Embryological Derivatives

Question 1

Surface ectoderm

(ECTODERM)

Answer 1

1. Anterior pituitary (Rathke pouch)
2. Lens & cornea
3. Inner ear sensory organs, olfactory epithelium
4. Nasal & oral epithelial linings, salivary glands
5. Epidermis, sweat & mammary glands

Question 2

Neural tube

(ECTODERM)

Answer 2

1. Brain & spinal cord
2. Posterior pituitary, pineal gland
3. Retina

Question 3

Neural crest

(ECTODERM)

Answer 3

1. Neural ganglia, adrenal medulla
2. Schwann cells; pia & arachnoid mater
3. Aorticopulmonary septum & endocardial cushions
4. Branchial arches (bones & cartilage)
5. Skull bones
6. Melanocytes

Question 4

Mesoderm

Answer 4

1. Muscles (skeletal, cardiac & smooth)
2. Connective tissue, bone & cartilage
3. Serosal linings (e.g., peritoneum)
4. Cardiovascular & lymphatic system
5. Spleen & hemopoietic cells
6. Kidney & ureters, internal genitalia
7. Adrenal cortex

Question 5

Endoderm

Answer 5

1. Gastrointestinal tract, liver, pancreas
2. Lungs
3. Thymus, parathyroids, thyroid follicular cells
4. Middle ear epithelium
5. Bladder & urethra
6. Parafollicular (C) cells*

Question 6

Brain development and derivatives

Prosencephalon

• Telencephalon:

Answer 6

1. Cerebral hemisphere
2. Lateral Ventricles

Question 7

Prosencephalon

• Diencephalon:

Answer 7

1. Thalamus
2. 3rd Ventricle

Question 8

Mesencephalon

Answer 8

Mid Brain & Aqueduct

Question 9

Rhombencephalon

Metencephalon

Answer 9

Pons, Cerebellum & Upper 4th Ventricle

Question 10

Rhombencephalon

Myelencephalon

Answer 10

Medulla & Lower 4th Ventricle