Question

Mr.Keys was driving to work when he was hit broadside by a car that ran through the red light. When freed from his car, his breathing had stopped and he was cyanotic. Although his heart was still beating, his pulse was fast. His head was tilted at an unusual angle, and the emergency crew stated that it appeared as though he had a fracture in the vicinity of the C, vertebra. Given his symptoms, which of the following is most likely?

A. Mr. Keys' pneumotaxic center had been injured.
B. Mr. Keyst medulla had been injured.
C. Mr. Keys was under control of the parasympathetic division of the autonomic nervous system
D. Mr. Keys received damage that was interfering with the pathway of the phrenic nerve.
E. Mr. Keys had damage to the diaphragm and intercostal muscles.

Answer 1

Mr. Keys' symptoms and the location of the suspected C1 vertebra fracture suggest that the most likely cause is damage interfering with the pathway of the phrenic nerve, which would lead to stopped breathing despite a still-beating heart.

Step-by-step explanation:

Given Mr. Keys' symptoms of stopped breathing, cyanosis, rapid pulse, and a head tilted at an unusual angle alongside information about a possible fracture around the C1 vertebra, it's critical to pinpoint the source of his condition. Option B suggests Mr. Keys' medulla had been injured, which is a vital part of the brain stem responsible for autonomic control of functions such as breathing and heart rate. Damage to the medulla could result in the loss of automatic respiratory function, leading to the symptoms observed. Option D indicates damage interfering with the pathway of the phrenic nerve, responsible for sending signals crucial for diaphragm movement and consequently breathing. As his heart is still beating, but his breathing has stopped, it is most plausible that the injury has affected the pathway related to respiratory functions, hence the phrenic nerve seems the most likely to have been impacted (Option D). This nerve originates from the cervical spinal cord (C3-C5), which is in close proximity to the site of the reported fracture. Moreover, the medulla also remains a crucial area for respiratory control and could be affected by trauma to the neck; thus, in a real-world scenario, both Option B and D are possible, but given the location of the suspected injury, Option D might be more specific to the situation.