Epithelial Barrier Flashcards
Epithelial cells have _____ morphology
Polarized
Epithelial cells are tightly joined together by?
Adhesion molecules and right junction proteins
What are the two sides of epithelial cells and what are each exposed to?
Apical side exposed to commensal microbes and environment. Basolateral side protected from microbial exposure.
PRRs are concentrated on what side of the epithelial cell?
Basolateral
Why are PRRs concentrated on the specific side they are?
To alert the immune system if invading microbes and/or tissue damage
This organ is a peripheral sensory organ, involved in nutrient synthesis, thermoregulation, osmoregulation, and act as a protective barrier against environmental stressors
The skin
What are examples of environmental stressors?
UV radiation, chemical exposure, and microbial invaders
What type of fish has placoid-scales that rose out of the epidermis to protect underlying skin?
Cartilaginous fish (ex. Sharks and rays)
What type of fish are covered with a multilayered epidermis that is coated with mucus that contains anti microbial proteins and peptides?
Bony fish species
What are the cells that produce mucus called?
Goblet cells
What are melanophores?
Provide skin pigmentation and help sequester reactive oxygen species generate during oxidative stress in bony fish
What is the non-viable layer of cells on the epidermis of birds and mammals called?
The stratum corneum
The non-viable layer of cells on the epithelial of birds and mammals is constantly replaced by epithelial cells called?
Keratinocytes that differentiate from pluripotent stem cells
Unlike mammalian skin, avian skin lacks what?
Sweat glands
Instead of having sebaceous glands, birds have what type of glands that do what?
Uropygial glands that produce lipids to condition the feathers to repel water
Avian feathers and mammalian hair are both comprised of _____ produced by ______?
Keratin, keratinocytes
True or false - keratinocytes are immune cells
True
The sub-epithelial immune system of the skin is referred to as?
Skin-associated lymphoid tissue (SALT)
What characteristics of the stratum corneum are highly variable within and across mammalian species?
Thickness, amount of melanocytes pigmentation, and sebaceous gland secretions
People of what race have a thicker stratum corneum, higher lipid content, and is replaced more rapidly?
Dark race