Integumentary System Flashcards
4 types of tissues
- Epithelial
- Connective
- Nervous
- Muscle
What are the two different types of intercellular attachment categories and junctions in each category?
- Communicating junctions (gap)
- Adhering junctions (tight, desmosome, plasmodesmata???)
What are the functions of the integumentary system?
- Protects the body
- Communication (blushing, coloring, warning)
- Vitamin D synthesis
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?
- Club cells - secrete alarm chemicals (a school of fish one is eaten the others hide)
- Goblet/mucus cells - secrete mucin (reacts with water to make mucous)
What are the two types of fish scales?
- dermal bony scales (Actinopterygii)
- placoid scales (Chondrichthyes)
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?
- microtubules
- actin
- intermediate filaments
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?
- hydrodynamics (maneuver through water)
- pathogens (protective keep out bacteria)
- repugnant chemicals
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?
- stratum laxum (little collagen)
- stratum compactum (packed dense compact collagen)
What is the amount of glands and keratinization in amphibians?
- low keratinization to the epidermis
- glandular secretions to keep skin moist
- no dermal scales
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?
- stratum corneum (thin)
- stratum basale (layer of epidermis that does mitosis)
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)
What are the steps of ecdysis:
- stratum basale grows a new epidermis
- lysosomes trigger autolysis - sep old layer from new
- new layer is now exposed
(all triggered by ecdysone)
Rest -> Renewal -> Shed -> Repeat
What is an example of a reptile integumentary gland?
femoral scent glands of lizards (fence lizards)
Layers of bird epidermis:
- stratum corneum (weak)
- transitional layer
- stratum basale
Compare and contrast body/wing of chicken/bird vs. legs
The body of a bird is weakly cornified (any area covered with feathers) vs. the increased cornified epidermal scales on the legs
What are the 2 types of bird glands?
- uropygial gland
- salt glands
Uropygial gland
oil gland right above tail feathers - used in preening - move lipid wax all over feathers which causes water to roll off back
Salt glands
are found in marine birds - excretes excess salt - located by eye
What are the 2 mechanisms of bird coloration?
- pigment with chromatophores
- structural coloration ( light reflectance)