Skin

Question 1

Shapes

Answer 1

“shapes” which can help you remember the six functions.
SENSATION – Feelings generated by tactile nerve endings just under the outer layer of the skin make you aware of heat, cold, touch, pain and pressure. The reaction to a sensation is called a reflex.
HEAT REGULATION – The skin helps control our body temperature so that it maintains our internal heat regardless of environmental climate. It does this through the excretion of sweat from the sudoriferous glands and the dilation of the blood vessels in the dermal layer.
ABSORPTION – The skin permits certain substances like water and oxygen to pass through its tissues. The skin is also able to absorb some oil or fat-based substances on a topical level, but deeper penetration is confined to either medication or application of a water-based substance by means of galvanic current. Penetration of cosmetic preparations is restricted to the epidermal layers only.
PROTECTION – The skin protects the body against blows and falls and direct impact of heat and cold through the fat cells in the subcutaneous tissue. A layer of the skin called the stratum corneum acts as a barrier against bacterial invasion. Another layer called the stratum basale produces melanin pigment as a natural protection or first line of defense against harmful ultraviolet light and environmental pollutants.
EXCRETION – The skin eliminates sweat, salt and wastes from the body, helping to remove toxins from the internal systems and regulate temperature.
SECRETION – The skin secretes sebum, a complex mixture of fatty substances that keeps it soft, supple and pliable. The sebum on the skin combines with moisture from the sweat glands to create the acid mantle, which serves as a protective barrier to prevent bacteria from invading the skin and affects the skin’s pH level. A sufficient amount of sebum on the skin helps to maintain a normal pH range of 4.5-5.5.

Question 2

3 main layers of the skin

Answer 2

1. Epidermis
   • Also called cuticle or scarf skin
   • Outermost layer of the skin
   • Consists of keratinized surface layers
2. Dermal
   • Also called dermis, derma, corium, cutis or true skin
   • Underlying, or inner, layer of the skin
   • Made up primarily of collagen (80%) and elastin (connective tissue, 3%) with sebaceous glands,
   apocrine glands, eccrine glands and hair follicles
   • Referred to as the living layer because anything that penetrates the dermal layer is absorbed into the
   blood and lymph supply
3. Subcutaneous
   • Also called hypodermis, adipose, subcutis, subdermis
   • Located below the dermal layer
   • Made up mostly of adipose (fatty) and loose connective tissue and blood vessels

Question 3

Epidermis

Answer 3

Outer most protective layer of the skin
Know as cuticle or scarf skin

No blood vessels gets nourishment from dermal

The epidermis is primarily composed of keratinocytes, also called corneocytes; these consist of the protein keratin and epithelial cells, which cover and protect the inside of the body.

Consists of 5 layers Stratum basale
•  Stratum spinosum
•  Stratum granulosum
•  Stratum lucidum
•  Stratum corneum

Question 4

Papillary dermal layer

Answer 4

The papillary layer lies directly beneath the epidermis.
• It is rich in blood vessels and capillaries, which provide nutrients to the upper layer.
• From the papillary layer, finger-like projections of the dermal layer extend into the epidermis and
nourish the skin.
• Tactile corpuscles (TAK-tile KOR-pus-uls), types of nerve endings responsible for sensitivity to light
touch, are found here within the dermal papillae (DUR-mul puh-PIL-eye), which are small, nipple-like extensions of the dermal layer into the epidermis; they appear as epidermal or papillary ridges (fingerprints) and are located at the base of hair follicles.

Question 5

Reticular dermal layer

Answer 5

The reticular is the lowest layer of the dermal layer, and is in direct contact with the next layer of skin, the subcutaneous layer. The reticular layer contains fewer blood vessels. This layer contains the collagen and elastin fibers that provide the skin with its strength and flexibility.
• Collagen protein fibers are strong and flexible, while the elastin fibers are soft and pliable.
• It is in this layer that the collagen and elastin fibers deteriorate, causing the skin to sag and wrinkle during the aging process

Question 6

Sudoriferous glands

Answer 6

The sudoriferous (sweat) glands, also called eccrine glands, are duct glands controlled by the nervous system of the body. Each gland consists of a coiled base and tube-like duct opening on the surface of the skin to form a sweat pore. Sweat, the amount of which varies with your body temperature and activity, is a weak salt solution. Besides water and salt, sweat contains other substances that include lactic acid and uric acid, both of which help create the acidic pH of sweat. The sudoriferous glands are widely distributed over the body surface and found in the greatest concentration on the palms of the hands, soles of the feet, scalp and forehead, underarms, anterior trunk and genital region