Body Systems - MCO Flashcards
What is the primary function of the respiratory system?
To facilitate gas exchange by bringing oxygen into the body and removing carbon dioxide.
What are alveoli, and why are they important?
Tiny air sacs in the lungs where gas exchange occurs; they provide a large surface area for efficient oxygen and carbon dioxide exchange.
How does gas exchange occur in the alveoli?
Oxygen diffuses from alveoli into the capillaries, while carbon dioxide diffuses from the capillaries into the alveoli to be exhaled.
What is the main function of the digestive system?
To break down food into smaller molecules for absorption and energy production.
What is the difference between mechanical and chemical digestion?
Mechanical digestion physically breaks down food (e.g., chewing), while chemical digestion uses enzymes and acids to break down molecules.
What are the main digestive enzymes and their functions?
Amylase (breaks down carbohydrates), protease (breaks down proteins), and lipase (breaks down fats).
How do villi in the small intestine aid absorption?
Villi increase the surface area for nutrient absorption into the bloodstream.
How are carbohydrates, proteins, and fats absorbed?
Carbohydrates → broken into glucose and absorbed into the blood; Proteins → broken into amino acids; Fats → broken into fatty acids and absorbed into lymphatic vessels.
What is the main function of the excretory system?
To remove metabolic waste and maintain homeostasis by regulating water, salt, and pH balance.
What are the main structural components of the kidney?
Cortex (outer layer), medulla (inner region), renal pelvis (collects urine), nephrons (functional units), and renal artery/vein (blood supply).
What is the function of the nephron?
To filter blood, reabsorb useful substances, and form urine.
Where does filtration occur in the nephron?
In the glomerulus, where blood pressure forces small molecules into the Bowman’s capsule.
What happens during selective reabsorption?
Useful substances like glucose, amino acids, and water are reabsorbed into the blood in the proximal tubule.
What is the function of the Loop of Henle?
It creates a concentration gradient to allow water reabsorption and urine concentration.
