The Thorax

Front 1

Describe the components and characteristics of the sternum.

Back 1

The sternum completes the anterior bony structure of the thorax and is made up of three sections: the manubrium, the body of the sternum, and the xiphoid process.

Front 2

Define and describe the importance of the sternal angle.

Back 2

The sternal angle (also known as the angle of Louis) is the junction of the manubrium and the body of the sternum. The site of attachment of the second rib and quickly allows the paramedic to identify the 2nd intercostal space.

Front 3

Define the term intercostals space.

Back 3

The space just inferior to each rib.

Front 4

Define the term xiphisternal joint.

Back 4

Union between xiphoid process and body of the sternum.

Front 5

Describe the characteristics of the esophagus.

Back 5

A muscular tube that is contiguous with the posterior wall of the trachea and conducts food and drink from the oral pharynx to the stomach.

Front 6

Describe the effect of changing intrathoracic pressure on blood pressure and pulse strength.

Back 6

Normally, the systolic blood pressure and pulse strength fall during inspiration and rise during expiration

Front 7

Describe the process of expiration.

Back 7

As the musculature relaxes, the diaphragm again intrudes upward into the thoracic cavity, the ribs and sternum move inferiorly, and the ribs move closer together in an inferior and posterior direction. This decreases the thoracic volume and increases the intrathoracic pressure. When the pressure within the thorax exceeds that of the surrounding atmosphere, air rushes out.

Front 8

Describe the process of inspiration.

Back 8

As the thoracic volume increases, the pressure within it becomes less than atmospheric. Air rushes in through the tracheobronchial tree and into the alveoli to equalize this pressure gradient, filling the lungs.

Front 9

Describe the structure and function of the pleura.

Back 9

The visceral pleura, a smooth membrane that lines the exterior of the lungs. It folds over on itself at the pulmonary hilum and then lines the inside of the thoracic cavity, becoming the parietal pleura.

Front 10

Describe the structure and function of the trachea.

Back 10

The trachea is the hollow and cartilage-supported respiratory pathway through which air moves in and out of the thorax and lungs.

Front 11

Describe the structure of the diaphragm.

Back 11

A muscular, dome-like structure that separates the abdominal cavity from the thoracic cavity

Front 12

Explain how the changing volume and pressure within the thoracic cage assist with the pumping blood and venous return from the systemic circulation.

Back 12

The decreased intrathoracic pressure of inspiration helps move venous blood toward the thorax and heart, while the increased pressure of expiration helps move arterial blood away from the heart and thorax.

Front 13

Explain the role of the diaphragm during inspiration.

Back 13

The diaphragm, which forms the floor of the thorax, contracts and flattens to further increase the volume of the thoracic cavity.

Front 14

Explain the role of the intercostals muscles during inspiration.

Back 14

The intercostal muscles contract to further elevate the ribs and increase the anterior-posterior dimension of the thorax.

Front 15

How many pairs of thoracic ribs are joined to each other by cartilage, and then to the sternum

Back 15

3 pairs.

Front 16

How many pairs of thoracic ribs have no anterior attachment and are known as 'floating ribs.'

Back 16

2 pairs.

Front 17

How many pairs of thoracic ribs join the sternum?

Back 17

7 pairs

Front 18

How many pairs or ribs make up the thoracic skeleton?

Back 18

12 pairs.

Front 19

Identify the location at which the trachea divides into the left and right mainstem bronchi.

Back 19

It enters through the thoracic inlet and divides into the right and left mainstem bronchi at the carina

Front 20

List the muscles of respiration.

Back 20

Chest wall muscles between the ribs, called the intercostal muscles, along with the diaphragm and the sternocleidomastoid muscles are the major muscles of respiration.

Front 21

List the number of lobes in the left and right lungs.

Back 21

The right lung has three lobes (upper, middle and lower) and the left lung has two lobes (upper and lower ).

Front 22

Name the two imaginary vertical lines used to indicate position on the external thorax.

Back 22

These lines include the midclavicular line, the anterior axillary line, the mid-axillary line, and the posterior axillary line

Front 23

The central space within the thoracic cavity bounded laterally by the lungs, inferiorly by the diaphragm, and superiorly by the thoracic outlet is known as the:

Back 23

mediastinum.

Front 24

The cord-like remnant of a fetal vessel connecting the pulmonary artery to the aorta at the aortic isthmus is known as the:

Back 24

Ligamentum arteriosum

Front 25

The dual layer forms a potential space called the:

Back 25

pleural space

Front 26

The large arteries and veins located in the mediastinum that enter and exit the heart; the aorta, superior and inferior vena cava, pulmonary arteries, and pulmonary veins are known as the:

Back 26

Great vessels.

Front 27

Describe the structure of the diaphragm.

Back 27

A muscular, dome-like structure that separates the abdominal cavity from the thoracic cavity.

Front 28

Explain the role of the sternocleidomatoid muscle during inspiration.

Back 28

The sternocleidomastoid muscles raise the upper rib and sternum and, with the sternum, the anterior attachments of the next nine ribs.