Diaphragmatic Function and Phrenic Nerve Anatomy

Phrenic Nerves and Diaphragmatic Function

• Each hemidiaphragm receives supply from its own phrenic nerve.
• Phrenic nerves originate from the spinal cord at level C3 to C5.
• Phrenic nerves descend through the mediastinum, accompanying the great vessels of the chest and pericardium.

Consequences of Phrenic Nerve Damage

• Damage to or interruption of a phrenic nerve leads to paralysis of the ipsilateral hemidiaphragm.

Causes of Unilateral Diaphragmatic Paralysis

• Trauma is a possible cause of unilateral diaphragmatic paralysis.
• Brachial plexus injury can also lead to unilateral diaphragmatic paralysis.
• Inflammation can cause unilateral diaphragmatic paralysis.
• Cardiac surgery is a possible cause of unilateral diaphragmatic paralysis.
• In many cases, the cause of unilateral diaphragmatic paralysis is idiopathic (unknown).

Types of Brain Injury

• Brain injuries, including traumatic brain injury, stroke, and intracranial hemorrhage, can lead to respiratory failure through various mechanisms, commonly due to failure to protect the airway, often associated with a decreased level of consciousness.

Traumatic Brain Injury

• Caused by a violent blow or jolt to the head or body, or by an object penetrating brain tissue, such as a bullet or shattered piece of skull.
• Classified into mild and severe types, with mild cases affecting brain cells temporarily, and severe cases resulting in bruising, torn tissues, bleeding, and physical damage to the brain.
• Can result in long-term complications or death.

Stroke

• Occurs when blood flow to the brain is blocked or there is sudden bleeding in the brain.
• Types of strokes:

Ischemic Stroke

• Occurs when blood flow to the brain is blocked.

Hemorrhagic Stroke

• Occurs due to sudden bleeding in the brain.

This quiz covers the anatomy of phrenic nerves and diaphragmatic function, including the consequences of phrenic nerve damage and causes of unilateral diaphragmatic paralysis.