Skin

Question 1

Epidermis is stratified ___ epithelium.

Answer 1

Squamous (flat)

Question 2

Dermis consists of 4 components:

Answer 2

Fibrous loose connective tissues
nerves
blood vessels
sensory receptors

Question 3

Hypodermis aka __ and ___, has 3 components:

Answer 3

Subcutis, superficial fascia;

adipose tissues, blood vessels, nerves

Question 4

What are the 5 layers of epidermis? (Top to bottom)

Stratum ___

Answer 4

Corneum (outermost)
Lucidum (transparent)
Granulosum (granules)
Spinosum (spiny due to desmosome)
Basale (attached to BM)

Question 5

Which layer of epidermis is the keratin layer?

Answer 5

Outermost; corneum

Question 6

How do you define keratinization? What happens as keratinocytes move from stratum basale to stratum cornea?

Answer 6

Process of maturation of keratinocytes; cells push upward and die at top, creating keratin

Question 7

Describe the stratum basale:

Answer 7

stem cell, one layer of cuboidal cells attached to BM by hemidesmosome

Question 8

What proteins does spinous layer produce and what is their function?

Answer 8

Cytokeratin; important for desmosome

Question 9

What are tonofibrils?

Answer 9

Composed of cytokeratin, an important component of desmosome

Question 10

What proteins does granular layer produce and what is their function?

Answer 10

Keratohyalin granules; combine with tonofibril to for keratin

Question 11

Keratin is made from combining:

Answer 11

Tonofibrils (cytokeratin) + keratohyaline granules

Question 12

What do keratinocytes in the stratum granulosum produce?

Answer 12

kertohyaline granules (proteins)
lamellar granules (lipid containing granule)

Question 13

What layer of the epidermis protect from dehydration?

Answer 13

Stratum granulosum

Question 14

What are the dark dots you see in the keratinocytes of stratum granulosum?

Answer 14

The keratohyaline granules

Question 15

Describe the stratum lucidum

Answer 15

It is a translucent layer of keratinocytes, flattened with no nucleus but filled with keratin. Desmosomes are still intact

Question 16

Psoriasis is characterized by increased number of keratinocyte production in stratum ___ and ___ in the epidermis.

Answer 16

Basale, spinosum

Question 17

Where are two layers where skin cancer arise from?

Answer 17

Basal, spinous (squamous)

Question 18

What are the three non-epithelial cells in epidermis?

Answer 18

Melaoncytes
Langerhans /dendritic cells
Merkel cells

Question 19

Where are melanocytes found?

Answer 19

Next to basal cells, on BM

Question 20

Define melanosomes and melanin

Answer 20

Melanosome is lysosome in melanocyte that contain and make melanin

Melanin arises from tyrosine –> DOPA –> melanin

Question 21

Langerhan cells, generated in __ and mostly found in ___ layer, executes immune function by __ (3).

Answer 21

Squamous (spinosum) layer

phagocytosis and migration to lymph node and prevention of tumor formation

Question 22

What type of cells are Merkel cells and where are they found?

Answer 22

Mechanoreceptors found in basal layer of epidermis.

Question 23

What cells in the basal layer of epidermis:

Answer 23

Basal cell, Melanocyte, Merkel cell

Question 24

Dermis is a fibrous dense/loose connective tissue.

Answer 24

loose

Question 25

Dermis contains (4):

Answer 25

Blood capillaries, lymphatic capillaries, nerve endings, other receptors

Question 26

Papillary/reticular is the thicker layer with richer fibers.

Answer 26

reticular

Question 27

Papillary/reticular layer has more cells.

Answer 27

papillary

Question 28

Fiber content of the two dermis layers:

Answer 28

elastin | collagen

Question 29

3 types of cells present in dermis

Answer 29

Fibroblats, histocyte (macrophages), mast cell

Question 30

Skin appendages:

Answer 30

``` hair follicle arrector pili muscle sebaceous gland (sebum) eccrine sweat gland apocrine gland (sweat) ```