Studied by 0 peopleList the functions of the integumentary system.
Create vitamin D Chemical, physical, and biological protection Hold structures(hair, nails, scales, feathers)
List the layers of the integumentary system and the germ layers that they developed from.
Epidermis-ectoderm Dermis-mesoderm Hypodermis- endoderm
What is keratin?
A protein that accumulates at the epidermal layer to prevent water loss. (associate dry, tough, non-flexible).
What is a keratinocyte?
Keratinocyte= a cell with Keratin
What is collagen?
A protein that is woven in fibers or piles found in the dermis(associated with flexibility, elasticity, and moisture/mucous.
What are the 3 major layers of the integumentary system?
Epidermis Dermis Hypodermis
List the layers of the epidermis in order from top to bottom.
Horny layer(stratum corneum)- peaks of mountains or horns (dead cells that shed constantly) Granular layer(stratum granulosum)- keratin looks like grains of sand Prickly layer(stratum spinosum)- keratin looks like spines or prickles Basal layer (stratum basale)- stem cells found here
What causes gray or white hair?
Loss of melanin
What is a hair follicle?
The root or the base of hair where hair will grow.
What are the two types of hair? Briefly explain them.
Terminal hair- dark, long, strong. Vellus- light, short, fragile.
Describe the process of thermoregulation(
Hair keeps the organism warm. Cold temps elicit goosebumps (which traps heat) Hot temps elicit activation of the sweat gland to produce water on the skin.
List 2 effects of aging on skin.
Wrinkles, thinning.
Describe the integument of a fish.
Fish skin is little to no keratin. Smooth, flexible, slimy.
Describe the integument of an amphibian.
Respiratory surface Glands are prominent(poison and mucous) Nuptial pad for breeding.
Describe the integument of a reptile.
Lots of keratin, dry, only shed all at once periodically(shedding)
Choose one of the 3 discussed avian integumentary features and explain what its function is.
Feathers- sexual selection, flight, warmth Brood patch- thin skin without feathers for incubating eggs Uropygial gland- waterproofing Salt gland in the beak to release accidental salt ingested.
What role do hair follicles play in hair growth?
Responsible for hair growth and hair type.
What hormone controls the development of vellus hair to terminal hair?
Androgen
How does the nail bed contribute to nail growth?
It contains stem cells that create continual cells.
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