Integument systm - skin & subcutaneous

what are the 3 layers of the integument?

epidermis, dermis, subcutaneous

what makes up the skin?

epidermis and dermis

what are the functions of the integument?

Protection

sensory perception

excretion

thermoregulation & water balance

fat metabolism

exchange with surface environment

production of vitamin D

sociosexual communication and identification

what are the different layers of the epidermis? (deep to superficial)

1. stratum basale

2. stratum spinosum

3. stratum granulosum

4. stratum lucidum (only palms and soles)

5. stratum corneum

Boys Say Girls Love Chocolate

what is the structure and function of the stratum basle?

1. made up of keratinocytes, melanocytes, myotic spindle

2. cell division to continue to make more layers and protection from UV rays

what is the structure and function of the stratum spinosum?

1. multiple layers of keratinocytes packed closely together

2. produce large amounts of keratin to protect from tearing

what is the structure and function for the stratum granulosum?

1. 3-5 layers of flattened granular keratinocytes that are wrinkling and the nucleus is decomposing

2. discharge lipids into intercellular spaces for waterproofing

what is the structure and function of the stratum lucidum?

1. clear layer, devoid of hairs only found in palms and soles,

what is the structure and function of the stratum coreum?

1. many many layers of very thinly packed dead cells with high conc. of keratin

2. protection from abrasion

what are the layers of the dermis?

papillary and reticular

what is structure and function of the papillary layer?

1. little ridges (papilla) on your hands and feet made of loose CT embedded with capillaries

2. increases surface area for vascular diffusion and increases structural strength so epidermis doesn't just slide off.

what is the different between the papilla on your fingers from the papilla on the palm?

on the palm the the papillae grow taller and in paired rows

what is the structure and function of the reticular layer?

1. made of dense irreg. CT but not super irregular. there are cleavage/tension lines where the collagen lines more regularly with a few collagen in irreg. directions

2. to indicate the area of maximum tensile strength

how are stretch marks formed?

tears along the cleavage lines

what is the subcutaneous layer made of?

can be adipose tissue or loose CT

what is the retinaculum cutis?

the upper region of the subcutaneous layer that is dominated by fat and binds the skin to the body

what is the fibrous layer?

dense connective tissue that anchors the fat for energy storage

what is invagination?

when epithelial cells rapidly divide causing it to concave and create a hollow space that allows for things like hair follicles and glands to develop

what is the structure of the follicular wall?

it is made of stratified squamous epithelium and has a papilla filled with capillaries for a vascular supply

what is hair made of?

dead skin cells

what is the arrector pili muscles structure and function?

1. smooth muscle that connects to the papillary of the skin and the papilla of the hair follicle

2. creates goosebumps but is an evolutionary remnant for insulation and to take up more volume.

what creates wavy vs. straight hair?

different shape of the cuticle and curve in the shaft

what are the different skin glands?

sebaceous holocrine gland

eccrine sweat gland

apocrine sweat gland

what is the SDF of the sebaceous gland?

1. simple cuboidal epithelium pocket that attaches to the hair follicle

2. associated with hair follicles

3. secretes sebum which is the bodies natural lotion

what is the SDF of the eccrine sweat gland?

1. simple cuboidal gland than exists in the dermis and excrete at the surface of the skin

2. everywhere there is skin

3. secretes sweat for thermo regulation

what is the SDF of the apocrine sweat gland?

1. goes to the hair follicle and is made of simple cuboidal epithelium

2. only in hair in the armpit and genitals

3. secretes sweat rich in pheromone proteins

Keratynocyte

makes keratin, creates protective umbrella over nucluos, prevents mutations

Melanocyte

produce mellanin, does not have uv protection because it needs to be stimulated to know when to increase production in mellanin

Myotic spindle

cell division