Scent gland
As scent glands are called glands in the skin of humans and animals, the fragrances may release. These substances are consciously or unconsciously absorbed by conspecifics or animals of other species through the olfactory system ; With the vomeronasal organ (VNO) (not reliably detectable in postembryonic humans and probably without function) there is a specialized sensory organ for this.
Animals
In animals, scent glands can have different functions and thus the defense and deterrence of enemies (e.g. stink glands in skunks ), the delimitation of territories, orientation in space (e.g. by placing scent marks), intra-species communication (e.g. . Stick odor in bees ) or to attract the opposite sex.
human
In humans, the scent glands are commonly counted among the sweat glands Glandulae sudoriferae and traditionally referred to as apocrine sweat glands (which secrete both merocrine (ekkrin) and apocrine ) compared to the other eccrine sweat glands . In contrast to the 2 to 4 million cholinergically innervated eccrine sweat glands, which are distributed over the entire body independently of hair follicles , which allow the naked primate to achieve extremely effective thermoregulation, its total of usually less than a hundred thousand odor glands are larger, limited to certain body regions and their ducts open in each case into the funnel of a hair follicle, next to that of a sebum gland of the hair follicle.
More than 100 / cm², scent glands are particularly dense in the subcutaneous tissue of the armpit, genito-anal region and areola and, more sparsely, of the face, scalp and periumbilical abdominal skin.
function
The unbranched, tubular single glands form special secretions that come to the surface mixed with sebum along a hair shaft and, with the help of a specifically adapted bacterial skin flora, are converted into often intense fragrances. Their different scent notes have at least intra-species communicative functions - usually unconscious - and can be understood as signals. The stimulus is absorbed via the normal olfactory epithelium .
From a phylogenetic point of view, the scent glands are much older than the eccrine sweat glands and, like these, are sympathetically innervated, but adrenergic . Especially in connection with emotional impulses such as anger, pain, fear, but also joy, lust and sexual arousal, the secretion of the scent glands is nervously mediated increased. Under certain circumstances this can also occur in response to olfactory detected substances with a pheromone-like effect. Sex hormones usually have a long-term stimulating effect on the activity of scent glands, which mainly only start their secreting activity at the beginning of sexual maturity .
Specialized apocrine sweat glands are the Moll's gland glandulae ciliares conjunctivales , which open into the hair follicle of the eyelashes at the edge of the eyelid, and the wax glands Glandulae ceruminosae of the external auditory canal, which secrete cerumen .
Individual evidence
- ↑ Hans-Christian Pape, Armin Kurtz, Stefan Silbernagl (eds.): Physiology . 7th edition. Georg Thieme Verlag, Stuttgart 2014, ISBN 978-3-13-796007-2 , p. 806, 814, 817 .
- ↑ Thomas Heinzeller, Carl M. Büsing: Histologie, Histopathologie und Zytologie , Thieme, 2001, ISBN 3-13-126831-X , p. 51 f. ; accessed on May 2, 2014.