Thoracic

Question 1

an irregularly shaped cylinder with a narrow opening (superior thoracic aperture) superiorly and a relatively large opening (inferior thoracic aperture) inferiorly (Fig. 3.1). The superior thoracic aperture is open, allowing continuity with the neck; the inferior thoracic aperture is closed by the diaphragm.

Answer 1

Thorax

Question 2

Thoracic cavity subdivisions:

Answer 2

a. Two pleural cavities
Each houses a lung
b. Mediastinum
Contains pericardial cavity
Surrounds thoracic organs
Pericardial cavity
Encloses heart

Question 3

a thick, flexible soft tissue partition oriented longitudinally in a median sagittal position. It contains the heart, esophagus, trachea, major nerves, and major systemic blood vessels.

Answer 3

Mediastinum

Question 4

Functions of the Thorax

Answer 4

Breathing
Protection of vital organs
Conduit

Question 5

Breathing

Answer 5

One of the most important functions of the thorax is breathing. The thorax not only contains the lungs but also provides the machinery necessary—the diaphragm, thoracic wall, and the ribs—for effectively moving air into and out of the lungs. Up and down movements of the diaphragm and changes in the lateral and anterior dimensions of the thoracic wall, caused by movements of the ribs, alter the volume of the thoracic cavity and are key elements in breathing (Inhailation and Exhailation)

Question 6

Protection of vital organs

Answer 6

The thorax houses and protects the heart, lungs, and great vessels. Because of the domed shape of the diaphragm, the thoracic wall also offers protection to the liver lies under the right dome of the diaphragm, and the stomach and spleen lie under the left. The posterior aspects of the superior poles of the kidneys lie on the diaphragm and are anterior to rib XII, on the right, and to ribs XI and XII, on the left.

Question 7

Conduit

Answer 7

The mediastinum acts as a conduit for structures that pass completely through the thorax.
The esophagus, vagus nerves, thoracic duct pass the phrenic nerves, the trachea, thoracic aorta, and superior vena cava course within the mediastinum.

Question 8

Thoracic wall Boundaries
Posteriorly it is made up of :

Answer 8

Twelve thoracic vertebrae and their intervening intervertebral discs

Question 9

Thoracic wall Boundaries
Laterally, the wall is formed by:

Answer 9

a. Ribs (twelve on each side)
b. Three layers of flat muscles, which span the intercostal spaces between adjacent ribs, move the ribs and provide support for the intercostal spaces

Question 10

Thoracic wall Boundaries
Anteriorly, the wall is made up of the

Answer 10

a. Sternum, which consists of the
1. Manubrium
2. Body of sternum
3. Xiphoid process
The manubrium of sternum, angled posteriorly on the body of sternum at the manubriosternal joint, forms the sternal angle, which is a major surface landmark used by clinicians in performing physical examinations of the thorax.

Question 11

The first ribs slope inferiorly from their posterior articulation with vertebra TI to their anterior attachment to the manubrium. Consequently, the plane of the superior thoracic aperture is at an oblique angle, facing somewhat anteriorly.
The superior margin of the manubrium is in approximately the same horizontal plane as the intervertebral disc between vertebrae TII and TIII.

Answer 11

Superior thoracic aperture

Question 12

is large and expandable and is closed by the diaphragm, and structures passing between the abdomen and thorax pierce or pass posteriorly to the diaphragm.
Four main apertures:
Esophageal
2. Thoracic duct and
3. Aortic together.
4. Inferior Vena Cava

Answer 12

Inferior thoracic aperture

Question 13

an abnormal collection of air or gas in the pleural space that causes an uncoupling of the lung from the chest wall. Like pleural effusion (liquid buildup in that space), pneumothorax may interfere with normal breathing. It is often called collapsed lung, although that term may also refer to atelectasis.

Answer 13

Pnuemothorax

Question 14

one that occurs without an apparent cause and in the absence of significant lung disease

Answer 14

primary pneumothorax

Question 15

occurs in the presence of existing lung pathology. In a minority of cases, the amount of air in the chest increases markedly when a one-way valve is formed by an area of damaged tissue, leading to a tension pneumothorax. This condition is a medical emergency that can cause steadily worsening oxygen shortage and low blood pressure. Unless reversed by effective treatment, these sequelae can progress and cause death

Answer 15

secondary pneumothorax

Question 16

a complete or partial collapse of a lung or lobe of a lung — develops when the tiny air sacs (alveoli) within the lung become deflated. It’s a breathing (respiratory) complication after surgery.
is also a possible complication of other respiratory problems, including cystic fibrosis, inhaled foreign objects, lung tumors, fluid in the lung, respiratory weakness and chest injuries

Answer 16

Atelectasis

Question 17

(pleural tap) is often performed here while a patient is in full expiration because of less risk of puncturing the lungs and thereby causing pneumothorax.

Answer 17

Thoracocentesis

Question 18

is a general term for swelling (usu. due to fluid)

Answer 18

Edema

Question 19

in blood maintain a “colloid osmotic pressure” to help draw fluid that leaks out into tissue bed via hydrostatic pressure

Answer 19

Plasma proteins

Question 20

(e.g. heart failure) and/or colloid pressure (decresased protein synthesis/retention) pushes out more fluid (transudate) into tissue bed

Answer 20

Dysregulation of hydrostatic pressure

Question 21

causes endothelial cells to separate, thus allowing fluid + protein (exudate) to enter tissue bed.

Answer 21

Inflammation