Skin Flashcards
1
Q
Layers of the Skin- Epidermis- Dermis- Hypodermis
A
- Keratinised stratified squamous epithelium- Fibrocollagenous and elastic connective tissue with blood vessels, nerves etc- Mostly adipose tissue with bundles of collagen for anchoring the skin to the underlying fascia
2
Q
Layers of the Epidermis- Stratum basale- Stratum Spinosum- Stratum granulosum- Stratum corneum
A
- Single layer on the basal lamina. Stem cells.- About 5 cells thick. Division below it displaces these cells which are called “prickle cells” because there are a lot of desmosomes.- Cells here aggregate cytokeratin intermediate filaments to eventually die and become keratin layer. Keratinocytes produce keratin and are most abundant in epidermis.- Water resistant layer of dead squamous cells packed with keratin.
3
Q
Non-keratinising cells of the epidermis- Melanocytes- Langerhan’s cells- Merkel cells
A
- Produce melanin which is responsible for skin pigmentation.- Antigen presenting cells- Touch receptors found in highly tactile areas
4
Q
Layers of the Dermis- Papillary dermis- Reticuar dermis
A
- Projections which interdigitate with rete ridges of the epidermis. Made of fine collagen and elastic tissue.- Thicker, deep layer. Forms a dense, irregular connective tissue. Bundles of collagen and elastic fibres.
5
Q
Hypodermis- Consists of- Bands of
A
- Mostly adipose tissue- Dense irregular connective tissue which connect the hypodermis to the deep underlying fascia.
6
Q
Hair follicles- Derived from- At the bottom there is-
A
- Epithelium of epidermis. Consists of 5 layers.- A hair bulb, which has the dermal hair papilla at the bottom. Cells proliferate here to produce the hair shaft.
7
Q
Sebaceous Glands- Normally produce- When associated with hair follicles
A
- Sebum which is oily and makes skin supple and water resistant- Puts it on the hair and it makes its way to the surface from there
8
Q
Erector Pili Muscles- What are they?
A
- Small band of muscle at the bottom of the hair follicle. Sympathetic innervation which can make the hair stand on end.
9
Q
Sweat gland types- Eccrine- Apocrine
A
- Found everywhere in the skin. Coiled and release watery substance onto surface.- Similar to eccrine but found in axillae, genitalia etc and produce a milky fluid
10
Q
Nails- What are they?
A
- Plates of keratin. Nail bed is underneath - analagous to the epidermis.
11
Q
Vascular Skin Supply- 3 plexuses
A
- Papillary, cutaneous and subcutaneous
12
Q
Sensory Innervation of the Skin- 3 Types of sensory receptor
A
- Free nerve endings, Meissner’s corpuscle and Pacinian corpuscle
