Cells Flashcards
(34 cards)
What do Keratinocytes produce?
Keratin
What does keratin do?
-Protects the skin & tissues below
-Responsible for production of water-resistant properties of the skin
-Prevents entry of foreign matter
What pigment does Melanocytes produce?
Melanin
What does Melanin do?
-Natural colour of skin
-Helps defend against damaging effects of the sun
What happens to melanocytes when exposed to the sun?
Multiply the quantity of melanin to absorb ultraviolet rays
What are moles(naevi)?
Group of melanocytes that lie close together
Do we all have the same number of melanocytes?
Do black & brown people have more?
Roughly the same
No, same amount but produce more pigment
What are Langerhans cells a part of?
Where do they arise from?
Part of the immune system
Arise from red bone marrow
What do Langerhans cells do?
Regulate immune reactions in the skin as a defence to microorganisms that invade
What do Merkel cells do?
What do they sit against?
-Capable of detecting touch sensations
-Sensory nerve ending or tactile disc
There are layers of keratinocytes, these are?
Stratum…basale, spinosum, granulosum, corneum etc
What membrane does the stratum basale lie on?
Is it the deepest layer of the epidermis?
Basal membrane
Yes
What does the stratum basale provide a border between?
Between the dermis & epidermis
What cells originate from the stratum basale?
What older cells are pushed up through this layer until they reach the surface?
Stem or mother cells
Daughter cells
What does the stratum spinosum lie above?
What does this provide to the skin?
Above the stratum basale
Provides flexibility & strength to the skin
How many layers of flattened keratinocytes in the stratum granulosum?
3-5 layers
What do the cells contain in the stratum granulosum?
Granules
What lipid does the stratum granulosum form?
Water-resistant lipid
What does the stratum granulosum protect the body from?
From losing excess fluid
Guards against entry of microbes
What do the cells undergo in the stratum granulosum?
Cells undergo apoptosis (lose nucleus) prior to dying
Cells become brittle & compact
Process known as keratinisation
What layer is the stratum corneum?
Outer layer of the epidermis
What is the stratum corneum made up of?
Scale like layers that are dead & overlap with each other
What is the main component of the dead cells within the stratum corneum?
Keratin
What do the cells in the stratum corneum do?
Provide structural strength
