integument REMAKE Flashcards
what are the 2 layers of the integumentary system
what is not a layer ?
- dermis
- epidermis
- hypodermis is NOT a layer
what are the 5 layers of the epidermis
Come Lets Get Sun Burn
- stratum corneum
- stratum lucdium
- Stratum granulosum
- Stratum Spinosum
- Stratum basale
what are the charecteristics of the stratum corneum
What does it protect against?
(3)
- it is the most superficial layer
- 20-30 layers of dead anucleated keratinocytes
- protects against friction and water loss
- what are the characteristics of the stratum lucdium (2)
- 2-3 layers of dead anucleate cells
- only in thick skin
what are the characteristics of stratum granulosom
- 3-5 layers of keratinocytes with distinct
- distinct kerato-hyaline granules
what are the characteristics of stratum spinosum
- several layers of keratinocytes joined by desmosomes
- langerhan cells are present
what are the characteristics of the stratum basale (5)
- deepest layer
- single layer of if cuboidal - low columnar cells
- in contact with the basement membrane
- mitosis occurs here to create new skin cells
- ## melanocytes and merkel cells are present
what is the basal layer also called what is a special characteristic about this layer
- stratum germanitivum
- only layer that has dividing cells
what type of cells make up the epidermis
- keratinized stratified squamous epithelium
what layer of the epidermis are hemi - desmosomes closely associated with
- basal layer
what is the difference between thick and thin skin
- thick - has no hair, no errector pilli, no sebaecous glands
- thin - no stratum lucidum
what is the origin of the epidermis
surface ectoderm
what is the origin of merkel cells and melanocytes
neural crest
what is the origin of langerhan cells and what are their function
- monocytic origin ,
- macrophages of the epidermis ( immune system)
what do merkel cells do?
light touch sensation
what is the function of melanocytes
produce melanin to protect the dna in the nucleus from UV damage
what is the function of the meisner corpuscle?
light touch and highly sensitive to sensation caused by low frequency vibrations
- tactile receptors
what is the function of the pacinian corpuscle cells and where are they located
- sense deep pressure and high frequency vibrations
- found in the deep reticular dermis
what are the layers of the dermis
-superficial papillary dermis
-deep reticular layer
what are the characteristics of the papillary dermis
- what type of cell is found here
- loose CT
- meisner corpuscles are found here ( only found here)
what are the characteristics of the reticular dermis
- what cells are found here
- dense irregular CT
- pacinian corpuscles are found here ( lamillae corpuscles)
what are the sweat and sebaceous glands an extension of and where do they extend to?
they are externtions of the epidermis and extend to the reticular dermis
what is the function of the epidermis
- water proof
- protects against mechanical stress
what makes the epidermis water proof?
glycolipids and lipids
what components of the epidermis protect against mechanical stress
the keratohyaline and tonofilaments
what structures are localized in the basement membrane
hemidesmosomes
what do the desmosomes do
they are in the lateral plasma membrane and connect cells btwn eachothers
what do tight junctions do
separate the apical domain from the basal lateral domain
what are the 2 different skin glands
- sweat glands
- sebaceous glands
through which mechanism do sebaceous glands secrete and why?
- holocrine secretion
- they don’t have myoepithelial cells to push the secretion through the ducts so they explode and have a layer of stem cells to regenerate the gland
what type of sweat gland are there and through which mechanisms do they secrete
- eccrine»_space; merocrine secretion
- apocrine»_space; apocrine secretion
what allows the sweat grands to secrete?
- myopepithelial cells- push out the secretion
what organ does not have myoepithelial cells
pancreas
where are sabecous glands found in the body and what allows them to secrete sebum here?
they are found in the hair and errector pilli pushes the sebum upwards
what type of muscle is found in errector pilli
smooth muscle
what layers of the integument is vascularized what is not?
- dermis and hypodermis
- NOT epidermis
where are the 2 capillary plexuses
- papillary dermis
- reticular dermis
is there a possibility to shut off the penetration of blood to the papillary dermis ? if so, how?
yes, through the arteriole-venous anastomosis/ areteriole-venous shunt
how are arteriole-venous shunts established
- blood goes directly from the artery to the vein and bypasses the papillary cappilaries
where are arteriole venous shunts present
ONLY in the reticular dermis NOT in the papillary or hypodermis
what layer of the epidermis do cancers arrise
basal layer
what disease is caused T-lymphocyte autoimmune disease
psoriasis
what vitamin does the skin make
vitamin D3 in the dermis under the influence of UV
