Glands of the Skin of the Ear Canal

*
Figure 1. The external (cartilaginous) one-third part of the ear canal (shown in red) is the place for the production of cerumen (earwax). The cartilaginous ear canal skin thickness is native 1 to 1.5 mm. The skin thickness basic the bony (inner two-thirds) of the ear canal is roughly 0.1 mm in “thinness,” and also as a result, has insufficient framework or thickness to contain sebaceous or modified apocrine glands.

You are watching: What type of skin gland secretes earwax?

Earwax is the an outcome of the activity of sweat and cerumen glands in the skin lining the the outer part of the ear canal (Figure 1). The dermis of the skin the the cartilaginous ear canal consists of two exocrine glands the are affiliated in the production of cerumen. Exocrine glands secrete their commodities via ducts opened through the skin fairly than straight into the bloodstream (endocrine glands). The two exocrine glands that the ear canal room the sebaceous (oil) glands and also sudoriferous apocrine (sweat) glands.

Sebaceous (oil) Glands

Sebaceous glands secrete an oily substance referred to as sebum (Latin, definition fat or tallow). This consists of fat (lipids) and the debris of dead fat-producing cells. The is sebum the acts to protect and waterproof the hair and also skin to keep them from ending up being dry, brittle, and cracked. The level of secretion increases throughout adolescence.

Sebaceous glands room usually found in hair-covered areas of the body where the ducts open right into hair follicles, deposit sebum come the hairs, and also bring it to the skin surface along the hair shaft (Figure 2). In the human ear, this occurs in the outer part of the ear canal whereby ear hairs space present. In other areas of the body without hair, sebum is carried to the skin surface ar through pores in the skin. In the glands, sebum is created within committed cells and also is released when these cells burst. Sebum is odorless, yet when broken down through bacteria, can create odors.

*
Figure 2. Illustration the a sebaceous (oil) gland as discovered in the ear canal, mirroring its place to a hair follicle where it store sebum to the hair, allowing it to be carried to the skin surface ar along the hair column to safeguard the hair and skin from ending up being dry, brittle, and cracked. (From body Guide)

The ingredient of sebum varies from varieties to species. Human being sebum is composed of squalene, esters the glycerol, wax and cholesterol, as well as totally free cholesterol and also fatty mountain (Table I). The fatty acids (lipid content) in humans, consists of about 25% wax monoesters, 41% triglycerides, 16% free fatty acids, and 12% squalene. Squalene (an oily substance) is an intermediate preceding cholesterol in that is biosynthesis, however for part unexplained reason is stopped in the pathway to form cholesterol. The high lipid contents in sebum provides good lubrication.

*

Ceruminous Glands

Ceruminous glands require a little much more explanation. They are exocrine glands belonging to a classification called sudoriferous, or sweat glands, of i beg your pardon there room two types: (a) eccrine (merocrine) and also (b) apocrine.

*
Figure 3. Eccrine sweat glands discovered in many of the body with the exemption of the ear canal. Your secretion (water and sodium chloride) emerges through the skin at surface pores. Eccrine sweat glands respond to heat. These room NOT discovered in the ear canal, however are figured out here to present how your secretions arise through pores in the skin together opposed come apocrine sweat glands whose secretions exit along the surface of hair shafts.

Eccrine Sweat Glands cover most of the human body except the ear canal. They develop a secretion of water and also sodium chloride and their role is to produce perspiration and also remove tiny amounts that waste. The ducts the eccrine sweat glands terminate at pores on the surface ar of the epidermis wherein it lowers the body temperature through evaporative cooling. Eccrine glands room coiled ducts deep in the skin that connect to the surface ar epithelium (Figure 3). Eccrine glands respond come heat.

Apocrine Sweat Glands (Cerumen Glands) are modified sudoriferous glands. In the ear canal, castle are described as modified apocrine sweat glands and are uncovered only in the external ear canal lining. They space larger, deeper, and also produce more thick secretions than eccrine glands. This thicker cheap is referred to as cerumen the helps trap international particles from entering the ear and lubricates the eardrum. The ducts the apocrine sweat glands expand into the follicles of hair so that the sweat produced by these glands exit the body follow me the surface ar of the hair shaft. The secretions save on computer pheromones, building materials that enable olfactory (sense that smell) communication with various other members the the species. They create a thick, oily liquid that is consumed by bacteria life on the skin. It is the decomposing the secretions by bacteria that produces human body odor.

*
Figure 4. Illustration reflecting the difference between eccrine and apocrine sweat glands. Eccrine sweat glands space smaller, not as deep, and also exit your secretions in pores that the skin. Eccrine glands are NOT discovered in the ear canal. Apocrine sweat glands are discovered in the outer part of the ear canal. They space larger, deeper, and also exit a more thick secretion along the surface of a hair shaft.

The difference in between eccrine and also apocrine sweat glands is shown in number 4. The variety of cerumen glands variety in the thousands and are mostly along the whole circumference that the cartilaginous canal (Perry, 1957). Perry comments additionally that cerumen glands might be under in number, possibly bring about dry cerumen uncovered in some individuals. The outer sac the the cerumen gland is created of smooth muscles, i beg your pardon by your contraction, force the ejection of its contents. Cerumen is do continuously, and also slowly pushes larger cerumen exterior toward the exterior that the ear canal wherein it falls out that the ear or is manually removed. Cerumen glands are thought to be stimulated by the forgiveness nervous system (SNS) throughout pain and stress.

As a result of the sebaceous glands’ secretions, cerumen’s organic ingredient comprises saturated and unsaturated long-chain fatty acids, alcohols, squalene (which account for in between 12% and also 20% that the wax) and also cholesterol, 6–9% (Guest et. Al, 2004).

Is Cerumen Earwax?

Yes, and no. Cerumen itself has a waxy composition. However, what most human being call earwax is generally an ext than simply cerumen. In fact, the components of less viscous cerumen and viscous sebaceous glands integrate on the surface ar of the outer ear canal, and are most regularly joined by shed skin cells (60% keratin), saturated and also unsaturated long-chain fat acids (12-20%) alcohols, squalene, cholesterol (6-9%), hair, dust, and dirt to kind the substance generally referred to together ear wax.

Is Cerumen one Antibacterial?

Cerumen likewise contains lysozyme, an antibacterial enzyme capable of damaging bacterial cell walls, according to part researchers. Various other researchers, however, are less convinced and claim that it is the perfect tool in which bacteria can grow.

See more: Is All Purpose Flour Safe For Dogs ? Can Dogs Eat All

References

Guest JF, Greener MJ, Robinson AC, smith AF (August 2004). “Impacted cerumen: composition, production, epidemiology and also management”. QJM 97 (8): 477–88.