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From: http://www.dummies.com/how-to/content/bones-and-joints-in-the-thoracic-region.html

 

Bony Anatomy:

  • The thoracic cage (commonly referred to as the rib cage) consists of 12 thoracic vertebrae, 12 ribs, costal cartilages, and the sternum.

  • The first seven ribs connect to the sternum through the costal cartilage.

  • The 8th-10th ribs connect with the 7th rib through costal cartilage to therefore connect to the sternum.

  • The 11th & 12th ribs are called ‘floating ribs’ due to the fact that they only connect posteriorly to the spine and not to the sternum.

  • The sternum is made of three parts: the manubrium, the body, and the xiphoid process.

 

And what about Joints?

The cartilaginous joints in your thoracic cage allow you to breathe.

  • Manubriosternal joint: The joint between the manubrium and the body of the sternum; forms the sternal angle

  • Xiphisternal joint: Formed between the sternal body and xiphoid process

  • Costovertebral joints: Formed between the heads of the ribs and the bodies of the vertebrae and the necks of the ribs and the transverse processes of the vertebrae

  • Sternocostal joints: Join the sternum to the costal cartilages

  • Sternoclavicular joints: Join the sternum and clavicles

  • Costochondral joints: Attach the ribs to the costal cartilages

  • Interchondral joints: Join cartilage to cartilage

                                                                                                                                                                                                            (Agur & Dalley, 2012)

Thoracic Anatomy

 

From: http://commons.wikimedia.org/wiki/File:1114_Thorax.jpg

 

Muscular anatomy:

There are five muscles that make up the thoracic cage: the intercostals (external, internal, and innermost), subcostals, and transverses thoracic. The Pectoralis major, minor, serratus anterior, and the scalene muscles do not make up the thoracic wall but do attach to it. 

 

External Intercostals: There are 11 pairs of external intercostals, assists with inhalation.

                       O: Inferior border of the rib above

                        I: Superior border of the rib below

                      N: Thoracic

                                                                                                                                                                                    (Biel, 2010)

 

Internal Intercostals: These muscles are deep to the external intercostals, assists with exhalation.

                      O: Inferior border of the rib above

                        I: Superior border of the rib below

                      N: Thoracic

                                                                                                                                                                                                                (Biel, 2010)

 

Innermost intercostals: These muscles are the deepest of the intercostal muscles and have the same structure as the internal intercostals. However, they are separated by the intercostal neurovascular bundle.

                      O: Inferior border of the rib above

                        I: Superior border of the rib below

                      N: Thoracic

                                                                                                                                                                                                                (Biel, 2010)

 

Subcostals: These muscles are found in the inferior portion of the thoracic wall.

                      O: Angle of the ribs

                       I: Angle of of the ribs, 2-3 ribs abve orgin

                      N: Intercostal nerves

                                                                                                                                                                                                   (Gest & Schlesinger, 1995)

                                                                                                                                                                                        

Transverses Thoracis: These muscles originate from the lower part of the manubrium and xiphoid process, and attach to the costal cartilages of ribs 2-6. They are also innervated by the intercostal nerves.

                     O: Inner lower part of the sternum and adjacent costal cartiliage

                       I: Lower border of the sternal ends of ribs 2 thru 6.

                     N: Intercostal nerves T3-T6

                                                                                                                                                                                               ("Transverse Thoracis". n.d.)

 

                           From: http://www.nhlbi.nih.gov/health/health-topics/topics/hhw/anatomy.html                                                                                  From: http://healthy-lifestyle.most-effective-solution.com/2010/09/08/human-anatomy-lungs/

 

Heart & Lung Anatomy 

Figure B (above) shows the inside of your heart and how it's divided into four chambers. The two upper chambers of your heart are called the atria. They receive and collect blood. The two lower chambers of your heart are called ventricles. The ventricles pump blood out of your heart to other parts of your body.

 

An internal wall of tissue divides the right and left sides of your heart. This wall is called the septum. The area of the septum that divides the atria is called the atrial or interatrial septum. The area of the septum that divides the ventricles is called the ventricular or interventricular septum.

 

Figure B also shows your heart's four valves. Shown counterclockwise in the picture, the valves include the aortic valve, the tricuspid valve, the pulmonary valve, and the mitral valve.

 

The arrows in figure B show the direction that blood flows through your heart. The light blue arrow shows that blood enters the right atrium of your heart from the superior and inferior vena cavae. From the right atrium, blood is pumped into the right ventricle. From the right ventricle, blood is pumped to your lungs through the pulmonary arteries.

 

The light red arrow shows oxygen-rich blood coming from your lungs through the pulmonary veins into your heart's left atrium. From the left atrium, the blood is pumped into the left ventricle. The left ventricle pumps the blood to the rest of your body through the aorta.

 

For the heart to work well, your blood must flow in only one direction. Your heart's valves make this possible. Both of your heart's ventricles have an "in" valve from the atria and an "out" valve leading to your arteries.

 

Healthy valves open and close in exact coordination with the pumping action of your heart's atria and ventricles. Each valve has a set of flaps called leaflets or cusps that seal or open the valve. This allows blood to pass through the chambers and into your arteries without backing up or flowing backward.

                                                                                                                                                                                                     ("Anatomy of the Heart", 2011)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

                                                                                                                                       From: https://www.youtube.com/watch?v=oZ1_TAwCUWw

 

Air enters the body through the nose or mouth and passes through the pharynx, larynx, and trachea. Just before reaching the lungs, the trachea then splits into the left and right bronchi. Each lung receives air from a single, large primary bronchus.

 

Many small bronchioles branch off from the tertiary bronchi. Bronchioles are smaller than bronchi and are made of elastin fibers and smooth muscle tissue. In response to dust or other environmental pollutants, the bronchioles can constrict to prevent the pollution of the lungs.

 

The bronchioles further branch off into many tiny terminal bronchioles. Terminal bronchioles are the smallest air tubes in the lungs and terminate at the alveoli of the lungs. Like bronchioles, the terminal bronchioles are elastic, capable of dilating or contracting to control airflow into the alveoli.

 

Alveoli are the functional units of the lungs that permit gas exchange between the air in the lungs and the blood in the capillaries of the lungs. Alveoli are found in small clusters called alveolar sacs at the end of the terminal bronchiole. Each alveolus is a hollow, cup-shaped cavity surrounded by many tiny capillaries.

 

                                                                                                                                                                                                                         (Taylor, n.d.)

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