Anatomy

Front 1

1. What are the boundaries of the thorax?

Back 1

Posteriorly – thoracic spine

Anteriorly – sternum

Inferiorly – dome diaphragm

Circumference – rib cage and intercostals muscles

Front 2

2. What does the diaphragm attach to?

Back 2

1. Twelfth thoracic and upper lumbar vertebrae

2. Inferior margin of rib cage

3. Xiphoid process of the sternum

Front 3

3. What are the contents of the thoracic cavity?

Back 3

1. Paired pleural sacs

2. Mediastium – region between the right and left pleural sacs

Front 4

4. What are the different parts of the thoracic vertebrae?

Back 4

Articular facets
-on lateral aspects of bodies
-on anterior aspects of transverse processes

**articulate respectively w/ heads and tubercles of ribs

Front 5

5. What are the three parts of the adult sternum?

Back 5

1. Upper manubrium

2. Elongated body

3. Lower small pointed xiphoid process

Front 6

6. What is the jugular (suprasternal) notch?

What is the sternal angle (of Louis)?

Back 6

Notch on the upper border of the manubrium

Transversely situated ridge which represents the slight angle at which the manubrium and sternal body join

Front 7

7. Why is the sternal angle an important landmark of the thorax?

Back 7

Where the costal cartilage of the second rib articulates w/ the sternum

**most reliably identified rib level

Also bifurcation of trachea into main bronchi and upper border of fibrous pericardium is at this level

Front 8

8. What does the body of the sternum articulate with?

What does the xiphoid process protrude into?

Back 8

1. Costal cartilage of 3rd through 7th ribs on its lateral border

2. Xiphoid process

Abdominal musculature

Front 9

9. What are the different parts of the rib?

Back 9

1. Head

2. Neck

3. Body

Front 10

10. What is the head of the rib?

What does it articulate with?

Back 10

Enlarged posterior extremity

Articulates w/ the costal articular surfaces on the lateral aspect of the vertebral body

Front 11

11. What is the body of the rib?

What does it articulate with?

Back 11

Point where there is a posteriorly directed tubercle that contains an articular surface

Articulates with the transverse process of a thoracic vertebra

Front 12

12. What does the angle of the rib mark?

What does each rib articulate with?

Back 12

The lateral extent of the deep back muscles

Costal cartilage at its anterior end

Front 13

13. What are the true ribs?

Why are they called this?

Back 13

Upper seven ribs

Costal cartilage articulates directly w/ the sternum

Front 14

14. What are the false ribs?

What are the floating ribs?

Back 14

Ribs 8 through 12

Ribs 8 through 10 have indirect sternal attachments b/c their costal cartilages attach to the next higher costal cartilage

Ribs 11 and 12 are floating ribs

**have no attachment to other ribs and end in abdominal musculature

Front 15

15. Why is the first rib unique?

Back 15

Unique in....

1. Shortness
2. Breadth
3. Tightness of curvature
4. Superior surface markings

Front 16

16. What does the upper surface of the first rib contain?

Back 16

1. Tubercle for the anterior scalene muscle insertion

2. Subclavian vein and artery groove the rib anterior and posterior to this tubercle

Front 17

17. Why on a PA chest film does the anterior portion of each rib project much lower than its posterior part?

Back 17

Because each rib has a significant downward slope as it is followed from its head to its costal cartilage

Front 18

18. During inspiration how do the three dimensions increases to expand the volume of the thoracic cavity?

Back 18

1. Superoinferior expansion
-rib elevation by muscles like the scalenes and depression of the diaphragm caused by its contraction

2. Anteroposterior dimension
-increases as the ribs are elevated

3. Mediolateral dimension (esp of lower ribs)
-caused by posterior rib artculations permitting some rotation of bucket handle shaped ribs

Front 19

19. Where can the jugular (suprasternal) notch be palpated?

What can be palpated below this notch?

Back 19

Between the sternal heads of origin of the sternocleidomastoid muscle and the sternoclavicular joint

The flat anterior aspect of the manubrium down to the transverse ridge of the sternal angle

Front 20

20. What does the sternal angle identify?

Where is the xiphoid process?

Back 20

The transverse plane which seperates the superior from the inferior mediastinum

T8 - 9 vertebral level and near the top of the dome of the diaphragm

Front 21

21. What are some posterior landmarks to identify posterioor rib levels?

Back 21

1. Medial end of scapular spine marks level of 4th rib

2. Inferior angle of scapula marks level of 8th rib

Front 22

22. What are the four vertical reference lines on the surface of the thorax?

Back 22

1. Parasternal line - lateral border of sternum

2. Midclavicular line - vertical line through middle of clavicle

3. Midaxillary line - vertical line dripped from middle of axilla

4. Scapular line - medial border of scapula

Front 23

23. What are the soft tissues of the thoracic wall

Back 23

1. Skin and subcutaneous tissues superficially

2. Intercostal muscles, nerves and vessels intermediatley

3. Parietal pleura deeply

Front 24

24. What innervates and provides blood to the skin and subcutaneous tissues of the anterolateral thorax?

Where do these emerge from?

Back 24

Anterior and lateral cutaneous branches of the intercostal nerves and vessels

Parasternally (anterior) and near midaxillary line (lateral)

Front 25

25. What can provide additional blood supple?

What does these anstomose with?

