Skin Structure (physiology)

Question 1

What makes up the epidermis ?

Answer 1

Stratified squamous (epithelium)

Question 2

What body part have stratified squamous ?

Answer 2

Vaginal canal
Anus
Esophagus

Question 3

What are the primary functions of the skin ?

Answer 3

Helps regulate temperature
Prevents loss of moisture
Provides a protective barrier against mechanical, thermal and physical injury.
Reduces harmful effects of UV radiation.

Question 4

The skin is split into 3 main sections what are they ?

Answer 4

Epidermis
Dermis
Hypodermis

Question 5

What’s the epidermis ?

Answer 5

It is the outermost layer of skin in the body.
Primary barrier between you and the outside world.

Question 6

What does the epidermis consist of ?

Answer 6

Several layers of keritonised at various stages of keritinisation.

Question 7

What is keratinization?

Answer 7

Process in which the cytoplasm of the outermost epidermal cells is replaced by keratin.

Question 8

There are the 2 types of epidermis ?

Answer 8

Thick skin - usually free from hair.
Thin skin - hair is associated with it.

Question 9

How many thick and thin layers are there?

Answer 9

4 thin
5 thick

Question 10

What are the layers ?

Answer 10

Stratum basale
Forming the stratum spinosum, stratum granulosum, stratum lucidum ( only thick skin).
And stratum corneum (outer moist).

Question 11

How long does it take for a keratinocyte to mature from the stratum basale tot he stratum corneum?

Answer 11

30 days

Question 12

How is skin pigmentation caused ?

Answer 12

Caused by cells in the stratum basale called melanocytes.
These extend processes and fill keratinocytes with melanin.
The more cells they contract the more pigmented the skin becomes.

Question 13

What is the main sensory cell in the stratum basale?

Answer 13

It’s the tactile epithelial (merkel) cell.
These are pale staining round cells that find free nerve ending and are accosted with the section of pain and itching.

Question 14

What are the consequences of loss of melocytes?

Answer 14

Vitiligo occurs when pigment producing cells (melanocytes) die or stop producing melanin.
Involves patches of skin becoming lighter/ white.

Question 15

What is the dermis?

Answer 15

The inner layer of the the two layer of the skin

Question 16

What’s is the dermis composed of ?

Answer 16

Composed entirely of connective tissue and is attached to the epidermis by the baseman membrane.
This itself is composed of modified fibers.

Question 17

Where are immune cells found ?

Answer 17

Found in various layers of the skin .
In the epidermis , epidermal dendritic cells can be ground up to the stratum granulosum.

Question 18

Where are dermal dendritic cells found ?

Answer 18

Can be found throughout the dermis often seen entering or leaving the lymph capillaries.

Question 19

What is the papillary Dermis?

Answer 19

Is the dermal region directly in contact with the epidermis.
Defined by its undulating dermal papillae.

Question 20

What is the reticular dermis?

Answer 20

The thick bottom layer of the dermis.
Has blood vessels and connective tissue that supports the skin.
Hair follicles, oil and seta glands are found.

Question 21

What does the dermis have?

Answer 21

Has a pattern of collagen fibers forming a distinctive net like design.
Where the first blood and lymph vessel are found.
Glandular tissues is found here.

Question 22

What is the hypodermis?

Answer 22

Bottom layer of skin in the body.
Composed of fat cells, contained in fibrous compartments.

Question 23

What’ is the function of hypodermis ?

Answer 23

Provides insulation
Protection
Temperature regulation
Connection between the bones and muscles.

Question 24

Where are hair follicles found?

Answer 24

Located deep in the dermis and rose to exit the skin to the outside world. Hair is mostly composed of keratin.
The entire hair follicle is composed of the peri dermis.

Question 25

How can hair be raised?

Answer 25

Raised during thermoregulation by the arrector pili muscle.
This connects to the base of the anti and is composed of smooth muscles.

Question 26

What does the papillary dermis consist of ?

Answer 26

Small capillaries only.
Fibroblasts
Some immune cells
Composed of connective tissue.

Question 27

What does the reticular dermis consist of ?

Answer 27

Collagen and elastin
Some immune cells Composed
Larger vessel ( blood and lymph)
Glandular tissue.
Merges into the hypodermis.

Question 28

What’s the hypodermis consisted of ?

Answer 28

Larger arteries and veins
Mainly adipose tissue
Fibrous regions forming compartments.