midterm

Question 1

what is the superior border of the thorax

Answer 1

suprasternal notch along the clavicle to the acromiclavicular joint which further passes into the spinous process of C7

Question 2

what’s the inferior border of thorax

Answer 2

xiphoid process along the margin of costal arch to the 10th rib which further passes through the tips of the 11-12th rib to the spinous process of the 12th rib

Question 3

what is the thoracic cage formed by

Answer 3

vertebral column behind, ribs and intercostal spaces on both sides and sternum and costal cartilages in the front

Question 4

layers of thoracic cage

Answer 4

1.skin
-supplied by supraclavicular nerves and anterior branches of intercostal nerves

2.subcutaneous tissue
-contains superficial nerves
-main vein is thoracoepigastric vein

3.superficial fascia
-forms the capsule of mammary gland

4.proper fascia
-covers superficial muscles

5.the superficial groups of muscles

• Pectoralis major muscle, pectoralis minor,subclavius anteriorly.
• Serratus anterior muscle laterally.
• Latissimus dorsi posteriorly and partially laterally;
• External oblique muscle inferiorly and laterally

6. endothoracic fascia

7.parietal pleura

8. a thin layer of fat

Question 5

borders of mammary glands

Answer 5

‣ Superiorly - from the 2nd -3rd rib.
‣ Inferiorly - to the 7th rib.
‣ Medially - from the sternal line.
‣ Laterally - to the anterior axillary line.

Question 6

where does the mammary gland lie and what does it cover

Answer 6

The gland lies in the superficial fascia and on the deep fascia covering the pectoralis maior and serratus anterior muscle

Question 7

what is the mammary gland composed of

Answer 7

-fifteen to twenty lobes containing a
-duct system
-lobules of glandular tissue
-supporting connective tissue
- surrounding fat.
•The lobes radiate out from the nipple. A single lactiferous duct from each lobe opens onto the nipple
-these ducts expand and becomes lactiferous sinus

Question 8

how are mammary glands separated from the deep fascia

Answer 8

by an area of lose connective tissues known as retro mammary space

Question 9

what is the arterial supply of mammary glands

Answer 9

-internal thoracic artery and intercostal arteries
-also the axillary artery

Question 10

lymphatic drainage of the mammary glands

Answer 10

-divided into 4 quadrants for practical purposes
-they are superior and inferior lateral quadrants and superior and inferior medial quadrants.
• The lateral quadrants of the breast drains into the anterior axillary or pectoral nodes.
• The medial quadrants of the breast is drained by means vessels, that pierce the intercostal spaces and enter nodes lying along the internal thoracic artery within the thorax.
• The inferior medial quadrant can drain into the extraperitoneal tissues and hence to nodes of the organs of the supracolic compartment abdominal cavity.

• The superior medial and lateral quadrants of the breast can drain into infraclavicular and supraclavicular nodes.

Question 11

where does intercostal spaces lie and what is it filled by

Answer 11

lies between the rib and filled by ext and int intercostal muscles

Question 12

neurovascular bundle

Answer 12

lies deep to each external intercostal muscle and under cover of the costal groove. It is made up by intercostal vein, artery and nerve arranged in that order from above downward

Question 13

intercostal muscles

Answer 13

The fibers of the external intercostal muscles:
- Run downward and forward from the lower border of the rib above to the upper border
of the rib below.
- The muscle deficient anteriorly being replaced by a fibrous membrane, the external
intercostal membrane.
The fibers of the internal intercostal muscles:
 Run downward and backward deep to the external muscles.
- The fibers of this muscle are deficient posteriorly and replaced by the internal
intercostal membrane.
 The transversus thoracic muscle forms a discontinuous layer on the deep surface of the thoracic cage linking ribs and costal cartilages to sternum. It is related Internally to endothoracic fascia and parietal pleurap

Question 14

blood supply of intercostal spaces

Answer 14

The intercostal arteries lie between the intercostal veins and nerves in the costal
grooves.
 Each space contains:
Anterior Intercostal artery: From the internal thoracic artery or one of its branches
Posterior intercostal artery: From the aorta.
 The anterior and posterior Intercostal arteries anastomose with each other and supply
the intercostal muscles and overlying superficial thoracic muscles, the breast and skin.
 The intercostal veins lie above the intercostal arteries in the subcostal groove.
Anterior intercostal veins: drain into the internal thoracic veins
Posterior intercostal veins: drain backward into the azygos or hemiazygos veins

Question 15

the internal thoracic artery

Answer 15

Branch of the 1st part of the subclavian artery.
 Descends anteriorly in the thorax deep to the cartilages of the upper 6 ribs and just
lateral the sternum.
 Divides at the level of the 6th intercostal space into superior epigastric artery
 Musculophrenic artery which continues around the costal margin giving off the lower
anterior intercostal arteries and supplying the diaphragm.
 The pericardiophrenic artery is a branch which accompanies the phrenic nerve and
supplies the pleura, pericardium and diaphragm