Development Of Special Senses

Question 1

Outer layer of optic cup

Answer 1

Pigment epithelium

Question 2

Cornea is naked ( no eyelids, except for primordium)

Answer 2

42 days pc

Question 3

Eyelids have grown over the cornea

Answer 3

77 days pc

Question 4

Eyelids separate to form the

Answer 4

Palpebral fissure

Question 5

Rapid optic nerve vascularization

Answer 5

12-14 wks pc

Question 6

Dura matter first appears around optic nerve

Answer 6

Wk 15

Question 7

Immunoreactivity for glial fibrillary acidic protein first appears in optic nerve

Answer 7

Wk 24?

Question 8

First myelinated fibers seen in intracranial part of optic nerve. Immunoreactivityor myelin basic protein appears in optic nerve

Answer 8

Wk 31-32

Question 9

First myelinated fibers seen in retrobulbar optic nerve

Answer 9

Wk 40

Question 10

Myelination of optic nerve proceeds to from chiasm to bulb

Answer 10

Week 32-40 and beyond

Question 11

The eyes are fused in the midline, because loss of midline structures has prevented the eye fields from separating

Answer 11

Synophthalmia

Question 12

postural muscles in the muscular compartment of the neck

Answer 12

Coloboma

Question 13

Lens opacification

May occur with developmental rubella infection

Answer 13

Congenital cataract

Question 14

May occur in developmental rubella or cytomegalovirus infection or be due to maternal alcohol infection

Answer 14

Microphthalmia (small eye)

Question 15

Origin of the external auditory meatus

Answer 15

1st pharyngeal cleft

Question 16

Origin of the auricle

Answer 16

Ectoderm and mesenchyme of 1st and 2nd arches

Question 17

External ear

Answer 17

External auditory meatus

Auricle

Question 18

Middle ear

Answer 18

Tympanic cavity and eustachian tube
Malleus and incus
Stapes

Question 19

Origin of the tympanic cavity and eustachian tube

Answer 19

1st pharyngeal pouch

Question 20

Origin of the malleus and incus

Answer 20

1st arch cartilage

Question 21

Origin of the stapes

Answer 21

2nd arch cartilage

Question 22

Origin of the membranous labyrinth (inner ear)

Answer 22

Otic vesicle

Question 23

Origin of the statoacoustic ganglion (inner ear)

Answer 23

Neural crest and otic vesicle

Question 24

Otic placode (surface ectoderm) invaginates

Answer 24

28 days pc

Question 25

Invaginating placode

Answer 25

24 days pc

Question 26

Otic pit

Answer 26

27 days pc

Question 27

Otic vesicle

Answer 27

32 days pc

Question 28

External ear abnormalities (ear tags) may indicate

Answer 28

Chromosomal abnormalities

Question 29

Olfactory pit forms bet the medial and lateral nasal processes

Answer 29

32 days pc

Question 30

What develops in the depths of the olfactory pit?

Answer 30

Olfactory placode (olfactory epithelium primordium)

Question 31

major source of gonadotropin releasing hormone (GnRH) producing cells for hypothalamus

Answer 31

Vomeronasal organ & terminal nerve

Question 32

GnRH can be detected in human olfactory epithelium as early as

Answer 32

5.5 weeks

Question 33

Migra;on of GnRH cells along the developing vomeronasal/terminal nerve complex occurs during

Answer 33

Wk 6-8

Question 34

Hypogonadotrophic hypogonadism associated with reproduction dysfunction

Answer 34

Kallmann syndrome

Question 35

the olfactory, vomeronasal and terminal nerves terminate in the meninges and do not enter the brain

Answer 35

Kallmann syndrome

Question 36

Two genes resp for kallmann's syndrome

Answer 36

KAL1 & KAL2

Question 37

encodes anosmin 1, present along the migration path of GnRH neurons and the central roots of the terminal nerve

Answer 37

KAL1

Question 38

encodes fibroblast growth factor receptor 1 (FGFR1)

Answer 38

KAL2

Question 39

lack of functioning olfaction; an inability to perceive odors.

Answer 39

Anosmia

Question 40

the loss of taste functions of the tongue, particularly the inability to detect sweetness, sourness, bitterness, saltiness, and umami

Answer 40

Ageusia

Question 41

Development of the optic vesicles starts from a progressively deepening groove in the neural plate called the optic sulcus.

Answer 41

Week 3

Question 42

The optc vesicles come into contact with the epithelum and induce the epidermis which will thicken to form the ------

Answer 42

lens placode

Question 43

migrates in during the forma;on of the op;c cup and is critical for the induction of the retinal pigment epithelium and the optic nerve.

Answer 43

Periocular mesenchyme

Question 44

The human ear develops from the auditory placode

Answer 44

Wk 4

Question 45

a thickening of the ectoderm that gives rise to the bipolar neurons of the cochlear and vestibular ganglions

Answer 45

Auditory placode

Question 46

The auditory vesicle will five rise to

Answer 46

Uricular and saccular components of the membranous labyrinth

Question 47

the auditory vesicle also gives rise to the cochlear duct, which contains the spiral organ of Corti and the endolymph that accumulates in the membranous labyrinth

Answer 47

Wk 5

Question 48

Neurons in the vestibular system mature during the

Answer 48

First 2-3 postnat weeks

Question 49

Inner layer of optic cup

Answer 49

Sensory retina (neurons and photoreceptors)