Some Embryology

Question 1

What does the epidermis of the skin derive from?

Answer 1

Ectoderm

Question 2

What does the dermis of the skin derive from?

Answer 2

Lateral plate of mesoderm

Question 3

What does the urogenital system derive from (kidneys, gonads, respective duct systems)?

Answer 3

Intermediate plate of the mesoderm

Question 4

What do somites derive from?

Answer 4

Paraxial plate mesoderm

Question 5

What do somites give rise to?

Answer 5

Supporting tissue of the body:

Myotome, Sclerotome, Dermatome

Question 6

What do myotomes become?

Answer 6

Muscle tissue

Question 7

What do sclerotomes become?

Answer 7

Cartilage and bone

Question 8

What do dermatomes become?

Answer 8

Dermis of skin

Question 9

What are the two layers of the Lateral plate mesoderm?

Answer 9

Somatic (parietal)

Splanchnic (visceral)

Question 10

What does the somatic/parietal layer of the lateral plate mesoderm form?

Answer 10

Future body wall

Question 11

What does the splanchnic/visceral layer of the lateral plate mesoderm form?

Answer 11

Circulatory System; Connective tissue of glands; muscle, connective tissue and peritoneal components of the Wall of the gut

Question 12

What gives rise to the epithelial lining of the GI tract?

Answer 12

Endoderm

Question 13

The endoderm forms the epithelial lining of which parts of the ear?

Answer 13

Tympanic membrane and Auditory Tube

Question 14

What gives rise to epithelial lining of the bladder and what type of epithelium of this?

Answer 14

Endoderm

Urothelium/Transtitional

Question 15

What gives rise to epithelial lining of respiratory tract and what type of epithelium of this?

Answer 15

Endoderm

Ciliated pseudo-stratified columnar epithelium (respiratory epithelium)

Question 16

What gives rise to the the pancreas?

Answer 16

2 endodermal buds (dorsal and ventral from respective aspects of the gut)

Question 17

What gives rise to the liver?

Answer 17

Endodermal bud (of Endoderm)

Question 18

What, around the thyroid gland, does the endoderm give rise to?

Answer 18

Parenchyma of thyroid gland and Parathyroid glands

Parenchyma = functional tissue of organ

Question 19

In general, what structures does the Ectoderm give rise to?

Answer 19

Structures that are in contact with outside of the body

Question 20

What gives rise to the PNS and CNS?

Answer 20

Ectoderm

Question 21

What gives rise to the enamel of the teeth?

Answer 21

Ectoderm

Question 22

Ectoderm gives rise to SENSORY epithelium of what structures?

Answer 22

Nose, ear, eye

Question 23

What gives rise to the epidermis of skin, hair and nails?

Answer 23

Ectoderm

Question 24

What glands does the ectoderm give rise to?

Answer 24

Pituitary glands
Mammary glands
Sweat glands

Question 25

What do neural crest cells give rise to?

Answer 25

``` Sensory dorsal root ganglion of spinal cord and cranial nerves V, VII, IX and X Schwann cells Adrenal Medulla Bony Skull Meninges Dermis ```

Question 26

What are the 3 primary brain vesicles that can be identified by the 5th WEEK?

Answer 26

Prosencephalon(forebrain) Mesencephalon (midbrain) Rhombencephalon (hindbrain)

Question 27

By what week do secondary brain vesicles appear?

Answer 27

7th week

Question 28

What secondary vesicles does Prosencephalon give rise to?

Answer 28

Telencephalon | Diencephalon

Question 29

What secondary vesicles does Rhombencephalon give rise to?

Answer 29

Metencephalon | Myelencephalon

Question 30

What does Telencephalon give rise to?

Answer 30

Cerebral Hemispheres | Lateral Ventricles

Question 31

What does Diencephalon give rise to?

Answer 31

Thalamus Hypothalamus 3rd ventricle

Question 32

What does Mesencephalon give rise to?

Answer 32

Midbrain (colliculi) | Aqueduct

Question 33

What does Metencephalon give rise to?

Answer 33

Cerebellum Pons UPPER part of 4th ventricle

Question 34

What does Myelencephalon give rise to?

Answer 34

Medulla oblongata | LOWER part of 4th ventricle

Question 35

What does the respiratory tract arise from?

Answer 35

Respiratory tract is derived from an out pouching of the foregut from endoderm and splanchnic mesoderm

Question 36

What parts of the respiratory tract arise from the endoderm?

Answer 36

``` Bronchi Alveoli Larynx Epithelia lining of tract (BALE) ```

Question 37

What parts of the respiratory tract derive from the splanchnic mesoderm?

