W1: Thoracic Anatomy Flashcards
How many thoracic vertebrae are there?
12
What features do the superior thoracic vertebrae demonstrate (T1-T4)?
Exhibit features typical of cervical vertebrae
What features do the middle thoracic vertebrae demonstrate (T5-T8)?
Typical thoracic vertebrae
What features do the inferior thoracic vertebrae demonstrate (T9-T12)?
Exhibit features typical of lumbar vertebrae
What vertebrae has the most prominent spinous process?
C7 or T1
The T1 Spinous process is in line with the…..
Superior angle of the scapula
The T3 spinous process is in line with the….
Base of spine of scapula
The T7 spinous process is in line with the….
Inferior angle of scapula
What connects the transverse process to the body?
Pedicle
What are the three main roles of the thoracic spine?
- Weight bearing and force transmission
- Attachment of ribs with associated synovial joints (breathing)
- Protection of organs
What connects the spinous process to the transverse process?
Lamina?
How would you describe the positioning of the thoracic transverse processes?
Obliquely Placed with facets for articulation from tubercle of rib
What shape is the thoracic vertebral body?
Heart shaped
How is the spinous process shaped?
Long downward slopping spinous process. Contains articular facets for ribs.
What is the finger rule related to?
The typical thoracic vertebrae are constructed with a difference in height between the spinous process and the transverse process. The extent of this difference varies.
Finger rule: T1/T2 spinous process
Plus one finger width
Finger rule: T3/T4 spinous process
Plus two finger width
Finger rule T5-T8 spinous process
Plus three finger widths
Finger rule: T9-10 spinous process
Plus two finger widths
Finger rule: T11, 12 spinous process
Plus one finger width
What structure forms the main part of the thoracic cage?
The ribs
True or false: each rib articulates posteriorly with two thoracic vertebrae by the costovertebral joint
True expect the first rib which articulates with T1 only
What connects the rib bone to the sternum?
Costal cartilage
What are considered true ribs?
Ribs 1-7 (costochondral joint)
What is considered false ribs
Ribs 8-10
What is considered floating ribs?
Ribs 11-12
What does the thoracic outlet refer to?
What is thoracic outlet syndrome?
Confined space between the clavicle and first rib. Structures that pass through this region includethe nerves of the brachial plexus, the subclavian artery, and the subclavian vein
Thoracic outlet syndrome: compression of blood vessels and nerves
What are the costovertebral vs costotransverse joints?
Costovertebral is connecting the rib to the body and costotransverse is connecting the transverse process to the rib
What joint is between the vertebral bodies? What is its classification?
Intervertebral discs ie the interbody joint (cartilaginous joint – symphysis)
What are the facet joints? What type of joint are they? To what degree are they inclined in the transverse plane?
Formed by articulation of the superior and inferior articular processes from adjacent vertebrae. Synovial joint (plane?). Inclined 60 deg in the transverse plane
In the thoracic region what degree of axial rotation, flexion/extension, lateral flexion is allowed?
Why is there reduced range in the thoracic region?
Axial rotation: 35 degrees in each direction
Flexion/extension - combined range is ~50-70 degrees
Lateral flexion: 20-25 degrees in each side
Limitations imposed by structures - rib cage, spinous processes and dimensions of vertebral bodies. Bodies are larger, more rounded compared to the cervical vertebrae. This design provides stability and strength to support the rib cage but limits the range of motion.
Actions of the latissimus dorsi?
Extents, adducts and medially rotates the arm
Action of the rhomboid minor and major?
Retraction
Action of the levator scapulae?
Elevation & lateral flexion/ipsilateral rotation of the neck
Origin of the trapezius and insertion?
Origin
- Nuchal line/external occipital protruberance (base of skull)
- C7-T12
Insertion
- Lateral third of clavicle, acromion and spine of scapula
Origin of the levator scapulae and insertion?
Origin: Transverse process of cervical vertebrae 1 to 4
Insertion: superior angle of scapula
Origin and insertion of the rhomboid major
Origin: spinous process of T2-T5.
Insertion: Inferior angle of scap
Origin and insertion of rhomboid minor?
Origin
- Nuchal ligament
- Spinous process of C7 & T1
Insertion
- Medial end of scapula spine
Origin and insertion of latissimus dorsi?
Origin
- T6-12 spinous process
- Thoracolumbar fascia
- Posterior iliac crest
- Inferior angle of the scapula
Distal attachment
- Bicipital groove of the humerus
What are the deep muscles?
Semispinalis thoracic
Erector spinae
Multifidus
What is the origin and insertion of the semispinalis thoracic and what is its role?
T6-T10 transverse processes
C6-T4 spinous processes
Responsible for maintaining posture and for movement of the head and the vertebral column
What three muscles make up the erector spinae?
- Spinalis thoracic
- Longissimus thoracic
- Ilicostalis
SLI
What is the movement of the erector spinae?
Bilateral: Back and head extension
Ipsilateral side flexion and rotation of the vertebral column
What is the origin and insertion of the multifidus?
Origin: transverse process of thoracic vertebrae
Insertion: tips of the spinous processes of vertebrae 2-5 levels above origin
What is the action of the multifidus?
Bilateral: extension of spine
Unilateral: lateral flexion of spine
Contralateral: rotation of spine
The parasympathetic vs sympathetic nervous. What is it? Where do the preganglionic neurons of the PNS come from?
The parasympathetic nervous system (PNS) controls homeostasis and the body at rest and is responsible for the body’s “rest and digest” function.
The preganglionic neurons of the PNS come from brainstem nuclei and the sacral spinal cord (specifically S2-S4).
What is the sympathetic nervous system?
Where are the neurons of the intermediolateral column of the spinal cord found?
The sympathetic nervous system (SNS) controls the body’s responses to a perceived threat and is responsible for the “fight or flight” response.
Levels T1-T12 and L1-L3
