Thoracic Vertebrae and Ribs

Question 1

Know the most cranial thoracic dorsal spinous process that is palpable.

Answer 1

T3

Question 2

Know how the orientation and shape of the facets differs from the cranial thoracic to the lumbars.

Answer 2

Cranial thoracic – flat, almost horizontal

Lumbars – concave/convex, vertical

Question 3

Know the how many joint surfaces there are on the mid-thoracic vertebrae (12) and be able to name them.

Answer 3

4 cranial and caudal facets, 2 cranial and caudal vertebral bodies, 4 demi-facets, 2 transverse fovea

Question 4

Know what happens at the thoracic vertebra when the spine flexes or extends. How the facets move and how it affects the diameter of the IVF etc.

Answer 4

• Flexes - facets diverge, diameter of the IVF increases, the caudal facet (of the cranial vertebra) moves cranially and ventrally, supraspinous ligament is placed under tension and the ventral longitudinal ligament is relaxed
• Extension – facets converge, diameter of the IVF decreases, caudal facet (of the cranial vertebra) moves dorsally and caudally, supraspinous ligament relaxes and the ventral longitudinal ligament is placed under tension

Question 5

Know how the rib articulates with the vertebrae.

Answer 5

Rib articulates with the costovertebral facets of two vertebrae and with the transverse process of the caudal vertebra

Question 6

Know the primary factor in proper oxygenation.

Answer 6

Mechanical movement of the ribs and spine

Question 7

Know the path of the intercapital ligament, and how a restriction of the rib may affect the contents of the IVF.

Answer 7

Originates from the neck of the rib, passes through the intervertebral foramen, runs under the dorsal longitudinal ligament in the spinal canal, through the other IVF to attach to the neck of the opposite rib

Question 8

Know how the first rib differs from the others and how its role in inspiration.

Answer 8

Straight and short, attaches to the sternum with a tight articulation that fixes the rib. Acts as a firm base. Other ribs are drawn towards it during inspiration

Question 9

Know why the double curve of the ribs is important of respiration.

Answer 9

Makes it possible for them to increase the volume of the thorax during respiration

Question 10

Know the definition of a group lesion and what a group lesion in the withers may indicate.

Answer 10

Several adjacent vertebra have the same restriction

Wither left – cardiac problem

Wither right – lung problem

Question 11

Know the relationship of the ribs and the sympathetic trunk.

Answer 11

Sympathetic trunk runs close to the rib heads. Caudal and middle cervicothoracic sympathetic ganglion are located close to the first rib

Question 12

Know what anatomic features help make the ribs flexible and strong.

Answer 12

Double curve and costal cartilage

Question 13

Know how the ribs move with inspiration and with expiration.

Answer 13

Inspiration – sternum moves cranially and ventrally, ribs move cranially and dorsally, ribs become more vertical, spine coes into extension

Expiration – sternum moves caudally and dorsally, ribs move caudally and ventrally, spine goes into flexion

Question 14

What muscles are epaxial to the thoracic vertebrae (3) and hypaxial (2)?

Answer 14

Epaxial – multifidus, longissimus, iliocostalis

Hypaxial – longus thoracis, psoas major

Question 15

The spine can best resist ventral pressure near the____ __________.

Answer 15

Thoracic spine