Unit 1: Respiration, blood cells, etc

• The respiratory system is responsible for gas exchange between the body's internal environment and external environment.
• Oxygen diffuses from the air into the alveolar spaces and then into the capillaries surrounding them.
• Oxygen diffuses from the air into the alveolar spaces and then into the capillaries surrounding them.
• The hemoglobin in red blood cells binds oxygen at the lungs and releases it in cells throughout the body.
• Carbon dioxide diffuses out of the capillaries and into the alveoli where it can be exhaled during breathing.
• Gas exchange occurs at the level of the alveoli due to their thin walls and large surface area.
• Alveoli are surrounded by capillary beds that allow for efficient diffusion of oxygen and carbon dioxide.
• Alveoli are small sac-like structures that form the walls of the lungs.
• Hemoglobin is an iron-containing protein that carries oxygen in the blood.
• White blood cells defend against infection by engulfing pathogens (phagocytosis) and producing antibodies.
• Red blood cells carry O2 from the lungs to other parts of the body.
• Red blood cells contain hemoglobin which is responsible for transporting oxygen throughout the body.
• Capillary walls have very small pores that allow gases like oxygen (O2) and carbon dioxide (CO2) to pass through easily.
• Diffusion is the movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.