👣 Epidermis Layer 👣
The five layers of the Epidermal strata
and
What two layers are below these five layers?
CLGSB
Stratum corneum - Corn dead
Stratum lucidum - Lucid dreams (not many organelles and not much metabolic activity)
Stratum granulosum - Grainy television static (final time where cells are alive, a lot of ribosome activity)
Stratum spinosum - Spines seen (cells just going about their life)
Stratum basale - Basement columns (made of long columnar cells)
The basement membrane, and then the Dermis
Function of Meissner's corpuscle?
Location of Meissner's corpuscle
- light touch
- texture
- lips and fingertips and other hairless skin
What is the function of free nerve endings in the papillary layer?
They detect
- environmental stimuli, primarily pain
- temperature (thermoreception)
- itch
- light touch/pressure
two types of sweat glands? + what are they for?
apocrine glands - they function in scent production (pheromones) + secrete substances that protect against bacteria. They are stimulated when we are going through emotional stress
eccrine glands - responsible for thermoregulation by secreting a watery, hypotonic fluid that cools the skin surface
Heat loss of gain via the skin:
radiation
evaporation
conduction
convection
heat is transferred to or from the skin
heat is transferred away from the skin
heat is transferred from the skin to an object
heat is transferred to the air after the skin is wet (getting out of the shower you feel cold)
How do calluses form?
The epidermis increases cell production, causing a build up of dead cells.
Function of Lamellar corpuscle?
Location of Lamellar corpuscle?
- detect vibration and pressure
- they respond to only sudden changes such as grasping and relaxing
- fingertips + palms
What are the four roles of the papillary layer?
- to increases the Bond Strength between the dermis and epidermis (dermal papillae)
- Nutrient Deliverly (because highly vascularized) to the higher up epidermal
- house Meissner's corpuscles that sense Light Touch
- immune surveillance and Wound Healing.
Function of melanocytes/melanin
Location of melanocytes
- they protect against UV radiation
- the stratum basal of the epidermis
1st vs 2nd vs 3rd degree burns
1st - minor redness + pain (sunburn, touching a hot object, carpet burn)
2nd - the second a blister forms, minor damage to glands/nerves, disrupted polysaccharide gel
3rd - all the way through the skin, nerves are burnt, and not burned to the hypodermis yet
Why do we survive without a second thought if we cut ourselves shaving?
The razor does not cut deep big blood vessels, and the clotting stops it fast.
Function of bulbous corpuscle + one more cool function?
Shape of bulbous corpuscle?
Location of bulbous corpuscle?
- feel stretching and finger position+movement
- the feeling of slipping
- thermoregulatory
- elongated spindle
- found distributed throughout the dermal papillae + hypodermis
type of connective tissue in reticular dermis?
Dense irregular connective tissue is a durable, fibroblast-rich connective tissue characterized by densely packed, randomly interwoven collagen fibers
what are the three pigments that contribute to skin color?
- melanin - protects the nucleus nagainst UV rays
- carotene - adds an orangish glow
- hemoglobin - the red color in your face
rule of palms vs rule of nines?
rule of palms) the palm is 1% of the surface area of the whole body
rule of nines) the body is divided into 11 areas each being 9% of the body's surface area
What is the significance of capillary loops?
And where are they located
located in the dermal papillae, they act as the primary site for exchanging nutrients, gases, and waste products between blood and tissues
Function of hair follicle receptors?
Location of hair follicle receptors?
- to feel pressure
- to feel positioning
- to feel edges + shapes
- found spanning the basal epidermis to the hair follicle base
blood vessels dilate and constrict
sweat glands cool you down
what percent of the body has to be burned for it to be critical/fatal?
20%-30%
What is proprioception and what nerve detects/understands it?
- Our bodies understanding of positioning, where we are positioned
- The hair follicle receptor
Which nerves are in the papillary layer and which are in the reticular layer
papillary - Messner's Corpuscles
reticular - Pacinian Corpuscles