Epidermis

Front 1

What layer is the epidermis

Back 1

top layer

Front 2

What are the 5 strata layers

Back 2

Corneum, Lucidum, granulosum, spinosum, basale

Front 3

state the functions of the integumentary system

Back 3

regulate body temperature, sweating, shivering (dilating/constricting blood vessles) Protection against mechanical, chemical, bacterial, thermal and UV damage.sensation,excretion, immunity, blood resivoir, synthesizing vitamin D.

Front 4

Describe the anatomy of the epidermis.

Back 4

5 layers of strata, epithelial tissue (Stratified squamous) Avascular. Keratinocytes,

Front 5

What are the epidermal cell types

Back 5

Keratinocytes, melanocytes, langerhans cells, merkle cells

Front 6

what is a keratinocytes function

Back 6

produces protein keratin, waterproofing, physical protection

Front 7

What is a melanocytes function

Back 7

produces pigmentation melanin, synthesizes it to protect from UV

Front 8

whats the function of a langerhans cell

Back 8

epidermal macrophages helping the immune system, passes message onto other white bloodcells that can destroy antigens

Front 9

What is the function of merkel cells

Back 9

touch receptors, the nerve fibre and merkle cell are called tactile discs

Front 10

Function of stratum corneum

Back 10

made entirely of keratin, cells overlap and surface cells flake off. Keratin provides tough coating, protects deeper layers from external environment. Protects against waterloss.

Front 11

Function of stratum basale

Back 11

single layer of keratinocytes, 10/25% of basale cells are melanocytes, recieves nourishment through diffusion (dermal blood supply). Tactile discs detect light touch

Front 12

Describe skin tanning.

Back 12

= Melanin granules close to the surface become oxidized by UVA radiation and become darker
=The radiation triggers a change in melanocyte activity, melanocytes deeper in the epidermis are stimulated to produce new malanin granules. These granules are transferred to keratinocytes in the upper layer of skin, they get positioned in the outer portions of the cells above the cell nuclei, providing additional protection.
= THird stage forms additional protection but indicates damage has already been done, melanocytes divide producing more melanin granule cells, production of more cells leads to more melanin.