RESPIRATORY SYSTEM Part 2 Lower Tract LUNGS spongy

RESPIRATORY SYSTEM Part 2 Lower Tract

LUNGS - spongy tissue that sit within the pleural cavity

The Pathway Primary bronchii --> bronchioles --> alveolar ducts --> alveoli * *gas exchange

Alveoli & Lungs

ALVEOLI

Right Lung = 3 lobes Left Lung = 2 lobes Serous fluid lubricates lungs during breathing

BREATHING MECHANISM ü ü https: //www. nhlbi. nih. gov/health-topics/how-lungs-work The diaphragm contracts and moves lower The chest cavity enlarges, reducing the pressure inside the lungs. To equalize the pressure, air enters the lungs. When the diaphragm relaxes and moves back up, the elasticity of the lungs and chest wall pushes air out of the lungs.

Diaphragm Structure • Three large openings in the diaphragm that allow certain structures to pass between the chest and the abdomen. 1. Esophageal opening. The esophagus and vagus nerve which controls much of the digestive system, pass through this opening. 2. Aortic opening. The aorta, the body’s main artery that transports blood from the heart, passes through the aortic opening. The Thoracic Duct, a main vessel of the lymphatic system, also passes through this opening. 3. Caval opening. The Inferior Vena Cava, a large vein that transports blood to the heart, passes through this opening

Other Breathing Muscles

Model A Lung

ATMOSPHERIC PRESSURE = 760 Hg ü Pressure is necessary for breathing, which is why it is difficult to breathe in high altitudes ü also why a punctured lung can be dangerous. ü A hole in the pleural cavity can cause the lung to collapse or deflate Pneumothorax = collapsed lung: https: //www. merckmanuals. com/home/multimedia/video/pneum othorax

NON RESPIRATORY MOVEMENTS Coughing, sneezing, laughing, crying Hiccup - spasm of the diaphragm Yawn – Current Theory Brain Cooling

Label Then entire into the 4/2 HW folder