Netter's Thorax

Question 1

Function of the Thorax

Answer 1

Protection: the thoracic cage and its muscles protect the vital structures in the thorax and lower 12th ribs provide some protection for liver and gallbladder on the right and stomach and spleen on the left

Support: the thoracic cage provides muscular support for the upper limb.

• *Conduit:** the thorax provides for a superior and an inferior thoracic aperture and a central mediastinum.
• *Segmentation:** the thorax provides an excellent example of segmentation, a hallmark of the vertebrate body plan.

Breathing: the movements of the respiratory diaphragm and intercostal muscles are essential for expanding the thoracic cavity to facilitate the entry of air into the lungs in the process of breathing.

Pumping blood: the thorax contains the heart, which pumps blood through the pulmonary and systemic circulations.

Question 2

Superior thoracic aperture

Answer 2

= anatomic thoracic inlet

Clinicans refer to this as the thoracic outlet, toracic outlet syndrome is the symptosm experienced when the brachial plexus (T1 anerior ramus) is comrpessed against the 1st rib

Question 3

Inferior thoracic aperture

Answer 3

=anatomical thoracic outlet

Conveys the inferior vena cava (IVC), aorta, esophagus, nerves, and thoracic lymphatic duct between the thorax and the abdominal cavity.

Question 4

Boundaries of the mediastinum and contents

Answer 4

Superior mediastinum: midline compartment that lies between transverse plan through angle of Luis and the intervertebral disc between
the T4 and T5 vertebrae

-contains the arch of the aorta

Inferior mediastinum: midline compartment midline compartment defined from the angle oof Luis down to the Xiphisternal joint

-which is further subdivided into an anterior, middle (contains the heart), and posterior mediastinum

Question 5

Surface marking of T4 dermatome

Answer 5

= line of the nipple

Question 6

Surface marking of anteriro attachment point of diaphragm

Answer 6

Xiphoid process: marks the inferior extent of
the sternum and the anterior attachment point
of the diaphragm

Question 7

Plane passing just medial to the nipple

Answer 7

=midclavicular line

Question 8

Plane passing along the inferiolateral margin of pectoralis major

Answer 8

=anterior axillary line

demarcates the anterior axillary fold

Question 9

Plane passing vertically down from mid-point in the axillar

Answer 9

=Mid-axillary line

Question 10

Plane passing along margin of latissimus dorsi and teres major muscles

Answer 10

=posterior axillar line, demarcates the posterior axillary fold.

Question 11

Plane that dissects the inferior angles of the scapula

Answer 11

=scapular line

Question 12

Plane that vertically bisects the verebral column

Answer 12

=Midvertebral line aka posteriro median line

Question 13

Description of a typical rib

Answer 13

Typical rib has:

-head: two facets, suprior facet articulates with inferior demifacet of names vertebra, articular with interveterbral disc and superior demifacet of vertebra below

Ribs 1, 10, 11 and 12 only have one articulation with same numbered vertebra

• neck
• tubercle: articulates with transverse process of vetrebrae of same number
• angle: marks limit of erector spainae attachement
• body

Question 14

Costovertebral articulations

Answer 14

Costovertebral articulations are plane synovial joints

Superior facet of head of rib articulates with inferiro demifacet of same number vertebra

Inferior facet articulates with superior demifacet of vertebra below

Ribs 1, 11 and 12 only have one articulation with same numbered vertebra

Question 15

Ligaements attaching the ribs to the vertebral column

Answer 15

1. Intraarticular ligament of head of rib
2. Radiate ligament of head of rib
3. Intertransverse ligament
4. Superior costotransverse ligament