Question 1

The muscles of the sphincter and dilator pupillae arise from the _________________.&#10;A)Mesoderm&#10;B)Neural crest&#10;C)Neurectoderm&#10;D)Pharyngeal arches&#10;E)Endoderm

Accepted Answer

The muscles of the sphincter and dilator pupillae arise from the neurectoderm, which is the origin of most of the nervous system and related structures.

Question 2

The otic placode is induced by the ______________.&#10;A)Notochord&#10;B)Second pharyngeal arch&#10;C)Rhombencephalon&#10;D)Primitive node&#10;E)None of the above

Accepted Answer

The otic placode, which gives rise to the inner ear, is induced by the rhombencephalon (hindbrain) during embryonic development.

Question 3

Coloboma is a structural abnormality of the _____________.&#10;A)Retina&#10;B)First pharyngeal arch&#10;C)Tympanic membrane&#10;D)Iris&#10;E)Second pharyngeal arch

Accepted Answer

Coloboma is a congenital condition where there is a gap or hole in the iris, causing an irregular shape. It can affect one or both eyes and is caused by abnormal development of the eye during embryonic growth.

Question 4

Sensory placodes arise from the _____________.&#10;A)Neural crest&#10;B)Lateral plate mesoderm&#10;C)Lateral ectoderm&#10;D)Neural tube&#10;E)None of the above

Accepted Answer

Sensory placodes arise from the lateral ectoderm, which is a specialized group of cells that differentiate into various sensory structures such as the olfactory epithelium, lens of the eye, and inner ear. The neural crest gives rise to a different set of structures, including neurons and glia of the peripheral nervous system, while the lateral plate mesoderm gives rise to the cardiovascular and skeletal systems. The neural tube forms the central nervous system.

Question 5

The development of corneal transparency by removal of water from the secondary stroma is mediated by ____________.&#10;A)Thyroxine&#10;B)Catecholamines&#10;C)Fibroblast growth factor&#10;D)Nerve growth factor&#10;E)Crystallins

Accepted Answer

Thyroxine mediates the development of corneal transparency by removing water from the secondary stroma, which is crucial for the cornea's refractive function.

Question 6

Coloboma is typically seen in individuals with mutants of ____________.&#10;A)Pax-2&#10;B)En-1&#10;C)Sonic hedgehog&#10;D)Pax-6&#10;E)En-2

Accepted Answer

The answer of Coloboma is typically seen in individuals with...

Question 7

Which of the following associations is incorrect?&#10;A)Optic cup - neural retina&#10;B)Neural crest - sphincter/dilator papillae muscles&#10;C)Ectodermal placode - lens&#10;D)Neural crest - pigment layer of the retina&#10;E)Neural crest - corneal endothelium

Accepted Answer

The pigment layer of the retina is derived from the optic cup, not the neural crest. The neural crest contributes to various structures in the eye, but the pigment layer of the retina originates from the outer layer of the optic cup.

Question 8

Which of the following associations is incorrect?&#10;A)Diencephalon - neural retina&#10;B)Optic cup - pigment layer of retina&#10;C)Surface ectoderm - lens&#10;D)Surface ectoderm - iris&#10;E)Surface ectoderm - cornea

Accepted Answer

The iris is derived from the neural crest cells and mesoderm, not the surface ectoderm.

Question 9

Surface ectoderm is induced to become corneal epithelium by an inductive event originating in the _____________.&#10;A)Optic cup&#10;B)Chordamesoderm&#10;C)Optic vesicle&#10;D)Lens vesicle&#10;E)Primitive neural retina

Accepted Answer

The answer of Surface ectoderm is induced to become corneal...

Question 10

The sensory hair cells of the inner ear originate from the _________________.&#10;A)Pinna&#10;B)Otic placode&#10;C)Neural crest&#10;D)Pharyngeal arch&#10;E)Prosencephalon

Accepted Answer

The otic placode is a thickening of ectoderm that gives rise to the inner ear and its sensory hair cells. The pinna (A) is the visible part of the outer ear and does not give rise to inner ear structures. The neural crest (C) gives rise to many different cell types, but not sensory hair cells. The pharyngeal arches (D) give rise to various structures in the face and neck, but not the inner ear. The prosencephalon (E) is a part of the developing brain and does not give rise to the inner ear or its hair cells.

Question 11

The otic placode is induced by interaction of the surface ectoderm with ____________.&#10;A)Prosencephalon&#10;B)Mesencephalon&#10;C)Rhombencephalon&#10;D)Cephalic mesoderm&#10;E)Spiral ganglion

Accepted Answer

The answer of The otic placode is induced by interaction...

Question 12

Neural crest-derived cells constitute a significant component of which of the following tissues of the eye?&#10;A)Neural retina&#10;B)Lens&#10;C)Optic nerve&#10;D)Cornea&#10;E)None of the above

Accepted Answer

The answer of Neural crest-derived cells constitute a significant component...

Question 13

Which embryonic tissue contains mesoderm?&#10;A)Oropharyngeal membrane&#10;B)Tympanic membrane&#10;C)Proctodeal membrane&#10;D)Lens&#10;E)None of the above

Accepted Answer

The answer of Which embryonic tissue contains mesoderm?&#10;A)Oropharyngeal membrane&#10;B)Tympanic membrane&#10;C)Proctodeal...

Question 14

Coloboma results from _________________.&#10;A)Nonclosure of the choroid fissure of the iris&#10;B)Lack of induction by the lens&#10;C)Lack of induction by the otic vesicle&#10;D)Hypoplasia of the first pharyngeal arch&#10;E)Incomplete migration of fourth pharyngeal pouch endoderm

Accepted Answer

The answer of Coloboma results from _________________.&#10;A)Nonclosure of the choroid...

Question 15

Which of the following associations is incorrect?&#10;A)Diencephalon - neural retina&#10;B)Optic cup - pigment layer of retina&#10;C)Surface ectoderm - lens&#10;D)Surface ectoderm - iris&#10;E)Surface ectoderm - cornea

Accepted Answer

The answer of Which of the following associations is incorrect?&#10;A)Diencephalon...

Question 16

The epithelial lining of the middle ear cavity and auditory tube arises from the ________________.&#10;A)Pharyngeal endoderm&#10;B)Neural crest&#10;C)Otic placode&#10;D)Paraxial mesoderm&#10;E)Otocyst

Accepted Answer

The answer of The epithelial lining of the middle ear...

Question 17

The _______________ gives rise to tissues of the external ear.&#10;A)Maxillary process&#10;B)Nasolateral process&#10;C)Pharyngeal arch 3&#10;D)Philtrum&#10;E)None of the above

Accepted Answer

The answer of The _______________ gives rise to tissues of...

Deck 13: Sense Organs