Thorax Anatomy Flashcards
Bones, Muscles, and VAN
Number of Articulating Vertebrae
24
7 cervical
12 Thoracic
5 lumbar
Number of Fused Vertebrae
9
5 Sacrum
4 coccyx
Spinous Process
Most posterior aspect of the vertebrae
can be palpated
Body of Vertebrae
Most anterior part
gives support to body weight
Superior facet
2 total, connects to the inferior facet of next vertebrae
Inferior Facet
2 total
connects to the superior facet of next vertebrae
Vertebral Arch
Posterior to body
contains pedicles and lamina
Pedicles
processes that project posteriorly from body towards the transverse process
Lamina
projects from the pedicles posteromedial
Pars Interarticularis
area where the pedicle and lamina meet
Transverse Process
projects posterolateral from pars interarticularis
True Ribs
ribs 1-7
articulate directly with the sternum
False Ribs
Ribs 8-10
attach to sternum indirectly by 7th ribs costal cartilage
Floating Ribs
Ribs 11-12
only attached posteriorly
Sternum
1 bone with 3 segments
Manubrium
superior aspect of sternum
articulates with 1st rib and clavicles
Sternal Body
middle and largest aspect
sternal angle - superior aspect of body at levels of T4-T5 and attachment sites of 2nd rib
Xiphoid Process
most inferior aspect
Landmark at T1
Superior angle of the scapula
Landmark at T7
inferior angle of the scapula
Costovertebral Joints
between head of rib and body of vertebrae
synovial joint
Costotransverse Joints
between tubercule of rib and transverse process of vertebrae
synovial joint
Diaphragm Origin
circumference of the thoracic inlet from the xiphoid process, costal cartilage of ribs 6-12 and lumbar vertebrae
Diaphragm Insertion
Central Tendon of the diaphragm
Diaphragm Action
inhalation
flattens and draws the central tendon forward
Diaphragm Innervation
Phrenic Nerve (C3-C5)
Internal Intercostals Origin
Longitudinal ridge on inner surface of ribs and costal cartilages
Internal Intercostals Insertion
Superior border of the rib below
Internal Intercostals Action
inhalation: elevate costal cartilage of ribs 1-4
Exhalation: depress all ribs
Internal Intercostals Innervation
Intercostal Branches of T1-T11
External Intercostals Origin
Inferior Border of Ribs
External Intercostals Insertion
Superior border of rib below
External Intercostals Action
Elevate ribs
External Intercostals Innervation
Intercostal branches of T1-T11
Erector Spinae 3 divisions
Iliocostalis
Longissimus
Spinalis
Iliocostalis Origin
Medial Iliac Crest
Thoracolumbar aponeurosis from sacrum
Posterior aspect of ribs 3-12
Iliocostalis Insertion
Posterior Ribs 1-12
Cervical transverse processes of 4-7
Iliocostalis Action
extension
lateral flexion
ipsilateral rotation of the spine and head
Iliocostalis Innervation
Posterior Branches of the Spinal Nerves
Longissimus Origin
Medial Iliac Crest
Thoracolumbar aponeurosis from sacrum
Lumbar transverse process 1-5
Thoracic transverse 1-5
cervical articular processes 5-7
Longissimus Insertion
Cervical 2-6 spinous processes
Thoracic transverse process 1-12
bottom 9 ribs
mastoid process
Longissimus Action
extension, lateral flexion, ipsilateral rotation of the spine and head
Longissimus Innervation
Posterior branches of the spinal nerves
Spinalis Origin
Ligamentum Nuchae
7th cervical spinous process
11-12 thoracic spinous processes
1-2 lumbar spinous process
Spinalis Insertion
2nd cervical spinous process
5-12 thoracic spinous processes
occipital bone
Spinalis Action
extension
lateral flexion
ipsilateral rotation of the spine and head
Spinalis Innervation
posterior branches of the spinal nerves
Transversus Thoracis Origin
inner surface of sternum and xiphoid process, sternal ends of costal cartilage of 3-6 ribs
Transversus Thoracis Insertion
inner surfaces and inferior borders of costal cartilages 3-6
Transversus Thoracis Action
depress ribs
Transversus Thoracis Innervation
intercostal branches of T3-T6
Intervertebral Disc Annulus Fibrosis
harder tissue that surrounds nucleus pulposus
“dough” in donut
Intervertebral Disc Nucleus Pulposus
center part
“jelly”
Intervertebral Disc Vertebral Endplates
sit on top and bottom
“icing”
Disc translation Flexion
disc moves posteriorly
Disc Translation Extension
disc moves anteriorly
Supraspinous Ligament
attaches on the spinous process of the vertebrae running from c7-sacrum
prevents spinal hyperflexion
Interspinous Ligament
From the root to the apex of each spinous process
joints the ligament flavum anteriorly and supraspinous ligament posteriorly
prevents spinal hyperflexion
Anterior Longitudinal Ligament
anterior aspect of the vertebral bodies and annulus fibrosis
runs form occipital bones to sacrum
prevents spinal hyperextension
Posterior Longitudinal Ligament
posterior aspect of vertebral bodies and annulus fibrosis
inside the vertebral cnal
runs from C2/Axis to sacrum
presents spinal hyperflexion also prevents nucleus pulposus
Ligamentum Nuchea
aka nuchal ligament
external occipital protuberance to the posterior tubercule of C1/atlas
posterior border of the foramen magnum of each cervical vertebrae down to C7 spinous process
presents cervical hyperflexion
Thoracic Aorta
through the posterior intercostal and subcostal arteries
coming from descending aorta
Subclavian Artery
through the internal thoracic and supreme intercostal arteries
has a R & L
L is directly off aorta
R is from brachiocephalic
Intercostal arteries
Go through the ribs
1 large posterior artery
2 small anterior arteries
Posterior Intercostal arteries
Origin: superior intercostal artery (1-2) thoracic aorta (rest
Course: pass between internal and innermost intercostal muscles
Distribution: intercostal muscles and parietal pleura
Internal Thoracic Artery
Origin: Subclavian artery
Course: passes inferiorly and lateral to the sternum
Distribution: by way of the anterior intercostal arteries to intercostal spaces
Spinal Flexion
anterior movement of the spine
thorax moves toward the pelvis
(chin to chest)
Spinal Extension
posterior movement of the spine
thorax moves away form the pelvis
Lateral Flexion
side bending
thorax moves lateral toward the pelvis
Spinal Rotation
thorax rotates toward an iliac crest
