Ribs - costae: General Overview

Which statement best describes true ribs (costae verae)?

• They are not attached to the sternum and float among muscles.

• They connect directly to the sternum (I–VII).

• They are connected by cartilage to the superior rib.

• They are present only as costal cartilage without bony parts.

Answer explanation

True ribs, also known as costae verae, are the first seven pairs of ribs (I–VII) that connect directly to the sternum, providing structural support and protection for the thoracic cavity.

How many pairs of ribs form the anterior and lateral walls of the thoracic cage?

• 10 pairs

• 11 pairs

• 12 pairs

• 14 pairs

Answer explanation

The thoracic cage is formed by 12 pairs of ribs, which create the anterior and lateral walls. Each rib pair connects to the thoracic vertebrae and contributes to the structure of the ribcage, making 12 pairs the correct answer.

False ribs (costae spuriae) are characterized by which connection?

• Direct bony attachment to the sternum

• Cartilage connection to the superior rib

• No anterior attachment, freely located among muscles

• Fusion with the vertebral column only

Answer explanation

False ribs, or costae spuriae, connect to the sternum indirectly via cartilage to the superior rib, unlike true ribs that attach directly. This cartilage connection allows for flexibility in the rib cage.

Which ribs are described as floating (costae fluctuantes)?

• Pairs I–VII with direct sternal attachment

• Pairs VIII–X with cartilaginous connection to superior rib

• Pairs XI and XII freely located among the muscles

• All ribs with pronounced head, neck, and body

Answer explanation

Floating ribs are pairs XI and XII, which do not attach to the sternum and are located freely among the muscles. The other options describe ribs with different types of attachments.

Which components are listed as parts of the bony rib?

• Head, neck, and body

• Manubrium, body, and xiphoid process

• Shaft, tubercle, and costal groove only

• Acromion, coracoid, and glenoid

Answer explanation

The bony rib consists of the head, neck, and body, which are essential components. The other options refer to different anatomical structures not related to the rib itself.

Which term refers to the head of the rib that bears an articular surface for the thoracic vertebrae?

• Caput costae

• Collum costae

• Corpus costae

• Angulus costae

• Sulcus costae

Answer explanation

The term 'Caput costae' refers to the head of the rib, which articulates with the thoracic vertebrae. It is specifically designed to connect with the vertebral bodies, making it the correct choice.

The crest that divides the articular surface on the head of a typical rib (except I, XI, and XII) is called:

• Crista colli costae

• Crista capitis costae

• Crista costae

• Tuberculum costae

• Facies articularis tuberculi costae

Answer explanation

The crest that divides the articular surface on the head of a typical rib is known as the 'Crista capitis costae'. This term specifically refers to the ridge found on the rib head, distinguishing it from other structures.

Which rib part is immediately distal to the head and is described as the narrow part of the rib?

• Corpus costae

• Tuberculum costae

• Collum costae

• Angulus costae

• Crista costae

Answer explanation

The 'Collum costae' is the narrow part of the rib located immediately distal to the head. It connects the head to the body of the rib, distinguishing it from other parts like the tuberculum and corpus.

What is found on the upper edge of the rib’s neck?

• Crista costae

• Crista capitis costae

• Sulcus costae

• Crista colli costae

• Facies articularis capitis costae

Answer explanation

The crista colli costae is located on the upper edge of the rib's neck, serving as a ridge that separates the head from the neck of the rib. This distinguishes it from other structures listed in the answer choices.

The tubercle of the rib (tuberculum costae) is present on which ribs according to the text?

• All ribs

• Upper seven ribs only

• Upper ten ribs

• Lower two ribs only

• Ribs I, XI, and XII only

Answer explanation

The tubercle of the rib is present on the upper ten ribs (ribs I to X). These tubercles articulate with the transverse processes of the thoracic vertebrae, while the lower ribs lack this feature.