CONTENTS:

 

Lab Objectives:

• Identify the lobes of the lungs:
                        Left Lung                                           Right Lung
            cranial lobe - cranial part                        cranial lobe
            cranial lobe - caudal part                         middle lobe
            caudal lobe                                                 caudal lobe
                                                                                 accessory lobe

• Find:
      - cardiac notch (between cranial & middle lobes of right lung)
      - tracheobronchial lymph nodes (between principal bronchi)
      - accessory lobe of the right lung (tucked within a pocket formed by plica vena cava)

• Veins:
      - caudal vena cava
      - azygos v.
      - cranial vena cava
              brachiocephalic v.
                    external jugular v.
                    subclavian v.

• Arteries:
      - ascending aorta
              (left & right coronary aa. will be seen later)
      - aortic arch
              brachiocephalic trunk
                    left & right common carotid aa.
                    right subclavian a.
              left subclavian a.
                    vertebral a.
                    costocervical trunk
                    internal thoracic a.
                    superficial cervical a.
                    (the subclavian a. becomes axillary a. lateral to ribs)
      - descending aorta
              intercostals aa.
                    bronchoesophageal a.

• Also:
      - identify phrenic n. bilaterally
      - look for the thoracic duct between the aorta & the azygos v. (the cisterna chyla will be seen later)

 

Anatomical Terms:

The Lungs
        left lung
                cranial lobe (cranial & caudal parts)
                caudal lobe
                      aortic impression
        right lung
                cranial lobe
                      cardiac notch
                middle lobe
                caudal lobe
                accesory lobe
        principal bronchi
                carina
                lobar bronchi
        tracheobronchial lymph nodes

Vessels Cranial to the Heart
        cranial vena cava
                brachiocephalic vein
                      external jugular vein
                      subclavian vein
                azygos vein
        thoracic duct
                cisterna chyli
                tracheal lymph ducts
        aorta:
                ascending aorta
                aortic arch
                descending aorta
        coronary arteries (right & left)
        brachiocephalic trunk
                left common carotid a.
                right common carotid a.
                right subclavian a.
        left subclavian a.
                vertebral artery
                costocervical trunk
                superficial cervical a.
                internal thoracic a.

Branches of the Thoracic Aorta
        intercostal arteries (dorsal intercostal arteries)
                bronchoesophageal a.
                      esophageal aa.
                      bronchial aa.

phrenic nerve

        Note:
                azygos = unpaired, from a = not & zygon [Greek] = pair or yoke

 

Instructor Commentary:

The number of lobes per lung is based on the pattern of lobar bronchi that branch from the principal bronchus, rather than the apparent lobation. Thus the left lung has a cranial lobe with two parts (based on lobar bronchi) rather than having cranial and middle lobes as defined for the right lung.

The term "root" of the lung refers collectively to the vessels and lobar bronchi that attach the lung to the mediastinum. The term "hilus" refers to the region of the lung where components of the root can be seen entering the lung.

Pulmonary arteries usually contain blue latex; pulmonary veins may contain red latex. (Latex does not pass through lung capillaries.):

Blue latex was injected into the external jugular vein of the cadaver. Given enough latex under sufficient pressure, the normal flow is right atrium, right ventricle, pulmonary trunk and pulmonary arteries.

Red latex was injected into the common carotid a. of the cadaver. The latex naturally fills the aorta. To enter the left ventricle, red latex must rupture the aortic valve. To enter the left atrium, red latex must rupture the left atrioventricular valve. Once in the left atrium red latex naturally fills pulmonary veins.

 

Dissection Images:

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