Integumentary System (EXAM #2) Flashcards
1
Q
What do the Integumentary System consists of?
A
- Skin
- Hair, Nails, Glands
- Muscles
- Sense Receptors (nervous)
- Hypodermis
2
Q
What are the 2 Layers of Skin?
A
- Epidermis - superficial layer (outermost layer)
- Dermis - deep layer
3
Q
What are the characteristics of Epidermis?
A
- Stratified squamous epithelium
- Avascular
- Separated into 4-5 strata (sub-layers) based on cell types:
- Stratum Basale
- Stratum Spinosum
- Stratum Granulosum
- Stratum Lucidum
- Stratum Corneum
4
Q
Stratum Basale
A
- Single row of cells
- 2 cell types:
- Keratinocytes (90%)
- Melanocytes (10%)
5
Q
Keratinocytes (90%)
A
- Actively undergo mitosis
- Make keratin (tough protein)
- Pushed towards surface as new cells are produced in basale
6
Q
Melanocytes (10%)
A
- Produce pigment (melanin) for UV light protection
- e.g. sunburns, wrinkles (collagen damage), cancer (DNA damage)
- Skin colour:
- We all have the same relative number of melanocytes, but cells produce different amounts/shades of melanin
- blood (hemoglobin) - in dermis can give a pinkish tinge to fair skinned people
7
Q
Stratum Spinosum
A
Low levels of mitosis
8
Q
Stratum Granulosum
A
- No mitosis
- Contains granules that help produce keratin (strength) and start to produce waterproofing glycolipids (prevents water loss)
- Last layer of living cells
9
Q
Stratum Lucidum
A
- No mitosis
- Flat, dead cells (too far from blood supply)
10
Q
Stratum Corneum
A
- Many layers of flat dead cells filled with keratin (tough protein)
- Glycolipids between cells create a waterproof layer (prevents water loss)
- Shed and replaced from below
11
Q
What are the characteristics of Dermis?
A
- Contains blood vessels, nerves, glands, hair follicles, arrector pili muscles
- 2 sub layers (connective tissue):
- Papillary Layer (connected to epidermis)
- Reticular Layer (between papillary layer and hypodermis)
12
Q
Papillary Layer (connected to epidermis)
A
- Areolar connective tissue
- Vascular
- Has projection into epidermis = dermal papillae
- In thick skin these form epidermal ridges = fingerprints (improve grip)
13
Q
Reticular Layer (between papillary layer and hypodermis)
A
- Forms most of dermis
- Dense irregular connective tissue
14
Q
Thin vs Thick Skin
A
Thickness refers to epidermis (not dermis)
15
Q
What are the characteristics of Thin Skin?
A
- Covers most of body
- Lucidum absent
- Has hair follicles, sebaceous glands, arrector pili muscles