Back 25

Thoracic branches of the axillary vessels

Anastomose below through the thoracoepigastric veins w/ the subcutaneous veins of the abdomen

Front 26

26. Is there a T1 dermatome?

What abuts the C4 dermatome then?

Back 26

No since the 1st intercostal nerve usually doesn't innervate thoracic skin

T2 dermatome around the upper thorax

Front 27

27. How do the external intercostal muscles descend?

Back 27

Run obliquely toward the sternal end of the next lower rib

**oblique in a medial direction

Front 28

28. How do the internal intercostal muscles descend?

Back 28

Angle obliquely toward the vertebral end of the next lower rib

**coursing perpendicular to the fibers of the external costal muscles

Front 29

29. What does this orientation of the intercostal muscles provide?

What innervates the intercostal muscles?

What provides a measure of the functional integrity of the intercostal muscles and their innervation?

Back 29

Provides good resistance to multidirectional stresses

Intercostal nerve of that intercostal space

Simple observation of the intercostal spaces

Front 30

30. How do the intercostal muscles function in changing the volume of the thoracic cage?

Back 30

Maintain resistance of intercostal space to both atmospheric and intrathoracic pressures

Intercostal spaces....

1. Suck in w/ inspiration as intrathoracic pressure decreases below atmospheric pressure

2. Bulge out w/ expiration as intrathoracic pressure increases above atmospheric pressure

Front 31

31. What arises from the eleven intercostal nerves?

What do the intercostal nerves innervate?

Back 31

Part of the ventral ramus of the T1 spinal nerves

All of the ventral ramus of the T2 to T11 spinal nerves

1. Full thickness of thoracic wall at the level of their intercostal space

2. Motor innervation to intercostal muscles

3. GSA sensory innervation to overlying skin, intercostal muscles, ribs and deep parietal plexus

Front 32

32. What forms the subcostal nerve?

Where does this run?

Back 32

Some of the ventral ramus of the T12 spinal nerve

Runs below the 12th rib

Front 33

33. What provides motor and sensory innervation to the full thickness of the abdominal wall?

Back 33

1. Lower 5 intercostal nerves

2. Thoracoabdominal intercostal nerves

3. Subcostal nerve

Front 34

34. How do somatic afferent pain and visceral afferent pain differ?

Why can pain arising from any thoracic wall structure be referred to the abdominal wall and vice versa?

Back 34

Somatic - sharp, stabbing, well localized

Visceral - dull, vague, poorly localized

B/c of the dual innervation of thoracic and abdominal wall by the thoracoabdominal intercostal and subcostal nerves

Front 35

35. Which arteries are in the posterior portion of the intercostal spaces?

What veins accompany them and where do they empty?

Back 35

Posterior intercostal arteries

**derived from the thoracic aorta

Posterior intercostal veins

**empty into the azygos system of veins

Front 36

36. What do the posterior intercostal vessels anastomose with?

What are these vessels derived from?

Back 36

Anterior intercostal vessels

Derived from the internal thoracic vessesl

Front 37

37. Where do the internal thoracic vessels course?

What does the internal thoracic (mammary) artery arise from?

What does the internal thoracic (mammary) vein empty into?

Back 37

Descends lateral to the sternum bwt the intercostal muscles and costal cartilage superficially and parietal pleura deeply

Subclavian artery at the base of the neck

Brachiocephalic vein

Front 38

38. What does the internal thoracic vessel divide into when it ends?

Where does these course?

Back 38

1. Musculophrenic vessels

**run along the diaphragmatic attachment to the lower margin of the rib cage

2. Superior epigastric vessels

**enter the deep abdominal wall

Front 39

39. What do the musculophrenic vessels supply and give off?

What do the superior epigastric vessels anastomose with when they enter the deep abdominal wall?

Back 39

Supply the peripheral diaphragm

Give off lower anterior intercostal vessels

1. Intercostal and lumbar branches of the aorta

2. Inferior vena cava

3. Inferior epigastric branches of the external iliac vessels

Front 40

40. If the upper thoracic aorta is obstructed distal to the origin of the left subclavian artery how can blood flow?

Back 40

1. Collaterally down the internal thoracic arteries

2. Through the intercostal and lumabr artery anastomoses

3. Enter the aorta below the obstruction

Front 41

41. Where is a needle introduced into the thoracic cavity through the intercostal space?

Why?

Back 41

Low in the space to avoid the major neurovascular structures

Major branches of the intercostal nerves and vessels are high in the intercostal space

Front 42

42. Where should the needle be introduced if the intercostal nerves are to be blocked by local anesthetic?

What arteries are commonly used surgically to bypass obstruction of a coronary artery?

Back 42

High in the intercostal space

Internal thoracic arteries

Front 43

43. What are the boundaries of the thoracic inlet?

What does the inlet contain?

Back 43

1. First thoracic vertebra

2. First ribs and upper border of the manubrium

Contains the apices of the lungs

Front 44

44. What are the boundaries of the thoracic outlet?

What fills the space of the outlet?

Back 44

1. Twelfth thoracic vertebra

2. Eleventh and twelfth ribs

3. Intercostal cartilage of ribs 7 - 10

4. Xiphoid process

Diaphragm fills the space