Rib Anatomy

T11 and T12 have no

transverse costal facets

Caliper ribs (Ribs 11-12 motion)

Caliper ribs Move Posterior and superior during inhalation Transverse plane Superior-inferior axis

"Principal" muscles of respiration:

Inhalation: Diaphragm (Primary muscle) External intercostals Internal intercostals

Ribs with only a single facet on head and articulate with only one vertebral body.

1,10,11,12

Atypical ribs

1,2, 10, 11, 12

Muscles that elevates rib 1

anterior scalene, middle scalene

Rib articulations

Anterior: chondrosternal joint -cartilage to sternum. costochondral joint- rib to cartilage Posterior: Costovertebral joint - between rib head and 1 or 2 vertebral bodies and the annulus fibrosus Costotransverse joint- rib tubercle to the transverse process of the same numbered vertebra.

Ribs 6-10 motion

Bucket handle Move lateral and superior during inhalation Coronal plane AP axis

Muscle that elevates ribs 9-11

Latissimus Dorsi

Which of the ribs has only pump handle motion only

None REMEMBER THAT RIBS NEVER MOVE IN ONE DIRECTION ONLY!

Muscle that elevates ribs 3-5

Pectoralis minor

Rib 2-5 motion

Pump handle Move anterior and superior during inhalation Sagittal plane transverse axis increases AP diameter

Muscle that stabilizes rib 12 during respiration

Quadratus Lumborum

True ribs

Ribs 1-7 Attach directly to sternum

Floating ribs

Ribs 11,12 Do not connect to the sternum costal cartilages end in the posterior abdominal musculature

Typical ribs

Ribs 3-9 Head: two facets • Superior facet articulates with vertebral body above • Inferior facet articulates with same number vertebral body Neck: connects rib head and body Tubercle: junction of neck and body of rib •Smooth articular part: meets with *transverse process articular facet of same number vertebra* •Rough non-articular part: attachment point of the *costotransverse ligament* Body (Shaft): thin, flat, curved •Apex of curve: "costal angle" •*contains the costal groove*: inferior aspect of rib - *contains a neurovascular bundle*

False ribs

Ribs 8-10 Costal cartilages connect to the cartilage of the rib above. Indirectly connect to the sternum

Muscle that elevates ribs 6-8

Serratus anterior

Ribs 11 and 12

Single facet on rib head articulates with same number vertebra Short with no neck or tubercle R12 has no angle

Ribs based on distal rib attachment

True ribs: 1-7 False ribs: 8-10 Floating: 11,12

Ribs based on morphology (typical vs atypical)

Typical (normal) : 3-9 Atypical: 1,2, 10, 11, 12

Costotransverse joint allows for

gliding and rotation of the ribs.

Costovertebral joint allows for

gliding or sliding motion of ribs.

Ribs 11 and 12 have no

neck, tubercles

Muscle that elevates rib 2

posterior scalene

Intercostal space is named by the

rib that forms the superior border of the space Ex: 5th intercostal space is below the 5th rib. The inferior aspect of the 5th rib forms the superior border of the intercostal space.

Ribs 10

single facet on head to articulate with T10 vertebral body

Rib 1

•Broad, shortest, most sharply curved •Only one facet on the head - articulates with T1 vertebral body. Superior surface has 2 transverse grooves separated by a tubercle - attachment for anterior scalene • Anterior groove: subclavian vein, phrenic nerve • Posterior groove: subclavian artery, brachial plexus.

Chondosternal articulations

•Rib 1- synarthrosis - immovable fixed joint • Ribs 2-7 - synovial joint