Week 12 - The Integumentary System Flashcards
(27 cards)
What are the key protective functions of the skin?
Acts as a barrier against UV radiation, pathogens, mechanical injury, and prevents water loss.
How does the skin contribute to immune defense?
Contains Langerhans cells that present antigens to the immune system.
What sensations can the skin detect?
Touch, pressure, temperature, and pain.
What waste products are excreted through the skin?
Urea, uric acid, and ammonium.
How is Vitamin D produced in the skin?
UV exposure triggers the conversion of a cholesterol derivative into Vitamin D.
What are the three main layers of the skin?
Epidermis, dermis, and hypodermis.
What type of tissue makes up the epidermis?
Stratified squamous keratinised epithelium.
Which layer of the skin is responsible for insulation and cushioning?
The hypodermis (subcutaneous layer).
What are the two layers of the dermis?
Papillary layer (loose CT) and reticular layer (dense CT).
What is the function of the stratum corneum?
Forms a waterproof, protective barrier with dead keratinised cells.
Which epidermal layer contains stem cells?
Stratum basale.
What is the stratum spinosum known for?
Cells with spiny projections; provides strength and flexibility.
Which layer contains keratin granules?
Stratum granulosum.
Where is the stratum lucidum found?
Only in thick skin like palms and soles.
What is the main function of keratinocytes?
Produce keratin for protection and barrier formation.
How do keratinocytes change as they migrate upward?
They flatten, lose nuclei, and accumulate keratin.
What is keratinisation?
The process of keratinocytes maturing and forming the outer protective layer.
What is the function of melanocytes?
Produce melanin to protect DNA from UV damage.
What do Merkel cells do?
Act as mechanoreceptors for touch and pressure.
Where are Langerhans cells primarily located?
In the stratum spinosum.
What are the main accessory structures of the skin?
Nerves, sweat glands, sebaceous glands, hair follicles, and nails.
What are the two types of sweat glands and their functions?
Eccrine (thermoregulation) and apocrine (associated with hair follicles).
What does sebum do?
Lubricates skin/hair and prevents water loss.
What is the function of arrector pili muscles?
Contract to trap heat and cause goosebumps.
