Human Anatomy - Chapter 5

Integumentary System

What does the integumentary system include

Hair, skin, fingernails

What are the layers of the skin

Epidermis and Dermis

What are the skin functions

Protects deeper tissue from damage, aids in heat regulation, aids in excretion of urea and uric acid, syntehsizes Vitamin D

What is the epidermis

The outerlayer of the skin

What is the dermis

Dense connective tissue

What is the Hypodermis

Not part of the skin, anchors skin to underlying organs, composed mostly of adipose tissue

What are the four cell types of epidermis

Keratinocytes, melanocytes, langerhan cells, merkel cells

What is Keratin function

Helps protect the skin and underlying tissues from heat microbes and chemicals

What do Keratinocytes produce and release

Produce lamellar granules and release a H2O repellant sealant

What is melanin

pigment produced by melanocytes, color is yellow to brown to black.

Where are most melanocytes located

Stratum basale

Amount of melanin produced depends on what?

Genetic and exposure to light

What is function of langerhans cells

Particpate in immune responses against microbes that invade skin

Where do Langerhan cells come from

Arise from red bone marrow

Where are Merkel cells located

deepest layer of epidermis

What is merkel cells function

detect certain aspects of touch

What areas of skin have 5 layers in epidermis

palms and soles

What is the layers of the epidermis

Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale

Explain characteristic of stratum basale

single layer cells in contact with dermis

Function of stratum spinosum

provides strength and flexibility

Appearance of stratum spinosum

spiny appearance because of keratinocytes

Function of Stratum granulosum

Slows loss of bodily fluids and entry of foreign objects

What are characteristics of stratum granulosum

3-4 rows of flattened cells, formation of H2O sealant between cells

What is the stratum lucidum

thick skin

Characteristic of stratum corneum

25-30 layers scale like cells

What are the two layers of the dermis

Papillary layer and reticular layer

What is the papillary layer function

projections called dermal papillae pain receptors and capillary loops

What is the reticular layer

Blood vessels glands and nerve receptors

What does hypodermis function

respond to motor impulses transmitted from CNS to skin

What areas have more sensory receptors

palms, lips, soles, external genatalia

What does thick skin cover

palms and soles

Dermal papillae in thick skin

higher narrower and more numerous

Does thin or thick skin have hair follicles, arrector pili muscles and sebaceous glands

Thin skin

Does thick or thin skin have more sweat glands

Thick skin

What are skin color determinantes

melanin, carolene, hemoglobin

How does hemoglobin influence skin color

Red coloring from blood cells in dermis cappilaries and oxygen content determines the extent of red coloring

What is carolene

Orange and yellow pigment from some vegtables