Respiratory System Purpose: Facilitates the exchange of gases (oxygen and carbon dioxide).
Difference from Cellular Respiration: Cellular respiration is the process by which cells use oxygen to produce ATP, releasing carbon dioxide as a byproduct.
Path of Air in the Respiratory System
Nasal Cavity
Air is warmed, humidified, and filtered using mucus and nasal hairs.
Pharynx
Junction for food and air.
Larynx (Voice Box)
Trachea
Supported by cartilage rings to remain open.
Primary Bronchi
Branch into lungs; left lung smaller due to cardiac notch.
Secondary and Tertiary Bronchi
Bronchioles
Alveolar Ducts and Alveoli
Alveoli are the site of gas exchange.
Gas Exchange
Alveoli: Thin-walled, large surface area, contact with capillaries.
Circulatory System Interaction: Red blood cells pick up oxygen and release carbon dioxide for exhalation.
Other Systems Involved
Skeletal System: Ribs protect lungs.
Muscular System: Involves intercostal muscles, diaphragm, and abdominal wall muscles for breathing.
Nervous System: Regulates involuntary breathing using blood pH as a signal.
pH and Breathing Regulation
pH Scale: Measures hydrogen ion concentration, affecting blood acidity.
Homeostasis: Brain adjusts breathing to maintain a stable blood pH (~7.4).
Variations in Respiratory Systems
Different Organisms:
Earthworms: Gas exchange through skin.
Fish: Utilize gills.
Insects: Tracheal systems with spiracles.
Respiratory Conditions and Careers
Medical Careers: Pulmonologists and respiratory therapists.
Conditions: Asthma, emphysema, and challenges in premature infants.
Surfactant and Premature Infants
Type 2 Alveolar Cells: Produce surfactant to lower surface tension in alveoli.
Respiratory Distress Syndrome (RDS): Caused by insufficient surfactant in premature infants.
Treatment: Artificial surfactants can aid in treatment.
Conclusion
Curiosity Encouragement: Understanding the respiratory system aids in grasping treatment of respiratory issues and highlights the interconnectedness of body systems.