Histo Lab: Skin and Glands

Question 1

How do you differentiate between thick and thin skin

Answer 1

Thick skin doesn’t have hair on it, it has more prominent stratum corneum and stratum lucidum

Question 2

What is the function of stratum basale

Answer 2

Contains keratinocyte stem cells that move up and add cells to the other layers of the skin

Question 3

What do the spines in the spinous layer represent

Answer 3

I think it is desmosomes but she said cytoplasmic extensions of the cells

Question 4

What is the function of stratum granulosum cells

Answer 4

They have keratohyalin granules in cytoplasm which are released into interstitial space and help epidermis maintain barrier against external environment.

Question 5

What cellular process occurs in the stratum granulosum and the stratum corneum

Answer 5

Water permeability barrier formation

Question 6

Where are epidermis and dermis derived from

Answer 6

Ectoderm and dermatome (derived from somites that are from paraxial mesoderm)

Question 7

Where are melanocytes derived from

Answer 7

Neural Crest cells

Question 8

Are there more melanocytes in pigmented skin

Answer 8

No

Question 9

What mode of secretion is used by sabecous glands

Answer 9

Holocrine

Question 10

What is the composition of sebum

Answer 10

Trglycerides, wax esters, squalene and free fatty acids

Question 11

How do you identify sebaceous glands and sweat glands

Answer 11

Sebaceous glands are light staining, next to the hair follicle whereas sweat glands are dark staining and lined by stratified cuboidal epithelium.

Also sweat glands are deeper into the skin and exhibit merocrine mode of secretion

Question 12

What is the sweat duct misfunction if cystic fibrosis

Answer 12

Unable to absorb Cloride ion back

Question 13

What structures of hair do we need to know

What is the one structure we may see

Answer 13

1. Erector pilli muscle
2. Internal Root Sheath
3. External root sheath (it has nuclei)

Sebaceous glands which are light staining may also be seen
Also know how the smooth muscles look like

Question 14

What are Meissner corpuscles? How do you identify them? Where are they found and where are they found in abundance?

Answer 14

They are found in areas of hairless skin areas such as the lips, skin and toes.
They are low frequency, FINE TOUCH receptors, they are found in abundance in the finger tips and highly sensitive region of the body.

Also they look like a spiral arrangement of a single layered cell.

These occur right underneath the basale layer, at the dermal papillae

Question 15

What are the 2 main types of glands

Answer 15

Exocrine and Endocrine, endocrine are ductless, mainly for hormones

Question 16

What are the 2 glands in the duodenum

Answer 16

The dark staining glands right underneath the “base” are known as crypts of glands of glands of Lieberkuhn which are simple tubular glands.

Underneath these glands is a layer that has lighter staining glands called the Brunner’s glands.

Question 17

What does the bruners glands secrete

Answer 17

Bicarbonate and mucus

Question 18

What are the 3 salivary glands

Answer 18

Parotid, sublingual and submandibular

Question 19

What kind of cells does glands consist of

Answer 19

Parenchymal (secreting) and stroma cells (supporting cells)

Question 20

What are the two types of glands

Answer 20

Tubulor and acinar

Question 21

What are the dark staining cells that form the acinar structure in the parotid glands

Answer 21

Serous cells, they have grape-like structures

Question 22

Expalin the cells in the sublingual gland

Answer 22

Here we see that there are mucous cells that are light pink staining and are capped by demi lune serous cells that are slightly dark staining

Question 23

How does the stroma and parenchyma cells arrange themselves in sublingual cells

Answer 23

The connecttive tissue which is the stroma partitions the parenchyma cells into lobs or lobules

Question 24

Inter and Intra lobular ducts

Answer 24

The interlobular ducts runs in the connective tissue in the stroma cells in these glands (these ducts have large lumens) whereas the intralobular duct runs between the parenchyma cells.

Question 25

Types of intra lobular ducts

Answer 25

There are 2 types: intercalated and striated.

Intercalated ducts have either simple or squamous epithelium and they drain the acinar whereas the striated ducts have simple columnar epithelium and are more round shaped

Question 26

Explain the features of Psoriasis

Answer 26

1. One of the most obvious features if the Rete ridges or Rete pegs which emerge from test tube acanthosis
2. Hyperkeratosis and acanthosis (thickened) of the epidermis
3. These rete pegs or some of these rete pegs can form Munro’s microabscess. They showed us a high power EM which of one of the microabscess. It contained several neutrophils.

Question 27

What is Koebner phenomenon

Answer 27

It is in Psoriasis patients, psoriasis of the skin is observed after injury where there was previously healthy tissue. This is because the injury activates an inflammatory response that causes the symptoms of psoriasis in that part of the skin

Question 28

What is lichenoid infilterate

Answer 28

It is a lymphytic infilterate that is just underneath the epidermis (in the dermal layer) and it is the one that secretes the cytokines

Question 29

What structures are affected in pemphigus vulgaris

Answer 29

desmosomes (desmoglein 3)

Question 30

What antibodies are directed towards these structures in pemphigus vulgaris and pemphigus foliaceous

Answer 30

IgG

Question 31

What layer is sloughed off in pemphigus vulgaris

Answer 31

Spinosum

Question 32

What is suprabasal acyntholysis

Answer 32

It is the destruction of the skin layers just above the basal layer of the skin, this is observed in pephigus vulgaris

Question 33

How do you differentiate Bullous Pemphigoid from Pemphigus Vulgaris

Answer 33

It is especially obvious in immunofluorescent stain as in BP the IgG bodies are only at the basal layers, affecting the BP180 protein