Consists of:
1. Skin and accessory structures
◆ hair
◆ glands
◆ nails
2. Subcutaneous tissue below the skin
Functions of Integumentary System
▪ protection
▪ sensation
▪ temperature regulation
▪ vitamin D production
▪ excretion
Skin
2 major layers
1. Epidermis
2. Dermis
Epidermis
Function:
• resists abrasion in skin surface and reduces water loss
• has no blood vessels but nourished by capillaries of dermis
Subdivided into 5 sub-layers:
From innermost to outermost:
▪ Stratum germinativum/ basale - innermost layer
✔ base of epidermis and attaches to dermis
✔where mitosis takes place
Important cells in epidermis
• Keratinocytes
👉 produce keratin which makes cells hard
• Melanocytes
👉 produce melanin contribute to skin color
• Merkel Cells ( or Merkel Discs)
👉 receptors for yhe sense of touch
• Langerhans Cells
👉 phagocytize/ engulfs foreign material
▪ Stratum spinosum
▪ Stratum granulosum
▪ Stratum lucidum
▪ Stratum corneum - outermost layer
👉 most superficial layer of epidermis and consists of many layers of dead cells joined by desmosomes
👉 desquamate as desmosomes break apart
Dandruff
👉 excessive desquamation of stratum corneum of scalp
Importance of Stratum Corneum
♨ Prevent most evaporation from body
♨ Prevents entry of water
♨ Barrier to pathogens and chemicals
Importance of Melanin
📌 Production is increased by exposure of the skin to ultraviolet rays
📌 Gives the skin a darker color, which prevents further exposure of the stratum germinativum/basale to ultraviolet rays
📌 Gives color to hair, iris and interior choroid layer of the eyeball
Dermis
🔥 made of irregular fibrous connective tissue, adipose cells and macrophages
With:
🍓 Collagen - provides strength
🍓 Elastin - provides elasticity
🍓 Capillaries - nourish the stratum germinativum
Divided into 2 layers :
1. Papillary - superficial layer; where capillaries are found
2. Reticular - deeper layer
Accessory Skin Structures
🌏 Hair
🌏 Smooth muscles (Arrector pili)
🌏 Glands
🌏 Nails
In dermis: (Parts) 😡😡😡😡😡😡😡 Functions
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Human Anatomy And Physiology
De TodoMidterm to Final Exams!! Midterm: ◆Tissue ◆Membranes ◆Integumentary ◆Skeletal System Finals: 👉 Muscular System 👉 Nervous System 👉 Special Senses 👉 Cardiovascular and Lymphatic Syste 👉 Respiratory System 👉 Vascular System 👉 Reproductive Syst...
