Throrax Nervous Flashcards
Costal pleura
Description:
• Subdivision of parietal pleura
• On inner surface of ribs and costal cartilages
• Pleura is a serous membrane which lines each pulmonary cavity (parietal pleura) and reflects onto the surface of each lung (visceral pleura)
Sympathetic innervation of bronchus
Preganglionic:
• Nerve cell body: lateral horn of T1-5 spinal cord
• Axon pathway: ventral root of spinal nerve > spinal nerve > ventral ramus of spinal nerve > white ramus communicans > upper thoracic sympathetic trunk > upper thoracic sympathetic ganglia
Postganglionic:
• Nerve cell body: upper thoracic sympathetic ganglia
• Axon pathway: enter pulmonary plexus at root of lung > bronchi and pulmonary arteries
Effect:
• Inhibit smooth muscle contraction (bronchodilation)
• Decrease glandular secretions
• Relax smooth muscle of pulmonary arteries (increase blood flow)
Mediastinal pleura
Description:
• Region of parietal pleura
• Forms lateral border of mediastinum
Comment:
• Parietal pleura is a serous membrane which lines each pulmonary cavity of the thorax
• Regions of parietal pleura:costal, cervical, diaphragmatic, and mediastinal
• Thoracic cavity divided into 3 parts: mediastinum and right and left pulmonary cavities
Mediastinum
Description:
• Middle region of thorax
• Lies between sternum and thoracic vertebral bodies
• Separates right and left pulmonary cavities
• Divided into superior and inferior parts
• Inferior mediastinum subdivided into middle, posterior, and anterior parts
Comment:
• Superior mediastinum includes: great vessels, thymus (remnant in adult), thoracic duct, and parts of trachea and esophagus
• Middle mediastinum includes: heart, pericardium, and roots of great vessels
• Posterior mediastinum contains: thoracic aorta, esophagus, and thoracic duct
• Anterior mediastinum contains: loose connective tissue (may include thymic remnant in adult)
• Thoracic cavity divided into three parts: mediastinum and right and left pulmonary
Intercostal nn.
Location:
• Intercostal spaces
• Between innermost and internal intercostal muscles
Contributions:
• Ventral rami of T1-11 spinal nerves
Motor:
• Intercostal muscles
• Anterior abdominal wall muscles (T7-11)
General sensation:
• Skin of thorax (T1-11), abdomen (T7-11) and upper limb (T2)
• Parietal pleura (costal and peripheral diaphragmatic) (T1-11)
• Parietal peritoneum (T7-11)
Ganglion of sympathetic trunk
Location:
• vertebral column (ventrolateral aspect)
Description:
• Location of postganglionic sympathetic neuronal cell bodies
• 22 pairs of ganglia connected by interganglionic segments
• Superior cervical ganglion at superior end of sympathetic trunk
• Ganglion impar is most inferior ganglion
Posterior intercostal v.
Posterior intercostal v. Drainage: • Thoracic and abdominal walls • Upper back • Mammary gland • Spinal cord and meninges
Course:
• Intercostal space between innermost and internal intercostal muscles
Comment:
• 11 pairs
• Anastomoses with anterior intercostal
• Anastomosis refers to the end-to-end union of vessels
Thoracic splanchnic nn.
Description:
• Sympathetic nerves that contain preganglionic sympathetic axons
• Greater splanchnic (T5-9)
• Lesser splanchnic (T10-11)
• Least splanchnic (T12)
• Enter abdomen to synapse in prevertebral ganglia
Comment:
• Sympathetic impulses from CNS to effector organ involve two neurons in series (preganglionic and postganglionic)
