1.) Anatomical dead space includes air in the:AConducting zoneBRespiratory zoneCPleural sacDBoth the conducting and respiratory zonesENeither the conducting or respiratory zones 2.) Negative pressure in the pleural sac is generated by __________ elastic recoil of the thoracic wall and ____________ elastic recoil of the lungs: AInward; inwardBOutward; outwardCInward; outwardDOutward; inwardENone of the above

The respiratory system is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies greatly, depending on the size of the organism, the environment in which it lives and its evolutionary history. The respiratory system is divided into two main zones: the conducting zone and the respiratory zone. The conducting zone includes structures that facilitate the movement of air into and out of the lungs but do not participate in gas exchange. These structures include the trachea, bronchi, and bronchioles. The respiratory zone, on the other hand, includes structures that are involved in gas exchange, such as the alveoli and alveolar ducts.Anatomical dead space refers to the volume of the respiratory system where gas exchange does not occur. This includes all the structures of the conducting zone. Therefore, the correct answer is A Conducting zone.The pleural sac is a thin, double-layered serous membrane that surrounds the lungs. The space between these two layers is known as the pleural cavity, which contains a small amount of lubricating pleural fluid. This fluid allows the two layers to slide over each other with minimal friction during breathing.The negative pressure in the pleural sac is generated by the opposing forces of the elastic recoil of the thoracic wall and the lungs. The thoracic wall tends to pull outward due to its elasticity, while the lungs tend to recoil inward due to their elasticity. This creates a negative pressure within the pleural cavity, which keeps the lungs inflated and prevents them from collapsing and allows normal lung functioning.Therefore, the correct answer is D Outward; inward.Hence,Anatomical dead space includes air in the A. Conducting zone.Negative pressure in the pleural sac is generated by outward elastic recoil of the thoracic wall and inward elastic recoil of the lungs.