Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of...

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Skin Epidermis and Dermis

Transcript of Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of...

Page 1: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

Skin

Epidermis and Dermis

Page 2: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

Epidermis• The epidermis is the outer layer of

our skin

• It is made of several layers:1. Stratum corneum2. Stratum lucidum3. Stratum granulosum4. Stratum germinativum

Page 3: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 4: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

Stratum corneum• The stratum corneum is the layer we

touch and care for; it is only dead cells

• This layer contains NO blood vessels (i.e. nutrients can’t be brought to the epidermis)

Page 5: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 6: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• When the cells die, they undergo a chemical process that changes them from soft, easily damaged cells into ones that are harder and tougher.

Page 7: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 8: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• Keratin is a protein that helps harden these cells and makes them waterproof, thereby helping to prevent water loss by the body

• Although dead, these cells can pass on sensations such as pressure to the nerve endings in the layers below the epidermis

Page 9: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

Stratum Germinativum

• The stratum germinativum (jer-min-a-tiv-um) is the bottom layer of cells in the epidermis, which is made up of cells which divide to produce new cells (cell division)

Page 10: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 11: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 12: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• As new cells are produced, they push older cells above them toward the surface of the skin.

• The outer layer is constantly shedding dead cells

Page 13: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 14: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• The SG layer of the epidermis produces the pigment melanin which gives skin color, and allows the skin to tan

Page 15: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• Melanin production is stimulated by exposure to ultraviolet light; doses of sunlight cause the skin to tan

• Prolonged exposure to the sun may destroy several layers of epidermal cells and cause sunburn/blisters

Page 16: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 17: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 18: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 19: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• Freckles are caused by uneven distribution of melanin (small irregular patches)

Page 20: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

Dermis• Underneath the epidermis

• Contains living tissues which are specialized to monitor the changes that occur in the environment immediately around the body

Page 21: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 22: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• Contain collagen fibres: limits how much the skin can be stretched

• Contains elastic fibres: pulls the skin back after stretching

Page 23: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• Contains blood vessels: for regulating body temperature in response to impulses from special heat/cold receptors

– There are also touch, pressure, and pain receptors; found within different levels of the dermis

Page 24: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 25: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• Contains many dermal papillae: blood in these dome-shaped structures nourish the germinative layer above

Page 26: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

Between the Dermis and Epidermis

• Where the epidermis and the dermis meet, there is a wavelike layer formed of many tiny cones and ridges

• These patterns show through the surface of the skin on the hands and feet, some of them becoming fingerprints

Page 27: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 28: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 29: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• The patterns emerge while the baby is developing in the uterus and never change, except with respect to size

• Patterns on the skin of fingers can be classified into 10 basic arrangements of loops and whorls

Page 30: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.
Page 31: Skin Epidermis and Dermis. Epidermis The epidermis is the outer layer of our skin It is made of several layers: 1.Stratum corneum 2.Stratum lucidum 3.Stratum.

• Even identical twins will have some differences (even if they are not obvious from facial feature, body size etc)