H10 & 11: Skin Flashcards
State the layers of the skin from outermost to innermost.
Epidermis
Dermis
Subcutis
What is the epidermis composed of?
Stratified squamous epithelia
What is between the epidermis and the dermis and how is the epidermis attached to this?
The basement membrane is between the epidermis & dermis.
The epidermis is attached to the basement membrane via hemidesmosmes & anchoring filaments.
What does the dermis contain?
Blood and lymph vessels.
What are the 2 sections of the dermis and how do these differ?
Dermis papillae & reticular dermis
Dermis papillae is thin while reticular dermis is thick.
Which of the 2 sections of the dermis is more superficial?
The dermis papillae.
Where are Meissner’s corpuscles found & what is their function?
They are found in the dermis of hairless skin. They are used in the detection of light touch.
What is the role of the subcutis?
It anchors the dermis to muscles.
State the layers of the epidermis from most superficial to deepest.
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
What happens during the process of maturation of keratinocytes?
They increase in size & synthesise tonofibrils, keratohyalin & lamellar granules.
Where are melanocytes found?
They are found in the stratum basale, in glands & follicles. They migrate to the periphery of the epidermis where they are phagocytosed by keratinocytes.
What do Langerhans cells do?
They have antigens so are involved in the skin’s immune system.
Where are Langerhans cells found?
In the stratum spinosum with keratinocytes.
What do Merkel cells do?
They detect pressure changes as they are mechanoreceptors.
Where are Merkel cells found?
in the stratum basale.
From innermost to outermost, state the components of a hair.
Medulla
Cortex
Cuticle
What is a hair follicle made up of?
Inner root sheath
Outer root sheath
Dermal papilla
Germinal hair matrix
CT sheath
What is the role of IRS?
It interlocks with the cuticle to attach the hair to a follicle.
What is the role of the dermal papilla?
It triggers the production of IRS & hair via chemical signals.
What do germinal hair matrix produce?
A special type of keratin that doesn’t desquamate.
Which muscle is associated to a hair follicle?
The arrector pili muscle
What is the role of the arrector pili m.?
It allows the hair to stand/rise.
What does the arrector pili m. attach to?
The CT surround the hair follicle & papillary dermis.
State the 4 subtypes of hair follicles.
Primary, secondary, simple & compound.
What is a characteristic of compound hair follicles and why is this characteristic possible?
They can produce multiple hairs due to fusing of hair follicles at the level of sebaceous glands.
What is a particularity of secondary hair follicles?
They are not associated with sweat glands.
