NEURO

Question 0

EMBRYO

When does Neurulation begin in fetal development?

(see note package)

Answer 0

3rd Week

Question 1

EMBRYO

Which structure induces the formation of the nervous system?

The formation of which 2 structures does it directly induce?

Answer 1

Notochord

Neuroectoderm + Neural folds

Question 2

EMBRYO

Describe development of Neuroectoderm.

Answer 2

Neuroectoderm -> Neural Plate -> CNS neurons
-> Ependymal cells
-> Astrocytes & Oligodendrocytes
(… then during closure of Neural Tube…)
-> Neural Crest Cells -> Sensory neurons
-> Postganglionic neurons

Question 3

EMBRYO

Describe development of Neural Folds.

Answer 3

Neural Folds -> Neural Tube

Question 4

EMBRYO

Describe (generally + specifically) the development of the Neural Tube.

Answer 4

(Neural tube runs along cranial-caudal axis of embryo)

General: Neural Tube -> Brain + SC

• Alar plate + Basal plate separated by sulcus limitans
• 3 primary vesicles -> 5 secondary vesicles

Specific: Neural Tube - Wall -> CNS tissue

                                - Hollow lumen -> SC canal + Ventricles
                                - Neural Crest   -> PNS neurons + Schwann c

Question 5

EMBRYO

Name:

• 3 primary vesicles
• 5 secondary vesicles
• Adult structures derived from the Neural Tube walls + cavities

Answer 5

(Neuro Embryo note package p 2)

Question 6

EMBRYO

Aortic Arch Derivatives #1

• When do they develop?
• What are they?
• What structure does each Aortic Arch travel through?
• What do they become after the 5th wk?

Answer 6

• 5th wk
• Series of paired arteries + veins that supply embryo.
• Pharyngeal arch
• Adult arterial system

Question 7

EMBRYO

Aortic Arch Derivatives #2

1st Arch -> ?
2nd Arch -> ?
3rd Arch -> ?
4th Arch -> ?
6th Arch -> ?

Answer 7

(Neuro Embryo note package p 3)

1st Arch -> Maxillary artery
2nd Arch -> Hyoid artery + Stapedial artery
3rd Arch -> Carotid artery (Common + Proximal Internal)
4th Arch -> Aortic Arch (left) + R Subclavian artery (right)
6th Arch -> Pulmonary arteries + Ductus arteriosus (left)

Question 8

EMBRYO

Branchial (Pharyngeal) Apparatus

3 components + derivations of each?

Answer 8

• Clefts / Grooves (ectoderm)
• Arches (mesoderm + neural crests = mesenchyme)
• Pouches (endoderm)

Question 9

EMBRYO

Branchial Clefts

1st Cleft -> ?
2nd - 4th Clefts -> ?

Answer 9

1st Cleft -> External Auditory Meatus
2nd-4th Clefts -> TEMPORARY cervical sinuses
(obliterated by prolif of 2nd Arch mesenchyme)

Question 10

EMBRYO

Branchial Arches #1

For each arch, name: cartilage, muscles, nerves, organs / region that it becomes.

1st Arch -> (cartilage, 4 muscles + 1 muscle group, 2 nerves,
organ / region)?

Answer 10

(Neuro Embryo note package p 3)

1st Arch -> Meckel’s cartilage
-> Mastication muscles, Mylohyoid, Digastric (ant belly),
Tensor tympani & Tensor veli palatini
-> V2 & V3
-> Ant 2/3 of Tongue

Question 11

EMBRYO

Branchial Arches #2

2nd Arch -> (cartilage, 3 muscles + 1 muscle group, 1 nerve)?

Answer 11

2nd Arch -> Reichert’s cartilage
-> Muscles of facial expression, Stapedius, Stylohyoid,
Digastric (post belly)
-> Facial nerve = CN 7

Question 12

EMBRYO

Branchial Arches #3

3rd Arch -> (cartilage forming ___,1 muscle, 1 nerve)?

Answer 12

3rd Arch -> GREATER horn of hyoid

           - > Stylopharyngeus
           - > Glossopharyngeal nerve = CN 9

Question 13

EMBRYO

Branchial Arches #4

4th Arch -> (2 muscles + 1 muscle group, nerve + branch)

Answer 13

4th Arch -> Pharyngeal constrictors,
Cricothyroid, Levator veli palatini
-> Vagus nerve = CN 10, superior laryngeal branch

Question 14

EMBRYO

Branchial Arches #5

6th Arch -> (1 muscle group, nerve + branch)?

Answer 14

6th Arch -> Intrinsic muscles of Larynx (except cricothyroid)
-> Vagus nerve = CN 10, recurrent laryngeal branch

Question 15

EMBRYO

Branchial Pouches #1
“Ear, Tonsils, Bottom To Top”

1st Pouch -> ?

Answer 15

(Neuro Embryo note package p 4)

1st Pouch -> Middle Ear cavity
(and eustachian tube + mastoid air cells
= endoderm-lined structures of ear)

Question 16

EMBRYO

Branchial Pouches #2

2nd Pouch -> ?

Answer 16

2nd Pouch -> Palatine Tonsils

Question 17

EMBRYO

Branchial Pouches #3

3rd Pouch - Dorsal wings -> ?
- Ventral wings -> ?

Answer 17

3rd Pouch - Dorsal wings -> Inferior Parathyroids

- Ventral wings -> Thymus

Question 18

EMBRYO

Branchial Pouches #4

4th Pouch -> ?

Answer 18

4th Pouch -> Superior Parathroids