Skin And Fasciae

Question 1

what is skin?

Answer 1

the general covering of entire external surface including external auditory meatus and outer surface of tympanic membrane. It is continuous with the mucous membrane at the orifices of the body.

Question 2

adult surface area of skin

Answer 2

1.5-2 sq. meter

Question 3

what is the Du Bois formula

Answer 3

thisformula is udes to calculate BSA
A= W (weight) x H (height) x 71.84

Question 4

what are the stuctures encountered during disscetion

Answer 4

1. skin
2. superficial fascis
3. deep fascia
4. muscles
5. perpheral nerves
6. blood vessels
7. lymphs
8. bones

Question 5

the skin has how many layers? name them

Answer 5

skin is further divided into 2 layers: 1. epidermis
2. dermis

Question 6

what are some features of epidermis?

Answer 6

it is the superficial layer, avascular made up of stratified squamous epithelium, is ectodermal in origin. It gives rise to appendages of the skin: hair, nail, sweat gland and sebaceousgland.

Question 7

epidermis is made up of how many layers?

Answer 7

it is made up f a deep germinativelayer, comprising of 5 layers:
1. stratum basale- deepest layer, aka germinal layer
2. stratum spinousom- malphigian layer
3. stratum granulosum- ketarohyline granules are present
4. stratum lucidum- lucidum means clear, this layer is present only in thick skin
5. stratum corneum- made up of dead cells, based corneum’s thickness skin is labelled thin or thick.

Question 8

what are the cells of the germinative zone?

Answer 8

1. “dopa” positive melanocytes (melanoblast, dendritic cells or clear cells) of neural crest origin
2. langerhan cells- phagicytic in nature, provide protection
3. merkel cells- sensory receptors in stratum basale

Question 9

what is dermis?

Answer 9

dermis aka corium is a deep, vascular layer derived from mesoderm. It is made up of connective tissue ( with variable elastic fibres) blood vessels lymph and nerves.

Question 10

dermis is divided into how many layers?

Answer 10

papillary and reticular layer

Question 11

what is the significance of papillary layer?

Answer 11

papillary layer forms conical projections called derma papilae which fit into the reciprocal depressions of undersurface of epidermis

Question 12

what is the significance of reticular layer?

Answer 12

it is made up of white fibrous tissue arranged mostly in parallel bundles. the direction of these bundles constitutes the flexor or cleavage line ( langer’s lines) - longitudinal in limbs and horizontal in trunk and abdomen.

Question 13

what happens to the fibres in old age ?

Answer 13

in old age these fibres atrophy ( smaller ) resulting in skin becoming wrinkled. overstretching of the skin may lead to rupture of the fibres resulting in scar formation. These scars appear as white streaks on the skin, called as linea gravidarum.

Question 14

why dermis the real skin?

Answer 14

when dried it makes green hide and when tanned it makes leather.