Thoracic Anatomy: Rib Cage, Lungs, Heart, and Diaphragm

Study Notes

The human body's torso region is called the thorax. This area includes several vital organs such as the rib cage, lungs, heart, and the diaphragm, which work together to enable breathing and support our internal system. Here's a more detailed look into each component of the thorax:

Rib Cage

The rib cage is formed by the rib bones and cartilages between them. It protects the lungs, heart, spinal cord, and other important structures within the chest cavity from injury. The sternum (breastbone) forms its base, while the vertebral column supports it above. The true ribs connect directly to the spine via their costal cartilages, false ribs attach indirectly via intercostals muscles, floating ribs have no connection with the thoracic wall and only function as attachment points for various abdominal muscles.

Lungs

Lungs are two large air sacs located near the bottom of the thorax. They facilitate gas exchange - taking in oxygen and expelling carbon dioxide through the process of respiration. Each lung has three layers: The outer layer contains bronchioles, small blood vessels, nerves, lymphatic vessels, and other structures; the middle layer is filled mostly with thin walls called alveoli where oxygen diffuses across from the trachea to reach your bloodstream; the inner core is composed mainly of elastic fibers to keep the lungs expanded during exhalation.

Heart

The heart acts like a pump inside the thorax, continually moving blood throughout the rest of our bodies. It pumps oxygenated blood towards the lungs so they can extract more oxygen before sending it back out again for circulation elsewhere. Blood returns to the right side when low on oxygen due to partial saturation, while returning fully oxygenated on left because there are higher concentrations of O2 here too.

Diaphragm

This essential muscle separates the chest cavity containing the organs, from the abdomen below. When we breathe deeply, this dome-like muscle contracts causing downward pressure against organs contained within the abdominal cavity, thereby raising the diaphragm upwards into the thorax increasing capacity allowing us to take deeper breaths. Conversely, during exhalation, gravity pulls everything back down into place forming an efficient system.

Mediastinum

This refers to all spaces occupied by any type of tissue lying between the pleural cavities containing lungs. In general terms though, most think of it simply as 'the space between the lungs.' Some key landmarks within the mediastinum include the pericardium enclosing the heart, esophagus traversing its center horizontally just behind and slightly above heart level, trachea running vertically downward in its posterior portion, and superior vena cava draining into the right atrium high upon top of the heart. Also note that various nerve trunks pass through areas around these structures.

Description

Explore the detailed components of the thorax, including the rib cage, lungs, heart, diaphragm, and mediastinum. Learn about their structures, functions, and how they work together to support breathing and circulation in the human body.