Integumentary system Flashcards
2 major parts of this system
cutaneous membrane (skin)
Accessory structures
Function of the integumentary system
- protection of underlying tissue
- maintains body temp.
- synthesizes vitamin D3
- stores lipids
- detects touch, pressure, pain and temperature
- excretes salts, water and organic wastes (glands)
name the 3 main layers
epidermis
dermis
hypodermis (subcutaneous layer)
What are the two types of skin of the epidermis that can be found
thin skin, covers most of the body (four layers)
thick skin, covers the palms of hands and soles of feet (five layers)
what is keratinization and where does it occur
formation of a layer of dead, protective cells filled with the protein keratin, occurs on all exposed skin surfaces except eyes
what is the skin life cycle
in 7-8 days, cells move from the innermost layer to the outermost layer of the skin and are shef off
what does the dermis do?
anchors epidermal accessory structures
what are the accessory structures of the dermis
hair, exocrine glands and nails
what is the function of the hypodermis
connects dermis to underlying tissue and lies below and stabilizes the skin
characteristics of hypodermis
elastic areolar and adipose tissue sare interwoven with the dermis, it has few capillaries and has no vital organs
what are the functions of hair
- protects and insulates against UV and temperature changes
- guards body openings against particles and insects
- sensitive to very light touch which provide warning system
name of the hair color pigment and what produces it
From the pigment melanin which is produced by melanocytes at the hair papilla and is determined by genes
What does sebaceous glands do and what is its function
It discharges oily lipid secetion (sebum) into hair follicles
Sebum inhibits the growth of bacteria, lubricates hair and conditions surrounding the skin
what is the function of sweat glands
cools skin, flushes microorganisms and harmful chemicals from skin
what are nails made of an their function
kertainized epidermal cells that protect the tips of fingers and toes
What are the factors that affect skin color
Epidermal pigmentation, namely the pigments carotene and melanin
Dermal circulationm, where oxygenated red blood contributes to skin color and cyanosis could result in a bluish skin tint due to reduction in blood flow/ oxygenation
What is carotene
A orange yellow pigment found in orange vegetables.
It can be converted to vitamin A which helps in the normal maintenance of epithelial tissues and the synthesis of photoreceptor pigments in the eye (defincy causes night blindness)
What is the importance of melanin
protects the skin from sun damage
UV radiation can cause DNA mutations and burns, leading to cancer and wrinkles
Skin colour depends on melanin production
What is the cause of albinism
A defincy or absence of melanin production, albinos have photophobia/ sensitivity to the sun
what is the effect of sunlight on the skin
The epidermal cels produce vitamin D3 (cholecalciferol) in the presence of UV radiation, which is converted to calcitrol in liver and kidneys and aids in the absorption of calcium and phosphorus
Insufficent vitamin D3 results in rickets or osteroporosis
Could also result in skin cancers like carcinoma, a cancer of epithelial cells and malignant melanoma, malignant (cancer cells) fomr in melanocytes and grow rapidly and metastasize through lympthatic system
effects of aging on the skin
- sensitivity of immune system reduces
- skin infection and injuries become more common
- sensitvity to sun exposure increases
- skin becomes dry and scaly
- hair thins and change colour
- sagging and wrinkling of skin
- ability to lose heat decreases
