Structure and function of the thoracic wall

Question 1

What is the function of the skeleton

Answer 1

Protects vital organs
Movement
Supports the body
Storage of minerals
Source of RBC

Question 2

What is the structure of the skeleton

Answer 2

Axial: skull, vertebrae, ribs
Appendicular: limbs

Question 3

What is the thoracic cage made up of

Answer 3

Vertebrae and Intervertebral disc
Ribs
Sternum
Costal Cartilages

Question 4

What is the function of the thoracic cage

Answer 4

Protection of viscera

Muscle attachment

Question 5

What is related next to the thoracic cage

Answer 5

Pectoral girdle (Clavicle/Scapula)

Question 6

What are the boundaries of the thoracic cage

Answer 6

Roof: Pleural membrane over apex of lungs
Floor: Diaphragm
Walls: Ribs, Sternum, Vertebrae and intercostal muscles

Question 7

Describe the costal element of the 12 pairs of ribs

Answer 7

1-7 true ribs
8-10 false ribs
11-12 floating ribs

Ribs also classified as:
Typical Ribs 3-9
Atypical 1,2,10th-12th

Question 8

Discuss the features of a typical rib

Answer 8

Head with two facets
Neck
Tubercle
Body (shaft) with costal (subcostal) grove
two facets are for articulation with vertebrae above and below
The tubercule articulate with transverse process of the vertabrae
Internal surface has costal groove has veins arteries and nerves running through it

Question 9

Describe the characterisitic features of the thoracic vertebrae

Answer 9

Heart shaped body with demi facets
Costal facets on transverse process
Inferior pointing spinous processes

Question 10

What are the different types of joints of the thoracic wall

Answer 10

Intervertebral
Costovertebral
Costochondral
Sternocostal
Sternoclavicular

Question 11

Discuss the costovertebral and costotransverse joints

Answer 11

Costovertebral: Head of rib articulates with costal (demifacet) on two adjacent vertebrae and the associated IV disc. Exceptions 1st, 11th and 12th which only articulate with one vertebrae.
Costotransverse: Tubercle of rib articulates with transverse process of vertebrae.

Question 12

Discuss the thoracic apertures

Answer 12

Superior thoracic aperture (Inlet) formed from body of T1, 1st Rib and manubrium.
Known as outlet syndrome!

Inferior thoracic aperture (Outlet) formed from body

T12, rib 11 and 12. Costal cartilage of rib 7-12 and xiphoid process

Question 13

Discuss paediatric anatomy

Answer 13

Horizontal ribs
More circular cavity

Prevents lateral expansion of chest cage in breathing

Xiphoid process may protrude

Question 14

Discuss pectoralis major

Answer 14

Origin or Proximal attachment: Clavicle and sternum

Insertion or distal attachment: Humerus

Function: Adducts and medially rotates humerus

Innervation: Lateral and Medial Pectoral nerves

Question 15

Discuss pectoralis minor

Answer 15

Origin or Proximal attachment: 3-5th rib.
Insertion or Distal attachment: coracoid process of scapula.
Function: Stabilizers scapula
Innervation: Medial pectoral nerve

Question 16

Discuss intercostal muscles

Answer 16

Three Layers of Muscles
External Intercostals
Internal Intercostals
Innermost Intercostals

Supplied by intercostal artery, vein and nerve which runs in subcostal groove

Question 17

Discuss the serratus anterior

Answer 17

Origin or Proximal attachment: 1-8th rib.

Insertion or Distal attachment: medial border of scapula.

Function: Protracts scapula

Innervation: Long Thoracic Nerve

Question 18

Discuss the arterial supply of the thoracic cage

Answer 18

Thoracic aorta-Posterior Intercostal arteries

Subclavian artery- Anterior Intercostal arteries

Question 19

Discuss breasts

Answer 19

Mammary glands located superficial to pectoralis major

Consist of glands that drain into 15-20 lactiferous ducts

Ducts open onto the nipple

Supplied by: axillary, internal thoracic artery and 2nd-4th intercostal arteries

Lymph drainage 75% axillary nodes, 25% parasternal