What is the epidermis composed of and where is it connected
epithelial tissue connected at it’s basement membrane to the underlying connective tissue, the dermis
What does the epidermis and dermis form
Cutaneous membrane
What type of tissue is the dermis composed
connective tissue
what are the layers of the dermis
superficial papillary layer and deep reticular layer
Papillary layer
-vascular or avasular
- composed of what
-forms what
-highly vascular
-loose areolar, connective tissue
-forms epidermal ridges known as finger prints
How is the papillae and ridge pattern is determined
genetically and environmentally
Reticular layer
-composed of what
- contains what
- composed of dense irregular connective tissue
- contains collagen and elastic fibers in gel like ground substance that allows for flexibility
the dermis houses what
-hair follicles
-sebaceous oil glands
-sweat glands
-nerves and sensory receptors
how are blisters formed
-high friction
-the epidermis becomes separated from the dermis and fluid accumulates
What happens if the cutaneous layer is damaged or lost
- skin is no longer able to regulate temperature
- extreme pain due to ongoing irritation of the sensory receptors
First degree burn
damage only the epidermis
second degree burn
blisters because they extended through the epidermis into the top of the dermis
third degree burn
damage both the entire epidermis and entire dermis
How does the skin regulate homeostasis
regulates body temp by:
- releasing heat when body is too warm
-retaining heat when the body is too cold
-contributes to the fluid balance of the body by altering the water and ion composition of sweat
What happens when the body temp rises
- skin blood vessels dilate and bring blood closer to the surface where heat can dissipate by radiation
-sweat glands release sweat which uses the energy from hot skin to evaporate, cooling the body
What happens when the body temp falls
-Skin blood vessels constrict and bring blood away from the body surface to be conserved
-arrector pili muscles contract standing the hair up on end in an attempt to “fluff the fur” and trap warm air close to the skin
- muscles contract rhythmically or shiver to generate body heat
Hypodermis (subcutaneous layer)
-location
- contains what
-
- below the skin cutaneous membrane
- contains loose connective tissue and adipose tissue
Adipose tissue provides what
- provides cushioning to protect the muscle and bone beneath the skin
-provides support for energy storage and metabolism
What are the different types of adipose tissue
-White adipose tissue
-Brown adipose tissue
-Beige adipose tissue
White adipose tissue
-stores calories as fatty acids
- secretes cytokines, called adipokines, that function as hormones to regulate hunger
-too many adipokines also cause inflammation
Brown adipose tissue
-contains many mitochondria, providing th darker color
-high concentrations in newborns to help the regulate body temp
-generates heat in cold environments
Beige adipose tissue
Chronic cold exposure and exercise both result in formation of islands of brown adipose tissue within the white adipose tissue
