(Ectoderm)Germ layers derivatives at a glance

In general ectoderm gives rise to organ and structures that maintain contact with the outside world

1. Ectoderm mainly divided into

a. Surface Ectoderm

b. Neuro ectoderm

a. Surface Ectoderm derivatives:

Divided into

1.       Epidermis

2.       Placode

3.       Stomstodaeum

4.       Proctodium

1. Epidermis derivatives:

·         Mammary gland

·         Nail

·         Hair follicle

·         Sebaceous gland (cutaneous gland )

·         Sweat gland (cutaneous gland )

2. Placode derivatives:

·         Olfactory placode – form Olfactory epithelium

·         Otic placode – form inner ear

·         Lens placode –Form’s lens

3. Stomatodium derivatives:

·         Epithelium of nasal cavity

·         Epithelium of vestibule ,gum, hard palate

·         Enamel of teeth

·         Parotid gland

·         Rathke’s pouch

4. Proctodium derivatives:

·         Lower part of anal canal.

·         Epithelium and glands

b. Neuro ectoderm derivatives:

a. Neural tube derivatives –

·         Brain

·         Spinal cord

·         Neurons of motor nerves

·         Retina and optic nerve and musculature of iris

·         Pineal gland

·         Pituitary gland ( neurohypophysis-posterior lobe and stalk )

·         Neuroglia

§  Ependymal cells

§  Microglia

a.Astrocyte

b.Oligodendrocyte

b. Neural Crest derivatives

·         Connective tissue and bones of the face and skull

·         Cranial nerve ganglia

(ciliary  for oculomotor nerve;

Trigeminal ganglia for trigeminal nerve;

superior,inferior,sphenoidal,submandibular for facial nerve ;

 Acoustic and vestibular for vestibulocochlear nerve;

Superior,inferior,otic for glossopharyngeal nerve;

Superior,inferior vagal parasympathetic ganglion for vagus nerve )

·         C cell of thyroid gland

·         Conotruncal septum in the heart

·         Odontoblast

·         Dermise in face and neck

·         Dorsal root ganglia

·         Sympathetic chain & paraaortic ganglia

·         Parasumpathetic ganglian ofGIT

·         Adrenal medulla

·         Schwann cell

·         Glial cell

·         Leptomeninges (Arachnoid and pia mater )

·         Melanocytes

·         Branchial cartilage

·         Uveal tract

Collected and concise only for post graduate students,Pictures are collected from Google.