Structure and Function 3 Flashcards
Support, anchorage, adhesion, growth and
differentiation of epidermal cells
Semi-permeable membrane acting as
barrier and filter
Dermoepidermal junction
Epidermolysis bullosa (simplex and dystrophic) affect which layer of the skin?
Dermo-epidermal junction
-due to a mutation in one of the proteins in the DEJ
Name 3 conditions with auto-antibodies to the proteins in the DEJ?
Pemphigus
Pemphigoid
Dermatitis herpetiformis
Epidermolysis bullosa simplex
Chromosomes 12q, 17q
Autosomal dominant
Superficial blistering
Scarring absent
Often shows intermittent blsitering especially in hot weather
Epidermolysis Bullosa Dystrophica
Deeper blistering associated with scarring
Skin, nails, mucosa and often the larynx involved
Repeated scarring results in squamous cell carcinoma and pts often die from complications in early life
Life expectancy significantly reduced
Recessive form is far worse than the dominat form
Which bullous disease shows positive immunofluorescence?
Bullous pemphigoid
Components of the dermis?
Cells - mainly fibroblasts, macrophages, mast cells, lymphocytes, Langerhans cells
Fibres – collagen, elastin
Ground substance
Blood vessels, lymphatics, nerves
Main type of cells in the dermis?
Fibroblasts
What type of cell secretes collagen?
Fibroblasts
These cells are scavengers and are involve in antigen presentation
Macrophages
Cells involved with immune reactions
Lymphocytes
Langerhans cells do what
Antigen presentation
What is dermogrpahism? (really cool)
Its like being able to write on your skin, whenever you stroke hard/scratch, it goes really red
Because of mast cell activation
Which layer of the skin is responsible for photo aging?
The fibres in the dermis
Flow of blood
Arteriole --> Precapillary sphincter --> Arterial capillaries --> Venous capillaries --> Post-capillary venules --> Collecting venules
What is an angioma?
Localised overgrowth of blood vessels
Eg: port wine stain, “stork marks”
(capillary or cavernous haemangiomas)
Which layer are the blood vessels found in?
The dermis
Histological findings of angioma
Dilated vascular spaces
Pacinian receptors sense what?
Pressure
these are dound slightly deeper in the dermis than the meissners
Meissners corpuscles sense what?
Vibration
Widely distributed:
largest glands present on face and chest
Hormone sensitive – quiescent pre-puberty
Produce sebum: squalene, wax esters, triglycerides and free fatty acids
Mainly open onto hair follicle
Functions:
control moisture loss
protection from bacterial and fungal infection
Sebaceous glands
Function of sebaceous glands?
Control moisture loss
Protection from bacterial and fungal infection
A mixture of increased sebum, blocked ducts and bacterial activity?
Acne
Develop as part of pilosebaceous unit
Axillae and perineum
Androgen dependent
Produce oily fluid odour after bacterial decompostion
Scent glands
Apocrine glands
Apocrine glands are dependent on which hormone?
Androgen
Whole skin surface palms, soles and axillae in particular
Sympathetic cholinergic nerve supply – mental, thermal and gustatory stimulation
Ultrafiltration : can be > 10L per day 2 - 4 million glands = 100g (= one kidney) NaCl + HCO3 reabsorbed - hypotonic fluid
Functions: cooling by evaporation moisten palms / soles to aid grip
Eccrine glands
Nerve supply to the eccrine sweat glands?
Sympathetic cholinergic
mental, thermal and gustatory regulation
Function of eccrine glands?
Cooling by evaporation
Moisten palms/soles to aid grip
