1. Comparative Anatomy - ZOO 420 2(1+1)
Zoology Department
Dr. Elsayed Younis

2. The skin of Amphibians
1- Epidermis : stratified squamous epithelium rest on
a basement membrane. Basal layer known as
germinative or malpighian layer while the
most outer layer is horny or stratum corneam.
2- Dermis : built up of a connective tissue differentiated into
two distinct layers:
A- The outer one known as spongy layer and formed of
areolar connective tissue

3. - Mucus gland: secretes mucus ( small in size but numerous)
B- The inner (called compact layer) formed of fibrous C.T.
arranged in parallel to the surface, but some them are
perpendicular to it forming a vertical strands.
Skin derivatives
1- Soft structures :-
- Mucus gland: secretes mucus ( small in size but numerous)
- Poisonous gland: produces venom ( large in size but few)
- Melanophores: contains black pigments in form of granules
responsible for the color of the skin.
2- Hard structures :- Absent

5. 1- Epidermis : stratified squamous epithelium rest on
The skin of Reptiles
1- Epidermis : stratified squamous epithelium rest on
a basement membrane. Basal layer known as
germinative or malpighian layer while the most outer
layer is horny or stratum corneam.
2- Dermis : built up of a connective tissue differentiated into
two distinct layers:
A- The outer one known as spongy layer and formed of
branched yellow fibers

6. arranged in parallel to the surface.
B- The inner (called compact layer) formed of white fibers
arranged in parallel to the surface.
Skin derivatives
1- Soft structures :-
- Scent glands or Pheromone secreting cells
- Chromatophores : contains pigments (black or melanin; yellow or
xanthophores and iridophores or colorless
guanine) responsible for the color of the skin.
2- Hard structures :- hard scales ( overlapping scales; not overlapping
scales; folding scales and side to side scales )