Keratinization/Skin Color/Skin Functions/Accessory Organs of the Skin A&P

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Keratin

Protein that waterproofs the skin

Keratinization

Process which the cytoplasm of epidermal cells are replaced by keratin

What is your skin color determined by

Presence of melanin

Melanin

Coloring pigment produced by melanocytes in stratum basale

Melanin function

Protect skin from UV radiation

What does amount of melanin depend on

Genetics, melanocytes variation, number of melanocytes

Cyanosis

Person who has low oxygenated blood

Skin functions

Protective barrier, insulation, regulation of body temp, sensory perception

Protective barrier

Provides skin with waterproof barrier that’s impenetrable to substances

Insulation

Hypodermis provides layer of insulation that helps keep body warm

Regulation of body temperature

Human bodies regulate temp of 98 degrees F

What happens when body is cold

Adipose tissue acts as insulation, blood vessels constrict

What happens when body is hot

Sweat excretion, blood vessels dilate

Sensory perception

There are several nerve endings found in dermal layer of skin

Nerve endings found in dermal layer

Meissner’s corpuscle, Ruffni corpuscle, Pacinian corpuscle, Krause corpuscle, free nerve endings

Meissner’s and Ruffini’s Corpuscle

Responds to touch

Pacinian Corpuscle

Responds to pressure

Krause’s Corpuscle

Responds to temperature

Free nerve endings

Responds to touch, pain, and temperature

Accessory organs

Hair, nails, and cutaneous glands

Hair functions

Insulation, protection, shading of eyes

Hair regions

Cuticle, cortex, medulla

Hair cuticle

Outermost layer that contains keratin

Hair Cortex

Middle layer that contains keratin and some pigment

Hair medulla

Innermost layer that contains pigment

What is hair color dependent on

Pigment produced by skin

Why does blonde hair contain no pigment

Lacks medulla and thinner than darker hair

What causes goosebumps

Arrector pili contracting

Nail function

Protection

Nail root

Region nail grows from

Lunula

Region of cell divisionn in nail root

What are the 2 types of cutaneous glands

Sebaceous glands (oil) and sudoriferous glands (sweat)

Where are sebaceous glands found

Mixed with hair follicles

What do sebaceous glands secrete

Sebum

Sebaceous glands function

Keep hair and skin soft/moisturized