What are the 2 classifications of the stratified squamous epithelium?
thin
thick
What are the 4 cell types of the epidermis?
keratinocytes
melanocytes
dendritic
tactile
what are the 5 layers of the epidermis?
1. stratum basale
2. stratum spinosum
3. stratum granulosum
4. stratum lucidum
5. stratum corneum
how is the stratum basale connected?
linked tightly by hemidesmosomes
how much of the stratum basale is made up of melanocytes?
10-25%
what are the functions of merkel cells?
touch and sensation
how many layers are in the stratum spinosum?
8-10
what are the actual coloring of your skin?
granules
the stratum spinosum is the most abundant site of _________ ___________ and ___________ _____________.
melanin granules
dendritic cells
what are dendritic cells in the spinosum?
branching immune cells
how many layers are in the stratum granulosum?
4-6
what is the main function of the stratum granulosum?
make keratin
what happens during the making of keratin?
cells flatten
organelles disintegrate
become water resistant
what happens at the end of the stratum granulosum?
the cells die
how many layers are in the stratum lucidum?
2-3
properties of stratum lucidum
clear layer
able to transmit light
only in thick skin
what are the properties of the cells in the stratum lucidum?
flattened
densely packed
dead
filled with keratin
stratum lucidum in a nutshell
nothing but water resistant membranes surrounding keratin
how many layers are in the stratum corneum?
20-30
where is the stratum corneum?
everywhere but the anterior eye
how long does it take for cells to move from SB to SC?
7-10 days
how long do cells spend in the stratum corneum?
2 weeks
skin color is affected by...(2)
pigmentation
dermal circulation
3 pigments
carotene
melanin
hemoglobin
carotene
corneum
in orange or yellow veggies
can make up visual pigments
melanin
basale
brown
color based on activity- not number
hemoglobin
circulation and oxygenation of blood
why is melanin more apical?
to get more sunlight
rickets
lack of cholecalcified or vitamin D3 on bone development
what are the 2 major components of the dermis ?
papillary layer
reticular layer
where can you find the papillary layer?
capillaries, lymphatics, and sensory neurons
what kind of tissue is papillary?
areolar loose connective tissue proper
the papillary layer allows _____ cells to ______
immune, patrol
nipple or fingerlike projection
papill (dermal papillae)
what causes the friction ridges in your fingers that are genetically determined (fingerprints)
dermal papillae
which layer makes up about 80% of your dermis?
reticular
what type of tissue is the reticular layer made of?
dense irregular connective tissue proper
the dense irregular connective tissue proper in the reticular layer includes:
pockets of adipocytes
interlacing collagen fibers
some elastic fibers
what is the structure of most of the interlacing collagen fibers in the reticular layer?
most run parallel to structure
where is the cutaneous plexus?
between the reticular layer and hypodermis
pattern of fiber bundles in skin
not visible externally
important to surgeons
cleavage (tension) lines
what do the tactile corpuscles detect?
light touch
what do the lamellar corpuscles detect?
deep touch and pressure
what type of tissue is the hypodermis made of?
areolar and adipose
because it is a superficial region with large vessels, the hyperdermis is considered a...
blood reservoir
true or false.
the hypodermis is not part of the integumentary system.
true
what is the main purpose of hair?
protection and sensation
what is the average amount of hair on the human body?
2.5 million
what percentage of hair is not on your head?
75%
hair is produced in...
hair follicles
nerve ending surrounding the follicle
root hair plexus
muscle pulling on hair follicle allowing it to stand up
arrector pili
epidermal derivatives
?????
what are the 2 types of hair?
vellus
terminal
majority of hairs on your body
vellus
the hair on top of your head
terminal
condition in which there is excessive hair growth
hirsutism
condition in which there is a lack of hair growth
alopecia
what type of tissue is the follicle wall made of?
epithelial
sebaceous glands
secret oil
simple, branched, alveolar glands
sebum
secretion made of oil and disintegrated pieces of cell
which follicle is:
large
not associated with hair follicles
discharge sebum onto epidermis to keep your skin conditioned
sebaceous follicles
this gland secretes sweat
sudoriferous
what are the 2 types of sudoriferous glands?
eccrine (merocrine)
apocrine
which type of sudoriferous gland is...
numerous and widespread
secretes (mainly sweat) onto skin surface sensible perspiration (you can sense your sweat)
eccrine
which type of sudoriferous gland is...
larger and deeper
empties into hair follicles
produces lipid in the secretion that is responsible for body odor
apocrine
what are 2 other integumentary glands?
mammary
ceruminous (ear wax)
What are the 4 stages of regeneration of integument?
1. scab or clot
2. cells of SB migrate along edge of wound
phagocytes remove debris
granulation tissue formed
3. epidermal cells migrate over mesh
4. fibroblasts in debris continue scar tissue creation