In humans, terminal hair is thick and long, such as what grows on the scalp, as compared with vellus hair
Vellus hair is short, thin, light-colored, and barely noticeable hair
Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals.
The human body, apart from areas of g ...
growing elsewhere.Marks, James G; Miller, Jeffery (2006)''Lookingbill and Marks' Principles of Dermatology''
(4th ed.), Elsevier Inc., p. 11. During
puberty
Puberty is the process of physical changes through which a child
Biologically, a child (plural children) is a human
Humans (''Homo sapiens'') are the most abundant and widespread species
In biology
Biology is the natur ...
, the increase in androgenic hormone levels causes vellus hair to be replaced with terminal hair in certain parts of the human body.Hiort, O. "Androgens and Puberty". ''Best Practice & Research Clinical Endocrinology & Metabolism'', Vol. 16, No. 1, pp. 31–41. These parts will have different levels of sensitivity to androgens, primarily of the testosterone family.Neal, Matthew; Lauren M. Sompayrac''How the Endocrine System Works''
Blackwell Publishing, 2001, p. 75. The is particularly sensitive to such hormones, as are the armpits which will develop
axillary hair
Underarm hair, also known as axillary hair, is the hair
Hair is a protein filament
In biology
Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chem ...
.Randall, Valerie A.; Nigel A. Hibberts, M. Julie Thornton, Kazuto Hamada, Alison E. Merrick, Shoji Kato, Tracey J. Jenner, Isobel De Oliveira, Andrew G. Messenger. "The Hair Follicle: A Paradoxical Androgen Target Organ", ''Hormone Research'', Vol. 54, No. 5–6, 2000. Pubic and axillary hair will develop on both men and women, to the extent that such hair qualifies as a secondary sex characteristic
Secondary sex characteristics are features that appear during puberty
Puberty is the process of physical changes through which a child
Biologically, a child (plural children) is a human
Humans (''Homo sapiens'') are the most ab ...
,Heffner, Linda J. ''Human Reproduction at a Glance''. Blackwell Publishing, 2001, p. 33. although males will generally develop terminal hair in more areas. This includes facial hair
Facial hair is hair
Hair is a protein filament
In biology
Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molec ...
, chest hair
Chest hair is hair that grows on the chest of a male in the region between the neck and the Human abdomen, abdomen. Chest hair develops during and after puberty along with other types of androgenic hair.
Development and growth
Although vellus ...
, abdominal hair
Abdominal hair is the hair
Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals.
The human body, apart from areas of glabrous skin, is covered in follicles which ...
, leg
A leg is a weight-bearingIn orthopedics
Orthopedic surgery or orthopedics, is the branch of surgery concerned with conditions involving the musculoskeletal system. Orthopedic surgeons use both surgical and nonsurgical means to treat muscul ...
and arm hair
Body hair, or androgenic hair, is the terminal hair that develops on the human body during and after puberty. It is differentiated from the head hair and less visible vellus hair, which is much finer and lighter in color. The growth of androgenic h ...
, and foot hair
Body hair, or androgenic hair, is the terminal hair that develops on the human body during and after puberty. It is differentiated from the head hair and less visible vellus hair, which is much finer and lighter in color. The growth of androgenic ...
.Robertson, James''Forensic Examination of Hair''
CRC Press, 1999, p. 47. Human females on the other hand can be expected to retain more of the vellus hair.Neal, Matthew; Lauren M. Sompayrac. ''How the Endocrine System Works''. Blackwell Publishing, 2001, pp. 70, 75. These hairs are present in the large apes but not in the small apes like gibbons and represent an evolutionary divergence.
See also
*Body hair
Body hair, or androgenic hair, is the terminal hair that develops on the human body during and after puberty. It is differentiated from the head hair and less visible vellus hair, which is much finer and lighter in color. The growth of androgenic ...
References
{{Human hair Hair anatomy