Anatomy of the Thorax and Anterior Neck pt. 1

Question 1

The thorax is a region of the torso bounded superiorly by:

Answer 1

the 1st ribs and thoracic inlet

Question 2

The thorax is a region of the torso bounded anteriorly by:

Answer 2

the sternum

Question 3

The thorax is a region of the torso bounded laterally by

Answer 3

the costae (ribs 12 pairs) and intercostal spaces

Question 4

The thorax is a region of the torso bounded posteriorly by:

Answer 4

the vertebral column (12 thoracic vertebrae)

Question 5

The thorax is a region of the torso bounded inferiorly by:

Answer 5

the diaphragm

Question 6

Pleural spaces contain:

Answer 6

pulmonary cavities, the pleurae, and the lungs

Question 7

Mediastinum contains:

Answer 7

pericardium and heart, great vessels, portions of the airway, esophagus, lymphatics, and various neurovascular elements

Question 8

Intercostal spaces

Answer 8

(between ribs) are occupied by layers of muscle and the neurovasculature which serves the muscle and overlying skin.

Question 9

Generally, the intercostal muscle is divided into 3 layers:

Answer 9

• external intercostal
• internal intercostal
• innermost intercostal

Question 10

External intercostal mm

Answer 10

pull ribs upwards and outwards, to slightly increase the volume of the thoracic cavity (inspiratory) present anteriorly as aponeuroses.

Question 11

Internal intercostal mm

Answer 11

pull ribs downwards and inwards, to slightly decrease the volume of the thoracic cavity (expiratory). Distributed from the sternum to costal angle (only present posteriorly as aponeuroses)

Question 12

Innermost intercostal mm

Answer 12

function akin to internal intercostal mm

Question 13

Anterior intercostal brs. 1-6

Answer 13

typically arise directly from internal thoracic

Question 14

Anterior intercostal brs 7-9

Answer 14

typically arise from musculophrenic br.

Question 15

Posterior intercostal aa.

Answer 15

branch off thoracic aorta-posterior intercostal brs. are typically the dominant source of blood to the intercostal spaces

Question 16

What arteries create anastomoses for intercostal spaces?

Answer 16

anterior and posterior intercostal arteries

Question 17

Where are intercostal aa. found?

Answer 17

subcostal groove of the rib forming the superior boundary of the intercostal space; accompanied by an intercostal v. and n.

Question 18

Where is the neurovascular serving the intercostal spaces found?

Answer 18

between the internal intercostal mm. and innermost intercostal mm.

Question 19

How are the parts of the subclavian artery delimited?

Answer 19

Conceptually divided into three parts, with respect to the vessel’s relationship to the anterior scalene m.

Question 20

First part of the SCA

Answer 20

found medial to the anterior scalene m.

Question 21

Second part of the SCA

Answer 21

posterior to the anterior scalene m.

Question 22

Third part of the SCA

Answer 22

lateral to the anterior scalene

Question 23

Beyond the ________________, the subclavian a. transitions into the axillary a.

Answer 23

lateral border of the first rib

Question 24

What are the boundaries of the mediastinum?

Answer 24

• superiorly by the thoracic inlet and first ribs
• inferiorly by the diaphragm
• laterally by the pleura
• anteriorly by the sternum and pleurae
• posteriorly by the vertebral column

Question 25

What are the two layers of the pericardium?

Answer 25

fibrous pericardium and serous pericardium

Question 26

The fibrous pericardium is made up of

Answer 26

dense connective tissue

Question 27

What are the functions of the pericardium?

Answer 27

• anchor to diaphhragm and surrounding structures
• inflexible and provides heart from overfilling during diastole
• reduce friction
• protect heart from infection

Question 28

The serous pericardium is composed of:

Answer 28

• parietal layer

- visceral layer (epicardium)

Question 29

Parietal and visceral serous layers are separated by:

Answer 29

the fluid-filled pericardial cavity

Question 30

Borders of the heart

Answer 30

• superior: atria
• right border: r. atrium
• left border (obtuse margin): L. ventricle + L. auricle
• Apex
• Inferior border (acute margin): ventricles

Question 31

Sternocostal surface (anterior)

Answer 31

formed predominantly by the R. ventricle with small contributions from the R. atrium and L. ventricle. The coronary and anterior interventricular sulcus are visible on this surface

Question 32

Diastole

Answer 32

ventricular filling

Question 33

systole

Answer 33

ventricular emptying

Question 34

Heart sounds

Answer 34

created by the shutting of valves (to prevent backwards flow)

Question 35

Lub (1st sound; S1)

Answer 35

AV valves close

Question 36

Dub (2nd sound; S2)

Answer 36

semilunar valves closure

Question 37

Where is the heart found?

Answer 37

The heart is found in the middle mediastinum of the thoracic cavity, surrounded by the pericardium

Question 38

Atria

Answer 38

receive blood that will be pumped into ventricles; weak contraction

Question 39

Ventricles

Answer 39

discharge blood either into pulmonary trunk or ascending aorta; more powerful contraction