1. Anatomy of the Hair, Nails, and Skin

2. Hair Three types Lanugo Vellus Terminal
Hair is a slender filament composed of keratinized cells . Hair grows from a tube located in the skin called the hair follicle.
There are 3 types of hair. One is lanugo which is fine, downy, not pigmented and generally appears on the fetus. By the time of birth this hair generally replaced
The second kind of skin is vellus which is also fine and pale.
This type of hair is mostly present on children however it is found on men and women.
Thee last type of hair is terminal hair. This hair is longer, coarser, and is usually more heavily pigmented

3. Hair structure Bulb Root Shaft Dermal papilla Hair matrix Medulla
Cortex
Cuticle
The bulb is a swelling at the base where the hair originates in either the dermis or hypodermis
The root is the remainder of the hair within the follicle and the shaft is the portion above the skin surface
The dermal papilla is the area in which the bulb grows around and provides the hair with its sole source of nutrition
The hair matrix is the hairs growth center and is the only area which contains live cells
The medulla is the inner core of the hair shaft
The cortex is the thickest part of the shaft and is composed of several layers of keratinized cells
The cuticle is made up of scaly cells that overlap each other like shingles on a roof

4. Hair Texture Straight hair= round Wavy hair= oval
Tight and curly= flat
The texture of hair is based on the differences in cross-sectional shape
When an individual has straight hair the shape of their hair tends to be round
A person with wavy hair had oval shaped hair and someone with tight and curly hair has flat hair

5. Hair Color Brown- Eumelanin Black- Eumelanin
Red- Eumelanin and pheomelanin
Blonde- Pheomelanin
Hair color is the result of pigment molecules in the cells of the hair shaft
Both brown and black hair are colored due eumelanin
Red hair has low concentration of eumelanin and a high concentration of pheomelanin
The pigment in blond hair is pheomelanin

6. Hair Growth and Loss Stages Anagen Catagen Telogen
The anagen stage is when the hair follicle is growing and 90% percent on the hair is in this stage.
Catagen in this stage hair growth has stopped
The Telogen hair is the phase when the hair begins to shed

7. Nails Thin, scaly cells Keratin Nail plate Nail body Nail fold
Nail groove
Nail bed
Eponychium
The nail is composed of thin scaly and dead cells and filled with keratin fibers
The nail plate is the hard part of the nail and the overhanging part of the nail is known as the free edge
The nail body is the part of the nail that is attached
The nail fold is the skin surrounding the nail plate and the nail groove separates the two
The nail bed is the skin underneath the nail plate
The (EP-o-NICK-ee-um) is the cuticle

8. Functions of Skin Resistance to trauma and infection Barrier
Vitamin D synthesis
Sensation
Thermoregulation
Non verbal communication
The skin receives more damage than any other organ in the body. The skin is able to cope with the damage it receives because of the epidermal cells which contain keratin. Very few infectious agents can actually penetrate the skin which helps protect the body from disease.
The skin is a very good barrier to water which is very important when you bathe and go swimming. The skin prevents the body from absorbing excess water during these activities. Not only does the skin prevent the body from taking in too much water it prevents the body from losing large amounts of water. The epidermis is one of the body’s main defense against cancer causing radiation.
The first step of vitamin D synthesis is carried out by the skin.
The skin is the body’s largest sense organ. The skin can detect many different environmental changes. The skin can help detect changes in temperature, textures, pressure and tissue injury.
Thermoregulation. The skin contains cutaneous nerve endings called thermoreceptors which are responsible for monitoring the bodies surface temperature.
The skin allows for humans to be much more expressive than other mammals. The skin, hair and nails are very important for humans when it comes to their social wellness.

9. Epithelial cells of the skin
Keratinized stratified Squamous
Non-keratinized stratified squamous
Keratinized stratified squamous- the function of these cells includes resistance to abrasion and penetration by pathogenic organisims. These cells help with water loss through skin. Also these cells contain a layer of dead skin making it easier to resist abrasion. These cells are mostly located on thick skin
Non-keratinized stratified squamous- the function of these cells is to resist abrasion and penetration by pathogenic organisms

10. 2 Main layers There are two main layers of the skin.
The first layer of the skin is called the epidermis
The second layer of the skin is the dermis
There are also two types of skin
The first type is thick skin which contains an extra layer in the epidermis. This type of skin is only located on the palms of your hands and the soles of your feet.
The second type of skin is thin skin which contains only 4 layers in the epidermis. This skin is located over the entire body.

11. Epidermis The epidermis is the first layer of the skin
The epidermis has 5 layers(deep to superficial)
Stratum Basale
Stratum Spinosum
Stratum Granulosum
Stratum Lucidum (thick skin only)
Stratum Corneum
The first layer of the skin is called the epidermis
from deep to superficial the layers of the epidermis are
The stratum lucidum is seen only in thick skin

12. Dermis The (dermis) is the underlying or inner layer of the skin.
The dermis is composed of three types of tissue that are present throughout and not in layers. These types of tissue are:
collagen
elastic tissue
reticular fibers

13. Subcutaneous Tissue
The subcutaneous tissue is a layer of fat and connective tissue that houses larger blood vessels and nerves. The size of this layer varies throughout the body and from person to person.

14. References
Saladin Anatomy and Physiology