19. C. Label the parts A. Diaphragm B. Nostrril C. bronchioles D. Bronchi E. lungs F. alveoli G. Trachea H. mouth I. diaphragm 20. 21 26 23. 22 24. 25.
-either of two external openings of the nasal cavity in vertebrates that admit air to the lungs and smells to the olfactory nerves.
-The mouth, or oral cavity, is the first part of the digestive tract. It is adapted to receive food by ingestion, break it into small particles by mastication, and mix it with saliva. The lips, cheeks, and palate form the boundaries.
-The trachea is the long tube that connects your larynx (voice box) to your bronchi. Your trachea is a key part of your respiratory system. The trachea is made of rings of cartilage. It is lined with cells that produce mucus. This mucus keeps allergens, dust particles or other debris out of your lungs.
-The lungs are a pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles), finally becoming microscopic.
-The bronchi are the two large tubes that carry air from your windpipe to your lungs. You have a left and right main bronchus in each lung. After the main bronchi, these tubes branch out into segments that look like tree branches. Many respiratory conditions, such as asthma or bronchitis, can affect your bronchi.
-Bronchioles are air passages inside the lungs that branch off like tree limbs from the bronchi—the two main air passages into which air flows from the trachea (windpipe) after being inhaled through the nose or mouth. The bronchioles deliver air to tiny sacs called alveoli where oxygen and carbon dioxide are exchanged.
-The diaphragm is a thin skeletal muscle that sits at the base of the chest and separates the abdomen from the chest. It contracts and flattens when you inhale. This creates a vacuum effect that pulls air into the lungs. When you exhale, the diaphragm relaxes and the air is pushed out of lungs.
