightarrow$ Body Cells.

Heartburn

A condition where acidic stomach contents move into the esophagus, causing burning chest pain and a sour taste.

Stomach Ulcers

Areas of tissue damaged by gastric acid, commonly caused by h. pylori infection, NSAID use, alcohol, or smoking.

Food Intolerances

A condition, such as lactose intolerance, which is often caused by enzyme deficiencies rather than an allergy.

Irritable Bowel Syndrome (IBS)

A disorder causing irregular bowel function that may be related to poor motility, stress, and food intolerances.