Station 5: Bones, Muscles, and Neurovasculature of the thoracic wall Flashcards
How many of each vertebrae are there?
C1-7 T1-12 L1-5 S1-5 (fused) C4(3-5) (fused)
What do you call excessive anterior concavity of the spine?
Kyphosis
Which structures form the vertebral arch?
The vertebral arch is the posterior portion of a thoracic vertebrae.
Consists of:
A pair of pedicles, a pair of lamina
Supports 7 processes:
4 Articular processes (2 superior L&R, and 2 inferior L&R)
2 Transverse processes (L&R have the costal facets)
1 Spinous process (attachment for muscles and ligaments)
What constitutes the borders of the intervertebral foramina?
Inferior vertebral notch (superiorly)
Superior articular process (inferiorly),
the body of the vertebrae (anteriorly)
The lamina (posteriorly)
What passes through the intervertebral foramina?
Spinal nerve root, dorsal root ganglion,
Spinal artery, segmental artery
Recurrent meningeal nerves
Transforaminal ligments
What is a Zygapophysial joint? What type of joint?
Synovial joint
Zygapophysial articular surfaces are covered with hyaline cartilage
Joint adjacent vertebrae together via inferior/superior articular processes
Name the ‘parts’ of a typical rib, and their function
Head: Articulates with vertebral bodies
Neck
Tubercule: Articulates with transverse processes of the vertebrae
Angle: A point just lateral to the tubercule where the shaft of the rib bends forward
Costal groove: lodges the intercostal V, A & Ns
What are the names of the joints that join the rib to the vertebrae, what are the articulations?
Costovertebral: between the head of the rib and the articular process of the body of the vertebrae
Costotransverse: between the tubercule of the rib and the articular surface of the tranasverse process of the vertebrae (part of the vertebral arch)
Costotransverse Joint: which articulations? WHat type of joint?
Tubercule of the rib with the articular surface of the transverse process of the vertebrae (part of the vertebral arch).
= Synovial Plane
Costovertebral Joint: Which articulation? What type of joint?
Head of the rib with the articular process of the vertebral body
= Synovial Plane
What are the bones, and important components of, the sternum? Joints, types of joints, etc
Manubrium (superiorly).
Houses the jugular notch on its superior edge.
Houses articulation of the first costal cartilage (of 1st rib)
Manubriosternal Joint: Symphisis (secondary cartilagenous) joint.
Articulation point of the 2nd costal cartilage (of 2nd rib)
Sternal bone - houses articulations with 3-7 costal cartilages
Xiphoid process
= a cartilagenous process which ossifies later in life, joined to the sternum via fibrous joint
Which ribs articulate anteriorly with the sternum, and which part of the sternum do they articulate with?
1-7
1: to the manubrium
2: to the manubriosternal joint
3-7 to the sternum
Which ribs articulate with the superior rib’s costal cartilage, instead of the sternum?
Ribs 8-10
What are the floating ribs? WHere do they attach?
11 & 12.
Attached only to thoracic vertebrae
What are the three layers of the intercostal muscles?
External (hands in pockets), Internal (opposite to externals), and innermost intercostals (more vertical arrangement of fibres)
Between which muscle layers are the intercostal aa, vv and nn present?
Between internal and innermost intercostals
Where do the posterior intercostal arteries arise from?
The 1st and 2nd posterior IC aa arise from the supreme intercostal artery, which is a branch of the costocervical trunk the SUBCLAVIAN artery
The lower 9 posterior IC aa arise from the posterior of the descending thoracic aorta
Describe the drainage of the posterior IC vv
On the LEFT:
The top few left PIC vv drain into the left superior intercostal vein, which drains directly into the brachiocephalic vein (may also communicate w/ accessory hemiazygos v).
The middle left PIC vv drain into the accessory hemiazygos v, which drains into the azygos v. (sometimes the accessory hemiazygos drains into the hemiazygos v)
The lower left PIC xx drain into the hemiazygos v which drains into the azygos vein.
On the RIGHT:
The top few right PIC vv drain into the right superior intercostal vein, which drains into the azygos vein
The remainder of the R PIC vv drain into the azygos.
The azygos then drains directly into the SVC
Origins of the anterior intercostal arteries?
From the internal thoracic artery, which arises from the subclavian artery near its origin
Where do the anterior intercostal vv drain?
Into the internal thoracic vein, then into the brachiocephalic vein
A spinal nerve forms from the union of which 2 structures? The spinal nerve then
almost immediately splits into which 2 structures? Of these 4 structures, which
corresponds to an intercostal nerve in the thorax?
Spinal nerves are formed by the union of a ventral and dorsal root. The ventral and dorsal roots arise from the ventral and dorsal lateral horns in the spinal cord. The spinal nerve then splits into Ventral and Dorsal Rami.
Ventral Rami = Intercostal nerves (T1-T5)
Before splitting, the spinal nerve gives off, and receives, white and grey ramus communicantes, respectfully. White ramus communicantes carry efferents to the sympathetic chain, and grey ones contain both afferent and efferents, but house afferent nerve fibers heading back to the spinal cord.
