By ; Ebtisam Ali ~

• a material that changes the color of reflected

or transmitted light . It’s found on Epidermis

Melanin is an example of pigment in human skin

• It’s produced by cells called .

• these cells manufacture melanin from an amino acid, tyrosin, with the help of an enzyme, tyrosinase .

protection against skin damage from the

sun .

Aging skin is a fact of life. As people getting older , Skin layers changedaccording to many factorssuch as exposure to sunlight and hormones level .

• " Increase in pigment "

• Darkening of an area of skin caused by theoverproduction of pigment or melanin .

• Types of Hyperpigmentation

• Liver-spot

• Melasma

• Solar Lentigenes " liver spots " pigmented flat spot on sun-exposed skin in older adults, especially on the back of the hands and on the forehead .

• Melasma Pigmentation of the cheeks of the face . caused by hormonal changes . appear after the age of 40 as the skin is less able to re-grow

• "decrease in pigment"

• Occurs when the skin cells lose pigment and become whiter .

•Vitiligo

• Tinea versicolor.

• Vitiligo a Condition that causes depigmentation of parts

of the skin. It occurs when melanocytes, the cells responsible

for skin pigmentation, die or are unable to function .

• Tinea versicolor (also known Tinea flava) is a

condition characterized by a rash on the trunk and proximal

extremities

• REFRENCES

• Anatomy & physiology in health and illness , By Ross &

Wilson, British Library ,11th edition , 2011

• Wheater's Functional histology , By Young and heath ;

churchil livingstone , 5th ed .

• James, William D.; Berger, Timothy G.; et al. (2006).

Andrews' Diseases of the Skin: clinical Dermatology.

Saunders Elsevier

• ADAM education Solution .