Across
- 2. Leukocytes found in the alveoli that engulf and destroy microorganisms and particles not removed by cilia, protecting the lungs from infection.
- 7. Cells covvering approximately 95% of the alveolar surface area, forming the thin barrier that separates air from blood for gas exchange.
- 8. A physiological action involving simultaneous closure of the laryngeal opening by the epiglottis and contraction of abdominal muscles, increasing abdominal pressure to facilitate urination, defecation, and childbirth.
- 10. The airway connecting the larynx to the bronchi, with a wall composed of four layers: mucose, submucosa, tracheal cartilage, and adventitia.
- 13. A funnel-shaped passageway posterior to the nasal cavity, oral cavity, and larynx, divided into nasopharynx, oropharynx, and laryngopharynx.
- 14. The branching network of airways from the pulmonary bronchi down to the terminal bronchioles, forming the conducting pathway of the lower respiratory tract.
- 16. The process of gas exchange between the atmosphere and body cells, providing oxygen for aerobic ATP production and removing carbon dioxide.
- 17. Autonomous units of the lungs encapsulated by connective tissue, each supplied by its own segmental bronchus, pulmonary artery, vein, and lymph vessels. There are 10 in the right lung and 8-10 in the left lung.
- 18. A structure of the larynx that prevents ingested materials from entering the respiratory tract and participates in the Valsalva maneuver by closing the laryngeal opening.
- 19. The region just inside the nostrils, lined by skin and particle-trapping hairs called vibrissae.
Down
- 1. Cells that secrete pulmonary surfactant, an oily substance that coats the inside of alveoli and prevents their collapse during respiration.
- 3. The mucous membrane lining the respiratory tract, consisting of ciliated epithelium and an underlying lamina propria of areolar connective tissue. It becomes thinner from the nasal cavity to the alveoli.
- 4. Epithelia cells that produce mucus containing mucin protein, which increases viscosity and traps dust, dirt, and pollen in the respiratory tract.
- 5. Three paired bony projections on the lateral walls of the nasal cavity that produce turbulence in inhaled air and partition the cavity into separate passages called nasal meatuses.
- 6. Two serous membranes surrounding the lungs: the visceral pleura, which adheres to the lungs, and the parietal pleura, which lines the interal thoracic walls, mediastinum, and diaphragm.
- 9. The pressure within the pleural cavity between the visceral and parietal pleural membranes. It is lower than intra-alveolar pressure, which keeps the lungs inflated.
- 11. Air-filled spaces within skull bones connected by ducts to the nasal cavity, named for the specific bone in which they are housed. Includes frontal, ethmoidal, sphenoidal, and maxillary sinuses.
- 12. Tiny air sacs in the lungs, numbering 300 to 400 million per lung, surrounded by pulmonary capillaries and separated by interalveolar septa. They are the primary sites of gas exchange.
- 15. Nosebleeds caused by the large number of superficial blood vessels in the respiratory region of the nasal cavity.