What is the carotid body?
Dating from the nerve ridge is an important anatomical structure that helps the body to achieve homeostasis. It is also called Glomus Caroticum or Carotid Glomus. This structure can detect changes in partial oxygen and carbon dioxide. It may also feel hydrogen changes (PH) and temperature. This color can be attributed to the fact that it is a highly vascular tissue, which means it has many capillaries. Its vascularity is related to its function of detection of concentration of important blood substances. The person has two carotid bodies, one on each side of the neck. Each of them is supplied by a carotid sinus nerve, a branch of a glossopharyngeal nerve. The vagus is also partially supplied.
The main components of the carotid body are chemoreceptors with accompanying support cells. Therefore, it is very similar to the aortic body, which is also a collection of chemoreceptors located near the aortic arch. The aortic body also contains baroreceptors that detect pressure changes and are more complex associated with cardiovascular system.
Carotid body chemoreceptors are called main cells. As cells derived from neuroectoderm, the main cells are able to release neurotransmitters such as acetylcholine, dopamine and adenosine triphosphate (ATP), which trigger excitation postsynaptic potentials (EPSPS). These neurotransmitters will reach the respiratory center to regulate breathing.
Supporting cells are called Sustentacular cells. These cells are similar to the glial cells of the nervous system. They provide structural and nutritional support of Chief cells.
Based on chemoreceptors, carotid changes in concentrations of several substances. Therefore, both carotid bodies act as peripheral chemoreceptors and are primarily stimulated by changing partial oxygen pressure. In partial oxygen pressures greater than 100 millimeters of mercury, the activity of the carotid body is low. When partial oxygen pressure drops below this level, there is a condition called hypoxia, increasing the activity of the carotid body. Similarly, when the content of carbon dioxide in the blood increases, it becomes more active.
As soon as oxygen levels decrease or carbon dioxide levels increase, signals in the form of action potentials are sent to the respiratory center in Medulle Obongata. The respiratory center then sends the signals back to the respiratory system to cause adaptive reactions. The primary adaptive reaction is to increase the level of breathing. Increassing speed or breathing, more oxygen is taken to the lungs and more carbon dioxide is removed from the body.