Hair and Nails

Question 1

Hair Functions

Answer 1

• Protection e.g. from UV, minor injury and eyelashes
• Sensation due to innervation
• Thermoregulation
• Communication/sexual attraction

Question 2

Hair Types

Answer 2

• Lanugo
• Vellus
• Terminal

Question 3

Lango Features

Answer 3

• fine/long
• formed in fetus first 20 weeks and normally shed before birth
• occur in anorexia

Question 4

Vellus Features

Answer 4

• short, fine and light coloured

- cover most of the body

Question 5

Terminal Features

Answer 5

• longer, thicker and darker
• found on the scalp, eyebors, eyelashes and pubic, axillary and beard areas
• originate as a velus but differentiation occurs at puberty by androgens

Question 6

Hair Growth Phases

Answer 6

• ANAGEN (lasts 3-7 years for scalp. at one point 80-90% of hair in this phase)
• CATAGEN (synthesis stops and follicle retreats towards the surface as dermal papilla moves to the base of muscle insertion)
• TELOGEN (shedding phase that is an active process)