4 types of tissues
What are the two different types of intercellular attachment categories and junctions in each category?
What are the functions of the integumentary system?
What does the integumentary system protect the body from?
pathogens, abrasions, uv radiation, desiccation
What do gap junctions do?
Allow rapid communication - link cytoplasm of one cell to another with connexin channel proteins (found in heart)
What do tight junctions do?
Limit transportation - proteins fuse plasma membranes together, intercellular space sealed shut - like pants pockets/seam (found in blood-brain barrier and intestinal/bladder cells)
What do desmosomes do?
Relates to the cytoskeleton which keeps structure of the cell - form strong cohesive tissue from falling apart - strongest of all attachments (skin) (gutter rivet)
Define desiccation
drying out
Do fish have a keratinized epidermis? Why or why not?
Fish lack a keratinized epidermis because they live in the water
What are the 2 types of unicellular epithelial glands in fish?
What are the two types of fish scales?
Compare and contrast types of fish scales
Dermal bony: scale does not pierce epidermis - scales are completely covered by tissue - none is exposed to outside environments in Actinopterygii
Placoid scales: scales and teeth form from the dermis - scales pierce epidermis - (sharks and Chondrichthyes
Is the keratinized epidermis the same across species?
No. Fish do not have a keratinized epidermis and the thickness will fluctuate through species (amphibians have thinner)
What 3 parts make up the cytoskeleton?
What is a hemidesmosome and where is it located?
Located on the basement membrane - it attaches to cytoskeleton of epidermis but connective tissue on basement membrane
What is the benefit of the mucous cuticle?
What gives the shark the ability to move without wrinkling and not taut skin?
helical cross-fibering of collagen
What are the two layers of shark skin?
What is the amount of glands and keratinization in amphibians?
How does Eastern newt skin vary?
Aquatic larvae - active mucus glands - no keratinization
Terrestrial juvenile - moderate keratinization (turn red)
Aquatic adult - weak keratinization - active mucus glands
What organisms (fish/amphibians) have unicellular glands and what have multicellular?
fish = unicellular (goblet)
amphibian = multicellular (poison)
What are the 2 layers of amphibian epidermis?
What is a xeric habitat?
dry habitat
What is ecdysis and what triggers it?
shedding of reptile skin all at once triggered by ecdysone (hormone)