The Arrector Pili Muscle Causes

Arrector pili muscle
	Base of pilosebaceous unit: An arrector pili muscle tin can be seen as the pink-staining band of tissue at the bottom center and bottom left of paradigm
Details
Nerve	Sympathetic postganglionic nervus fibers
Identifiers
Latin	Muscle arrector pili
TA	A16.0.00.024
Th	H3.12.00.three.01041
FMA	67821
	Anatomical terms of muscle

Arrector pili muscle

The arrector pili muscles are small muscles attached to hair follicles in mammals. Contraction of these muscles causes the hairs to stand up on finish, [ane] known colloquially as goose bumps.

Each arrector pili is composed of a parcel of smoothen muscle fibres which attach to several follicles (a follicular unit), and is innervated by the sympathetic co-operative of the autonomic nervous system. The wrinkle of the muscle is and so involuntary–stresses such as cold, fear etc. may stimulate the sympathetic nervous system, and thus crusade contraction.

Contraction of the muscles has a number of dissimilar purposes. Its master function in the majority of mammals is to provide insulation: air becomes trapped between the cock hairs, helping the animal retain heat. Erection of the porcupine's long, thick hairs causes the animal to become more intimidating, scaring predators. Pressure exerted past the muscle may cause sebum to exist forced along the hair follicle towards the surface, protecting the pilus.

Additional images

Cross-section of all skin layers

References

David H. Cormack (one June 2001). Essential histology. Lippincott Williams & Wilkins. pp.1–. ISBN 978-0-7817-1668-0 . Retrieved fifteen May 2011.

Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2006. The Animal Diversity Web; http://animaldiversity.ummz.umich.edu/site/topics/mammal_anatomy/pilus.html
Burkitt, Immature; et al. (1993). Wheater's Functional Histology: a text and colour atlas. Heath. p.162.