Thoracic Cage and Intercostal Space Flashcards
What are the primary components of the thoracic cage?
The thoracic cage consists of the sternum, 12 pairs of ribs, costal cartilages, and 12 thoracic vertebrae.
What is the function of the thoracic cage?
It protects thoracic organs, provides attachment for muscles, and assists in respiration.
How many pairs of ribs are in the human thoracic cage?
There are 12 pairs of ribs.
What are the three types of ribs, and how are they classified?
Ribs are classified as true (1-7, directly articulate with the sternum), false (8-10, articulate via costal cartilage of rib 7), and floating (11-12, no anterior attachment).
What are the distinguishing features of typical ribs?
Typical ribs have a head with two facets, a neck, a tubercle, a shaft, and a costal groove.
Which ribs are classified as typical ribs?
Ribs 3-9 are considered typical ribs.
What are the distinguishing features of atypical ribs?
Atypical ribs have unique features, such as a single facet, no tubercle, or special articulations.
Which ribs are classified as atypical ribs?
Ribs 1, 2, 10, 11, and 12 are atypical ribs.
What is the structure and function of the costal cartilage?
Costal cartilages connect ribs to the sternum and contribute to rib cage elasticity.
What are the components of the sternum?
The sternum consists of the manubrium, body, and xiphoid process.
What is the significance of the sternal angle (Angle of Louis)?
The sternal angle marks the level of the second rib and the bifurcation of the trachea.
Which ribs articulate directly with the sternum?
Ribs 1-7 articulate directly with the sternum.
What are the three types of costovertebral articulations?
Costovertebral joints include the head of the rib with the vertebral body, costotransverse joints, and costochondral joints.
What is the role of the intercostal muscles?
The intercostal muscles facilitate respiration by altering thoracic volume.
What are the three layers of intercostal muscles?
The three layers are external, internal, and innermost intercostal muscles.
What is the primary function of the external intercostal muscles?
The external intercostal muscles elevate the ribs during inspiration.
What is the primary function of the internal intercostal muscles?
The internal intercostal muscles depress the ribs during forced expiration.
What is the primary function of the innermost intercostal muscles?
The innermost intercostal muscles assist with respiration by stabilizing the intercostal spaces.
What structures are contained within the intercostal space?
The intercostal space contains intercostal muscles, nerves, arteries, and veins.
What is the order of the neurovascular structures in the intercostal space?
The order is vein (superior), artery (middle), and nerve (inferior) (VAN).
What is the origin of the intercostal arteries?
The intercostal arteries arise from the thoracic aorta and internal thoracic artery.
What is the origin of the intercostal veins?
The intercostal veins drain into the azygos and hemiazygos venous systems.
What is the origin and course of the intercostal nerves?
Intercostal nerves originate from the anterior rami of thoracic spinal nerves (T1-T11).
What is the clinical significance of the neurovascular bundle’s location in the intercostal space?
The neurovascular bundle runs along the inferior border of the rib, making it vulnerable during procedures like thoracentesis.
What is the function of the diaphragm in relation to the thoracic cage?
The diaphragm is the primary muscle of respiration, altering thoracic pressure for lung expansion.
How does the thoracic cage contribute to respiration?
The thoracic cage expands and contracts, facilitating lung inflation and deflation.
What are the movements of the ribs during respiration?
Ribs move in pump-handle and bucket-handle motions to increase thoracic volume.
What is the pump-handle movement of the ribs?
The pump-handle movement elevates the sternum and increases the anteroposterior diameter.
What is the bucket-handle movement of the ribs?
The bucket-handle movement elevates the lateral aspects of the ribs, increasing the transverse diameter.
What are the common clinical conditions affecting the thoracic cage and intercostal space?
Common conditions include rib fractures, flail chest, intercostal neuralgia, and thoracic outlet syndrome.
