Week Two - Anatomy

Question 1

How do the ribs differ from each other? Hint, three groups

Answer 1

Ribs 1-7 connected by costal cartilages to sternum
Ribs 8-10 connect to the costal cartilage above
Ribs 11 and 12 floating ribs - end free in muscles in abdominal muscles

Question 2

Ribs 3-9 are considered typical, what are the defining features?

Answer 2

Head - wedge shaped and two facets separated by the crest
Neck
Tubercle - articulates with corresponding transverse process of the vertebra and a rough non articular part provides attachment for the costotransverse ligament
Body - concave internal posterior surface has the costal groove - VAN

Question 3

How many costovertebral joints are there and explain them?

Answer 3

1) joint of the head of the rib : body of vert superior to rib, IVD, head of rib, body of vert of same rib
2) costotransverse joint: transverse process of vertebra of same number as rib and tubercle of rib

Question 4

What is the arterial supply of the intercostal muscles?

Answer 4

Anterior intercostal artery arises from the internal thoracic artery - usually 2
Posterior intercostal artery arises from the thoracic aorta - the exception is one arises from the subclavian

They anastomose posteriorly

Question 5

What is the venous drainage of the thoracic wall?

Answer 5

Primarily into the Azygos system and then in to the SVC. There is some drainage into the internal thoracic vein.

Question 6

What three bones make up the sternum?

Answer 6

Manubrium, body and xiphoid process (cartilaginous until mid 40s)

Question 7

Where are the openings in to the diaphragm?

Answer 7

T8 - vena cava
T10 - oesophagus
T12 - aorta

Question 8

Where is the diaphragm during expiration?

Answer 8

Right dome - behind 5th rib in mid clavicular line - liver pushes up
Left dome - behind 5th ICS in MCL

Question 9

What nerve supplies the diaphragm?

Answer 9

The phrenic - c3,4,5 keep you alive! Gives motor to diaphragm and sensory to the pericardium, mediastinal part of parietal pleura, diaphragmatic part of parietal pleura and both sides of diaphragm.

The margins of the diaphragm receive innervation from intercostal muscles too

Question 10

What are the main muscles of inspiration?

Answer 10

External intercostal muscles - elevate
Diaphragm

Accessory = sternocleidomastoid, scalenes and pec major

Question 11

What are the muscles used in expiration?

Answer 11

Passive recoil!

In active breathing the internal intercostal, recite abdominis, external oblique, internal oblique, transverse abdominis - these abdominal muscles push up on the diaphragm.

Question 12

The parietal pleura consists of four parts, what are these?

Answer 12

Cervical, mediastinal, costal (majority), diaphragmatic

Question 13

Anatomically where does the trachea extend from?

Answer 13

Lower border of cricoid cartilage tot eh division into right and left bronchi at the carina

Question 14

How many C shaped cartilage rings are there?

Answer 14

18-22 - posterior to trachealis muscle

Question 15

Which bronchi is shorter? Describe both of the bronchis anatomical directions

Answer 15

Right is shorter, wider and more vertical - hence why more likely to aspirated in to this side
Left is longer and more horizontal

Question 16

Describe the bronchial tree..

Answer 16

Trachea, bronchi, lobar bronchi, segmental brochi which supplies a brocho-pulmonary segment which is an area of lung supplied by own segmental bronchus and segmental branches of the pulmonary artery and vein. This is surgically important - can remove segment.

Question 17

Where do the oblique and horizontal fissures run?

Answer 17

Oblique - t2 to 6th costal cartilage

Horizontal - from oblique fissure along border of 4th rib and costal cartilage

Question 19

Where does the diaphragms peripheral muscular part arise from?

Answer 19

Lower ribs

Arcuate ligaments - lateral, medial, median (thickening of fascia over posterior muscles)