Comparative Anatomy
Integument
,Integument
• Epidermis derived from ectoderm
• Gives rise to glands
• Dermis derived from mesoderm
, There are five distinct sub-layers of the Epidermis:
1. Stratum corneum: the outermost layer,
made of 25-30 layers of dead flat
keratinocytes. It provides water repellent
action and are continuously shed & replaced.
2. Stratum lucidum: Only found in the
fingertips, palms of hands, & soles of feet.
This layer is made up of 3-5 layers of flat
dead keratinocytes. It is a smooth and
seemingly translucent layer
3. Stratum granulosum: made up of 3-5
layers of keratinocytes, site of keratin
formation. Keratohyalin gives the granular
appearance and help to bind keratin
filaments.
4. Stratum spinosum: appears covered in
thornlike spikes, provide strength & flexibility
to the skin.
5. Stratum basale: The deepest layer, made
up of a single layer of cuboidal or columnar
cells. Cells produced here are constantly
divide & move up to apical surface.
Integument
,Integument
• Epidermis derived from ectoderm
• Gives rise to glands
• Dermis derived from mesoderm
, There are five distinct sub-layers of the Epidermis:
1. Stratum corneum: the outermost layer,
made of 25-30 layers of dead flat
keratinocytes. It provides water repellent
action and are continuously shed & replaced.
2. Stratum lucidum: Only found in the
fingertips, palms of hands, & soles of feet.
This layer is made up of 3-5 layers of flat
dead keratinocytes. It is a smooth and
seemingly translucent layer
3. Stratum granulosum: made up of 3-5
layers of keratinocytes, site of keratin
formation. Keratohyalin gives the granular
appearance and help to bind keratin
filaments.
4. Stratum spinosum: appears covered in
thornlike spikes, provide strength & flexibility
to the skin.
5. Stratum basale: The deepest layer, made
up of a single layer of cuboidal or columnar
cells. Cells produced here are constantly
divide & move up to apical surface.
