The Thorax

Front 1

External Intercostal muscle

Back 1

Superior Att: inferior border of the rib above. Ex: 4th external Intercostal muscle attached to bottom of rib 4.

Inferior Att: superior border of the rib below. Ex: 4th external intercostal muscle attached to top of rib 5.

Actions: elevates the rib below.

Innervation: Intercostal nerve, Ex: 4th Intercostal nerve.

Front 2

Internal Intercostal muscle

Back 2

Superior Att: inferior border of the rib above.

Inferior Att: superior border of the rib below.

Actions: depresses the rib above.

Innervation: Intercostal nerve

Front 3

Innermost Intercostal muscle

Back 3

Superior Att: inferior border of the rib above.

Inferior Att: superior border of the rib below.

Actions: depresses the rib above.

Innervation: intercostal nerve

Front 4

Parietal pluera

Back 4

The outer lining of serous membrane enclosing the plueral cavity.

Front 5

Costal pleura

Back 5

Inner surface of the thoracic wall

Front 6

Mediastinal parietal pleura

Back 6

Lining the mediastinum medially

Front 7

Diaphragmatic parietal pleura

Back 7

Covering the superior surface of the diaphragm

Front 8

Cervical pleura

Back 8

Extends superior to the 1st rib

Front 9

Pleural recesses

Back 9

Areas where one parietal pleura contacts another parietal pleura

Front 10

Visceral pleura

Back 10

Delicate serous membrane that covers each lung

Front 11

Pleural cavity

Back 11

The space between the parietal pleura and visceral pleura.

Front 12

How many lobes does the right lung have?

Back 12

3 lobes; superior, middle, & inferior

Front 13

How many lobes does the left lung have?

Back 13

2 lobes; superior & inferior

Front 14

Pericardium

Back 14

Between right & left pleural cavities. Occupies the midline between lungs, lies posterior to the sternum, & contains the heart

Front 15

Phrenic nerve

Back 15

Innervates diaphragm, motor and sensory nerves. Important for breathing. Located between mediastinal pleura and pericardium, passes down the heart. Anterior to the root of the lung.

Front 16

Lingula

Back 16

On the left lung, inferior, medial portion of the superior love. Homolog of the middle lobe of right lung.

Front 17

Mediastinum Boundaries

Back 17

Superior: superior thoracic aperture.

Inferior: diaphragm.

Anterior: sternum.

Posterior: vertebral bodies of T1-T12.

Lateral: mediastinal pleura (left & right).

Front 18

Pericardium (pericardial sac)

Back 18

Encloses the heart. Pierced by the aorta, pulmonary trunk, superior vena cava, the 4 pulmonary veins, & inferior vena cava

Front 19

Fibrous pericardium (parietal pleura)

Back 19

Layer of connective tissue that is non-elastic. Provides support and protection to the heart.

Front 20

Serous pericardium (visceral/parietal)

Back 20

Visceral and Parietal layers. The visceral layer is intimately attached to the heart and the roots of the great vessels. The Parietal layer is attached to the inner lining of the fibrous pericardium.

Front 21

Pericardial cavity

Back 21

The space between the Parietal serous pericardium and the visceral serous pericardium. It contains small amounts of serous fluid that acts to reduce surface tension and lubricate.

Front 22

Oblique pericardial sinus

Back 22

Posterior to the heart within the pericardial cavity.

Front 23

Transverse pericardial sinus

Back 23

Posterior to the pulmonary trunk and ascending aorta within the pericardial cavity.

Front 24

Apex of the heart

Back 24

Inferior left side of heart, part of left ventricle.

Front 25

Base of the heart

Back 25

Formed by the left atrium and part of the right atrium and the emergence of the great vessels.

Front 26

Vagus nerve (CN X)

Back 26

Stimulates some muscles in the heart to slow down the heart rate. Descends within the thorax posterior to the root of the lung.

Front 27

Left Recurrent Laryngeal nerve

Back 27

Branches from left vagus nerve inferior to the aortic arch and posterior to the ligamentum arteriosum.

Front 28

Ligamentum arteriosum

Back 28

Between the aortic arch and pulmonary trunk. Connects the left pulmonary artery to the inferior part of the arch of the aorta.

Front 29

Coronary Sulcus

Back 29

Courses the circumference of the heart, separating the atria from the ventricles.

Front 30

Anterior interventricular sulcus

Back 30

Separates the right & left ventricles. Also, indicates the location of the interventricular septum internally.

Front 31

Right auricle

Back 31

Extends from the right atrium.

Front 32

Left auricle

Back 32

Extends over the left atrium

Front 33

Aortic semilunar valve

Back 33

A valve between the left ventricle and the aorta

Front 34

Pulmonary semilunar valve

Back 34

A valve between the pulmonary trunk and the right ventricle.

Front 35

Coronary Sinus

Back 35

On the diaphragmatic surface of the heart, located on the coronary sulcus. Opens into the right atrium.

Front 36

Great cardiac vein

Back 36

Runs into the coronary Sinus. Passes deep to the arteries on the anterior aspect of the heart. Returns deoxygenated blood from anterior surfaces of the left ventricle.

Front 37

Middle cardiac vein

Back 37

Runs along the posterior interventricular artery. Drains into the coronary sinus and drains part of the right and left ventricles.

Front 38

Small Cardiac vein

Back 38

Runs along side the marginal artery. Runs into the coronary sinus between right atrium and ventricle. Drains the coronary sinus and the right atrium

Front 39

Left Coronary artery

Back 39

Arises from the aorta, above the left cusp of the aortic valve. Feeds blood to the left side of the heart. Divides into the LAD branch & circumflex branch.

Front 40

Anterior interventricular artery

LAD (left anterior descending artery)

Back 40

Major blood supply to the interventricular septum.

Front 41

Circumflex artery

Back 41

In the coronary sulcus around the left side of the heart. Supplies the left atrium with oxygenated blood.

Front 42

Right coronary artery

Back 42

Opens into the right aortic sinus.

Begins in the coronary sulcus between the right auricle and the ascending aorta.

Front 43

Anterior right atrial branch

Back 43

Arises close to origin of the right coronary artery and ascends along the anterior wall of the right atrium toward the superior vena cava.

Front 44

Sinuatrial nodal branch

Back 44

Supplies the sinuatrial node

Front 45

Right marginal branch

Back 45

Follows the margin of the heart off of the right coronary artery. Arises near the inferior border of the heart, where it accompanies the small cardiac vein.

Front 46

Posterior interventricular branch or

PDA (Posterior descending artery)

Back 46

Runs off the right coronary artery (right dominant heart) or runs off the left coronary artery (left dominant heart). Accompanies the middle cardiac vein. Supplies oxygenated blood to posterior part of interventricular septum and posterior inferior wall of the left ventricle.

Front 47

Crux of the heart

Back 47

The point where the posterior interventricular sulcus meets the coronary sulcus. The artery to the AV node arises from the right coronary artery at this location.