Give me a D! Give me an E! Give me a R and a M! What does that stand for? Derm!
Let’s go Cheer Squad! Roll out those pom poms – Oh wait, wrong place!
Nonetheless, pom poms or not, how can we not get excited over “derm?” The suffix ‘derm’ means layer or covering, and is also known as the ‘dermis.’ Based on the incorporation of ‘derm’ in all three of the terms – ectoderm, endoderm, and mesoderm – we can understand that ectoderm, endoderm, and mesoderm are all related to layers, specifically germ cell layers.
Germ cell layers
What are germ layers? During embryogenesis, germ layers are the cellular layers in which our organs and tissues first derive from. Certain layers produce specific types of organs, tissues, and groups of cells. We have three primary germ cell layers: the ectoderm, endoderm, and mesoderm.
Ectoderm = “Attract” oderm. Literally, what aspects of our bodies attract the opposite sex? Intelligence, physical attractiveness, beautiful eyes- you name it! Our nervous system, epidermis, eye lens, mouth, and inner ear derive from the ectoderm.
To ingrain this further, if she is smart and has nice hair, smooth skin, and beautiful eyes, where did that all come from? Ectoderm!
Ectoderm is usually referred to as the outer layer.
Mesoderm = Muscle , skeleton, circulatory system, gonads, and kidneys come from the mesoderm layer. A handy-dandy mnemonic for mesoderm spells out the following:
M uscle (skeletal, cardiac, smooth)
E ndothelium of our blood vessels
O varies and other gonads
D ducts of genital system
E ndothelium of our lympathic vessels
R enal for the kidneys
M ale gonads
Endoderm = Endoderm has the prefix “endo,” which means inner. Endoderm is the inner most layer of all three layers. The endoderm layer often includes the digestive tract lining, our lungs, liver, and pancreas, to name a few. The digestive and respiratory systems derive from the endoderm layer. Remember, anus is your end or “end-o!”
Other endoderm derivatives can go by the random mnemonic GFPPLLT:
G= gut tube epithelium
F= follicular cells of thyroid
L=Lungs (inner layers like bronchi)
Here’s a general summary:
|Ectoderm “Attract” oderm||· Nervous System
· Epidermis (skin, hair, nails)
· Eye lens
· Inner ear
|Endoderm||· Digestive Lining
· Lungs (Inner layers)
· Digestive and Respiratory System
|Mesoderm||· Muscles (skeletal, cardiac)
· Circulatory systems
Got milk? I mean derm…green ectoderm, anyone?
Open Stax: Embryonic Development: https://cnx.org/contents/1704097d-1012-4798-8ef6-1598d73e7b15@3/Embryonic_Development
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