Structure and Function of the Skin Flashcards
Which part of the skin is comprised of stratified squamous epithelium?
Epidermis
Merkel cells reside in which layer of the epidermis?
Basal cell layer
Where do langerhans cells in the skin originate?
Bone marrow
Basic skin atomy develops after how many weeks of gestation?
16 weeks
Which parts of the skin have developed by 4 weeks of gestation?
- Periderm
- Basal layer
- Dermis
After how many weeks of gestation is the skin considered fully formed?
26 weeks
Which structures within the skin are hairs always associated with?
- Arrector pili muscles
- Hair bulbs
- Sebaceous sweat glands
What causes albinism?
Absence of genes which allow melanin to be formed
Which hormone is required for melanosomes to be produced to allow for melanin production?
Melanocyte stimulating hormone
(derived from ACTH from the pituitary)
What are Blaschko’s lines?
Lines which show developmental growth patterns of skin
(related to different cell groups which grow, divide and migrate over time - the lines are the separations between such populations)
The dermis is comprised mostly of what?
Connective tissue
In which cell can mechanoreceptors be found?
Merkel cells
What causes vitiligo?
Autoimmune condition causing a relative lack of melanocytes
What are the layers of the epidermis from superficial to deep?
- Keratin layer (stratum corneum)
- Clear layer (Stratum lucidum)*
- Granular layer (Stratum granulosum)
- Prickle layer (Stratum spinosum)
- Basal layer (Stratum basale)
*Not considered a major layer
Why is it important the cells in the basal layer are protected most by melanin?
Stem cells reside here
DNA must be capped by melanin as this cannot be replaced
Which cell type of most prominent in the epidermis?
Keratinocytes (95%)
Which two major conditions involves increased epidermal turnover?
- Psoriasis
- Skin cancer
What induces merkel cell cancer?
Infection from viruses
(Rare and high mortality cancer)
In which cell may Birbeck granules be found?
Langerhans cells
(they look like tennis rackets)
What is the name given to melanin that is black/brown in colour?
Eumelanin
What is the name given to melanin that is red/yellow in colour?
Pheomelanin
What is the correct order for the stages of hair growth?
- Anagen (Growing)
- Catagen (Involuting)
- Telogen (resting
Where do melanocytes originate?
Neural crest
(in ectoderm during embryogenesis)
What may increase within the skin in reponse to mechanical pressures?
Keratin
(for increased strength)
The epidermis arises from whcih embryological tissue?
Ectoderm
Which cells within the skin are the outermost cells able to detect microbes?
Langerhans cells
What is the treatment for vitiligo?
Phototherapy
(filtered phototherapy can control the autoimmune response)
Which layer of the epidermis contains filaggrin and involucrin?
Granular layer
(provides such substances to maintain water barrier of skin)