Thoracic Anatomy and Physiology

Question 1

Overall framework of the thorax?

Answer 1

Ribs, sternum, vertebrae, scapula, clavicles

Question 2

Inner pleural cavity? Pleural covering of the lungs?

Answer 2

Parietal pleura; visceral pleura

Question 3

The trachea bifurcates into the R and L mainstem bronchi; subsequent branching results in a total of ___ generations of airways. The right lung is made of ___ lobes; the left has ___ lobes. Each lobe is further sub-divided into bronchopulmonary segments. These are the anatomic units fo the lung with an individual blood supply and bronchus. How many segments are there in general?

Answer 3

23; 3 (upper, middle, lower); 2 (upper, lower); 10 on the right, 8 on the left

Question 4

Inspiration is an active process caused by coordinated muscular contraction - what muscles are involved?

Answer 4

Mainly the intercostal muscles and diaphragm; SCM and serratus posterior muscles to a lesser degree

Question 5

What keeps the alveoli open?

Answer 5

Outward elastic recoil fo the chest
Inward collapse of the lungs
Pulmonary surfactant (secreted by type II pneumocytes) helps keep alveoli open by decreasing the surface tension with the alveoli