Anatomy of the Ribs Flashcards

Practice vocabulary flashcards covering the anatomical features, side determination, and muscle/ligament attachments of the first, second, tenth, eleventh, and twelfth ribs.

First Rib (Side Determination)

Determined by the larger end being anterior, the smaller end posterior, and the superior surface of the shaft having two grooves separated by a ridge.

Scalene tubercle

A middle tubercle on the inner border of the first rib providing attachment to the scalenus anterior muscle.

Sibson’s fascia

Also known as the suprapleural membrane, it attaches to the inner border of the first rib.

Anterior groove (First Rib)

A shallow groove on the superior surface of the first rib that lodges the subclavian vein.

Posterior groove (First Rib)

A shallow groove on the superior surface of the first rib that lodges the subclavian artery and the lower trunk of the brachial plexus.

Scalenus medius

Muscle that attaches to the area behind the posterior groove up to the costal tubercle on the first rib.

Subclavius muscle

Muscle that attaches to the area in front of the anterior groove near the anterior end of the first rib.

Costoclavicular ligament

A ligament attached posteriorly to the area in front of the anterior groove on the first rib.

Neck of the first rib (Anterior relations)

Structures from medial to lateral: Sympathetic chain, first posterior intercostal Vein, Superior intercostal Artery, and Ventral ramus of first thoracic Nerve (‘Chain pulling the VAN’).

Second Rib (Comparison)

Its length is twice that of the first rib, its shaft is highly curved but not twisted, and both ends touch a flat surface.

Serratus anterior (Second Rib attachment)

A rough impression or prominent tubercle near the middle of the outer shaft surface for the lower part of the first and whole of the second digitation.

Scalenus posterior

A muscle that attaches to the upper border and adjoining part of the upper surface of the second rib.

Tenth Rib

Distinguished by having a single articular facet on its head and being slightly shorter than a typical rib.

Eleventh Rib

Features a single large articular facet on its head, no neck, no tubercle, and a pointed anterior end tipped with cartilage.

Twelfth Rib (Comparison)

Similar to the eleventh rib but has no angle, no costal groove, and is much shorter.

Twelfth Rib (Side Determination)

Determined by the pointed anterior end being anterolateral, the concave surface facing inwards and upwards, and the sharper border being inferior.

Pleural reflection (Twelfth Rib)

Marked by an oblique line crossing the middle of the inner surface of the twelfth rib.

Quadratus lumborum (Twelfth Rib attachment)

Attaches to the lower part of the medial half of the inner surface of the twelfth rib.

Lateral arcuate ligament

Attached to the lower border of the twelfth rib just lateral to the quadratus lumborum muscle.

Lumbocostal ligament

Attached to the lower border of the twelfth rib close to the head; stretches from the transverse process of the $L1$ vertebra.