Your nose contains a rich network of blood vessels, including veins, arteries, and capillaries. This dense vascular system supports important functions, primarily preparing the air you breathe for your lungs.
Nasal Blood Vessels Explained
The inner lining of the nose, known as the nasal mucosa, is highly vascularized. This intricate network includes arteries, veins, and tiny capillaries that connect them. Capillaries are especially numerous and lie close to the surface.
A particularly dense and superficial cluster of these vessels is found in the anterior (front) part of the nasal septum, the wall dividing the nostrils. This area is known as Kiesselbach’s plexus or Little’s area. This plexus is primarily an arterial network where several arteries converge, including branches from the internal and external carotid arteries, such as the anterior ethmoidal, sphenopalatine, greater palatine, and superior labial arteries. The veins in the nose generally follow the arterial pattern, draining into systems like the pterygoid plexus, facial vein, or cavernous sinus.
The Vital Role of Nasal Blood Flow
The abundant blood supply within the nose serves important functions. A primary role is to condition inhaled air, regulating its temperature and humidity before it reaches the lungs.
As air passes through the nasal passages, the warmth from the blood flowing through these vessels heats cold air, bringing it closer to body temperature. Simultaneously, the moisture from the blood vessels humidifies dry air, ensuring it reaches the lungs with adequate moisture levels. This conditioning process protects the delicate tissues of the lungs and respiratory tract from damage caused by cold or dry air.
The nasal blood flow also supports immune defense by bringing immune cells to the nasal lining to help trap and fight inhaled pathogens.
Why Nosebleeds Occur
Nosebleeds, medically known as epistaxis, are common due to the superficial and delicate nature of many nasal blood vessels. The small capillaries and veins, particularly those in Kiesselbach’s plexus, are prone to injury and rupture. When these fragile vessels are damaged, blood can leak out, leading to a nosebleed.
Common causes of nosebleeds include dry air, which can irritate and dry out the nasal membranes, making vessels more susceptible to breaking. Physical trauma, such as nose picking or a blow to the nose, can also directly damage these vulnerable vessels. Other contributing factors include allergies, upper respiratory infections, or the use of certain medications like blood thinners.