Nasal concha

A nasal concha (; pl.: conchae; ; Latin for 'shell') is a long, narrow, curled shelf of bone that protrudes into the breathing passage of the nose in humans and various other animals. The conchae are shaped like an elongated seashell, which gave them their name (Latin concha from Greek κόγχη). A concha is any of the scrolled spongy bones of the nasal passages in vertebrates. The term concha refers to the actual bone; when covered by soft tissue and mucosa, and functioning, a concha is termed a turbinate. In the human nose, the nasal conchae divide the nasal airway into four groove-like air passages and play a major role in conditioning inspired air by increasing surface area to warm, humidify, and filter the air before it reaches the lungs. As a ciliated mucous membrane with shallow blood supply, the nasal mucosa cleans, humidifies and warms the inhaled air in preparation for the lungs. A rapidly dilating arteriolar circulation to these bones may lead to a sharp increase in the pressure within, in response to acute cooling of the body core. The pain from this pressure is often referred to as "brain freeze", and is frequently associated with the rapid consumption of ice cream. The shallowness of the venous blood supply of the mucosa contributes to the ease with which nosebleed can occur.