Skin Flashcards
How do Langerhanns cells work?
The innate imune system causes tight junctions to relax, allowing Langerhann cells to move into the Stratum Corneum and sample and foreign antigens
What is a tight junction?
A junction that links together two adjacent cells, holding them together tightly
These can be relaxed occasionaly to allow small molecules to pass through
What is the difference between desmosomes and hemidesmosomes?
Desmosomes link cells together
Hemidesmosomes link the cell and basal lamina together (basement membrane)
Name and describe the structure of the 2 layers of the dermis
Papillary - loose connective tissue, interspread with nerve fibres
Reticular - dense connective tissue, with randomly arranged collagen fibres
What is the order of the layers of the skin? (starting from the bottom)
Stratum Basale –> Stratum Spinosum –> Stratum Granulosum –> Stratum Lucidium –> Stratum Corneum
How is the adaptive immune system activated?
Cytonkines/toxins activate dendritic cells which then bind to lymphocytes
Memory T cells are then produced to speed up the immune system next time the same infection occurs
What are the two types of sweat glands in the skin, and what are the subdivisions of one of them?
Sebaceous - Contains a lipid-rich secretion, which occurs via holocrine action. It is present in all area but not plantar and palmar surfaces
Sudoriferous - Eccrine/Apocrine
Eccrine - The most common and widely distributed. The duct opens up at the epidermal surface. Secreted via merocrine action
Apocrine - Only found in a few places such as the groin and bearded regions. The duct open into the hair folicle, and its secreted via merocrine action
What is the Integumentary System?
The skin and its accessory structures Eg, hairs, nails, glands and sensory receptors
What is interwoven between the Stratum Corneum in order to prevent water loss?
A lipid matrix
Name and explain the differences between the 3 types of exocrine glands in the skin
Merocrine - The molecule is released from its vesicle in the secretory cell –> and into the duct
Apocrine - Parts of the vesicle is pinched off (with the molecule) and enters the duct
Holocrine - The secretory cells die and shed into the duct –> thus releasing its components
From where are Antimicrobial Peptides (AMPS) formed? And which type of immune system is this part of? And why?
They are formed form Keratinocytes
Part of the Innate immune system, because no triggering event has occured to cause it (done genetically)
What is the difference between the following forms of relationship….
Commensal - Mutualistic - Pathogenic
Commensal - One of the partners benefit from the relationship, but the other suffers no harm
Mutualistic - Both partners benefit from the relationship
Pathogenic - One partner can cause a disease on the other
What are the 4 phases of hair growth?
Anagen (growth)
Catagen (transition)
Telogen (resting)
Exogen (shedding)
What is the role or keratin?
And where is most of it found?
To link keratinocytes together (via desmosomes), allowing the skin to resist and dissapate mechanical forces
How do melanosomes get into keratinocytes?
Melanosomes are creates by the golgi of melanocytes, which then leave and travel and move into keratinocytes
They then position themselves in the peri-nucleur region of the cell (blocking the nucleus from UV)
What are the 4 types of mechanoreceptors in the human hand?
Meissners Corpuscle - Strong and prolonged pressure
Merkel Cells - Sharp and small area pressure
Pacinian Corpuscle - Light but targeted pressure
Ruffini Endings - Light pressure over a wide area
