Integumentary System

Question 1

Function of skin

Answer 1

1. First line of defense, protect body from disease, acts as barrier
2. Temp reg.
3. Sense info, via touch
4. Prod. Vitamin D
5. Elim. Waste via sweat

Question 2

Skin layers + the sometimes layer

Answer 2

Epidermis

Dermis/Corium

SubQ / hypodermis

Question 4

Epidermal layers

Answer 4

Basic info: stratified squamous tissue as a result of layered scaly appearance.
Avascular epithelial tissue

1. Stratum Corneum - many roles of cells that are cornified (characterized by hardened horny nature) and shed regularly.
2. Stratum lucidum - only present in thicken skin like soles of feet or palms of hand, not present everywhere
3. Stratum Granulosum - cells become filled with granules in this layer
4. Stratum Spinosum - composed of flattened keratinocytes
   - named so as cell look spikey under microscope as the spikes normally bind the cells together
5. Stratum Germinativum (Basale) - where skin cells sprout (germ/I & nat/o) and are born.
   - Also site of melanin prod. By melanocytes
   - - individuals have different skin colour due to diff numbers of melanocytes

Question 5

Keratinocytes

Answer 5

What cells of the dermis turn into as they move up layers.
- filled with keratin a hard protein material
- - is protective and adds a level of waterproofing to skin to help moisture retention
- - - note kerat/o and corne/o both refer to hardness

Question 6

Dermis

Answer 6

1. Aka Corium - thick underlying layer, composed of 2 layers of vascular connective tissue.
2. Papillary layer - thin upper layer composed of fibers made from protein and collagen
   - regulate blood flow through extensive vascular supply
3. Reticular layer- lower thicker layer
   - composed of collagen fibers
   - holds hair follicles, sudoriferous glands & sebaceous glands
   - - sudoriferous glands - sweat glands - two types:
   - - - apocrine: armpits & groin - post pubescent musk
   - - - eccrine: most densely packed in hands, feet forehead
   - - sebaceous glands- secrete sebum from hair follicles
   - - - lubricates hairs and skin
   -also holds sensory organs - such as:
   - - Meissner’s corpuscles - sensitivity to light touch
   - - Pacinian Corpuscles - sense pressure
   - - specialized heat and cold receptors

Question 7

Hair

Answer 7

Roots in dermis /Corium - roots + covering called hair follicles

Visible portion called shaft

Beneath follicles, nipple shaped structure that encloses capillaries called papilla.
- epithelial cells