Skin Flashcards
Describe the structure of skin
Startup cornea Epidermis Papillary dermis Reticular dermis Hypodermis
Describe the structure of the epidermis
Made up of keratinocytes.
arranged in 4 layers (stratum corneum, stratum granulosum, stratum spinosum and stratum basale,)
3 cell types found in the epidermis and their functions
Langerhan cells = antigen presenting Merkel = sensation Melanocytes = produce melanin
What is the result of a mutation in filagrin gene?
Glue between corneocytes in epidermis is not normal = eczema
Name 4 layers of the epidermis
Stratum basale Stratum spinous Stratum granulosum = cells have keratin granules Stratum corneum = cells have no nuclei
Where are melanocytes found, what type of cell are they, and what do they do and explain fully how?
Basement membrane of epidermis.
Dendritic cells and produce melanin in melanosome.They produce the pigment melanin in organelles known as melanosomes. Melanosome are packaged into granules which move down the dendritic processes and transferred by phagocytosis to adjacent keratinocytes. The melanin granules form a protective cap around the keratinocyte nuclei and protect the DNA within the nucleus from UV and lead to skin pigmentation.
Vitamin D deficiency in children is called?
Rickets = soft and fragile bones
How are the dermis and epidermis held together?
Connected via hemi-desmosomes, anchoring plaques and a multitude of proteins.
What happens if there is a mutation in one of these proteins?
Layers aren’t connected properly Get blisters Epidermolysis bullosa
What does the dermis contain and the subcutaneous layer?
The dermis is supportive connective tissue consisting of collagen , elastin and glycosaminoglycans.
The dermis contains fibroblasts that synthesize collagen, elastin and glycosaminoglycans. Dermal dendritic cells are found along with other immunocompetent cells.
Varies in thickness
Subcutaneous layer
This consists of connective tissue and fat.
2 types of sweat glands
Eccrine = all over body, salty sweat Apocrine = under hair follicle, viscous sweat can be metabolised by bacteria
Embryology of epidermis, dermis and melanocytes
Epidermis = ectoderm Dermis = mesoderm Melanocytes = neural crest
Functions of skin
Protection against injury Protection against pathogenic organisms Waterproofing and fluid conservation Thermoregulation Absorption of ultra violet radiation and vitamin D production Sensory organ Cosmetic
What causes different racial colours
Different numbers and sizes of melanosome produced
