L19
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (24 张)
What is the overall purpose of the human digestive system?
To obtain raw materials for energy, growth, and repair of cells.
What is the first stage of food processing?
• Ingestion: Eating.
What is the second stage of food processing?
• Digestion: Breaking down food into small molecules.
What is the third stage of food processing?
• Absorption: Uptake of nutrient molecules by cells lining the digestive tract.
What is the fourth stage of food processing?
• Elimination: Disposing of undigested/unabsorbed materials.
What is the function of the mouth/oral cavity?
Site of ingestion; oral cavity and tongue are components of the alimentary canal.
What is the function of the esophagus?
Muscular tube that connects pharynx to stomach; moves food by peristalsis.
What are the main functions of the stomach?
Food storage, protein digestion, killing foodborne bacteria. Stage of digestion: digestion
What enzyme does the stomach use for protein digestion?
Pepsin.
What are the main functions of the small intestine?
Finishes digestion and is the major site of absorption.
What does the small intestine digest and absorb?
Proteins, lipids, and carbohydrates (everything).
What are villi and what is their function?
Folds on the intestinal wall that increase surface area for absorption.
How do nutrients from villi enter circulation?
Glucose/amino acids → blood capillaries; fats → lymphatic capillaries. cross the cell membrane of microvilli into blood capillaries
What are the functions of the large intestine?
Absorbs remaining water, electrolytes, vitamins/minerals, and transports undigested food.
What role does bacteria play in the large intestine?
Beneficial bacteria produce vitamins, intestinal lining regulation, nutrient source, and feces composition
What are the three accessory digestive organs?
Pancreas, Liver, Gallbladder.
What is the function of the pancreas?
Releases digestive enzymes such as trypsin and pancreatic amylase.
What is the function of the liver?
Produces bile for fat digestion.
What is the function of the gallbladder?
Stores and releases bile into the small intestine.
What is the function of protease enzymes?
Digest proteins (e.g., Pepsin, Trypsin).
What is the function of amylase enzymes?
Break down carbohydrates (e.g., pancreatic amylase).
What is the function of lipase enzymes?
Break down lipids (fats).
What are macronutrients?
Caloric, energy-yielding nutrients (carbohydrates, protein, fats).
What are micronutrients?
Non-caloric substances (vitamins, minerals, water).