Skin Embro

Question 1

The skin takes about ___% of the body weight

Answer 1

16%

Question 2

The skin is thinnest @_____
And thickest @_____

Answer 2

Eyelids
Heels

Question 3

What are the major layer of the skin?
And d minor

Answer 3

Outer thinner layer called epidermis
Inner thicker layer called dermis
Minor- hypodermis(subcutaneous)

Question 4

The skin color can be divided into?

Answer 4

Constitutive color– color determined by genetics
Facultative color– color as a result of external influence

Question 5

The epidermis consists of?

Answer 5

Hair follicles, glands(sebaceous, apocrine, sweat),!nails,
Melanocytes(Merkel and Langerhans cells)

Question 6

What’s the origins of the skin

Answer 6

Epidermis is from ectoderm
Dermis is from the underlying mesenchyne (lateral plate mesoderm)

Question 7

What are the layers of the epidermis?

Answer 7

Stratum basale(deepest layer)
Stratum spinosum (keratinocyte)
Stratum granulosum (keratohyalin & lamela granules)
Stratum lucidum– only in THICK skin
Stratum corneum– contains dead keratinocyte called corneocyte or squames

Question 8

What’s dandruff and where does it occur?

Answer 8

Accumulation of keratinized cells shed from the scalp
Epidermis

Question 9

The skin originates @ _____
And forms stratified squamous epithelium @ ___ month?

Answer 9

Single layer if ectoderm
2nd month

Question 10

What’s vernix caseosa?

Answer 10

These are superficial layer of the epidermis that mixes with content of the sebaceous gland and appears whitish at birth

Question 11

The epidermal ridge develops @

Answer 11

3 and 5th month of fetal age

Question 12

What are Melanoblast, their origin?

Answer 12

Melanoblast are dendritic cells of the epidermis but only migrated their
But their origin is Neural crest

Question 13

Which cells of the epidermis are part of the immune system?

Answer 13

Langerhans

Question 14

Cells of merkel originates from?
While Langerhans originates from?
And appears in the epidermis @

Answer 14

Neural crest
Percusors of the bone marrow
8 to 12 weeks of fetal life

Question 15

____ part of the skin contain collagin and elastic fibres

Answer 15

Dermis

Question 16

What are the layers of the dermis and it’s content

Answer 16

Papillary layer( collagin, elastic fibres, dermal papillae, corpuscles of touch and free nerve endings)
Reticullar Region( dense irregular CT, collagin and elastic fibres, hair follicles, sebaceous glands, sweat glamds, nerve

Question 17

Stretch marks occurs @ _____

Answer 17

Deemis

Question 18

Dermatomes originates from?

Answer 18

Somites

Question 19

The dermis in what part of the body originates from the dermatomes,
Lateral plate of the mesoderm
And neural crest?

Answer 19

Dorsal part of the head and trunk
The dermis of the limbs, lateral and ventral aspect of the trunk originates from?
The dermis over most of the head and ant. Of the neck

Question 20

The arrector pili and dermal root sheath are formed fro

Answer 20

Mesenchymal cells