Session 2 Skin

Question 1

Stratum Basale

Answer 1

Primary mitosis layer; partly responsible for constant renewal of underlying layers

produces abundant protein (rough ER)

Single cell layer on the basal lamina

Desmosome and hemidesmosomes isomers to attach layer to underlying layer

Produce cytokeratins (filaments)

Question 2

Stratum Spinosum

Answer 2

A variety of cell shapes; cuboidal, polygonal, slightly squamous; partially mitosis

Tonofibrils: run through and create a “prickly” appearance; attach to the desmosomes interconnecting each cell (anchored here)

Thicker in areas of abrasion

Question 3

Stratum Granulosum

Answer 3

Stains dark blue due to keratohyalin granules; lamellar granules as well

Start to lose mitosis ability;

Pumps out keratin!

Produces a waxy covering to resist dehydration (extra cellular cement)

Question 4

Stratum Lucidum

Answer 4

More apparent in thick skin;

Extremely flattened cells (eosiniphilic cell) that lack protein synthesis

Densely packed cytokeratins filaments

Cells in a large amount of waxy coating; resist friction

Cells begin to die

Question 5

Stratum Corneum

Answer 5

Flattened non-nucleated cells; dead keratinocytes

Filled with keratin and embedded in a matrix of keratohyalin granules;

Sloughs off easily; wax dried out and barely anchored by desmosomes

Question 6

Epidermis

Answer 6

Epithelial layer (ectoderm); has ridges that interdigitates with dermis; contains keratinocytes, melanocytes, langerhan cells, and merkel cells

Question 7

Dermis

Answer 7

connective tissue (mesoderm); has dermal papillae for interdigitation; has a rich blood supply, encapsulated nerve endings; hair, sweat, and sebaceous glands within epithelial invaginations

Question 8

Peg and Socket Configuration of Interdigitation

Answer 8

A form the dermal/epidermal connection can take; seen in thin skin

Question 9

Ridges and Groove Interdigitation

Answer 9

Seen in thick skin between dermis and epidermis

Question 10

Hypodermis

Answer 10

deep to the dermis; subcutaneous loose connective tissue; contains adipocytes (fat cells); not part of the skin, but forms loose adhesion of skin to underlying tissue; the underlying tissue is covered by a fascia plane that has a variable appearance

Question 11

Functions of Skin

Answer 11

receptor organ

protects against impact and friction

protection agains UV-pigment melanin

glands, blood vessels, and adipose; thermoregulation, body metabolism, and excretion

Question 12

Keratinocytes

Answer 12

keratinizing epidermal cells

Question 13

Langerhans Cells

Answer 13

part of the immune system; bone marrow derived macrophages; binds antigens

Question 14

Merkel Cells

Answer 14

sensory receptors; within the thick skin; may be sensory due to association with free nerve endings; but most nerve endings are in the dermal layer of the skin

Question 15

Thick Skin

Answer 15

smooth, non-hairy, on the palms and heels where lots of abrasion/friction occurs; the stratum lucidum as a marker for this type of skin

Question 16

Thin Skin

Answer 16

hairy layer; covers most of the body; does not have a well developed lucidum

Question 17

Melanocytes

Answer 17

neural crest in origin; found in and beneath stratum basale

Produces melanin; protects/darkens against UV damage; encircle the nucleus of the keratinocytes protecting the genetic material from UV radiation; melanin is packaged into vesicles that are extruded and picked up by cells;

Sun tanning speeds up the release of melanin

Question 18

Papillary Layer of Dermis

Answer 18

contains dermal pegs to attach to epidermis

Question 19

Reticular Layer of Dermis

Answer 19

dermatan sulfate elastic fiber network

Question 20

Lamina Reticularis of Dermis

Answer 20

reticular fibers that contribute to basement membrane

Question 21

Sebaceous Glands

Answer 21

produces sebum-fat of the gland and remnant of dead secretory cells-holocrine secretion (whole cell is secreted)

Begin to function at puberty; if plugged= acne

Ducted into hair follicle

Question 22

Sweat Glands

Answer 22

eccrine and apocrine;

Question 23

Eccrine Glands

Answer 23

open to the skin surface; simple coiled tubular glands; watery secretion produced as response to changes in body temperature

Question 24

Apocrine Glands

Answer 24

larger and can extend all the way to the hypodermis; open to hair follicles; responsible for body odor; secretion is viscous and allows for bacterial decomposition

Question 25

Actinic Keratosis

Answer 25

precancerous changes to corneal layer of epidermis; may turn into squamous cell carcinoma; also known as solar keratoses due to prevalence on exposed skin surfaces; arms, face, scalp

Question 26

Squamos Cell Carcinoma

Answer 26

locally invasive, yet can metastisize

Question 27

Basal Cell Carcinoma

Answer 27

most common type of epidermal cancer; destructive to local tissue

Question 28

Malignant Melanoma

Answer 28

since melanocytes migrate into the epidermal layers, they readily will leave this tissue and travel throughout the body and invade all tissues and organs. This is a highly metastatic type of cancer

Question 29

Wound Healing: Stages

Answer 29

immediate- blood floods to the area

Inflammation- immune system response

Proliferation- new vessles form in the area

Maturation