Week 6 Digestive System Flashcards
What are the major functions of the digestive system?
Ingestion, digestion, absorption, defecation.
What is the function of the buccal cavity in digestion?
Mastication, mixing food with saliva, forming bolus, and initial digestion of starch.
What prevents food from entering the respiratory tract during swallowing?
The epiglottis covers the trachea, and the soft palate and uvula prevent entry into the nasal cavity.
What is the function of the esophagus?
It transports food from the pharynx to the stomach using peristalsis.
What is the role of the stomach in digestion?
Mixes food with gastric juice, starts digestion of proteins and lipids, and regulates release into the small intestine.
What are the four major digestive processes?
Ingestion, propulsion, digestion (mechanical and chemical), absorption, and defecation.
What is peristalsis?
Wave-like contractions of smooth muscle that move food through the digestive tract.
Where does the majority of nutrient absorption occur?
In the small intestine.
What is segmentation in digestion?
Rhythmic contractions in the small intestine that mix food and digestive enzymes.
What enzyme is responsible for carbohydrate digestion in the mouth?
Salivary amylase.
Where does protein digestion begin and which enzyme is involved?
In the stomach with the enzyme pepsin.
Which enzyme digests lipids and where does it primarily function?
Pancreatic lipase in the small intestine.
What role do bile salts play in digestion?
They emulsify fats to increase the surface area for lipase action.
What are the end products of carbohydrate digestion?
Monosaccharides such as glucose, fructose, and galactose.
How are amino acids absorbed into the bloodstream?
By active co-transport with sodium ions into intestinal epithelial cells.
How are lipids absorbed in the small intestine?
Through micelles and chylomicrons before entering the lymphatic system.
What are the three phases of gastric secretion?
Cephalic phase, gastric phase, and intestinal phase.
What triggers the cephalic phase of digestion?
The sight, smell, thought, or taste of food.
What hormone stimulates gastric juice secretion?
Gastrin.
Which hormone stimulates the release of pancreatic enzymes and bile?
Cholecystokinin (CCK).
What hormone neutralizes acid in the duodenum?
Secretin, by stimulating the pancreas to release bicarbonate.
What are the five essential nutrients?
Fatty acids, amino acids, water, vitamins, and minerals.
Which vitamin is essential for calcium absorption?
Vitamin D.
What is the function of Vitamin K?
It is required for blood clotting protein synthesis.
