Thorax 1 Flashcards
List the functions of the thorax
Protection, Rigidity and elasticity, respirtaion, locomotion as it allows attachment for muscles, heamatopoiesis and connections with neck, UL and abdo
Describe what makes the thorax
Thoracic cage - Sternum, 12 pairs of ribs, 12 thoracic vertebrate and IV discs.
Thoracic wall - Thoracic cage, skin, subcutaneous tissue, 3 layers of intercostal muscles and breast tissue
Name the true, false and floating ribs.
True = Ribs 1-7, these attach directly to sternum via costal cartilage (CC) False = Ribs 8-10, attach indirectly via the CC of rib 7 Floating = Ribs 11-12, do not articulate with sternum
Name the typical ribs and their features
Ribs 2-10. They have a head, neck, tubercle, body, costal angel and costal groove ( on the inner surface near inferior boarder, passage of intercostal vessels and nerve)
Describe the features of the atypical rib 1
Scalene tubercle for attachment of anterior scalene muscle, groove for subclavian artery, vein and inferior trunk of brachial plexus, articulates with T1 only, no costal groove and cannot be palpated
Describe features of the floating ribs
Does not attach to sternum, heads only articulate with corresponding vertebra and they do not articulate with transverse processes.
The sternal angle is at the level of…what?
- 2nd CC
- IV disc between T4 and T5
- Prox and distal boarders of aortic arch
- Bification of trachea
- Superior limit of pulmonary trunk
- Azygos opening into SVC
- ligamentum ateriosum
Why is the sternum important?
Because it is a site of blood cell production so is one of the sites for bone marrow aspiration.
Where is the T6 dermatome located?
Solar plexus region which is the Xiphoid region
Describe features of the costovertebral joint
Ribs 2-10 articulate with superior costal facet of corresponding vertebra and the inferior costal facet of vertebra above. Synovial joints supported by capsule with ligaments.
Describe the costal facets of the thoracic vertebrae
T1 - 1 and 1/2 costal facets.
T2 -T9 have 2 half costal facets
T10 has 1 half costal facets.
T11 and T12 have 1 oval costal facet
Describe features of the costotransverse joint
Joint between rib tuberce on ribs 1-10 and the transverse process of corresponding vertebrate. Costotransverse joints 1-7 have curved facets allowing for rotation but joints 8-10 have flat facets allowing for gliding.
Describe features of the costochondral joints and the costosternal joints
All ribs articulate with a CC via a primary cartilaginous joint. The CC of ribs 1-7 articulate directly with sternum but 8-10 articulate with the CC above
Describe the shapes of the CC
Ribs 1 - 4 have horizonal CCs while the shape of the CCs for ribs 5-10 increase in their oblique direction. Significant in respiration
Describe features of the thoracic inlet (superior aperture)
Bound by T1, first rib and its CC and the manubrium. It sloaps antero-inferiorly to the level of T2/3 and the lung extends 2/3 cm above the anterior part of 1st rib.
What structures pass between the thorax and the neck, and the thorax and the UL?
Neck - Vessels, trachea, oesophagus, vagus and recurrent laryngeal nerves and the phrenic nerve.
UL- Subclavian vein, artery and inferior trunk of brachial plexus
What is the thoracic outlet bound by?
T12, 11th and 12th ribs, the CC’s of ribs 7-10, the xiphoid process and it is closed incompletely by the diaphragm.
What is thoracic outlet syndrome?
Where the brachial plexus and the subclavian vein and artery can be compressed as they are closely related to the 1st rib and inferior surface of clavical.
Name the common sites of compression during thoracic outlet syndrome
Scalene triangle, Costoclavicular site and the subpectoral space.
What are breasts?
Accessory glands consisting of mammary glands, skin and connective tissue. They consist of 15-25 lobes formed from lobules and ducts
What are montgomery tubercles?
Visible sebaceous glands on the surface of the areola
Where does the base of the breast lie?
At the levels of the 2nd to 6th rib, from the lateral boarder of the sternum to the axilla
What is the axillary process?
Axillary tail of spence is upper lateral breast tissue that extends to the axilla, it may even perforate the deep fascia.
Where is the breast tissue found?
Between the deep and superfical layers of the superficial fascia. It sits on pec major, serratus anterior and external oblique muscle.
What are cooper’s ligamnets? and their function
Condense connective tissue that forms suspensory ligaments of the breast, they connect deep fascia to the dermis and support the breast
What is the retromammary space and what is its function?
It is a layer of loose connective tissue between the deep layer of superficial fascia and the deep fascia. It allows for movement of the breast over underlying tissue.
Describe the vascular supply of the breast
From the internal thoracic artery are mammary branches and anterior intercostal arteries that supply the breast as well as the lateral thoracic artery and the thoraco-acromial artery from the axillary artery.
Veins of the breast mainly drain to where?
The axillary vein and the internal thoracic vein
Describe the lymphatic drainage of the breast
Areola and lateral quadrents to axillary LN.
Medial quadrents to parasternal LN.
Inferior quadrents to inferior phrenic LN
