You may also submit a request by e-mail. Be sure to include the business identification number, and the business name and address in the text of your message. If you write to PO Box 252, Trenton, NJ 08646-0252, please allow 15 to 20 working days to receive your certificate.e sure to include the business identification number, and the business name and address in the text of your message. If you write to PO Box 252, Trenton, NJ 08646-0252, please allow 15 to 20 working days to receive your certificate.
A) End expiration: At rest, intrapleural pressure must remain slightly negative (here it is shown as -5 mmHg) as i) the lung is elastic and has a tendency to collapse or shrink, and ii) the fluid lining the alveolar surfaces generates surface tension that works to collapse the lung.
Pulmonary ventilation, or gas flow into and out of the lungs, relies on the pressure gra-dient between the atmosphere and alveoli, and airway diameter. Given that gas flow in a system is equal to the pressure gradient divided by the resistance, when resistance increases, gas flow decreases, and vice versa. Changes in resistance are related to airway diameter, which is greatest in medium-sized bronchi.