What are the components of the integumentary system?
- The skin
- Hair
- Nails
- Associated exocrine glands
The integumentary system plays a crucial role in protecting the body.
What are the primary functions of the integumentary system?
- Protection of internal organs
- Sensory function
- Thermoregulation
- Vitamin D synthesis
These functions are vital for maintaining homeostasis and overall health.
What are the layers of the skin?
- Epidermis
- Dermis
- Hypodermis (Subcutaneous layer)
The hypodermis connects the skin to underlying muscle.
What type of epithelium composes the epidermis?
Keratinized stratified squamous epithelium
This structure contributes to the protective function of the skin.
How many layers does thick skin have?
Five layers
Thick skin is found on the palms of hands and soles of feet.
What are keratinocytes?
Mature cells in the epidermis that produce keratin
Keratin provides toughness and water resistance to the skin.
What are the four to five layers of the epidermis from superficial to deep?
- Stratum corneum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
Thick skin includes an additional layer.
What is the function of melanocytes?
Produce melanin to protect cells from UV radiation
Melanin is crucial for skin pigmentation and UV protection.
What are the two forms of melanin?
- Eumelanin (black and brown pigment)
- Pheomelanin (reddish pigment)
The concentration and activity of melanocytes result in different skin tones.
What is the stratum spinosum known for?
Containing eight to ten cell layers thick with keratinocytes
This layer also includes Langerhans cells for immune protection.
What happens in the stratum granulosum?
Cells begin to flatten and accumulate keratin
This layer is characterized by its granular appearance.
Where is the stratum lucidum found?
Only in thick skin, such as palms and soles
This layer consists of tightly packed, dead keratinocytes.
What characterizes the stratum corneum?
Most superficial layer with 15 to 30 layers of dead keratinocytes
Cells in this layer are continuously shed and replaced.
What is the difference between thin skin and thick skin?
- Thin skin has four layers of epidermis
- Thick skin has five layers of epidermis
- Thick skin contains stratum lucidum
- Thick skin has more sensory receptors
Thin skin covers most of the body.
What are dermal papillae?
Fingerlike projections of the dermis into the epidermis
They help anchor the epidermis to the dermis and are noticeable as fingerprints.
What is the primary composition of the dermis?
Mainly connective tissue
The dermis also contains blood vessels, hair follicles, and glands.
What are the two layers of the dermis?
- Papillary layer
- Reticular layer
The papillary layer is more superficial, while the reticular layer is deeper and thicker.
What is the function of the hypodermis?
Provides insulation and cushioning
The hypodermis is also highly vascularized and contains adipose tissue.
What are the accessory structures of the skin?
- Hair
- Nails
- Sweat glands
- Sebaceous glands
These structures contribute to the overall function of the integumentary system.
What is the role of hair?
- Physical protection
- Sensory input
- Thermoregulation
- UV protection
Hair serves multiple protective and sensory functions.
What are the components of hair from deep to superficial?
- Hair papilla
- Hair bulb
- Hair root
- Hair shaft
- Medulla
- Cortex
- Cuticle
These components contribute to hair structure and growth.
True or False: Hair growth is continuous.
False
Hair follicles alternate between growth and rest cycles.
What is the cycle of hair growth?
Follicles alternate between growth and rest cycles. New growth pushes old hair out.
What are nails composed of?
Keratinized epidermal cells.
