skin Flashcards
Describe the difference between simple and compound epithelial tissue?
Simple is a single layer of cells attached to a basement membrane –
compound is multiple layers with no basement membrane
Name 4 types of simple epithelial
Squamous, cuboidal, columnar, ciliated
Name 2 types of compound epithelial
Stratified, transitional
what is the integumentary system, and what does it comprise of?
Protects the body from various kinds of damage, like water loss or abrasions.
system compromises of the skin, hair and nails,
Define the epidermis?
The upper or outer layer of the two main layers of cells that make up the skin, and mainly connective tissue, and cells are constantly shedding and being replaced.
What 5 layers make up the epidermis?
Stratum basale (deepest), Stratum spinosum,
Stratum granulosum,
Stratum lucidum,
Stratum corneum.
Explain the role of the Stratum basale?
It is the primary site of mitosis for the skin, (reproduction of new skin cells),2. contain living cells and melanin providing skin pigment, Langerhans cells (immune cells), andMerkel cells(touch receptors).
3. made mostly of basal keratinocyte stem cells, which form keratinocytes of the stratum spinosum and stem cells for the epidermis,.
Define what Keratin does?
to adhere cells to each other and to form a protective layer on the outside of the skin. … This prevents bacteria from slipping in between the cells and keeps a sturdy barrier between the body and the environment.
What is the role of the Stratum Spinosum?
Cells are living, and capable of mitosis, Aids in flexibility, enables the epidermis to better withstand the effects of friction and abrasion.
- Where keratinization begins,
- active area for syntehsing cytokeratin, its function is to enable cells to withstand mechanical stress, by increasing thickness of skin to protect inside systems, in feet or hands for example.
What is the role of the Stratum granulosum?
- cells containt nuclues but are dying,
2. has granules which contain lipids &fats which act as skins water sealant, and help heal tissue after trauma.
What is the role of lamellar bodies?
Lamellar bodies are cells secreted between the stratum granulosum and corneum into the extracellular space, and contains lipids & proteins.
this forms a hydrophobic lipid envelope responsible for the skin’s barrier properties.
what is the role of the stratum lucidum?
Contains a quick-release form of keratin which helps to lower friction between the layers,
2.denuclueted cells, which look clear under a microscope as the membranes also become less visible.
what is the role of the stratum corneum?
Composed of 15-20 layers of dead cells, no nuclei, and cell organelles, they are constantly shedding.
2. forms a barrier to protect underlying tissues from infection, dehydration, chemicals, and mechanical stress.
Explain the balance between desquamation and keratinocytes.
Desquamation, the process of cell shedding from the surface of thestratum corneum, balances proliferating keratinocytesthat form in thestratum basale.
These cells migrate through the epidermis towards the surface in a journey that takes approximately fourteen days.
replacement of dead cells with living.
What is the dermis?
Layer superficial to the epidermis and is connected to the blood & lymph supply and nerves.
Contains sweat & sebaceous glands and hair follicles.
Made up of areolar connective tissue (tough ad elastic) and white fibrous collagen to give skin elasticity.
Explain the role of fibroblasts in the dermis?
Produce areolar connective tissue, collagen and elastin (allows skin to stretch and recoil).
This can be damaged by UV light.
Explain the role of Mast cells in the Dermis>?
as well as histiocytes, it produces histamine (how we respond to the environment and can trigger inflammation)
& Produce heparin (an anticoagulant (blood thinner) that prevents the formation of blood clots.
What is the role of leucocytes in the dermis?
To produce white blood cells, which helps the immune system to fight infections and foreign matter.
Explain the role of the sebaceous glands in the dermis?
Connected with hair follicles and produces sebum.
Sebum is a fatty acid that moistens and waterproofs the skin and lubricates hair.
Sweat and sebum combine on the skin to form an acid mantle (protective shield) to control bacteria levels and prevent infection.
- combines to form a pH level of 4.5-5.6 which helps prevent bacteria growth.
What are the 7 main vital roles of the intergumentary system?
Secretion - sebum, natural moisturiser.
Heat regulation - sweating, vasodilation/constriction to maintain 37 degrees.
Absoportion - essential oils and chemicals like drugs into skin.
Protection - prevent abrasion, bacteria and UV radiation.
Excretion - Heat, water, salts,
Senesation - Temperaute, pressure, pain
Synthesis - Vitamin D production stimulated by UV light which converts sebum to vitamin D. Synthesis of melanin to darken skin and adapt to increase sunlight exposure.
