21. The blood supply, innervation and lymphatic drainage of the lungs.

Question 1

innervation

Answer 1

Parasympathetic Innervation:

Nerve: Vagus nerve (Cranial Nerve X).

Function: Causes bronchoconstriction, mucus secretion, and vasodilation.

Sympathetic Innervation:

Nerves: Derived from the sympathetic trunks (thoracic sympathetic ganglia T1-T5).

Function: Causes bronchodilation, reduced mucus secretion, and vasoconstriction.

Sensory Innervation:

Nerves: Sensory fibers travel with the vagus nerve and sympathetic nerves.

Function: Carry information about lung stretch, irritants, and other sensory inputs to the central nervous system.

Question 2

lymphatic drainage

Answer 2

Superficial/Subpleural Lymphatic Plexus:
Location: Lies beneath the visceral pleura.
Function: Drains the lung surface and visceral pleura.
Drainage Path: Lymph from this plexus drains into bronchopulmonary (hilar) lymph nodes.

Deep Lymphatic Plexus:
Location: Follows/ courses with the bronchi and pulmonary vessels.
Function: Drains the structures of the root of lung , bronchi, and surrounding lung tissue.
Drainage Path: Lymph from this plexus drains into the pulmonary lymph nodes (along the bronchi) and then to the bronchopulmonary (hilar) lymph nodes.

then all the collected lymph will enter left & right tracheobroncho lymph nodes then continue into right & left bronchomediastinal trunk to drain into the venous system through right lymphatic & thoracic ducts

Question 3

functional blood supply:

Answer 3

Right ventricle - right & left pulmonary aa(pulmonary trunk) - lungs - right & left pulmonary veins - left atrium - left ventricle - aorta

Question 4

nutrient circulation

Answer 4

artery:

thoracic aorta - bronchial branches

veins:
bronchial veins : split into azygous& hemiazygous &right-left pulmonary veins