Epidermis Chapter 3 Flashcards
How many layers is epidermis composed of
5
Epidermis is composed of five layers of what kind of squamous epithelial tissue
Layers of stratified squamous epithelial tissue
That become tough and hard through a process called keratinisation
What is the process called When stratified squamous epithelium tissue becomes tough and hard
Keratinisation
What makes up 90% of epidermal cells (they produce a protein called Keratin)
Keratinocytes 
Keratin helps protect the skin it also helps do what
Waterproof the skin
Melanocytes produces a black-brown pigment called what
Melanin
Melatonin contributes to the skin colour by absorbing what
Ultraviolet light
Melanin granules actually for protective layer over what
The nuclei of cells
Melanin granules actually form a protective layer over the nuclei of cells but it’s only over one side of the nuclei which faces which direction
The surface of the skin - the melanin is like a sun hat protecting the nuclei from ultraviolet light
Langerhans cells Arise from bone marrow and move to the what
Epidermis
Langerhans cells respond to foreign bodies and thus play a role in what
Skin immunity
Merkel cells are found in the stratum basale of hairless skin and are attached to what
Keratinocytes
Merkel cells make contact with nerve cells from the merkel discs which function in which sensation
Touch
The deepest layer of the skin is called what
stratum basale (Or stratum germinativum)
The stratum basale Is the deepest layer of the epidermis and is the base for what
New cells to germinate (sprout)
Stratum spinosum Is the second deepest layer of epidermis and consists of prickly cells that are beginning to go through what process
Keratinisation
Stratum granulosum is the third deepestLayer of cells and is made up of two degenerating cells that are becoming increasingly what
Becoming increasingly filled with little grains or granules of keratin
Stratum lucidum is the second shallowest Layer of cells this is a waterproof layer of what kind of cells
Dead and clear cells
Stratum corneum Is the shadow set of cells this is the outermost layer of skin what are the cells like
The cells are dead and now completely filled with Keratin they are tough, durable and horny
Can also be divided into two major layers called what
The inner layer (Malpighian layer)
The outer layer
The inner layer of the epidermis contains only dividing… Kinds of cells
Non-keratinised cells
The inner layer of the epidermis contains only dividing non-keratinised cells it includes the stratum basale were sales are constantly being what:
And the stratum spinosum where cells are only beginning to what:
Produced
Beginning to go to the process of keratinisation 
The outer layer of the epidermis is composed of keratinised non-dividing cells these include what three things
Strata granulosum
Lucidum
Corneum
What does avascular mean?
Contains no blood vessels
The stratum basale form is the deepest layer of epidermis this layer is closest to the what
Dermis
Because the stratum basale is the closest to the dermis it receives nutrients and oxygen for a process called what
This nourishment enables the stratum basale to do what
Diffusion
Create millions of new cells each day
The stratum basale has the following characteristics (finish the sentence)
1) It composed of a… Layer of cuboidal or… Cells that have nuclei
2) Constantly producing… This is the reason it is sometimes called…
3)The cells are pushed upwards towards the… By… Produced cells below
4) The different cells present in the stratum basale are (4)
1) Single…columnar
2)New cells… Stratum germinativeum
3) Superficial layer… Newly produced
4) Stem cells for reproduction
Keratinocytes
Melanocytes
Merkel discs 
The stratum spinosum Consists of 8 to 10 layers of many sided, irregular cells that appear to be covered with … … Or…
Prickly thorns or spines (These spines join the cells tightly to one another)
The stratum spinosum Is a transitional layer between the stratum basale and the stratum granulosum and it contains some dividing cells as well as some cells that are
Beginning to go through the process of keratinisation
Stratum spinosum is also called the……layer
Prickle-cell
Stratum granulosum is also called the….layer
Granular-cell layer
Stratum lucidum Is also called the… Layer
Clear – cell layer
The stratum corneum is also called the… Layer
Honey – cell layer
The stratum granulosum consists of 3 to 5 layers of flattened cells whose nuclei are beginning to what
This is why
Degenerate and die
Because the cells are now far away from the nutrient – supplying dermis and I’m becoming increasingly keratinised
The Stratton Lucidum Is composed of 3 to 5 layers of clear flat dead cells that have no
This layer is waterproof and most apparent wear
Nuclei and contain eleidin ( The producer of keratin)
In thick skin on the palms of the hands and soles of the feet
Stratum corneum is the uppermost layer of skin and is exposed to all the harsh changes in the external environment. Because it needs to be strongest and toughest of all the layers it is made up of what
The cells are constantly shed reply process called what
25 to 30 layers of flat dead cells that are completely filled with keratin
(dead cells have no nuclei)
The process is called desquamation

Dermis is the supporter layer beneath the epidermis and is composed of connective tissue that contains both collagen and…
Elastic fibres
Dermis contains many different cells and structures including
1) Fibroblasts (Contains three fibres)
2) macrophages (Cells that engulf and destroy bacteria)
3) adipocytes (Fat cells)
4) mast cells (Cells produce histamine which dilates small blood vessels during information)
5)blood and lymphatic vessels
6)nerves
7) glands
8)hair follicles
Fibroblasts a large flat cells that synthesise the following fibres (3)
1)Collagen fibres (very tough yet flexible give skin it’s stretchiness + Attract water so keep skin hydrated 
2) Elastic fibres (Strong thin fibres that give elasticity to the skin)
3)Reticular fibres (Thin fibres that form branching that works around other cells and give support and strength)
Dermis can be divided into two layers called
1) the papillary layer - A nipple shaped projection that go into the epidermis
2) the reticular layer - Vary in thickness
