Special Senses Skin/Dermis

Question 0

What are the two layers of the dermis? What kind of connective tissues are they?

Answer 0

Papillary (closest to epidermis) - loose ct

Reticular- densley stained irregular ct

Question 1

What are the three main layers of thick skin?

Answer 1

Epidermis, Dermis, Hypodermis

Question 2

What layer of the skin has sensory cells, hair cells and sweat glands?

Answer 2

Dermis

Question 3

What layer do you find the major blood vessels serving the skin

Answer 3

Hypodermis

Question 4

What are the 5 layers of epidermis? superficial to visceral

Answer 4

Str Corneum
Str Lucidum
Str Granulosum
Str Spinosum
Str Basale

Question 5

How many cell layers thick is the str basale? What does it stain with?

Answer 5

Single cell layer, stains deeply with hematoxylin

Question 6

What is the most superficial layer of epidermis of with cell nuclei

Answer 6

Str Granulosum

Question 7

What is the Str. Granulosum

Answer 7

Its the middle layer of the epidermis it has 3-5 layers of keratinocytes that have granular particles.
- the most superficial layer with presence of cell nuclei.

Question 8

What is the str. spinosum?

Answer 8

The thickest epidermal layer, with mitotically active cells. cells have adherns junctions to each other on numerous processes

Question 9

Where do you find the str. lucidum?

Answer 9

It is only found in thick skin. like palms and soles.

Question 10

What do you find in the str. lucidum

Answer 10

Densley packed keratin filaments in the cytoplasm (no organelles!)

Question 11

What is the str. corneum?

Answer 11

the most superficial layer of epidermis, and there are several alyers of flattened, keratinized dead cells

Question 12

DO all layers of the epidermis produce keratin

Answer 12

yes. it is a fibrous protein.

Question 13

Where do you find melanocytes? What are they

Answer 13

Mostly in the basal layer (some is str. spinosum). produce and release melanin. melanin granules are found in the dendrites.

Question 14

WHat are merkel’s cells? Where do you find them?

Answer 14

In Basal layers. they are sensory, touch receptors that attach to sensory nerve fibers

Question 15

What kind of nerve cells are contacted with Merkel cells

Answer 15

afferent

Question 16

What layer do merkel cells derive from

Answer 16

mesoderm

Question 17

What are Langerhans cells? Where are they

Answer 17

In the spiny layer. They are antigen presenting cells as part of the immune system.

Question 18

What is the fxn of glycolipids in epidermis?

Answer 18

Prevent flow of fluids into or out of the body. a “mortar” around the keratinocytes.

Question 19

What is keratin

Answer 19

A intermediate intracellular tonofilament that provides structural support. start to form in the stratum spinosum

Question 20

Does thick skin have hair follicles, glands?

Answer 20

No hair follicles or sebaceous glands (but does have sweat glands)

Question 21

Where do you find most of the melanin in skin

Answer 21

Even though mealoncytes make melanin that secrete it and it is transfered to keranocytes.

Question 22

Where can you find melanin

Answer 22

Str Basale and Spinosum

Question 23

Where in the dermis do you find capillaries?

Answer 23

The dermal papillae in the papillary layer is rich with capillaries.

Question 24

What makes the shape of finger prints?

Answer 24

Dermal papillae

Question 25

Where is the glycolipid layer?

Answer 25

between the str. lucidum (or cornuem) and the str. granulosum

Question 26

Which type of sweat gland is more common?

Answer 26

Eccrine

Question 27

What is an eccrine gland?

Answer 27

Small sweat glands are simple cubodial tubular glands in dermis/hypodermis. they produce “true sweat”
-numerous and important for body thermoregulation.

Question 28

What is an apocrine gland? Where are they found

Answer 28

large sweat glands that release cytoplasm with watery sweat. they ducts open into the canals of hair follicles.

Question 29

What kind of cells are around eccrine sweat glands? sweat gland ducts?

Answer 29

glands- simple cubodial

ductile segment- 2 layer thick. stain darker

Question 30

What layers of the epidermis make nails?

Answer 30

Made by basal/spiny layers and it takes the position of the stratum corneum

Question 31

What is a Meissners corpsucle? where is it found

Answer 31

located in dermal papillae and specialized for fine touch and tactile discrimination.

Question 32

What is a pacinian corpsucle?

Answer 32

located in dermis/hypodermis and specialized for pressure, touch and vibration perception. kinda looks like a sliced onion in stains

Question 33

Ruffinis ending

Answer 33

located in papillary dermis and joints

perceives stretching and pressure.

Question 34

What are meissners, pacinian and ruffini

Answer 34

encapsulated mechanoreceptors. merkel cells are NOT encapsulated

Question 35

what is the difference in the nerves associated with Meissners and ruffinis?

Answer 35

meissners are associated with 3-4 nerve endings and their associated schwann cells
ruffinis is associated with 1 unmyelinated nerve fiber wrapped in layers of modified fibroblasts.