Thoracic Anatomy Flashcards
What is the thoracic cage made of?
12 thoracic vertebrae
Sternum
Twelve pairs of ribs
What are the anatomical parts of the sternum?
Manubrium, body, xiphoid
What does the manubrium articulate with?
1st ribs, part of the 2nd rib, and body of sternum
What type of joint is the body-manubrium joint of the sternum?
Symphoseal
What does the body articulate with?
Ribs 2 to 6 via synovial joints
What type of joint joins the body and xiphoid of the sternum?
Symphoseal
What may ribs be classified as?
Vertebrosternal (true)
Vertebrochondral (false)
Vertebral (floating)
Which ribs are vertebrosternal?
1-7
What ribs are vertebrochondral ribs?
8-10
What ribs are vertebral?
11-12
Which ribs are considered typical?
3-9
What features are on the head of a typical rib?
An upper and lower demi-facets
What features are on the neck of a typical rib?
Crest for the superior costotransverse ligament
What features are on the tubercle of a typical rib?
Facet for the transverse process and a rough part for the lateral costotransverse ligament
What is between the tubercle and shaft of a typical rib?
The angle
What characteristics does the upper border of the shaft of a typical rib have?
It is smooth and rounded
What characteristics does the lower border of the shaft of a typical rib have?
Sharp and shelters the costal groove
Which ribs are atypical?
1st, 2nd, 10th, 11th, 12th
What is unique about rib 1?
Shortest
Only 1 articular facet
Additional tubercle for anterior scalene
Has no costal grove, but a groove for the subclavian artery
What is unique about rib 2?
Has a large rough tuberosity for the attachment of serratus anterior
What is unique about ribs 10-12?
They only posess one facet head
What is the muscle fiber orientation of the intercostal muscles?
External - downwards and medially
Internal - upwards and medially
Innermost - upwards and medially
Where does the neurovascular bundle lie in the intercostal space?
Internal and innermost intercostal muscles
Where does the intercostal vein drain?
Azygos venous system
Where does the intercostal artery receive blood from?
Internal thoracic artery and the thoracic aorta
What is the intercostal nerve a branch of?
The ventral ramus of a thoracic spinal nerve
What covers the intercostal space externally and internally?
Skin, Parietal pleura
What structure is the breast a modified version of?
Apocrine sweat gland
Where is the breast located?
In superficial fascia mostly, the tail is under the deep fascia of the axilla
What ribs does the breast sit between?
2nd and 6th
How many lobules does the breast contain?
15-20
What type of tissue are the lobules made of?
Acinar glandular tissue
Glandular tissue, of the breast, is attached to skin and pectoral fascia how?
Suspensory ligaments of Cooper
Where does the glandular tissue of the breast open?
The lactiferous ducts
What is the dilation at the end of the lactiferous duct?
Lactiferous sinus
What supplies the breast with blood?
Lateral thoracic, Internal thoracic, 2nd to 4th anterior intercostal, and thoraco-acromial artery
What drains 75% of the breast lymphatics?
Anterior group of lymph nodes
What drains the rest of the lymph from the breast?
Central and apical axillary lymph noes
What is the mediastinum?
Space between the lungs
What separates the mediastinum into superior and inferior?
A horizontal line between the manubriosternal joint (angle of Louis) and the IV disc of T4/5
At the horizontal line dividing inferior and superior mediastinum, what other anatomical events are there?
The articulation of the second rib, bifurcation of the trachea, bifurcation of the pulmonary trunk, Arch of the aorta begins, arch of the aorta ends, thoracic duct crosses from right to left, Left recurrent laryngeal nerve passes under the aortic arch
What structures are in the superior mediastinum?
Trachea, Vagus nerves, Phrenic nerves, Arch of the aorta, SVC, T. Duct, Esophagus, Remnant of the thymus
What three compartments are in the inferior mediastinum?
Middle, Anterior (between sternum and heart), Posterior (between heart and T. vertebra)
What is in the anterior inferior mediastinum?
Connective tissue, lymph nodes, remnants of the thymus
What is in the middle inferior mediastinum?
Heart, pericardium, roots of the great vessels, phrenic nerves
What is in the posterior inferior mediastinum?
Vagus, Splanchnic, Descending thoracic aorta, Azygous venous system, Esophagus, Sympathetic trunks
What cell lines the esophagus?
Stratified squamous epithelium
Where does the esophagus begin?
Cricoid cartilage C6
What structures does the esophagus pass behind?
The trachea and left atrium
Where does the esophagus end?
T11
What layers of cells does the esophagus have?
Stratified non-keratinized squamous
Submucosa
Outer 2 muscular layers, (longitudinal and inner circular)
What supplies the upper, middle and inferior esophagus?
U - Inferior thyroid
M - T. Aorta
I - Left gastric
What drains the upper, middle, and esophageal lymph?
U - Lower deep cervicals
M - Mediastinal
I - Left gastric
What levels have narrow portions of the esophagus?
C6, T5 at the left bronchus, T10
