AXIAL SKELETON: Thorax

Question 1

What is the Anterior median line?

Answer 1

Indicates the intersection of the median plane with the anterior thoracic wall

Question 2

What is the Midclavicular line?

Answer 2

Pass through the midpoints of the clavicles, parallel to the anterior median line

Question 3

What is the Anterior axillary line?

Answer 3

Runs vertically along the anterior axillary fold, which is formed by the border of the pectoralis major as it spans from the thorax to the humerus (arm bone)

*lateral anterior side of thorax

Question 4

What is the Midaxillary line?

Answer 4

Runs from the apex (deepest part) of the
axilla, parallel to the anterior axillary line

*between the anterior and posterior axillary line

Question 5

What is the Posterior axillary line?

Answer 5

Parallel to the anterior axillary line, is drawn vertically along the posterior axillary fold
formed by the latissimus dorsi and teres major muscles as they span from the back to the humerus

*lateral posterior side of the thorax

Question 6

What is the Sternal angle?

Answer 6

Is a palpable landmark that lies at the level of the second pair of costal cartilages

Question 7

What are the costal margins?

Answer 7

Formed by the medial borders of the 7th–
10th costal cartilages, are easily palpable where they extend
inferolaterally from the xiphisternal joint

Question 8

What is the Sternal Joints?

Answer 8

1. Anteroposterior displacement for respiration

2.

Question 9

What is the Manubriosternal joint?

Answer 9

1. Is symphysis (secondary cartilaginous joint) between manubrium and body of the sternum
   * At the level of the 2nd costal cartilage and posteriorly at the T4-T5 disc

Question 10

What is the Sternocostal joints?

Answer 10

1. Are the articulation of the sternum with the first seven cartilages. 2. The sternum (manubrium) forms synchondrosis with the first costal cartilage, whereas the second to seventh costal cartilages form synovial plane joints with the sternum
   * Used for gliding movements for respiration (due to plane joint)

Question 11

What is the Interchondral joints?

Answer 11

1. 6th to 9th are synovial plane joints

2. 9th to 10th are Fibrous joints

Question 12

What are Costochondral joints?

Answer 12

1. Are synchondrosis in which the ribs articulate with their respective costal cartilages
2. No movement!

Question 13

What are 2 joints of the costal head?

Answer 13

1. Intrarticular ligament
2. Radiate ligament

• Tightly connect the head of the rib to the vertebral body at the inferior and superior costal facet
  (except: 1st, 10th to 12th ribs articulate with a single vertebra; no intra-articular ligament)

*Allows only gliding movements

Question 14

What is the Costotransverse joints?

Answer 14

1. Is synovial plane joint of tubercle of rib with transverse process of corresponding vertebra
   * strengthened by costotransverse ligaments
   * Allow only gliding movement

Question 15

What is the relationship between joints of the costal head and the costotransverse joints?

Answer 15

1. Move simultaneously and in the same direction

2. Slight gliding movement; determined by the shape and direction of the articular surfaces

Question 16

What are the movements of the ribs?

Answer 16

• Upper 6 ribs movement is minimum going upward and downward(like a pump)
• 7th to 10th ribs move upward, backward, downward, and forward (bucket-handle movement)
• 11th and 12th ribs move a little in all directions