Answer 37

Cartilages Connective tissue of tract Muscle VISCERAL Pleura

Question 38

What does CVS system develop from?

Answer 38

Mostly form MESOderm (heart, blood, smooth muscles, endothelium) Some contribution from Cardiac Neural Crest cells of ECTOderm

Question 39

What does the Primitive/Primordial Ventricle form?

Answer 39

Left Ventricle

Question 40

What does the Primitive/Primordial atrium form?

Answer 40

Anterior Right Atrium (Entire) Left Atrium Left and Right Auricles

Question 41

What does the sinus venosus form? | bottom left and right branched horns

Answer 41

part of Right Atrium Vena Cava Coronary Sinus

Question 42

What does the Aortic Sac form?

Answer 42

Aorta | Pulmonary Artery

Question 43

What are the different parts of the Bulbus Cordis (BC)?

Answer 43

Proximal third of BC LOWER part of BC = Conus Cordis UPPER part of BC = Truncus Cordis

Question 44

What does proximal third of bulbus cordis form?

Answer 44

Muscular Right Ventricle

Question 45

What does Conus Cordis give rise to? (lower part of Bulbus cordis)

Answer 45

Smooth outflow portion of Right and Left Ventricles

Question 46

What does Truncus Cordis give rise to? (upper part of bulbus cordis)

Answer 46

Proximal Aorta | Pulmonary Trunk

Question 47

By what day do the two endocardial tubes form?

Answer 47

Day 19 of 3rd week

Question 48

By what day do endocardial tubes fuse into one? | How?

Answer 48

Day 21 By lateral folding Single heart tube then grows and bulges

Question 49

By what day does the heart start to beat?

Answer 49

Day 22

Question 50

By what day does the heart start to fold?

Answer 50

Day 23

Question 51

What is the Fossa Ovalis a remnant of?

Answer 51

``` Foramen Ovale Interatrial septum (valve between atriums) ```

Question 52

What connected the anterior abdominal wall to the Liver?

Answer 52

Falciform Ligament

Question 53

What connects the liver to the stomach?

Answer 53

Lesser Omentum

Question 54

What connects the stomach to the spleen?

Answer 54

Gastrosplenic Ligament

Question 55

What connects the spleen to the kidney?

Answer 55

Splenorenal Ligament

Question 56

What 'narrow stalk' temporarily connects the midgut to the yolk sac until the 5th week?

Answer 56

Vitelline Duct

Question 57

What does the pharynx develop from?

Answer 57

Pharyngeal Pouches

Question 58

What is the Ligamentum Teres a remnant of?

Answer 58

Umbilical Vein

Question 59

What does the first Pharyngeal Pouch give rise to?

Answer 59

Middle ear cavity | Auditory Tube

Question 60

What does the second pouch give rise to?

Answer 60

Palatine Tonsil | Tonsilar Fossa

Question 61

What does the third pouch give rise to?

Answer 61

Inferior Parathyroid gland

Question 62

What does the 4th pouch give rise to?

Answer 62

Ultimobranchial body | Parafollicular cells of thyroid gland and Superior Parathyroid body

Question 63

What does the 6th pouch give rise to?

Answer 63

Cervical Body

Question 64

What does the first Pharyngeal CLEFT give rise to?

Answer 64

External Auditory Meatus | Epithelium of Eardrum

Question 65

What do the 2nd, 3RD AND 4TH Pharyngeal Clefts give rise to?

Answer 65

Cervical Sinus

Question 66

What are Retroperitoneal Organs?

Answer 66

DADPOK | Descending colon, Ascending Colon, Duodenum, Pancreas, Oesophagus, Kidneys

Question 67

What are Intraperitoneal Organs?

Answer 67

SALTSS | Stomach, Appendix, Liver, Transverse colon, Sigmoid colon, Small intestine

Question 68

What do limb bones develop from?

Answer 68

Endochondrial Ossification of Cartilaginous Precusors | Exception of the Clavicle which is intramembranous