Skin & Mucous Membrane Flashcards Preview

BDS1 - BAMS - Histology > Skin & Mucous Membrane > Flashcards

Flashcards in Skin & Mucous Membrane Deck (44)
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1

What are the functions of the skin

Protection
Thermoregulation
Water regulation
Sensation
Absorption
Storage and synthesis

2

What are the basic parts of the skin

Epidermis
Dermis
Subcutaneous layer

3

What are the skin appendages

nails
sweat glands
sebaceous glands
hair follicles

4

Define the epidermis

Continuously proliferating stratified squamous epithelium which produce a non living surface layer of the protein keratin with associated lipids which is in direct contact with the external environment and constantly shed

5

How does the epithelial in the epidermis get it's required oxygen and nutrients since it doesn't have blood vessels

It gets them from the deeper tissue, the dermis
They are close enough to the blood supply in the dermis to get the adequate oxygen and nutrients for survival

6

What are the layers of the epidermis

Basal layer
Stratum spinosum
Stratum granulosum
Stratum lucidum (only in thick skin)
Straum corneum

7

What is the basal layer

Cells divide to make new cells for epithelium
Some of these cells are stem cells

8

What is the stratum spinosum

prickle cell layer
Cells in this layer have lots of desmosomes
Desmosomes anchor the cells together

9

What do cells of the stratum spinosum look like prickles

Cells shrink slightly during fixation but the desmosomes from neighboring cells remain tightly bound to each other so these connections look like prickles

10

What is the stratum granulosum

Cells start to lose their nuclei and cytoplasmic organelles

11

What is the stratum lucidum

it is a transparent layer
only appears in thick skin
thickest on palms and soles of our feet

12

What is the stratum corneum

layers of dead cells which are reduced to flattened squames filled with densely packed keratin
Squames on the surface of the layer flake off

13

What are the cells of the epidermis

Keratinocytes
Langerhans cells
Merkel cells
Melanocytes

14

What are keratinocytes

They are also called prickle cells
Most common cell
Make up the majority of cells in the epidermis

15

What are langerhans cells

Antigen presenting cells
Present in all layers of the epidermis & in the upper dermis around small blood vessels

16

What are merkel cells

Granular basal epidermal cells
Attached to a free nerve ending which finishes at the basal layer where the sensory nerve ending is
Mostly found in thick skin

17

What are melanocytes

Produce melanin - has protective function against UV
Present in basal cell layer and the melanin is taken out by the epithelial cells
Present in oral cavity but not active

18

What causes the pigmentation of skin

The activity of the melanocytes not the number of them!

19

What is the appearance of melanocytes under the microscope

Tend to be slightly lighter in color with space surrounding them because there are no desmosomes so when they shrink there is space surrounding them

20

Describe thick skin

Stratum lucid present
Thicker stratum corneum
Present in palms of hands and soles of feet

21

Describe thin skin

No stratum lucid
All strata are thinner
Covers the rest of the body Layers of epithelia are much less
Thickness of keratin is much less

22

What is the dermis

A strong flexible connective tissue layer rich in collagen and elastin fibers

23

What does the dermis contain

fibroblasts
macrophages
a few adipocytes
nerve endings
blood vessels
glands
smooth muscle
lymphatics
hair follicles

24

What is the interface

Area of contact between epithelium and dermis

25

What is the papillary layer

Lies directly under epithelium
Projects into intervals between epidermal ridges forming dermal papillae
Loose areolar connective tissue, interlacing collagen and elastic fibers

26

What is the reticular layer

Made of dense irregular connective tissue and fiber components
Collagen bundles and elastic fibers are much thicker
Also contains blood vessels and nerves and the skin appendages

27

What are some diseases

Acne
Psoriasis
Pemphigus
Vitiligo
Skin Cancer

28

What is psoriasis

Autoimmune
Affects the skin but not the mouth
Accelerated maturation of epithelium meaning epithelium is much thicker

29

What is pemphigus

Antibodies are formed against part of the desmosomes so the epithelial cells fall apart resulting in blisters

30

What are mucous membranes

Specialized epithelial lining which produces a lubricating fluid contains the sticky protein mucin