Lecture 2 - SQ

Question 1

1. How many pairs of ribs usually articulate directly with the sternum?

Answer 1

1. The upper seven pairs of ribs (true ribs) usually articulate directly with the sternum through
   their costal cartilages.

Question 2

2. At what vertebral level does the jugular notch and the sternal angle lie in a person at rest?

Answer 2

2. The jugular notch (or supra-sternal notch) lies at the level of the 2nd thoracic vertebral body.
   The sternal angle (or angle of Louis) lies at the level between 4th and 5th thoracic vertebral
   bodies.

Question 3

What common abnormalities of the ribs can be seen on a routine chest x-ray?

Answer 3

3. Calcification of costal cartilages, fractures of ribs, bifid ribs and cervical ribs.

Question 4

4. Where is the weakest part of a typical rib?

Answer 4

4. The weakest part of a typical rib is the shaft near the angle of the rib.

Question 5

5. Which is the lowest rib to form part of the costal margin?

Answer 5

5. The lowest rib to form part of the costal margin is the 10th rib and its costal cartilage.

Question 6

6. What is the Angle of Louis?

Answer 6

6. The Angle of Louis, also known as the sternal angle, is the slight elevation at the junction
   between the manubrium and the body of the sternum. The sternal angle indicates the place
   where the second rib articulates with the sternum. It is at the level of the intervertebral disc
   between the 4th and 5th thoracic vertebrae.

Question 7

7. What is the most common pathway for lymph drainage for the breast?

Answer 7

7. Approximately 75% of the lymph from the breast drains to axillary nodes, specifically to the
   pectoral nodes.

Question 8

8. What is the difference between a true rib and a false rib?

Answer 8

8. True ribs (1 to 7) all attach to the sternum directly through their own costal cartilages. False
   ribs (8 to 12) connect to the costal cartilages immediately above them, rather than directly to
   the sternum.

Question 9

9. What is unusual about the organization of the components of the neurovascular bundle in a
   typical intercostal space?

Answer 9

9. Typically, veins lie superficial to arteries which, in turn, lie superficial to nerves. In the
   intercostal spaces, however, the vein lies superior rather than superficial and the nerve lies
   inferior rather than deep. The nerve is unusually susceptible to trauma in this superficial
   position.

Question 10

10. Sternal joints commonly change with age in a way that is not pathological. Describe what
    types of changes one might expect to see in the manubriosternal and xiphisternal joints in the
    elderly. How would these changes appear on X-ray?

Answer 10

10. With aging these joints often become synostotic. They would then appear on X-ray as a
    single osseous element.

Question 11

11. What is (are) the function(s) of the external and internal intercostal muscles? Under what
    natural circumstances would you expect these muscles to be concurrently active yet there be
    no movement of the rib cage?

Answer 11

11. The external and internal intercostals are muscles of respiration that help expand and
    compress the rib cage. When they are concurrently active, the rib cage is stiffened or fixed.
    We typically do this when we pull ourselves up by our arms. In that situation the origin of
    the pectoralis major is on the humerus and its insertion is on the chest wall.

Question 12

12. What thoracic organs are most likely damaged by a penetrating injury from the sharp end of a
    broken rib?

Answer 12

12. The thoracic organs which are liable for injury from a broken rib are: the parietal pleura, then
    the visceral pleura and then the lung. There might be damage to the intercostal nerve and
    vessels as well. Rarely the pericardium and heart.

Question 13

13. Can cutting the visceral pleura cause pain? If yes/no – why?

Answer 13

13. No, because it is not sensitive, i.e., it has no sensory nerves.

Question 14

14. Where is the pleural cavity? Explain it to your table partners.

Answer 14

14. The pleural cavity is a potential space lying between the parietal pleura and the visceral (or
    pulmonary) pleura and the two layers of the pleura unit at the hilum of the lung.

Question 15

15. What structures pass through the roots of the lungs?

Answer 15

15. Structures passing through the roots of the lungs are: the main bronchus, pulmonary artery,
    and two pulmonary veins (a superior and inferior pulmonary vein), lymph nodes, nerves and
    lymphatics.

Question 16

16. What is meant by the anatomical position?

Answer 16

16. In the anatomical position the upper limbs hang by the sides with the palms forward and the
    thumbs directed laterally. This is the internationally recognized position of reference for
    anatomical discussion.

Question 17

17. What is the difference between medial and median?

Answer 17

17. Median refers to the midline proper; medial means directed toward that midline.

Question 18

18. What is a coronal plane?

Answer 18

18. A coronal plane, which is synonymous with a frontal plane, is any plane that divides the
    cadaver into anterior and posterior sections perpendicular to the median plane. There is a
    coronal suture that goes across the top of the skull, from one temporal area to the other.
    Coronal planes are approximately parallel to that suture.

Question 19

19. Distinguish between a suture and a symphysis

Answer 19

19. Both sutures and symphyses have fibrous tissue connecting two bony elements. In sutures
    there is only fibrous tissue between the bones, while the interosseous elements in a
    symphysis is fibrocartilage. Sutures permit little or no movement. Symphyses are
    particularly strong joints that allow slight movement and act as shock absorbers. The joints
    between the flat bones of the skull are sutures. Intervertebral discs are symphyses.

Question 20

20. What is the major difference between a tendon and an aponeurosis?

Answer 20

20. Shape—a tendon is thick and cord-like, whereas an aponeurosis is broad, flat and relatively
    thin.

Question 21

21. True or false: Males don’t get breast cancer because they have no mammary glands.

Answer 21

21. False: Males retain undeveloped mammary glands and, as such, they can and do get breast
    cancer. The incidence of breast cancer in males is about 1/200th that of females.