Anatomy of the Gastrointestinal System Flashcards
What is the main function of the digestive system?
To break down food into nutrients the body can absorb and use for energy, growth, and repair.
What organs are included in the gastrointestinal tract?
Mouth, pharynx, esophagus, stomach, small intestine, and large intestine.
What are the accessory organs of digestion?
Liver, gallbladder, and pancreas.
What happens during the cephalic phase of digestion?
The brain signals the stomach to release gastric juices in response to the sight, smell, or thought of food.
What begins digestion in the oral cavity?
Mechanical chewing and enzymes in saliva.
What enzyme in saliva breaks down starch?
Salivary amylase.
What protects against microbes in saliva?
Immunoglobulin A (IgA) and lysozymes.
What is the role of the epiglottis during swallowing?
It closes over the trachea to prevent food from entering the airway.
What is peristalsis?
A series of muscular contractions that move food through the esophagus.
What prevents acid reflux in the stomach?
The lower esophageal sphincter (LES).
What is chyme?
A semi-liquid mixture of partially digested food formed in the stomach.
What does hydrochloric acid (HCl) do in the stomach?
It creates an acidic environment to denature proteins and activate enzymes.
What is the function of intrinsic factor?
It is needed for vitamin B12 absorption in the small intestine.
What increases surface area for absorption in the small intestine?
Villi and microvilli.
What nutrients are absorbed into capillaries in the villi?
Water-soluble nutrients like amino acids and monosaccharides.
What are lacteals and what do they absorb?
Part of the lymphatic system; they absorb dietary lipids and fat-soluble vitamins.
What are key functions of the large intestine?
Reabsorb water and electrolytes, ferment indigestible carbs, and produce vitamins.
What is the role of gut microbiota?
Aid digestion, support immunity, and improve mental health.
What does the liver produce and what is its role in digestion?
Bile, which emulsifies fats.
What is the function of the gallbladder?
It stores and concentrates bile.
What does the pancreas release into the duodenum?
Digestive enzymes and bicarbonate.
