ANAT2341 Lab 10 - Early Embryo - Revision history

Z8600021 at 21:53, 14 October 2015

2015-10-14T21:53:08Z

← Older revision		Revision as of 07:53, 15 October 2015
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	[[File:Stage12 sem4.jpg\|300px]] [[File:Stage12 sem5.jpg\|300px]]		[[File:Stage12 sem4.jpg\|300px]] [[File:Stage12 sem5.jpg\|300px]]

	~~'''~~Week 4 ~~Vision'''~~ (data based upon<ref><pubmed>7364662</pubmed></ref> and other sources).		===Vision - Week 4===
			(data based upon<ref><pubmed>7364662</pubmed></ref> and other sources).
	* [[Carnegie_stage_10\|Stage 10]] - optic primordia appear.		* [[Carnegie_stage_10\|Stage 10]] - optic primordia appear.
	* [[Carnegie_stage_11\|Stage 11]] - right and left optic primordia meet at the optic chiasma forming a U-shaped rim.		* [[Carnegie_stage_11\|Stage 11]] - right and left optic primordia meet at the optic chiasma forming a U-shaped rim.
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	[[File:Stage 13 image 055.jpg\|500px]]		[[File:Stage 13 image 055.jpg\|500px]]

	~~'''~~Week 5 ~~Vision'''~~ (data based upon<ref><pubmed>7364662</pubmed></ref> and other sources).		===Vision - Week 4 to 5 ===
	* [[Carnegie_stage_13\|Stage 13]] - By the end of the fourth week the optic vesicle lies close to the surface ectoderm. Optic evagination differentiation allows identification of optic part of retina, future pigmented layer of retina, and optic stalk. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lense placode.		(data based upon<ref><pubmed>7364662</pubmed></ref> and other sources).
	* [[Carnegie_stage_14\|Stage 14]] - (about 32 days) the lens placode is indented by the lens pit, cup-shaped and still communicates with the surface by a narrowing pore.		* Week 4 - [[Carnegie_stage_13\|Stage 13]] - By the end of the fourth week the optic vesicle lies close to the surface ectoderm. Optic evagination differentiation allows identification of optic part of retina, future pigmented layer of retina, and optic stalk. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lense placode.
			* Week 5 - [[Carnegie_stage_14\|Stage 14]] - (about 32 days) the lens placode is indented by the lens pit, cup-shaped and still communicates with the surface by a narrowing pore. [[Carnegie_stage_15\|Stage 15]] - (about 33 days) the lens pit is closed. The lens vesicle and optic cup lie close to the surface ectoderm and appear to press against the surface.

Z8600021 at 21:45, 14 October 2015

2015-10-14T21:45:18Z

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 [[File:Stage12 sem4.jpg|300px]] [[File:Stage12 sem5.jpg|300px]]
 ===Week 5===
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 Named by the sensory system and components they will form: otic placode, lens placode and nasal placode.
 |}
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 [[File:Stage 13 image 055.jpg|500px]]
 ==Pharyngeal Arches==

Z8600021 at 09:00, 14 October 2015

2015-10-14T09:00:50Z

← Older revision		Revision as of 19:00, 14 October 2015
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	==Additional Information==		==Additional Information==
	{{~~Additional~~ Information}}		{{Med Prac additional Information}}
	{\|		{\|
	\| [[File:Cranial neural crest skeletal fate 01.jpg\|600px]]		\| [[File:Cranial neural crest skeletal fate 01.jpg\|600px]]

Z8600021 at 08:59, 14 October 2015

2015-10-14T08:59:58Z

← Older revision		Revision as of 18:59, 14 October 2015
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	==Additional Information==		==Additional Information==
			{{Additional Information}}
	{\|		{\|
	\| [[File:Cranial neural crest skeletal fate 01.jpg\|600px]]		\| [[File:Cranial neural crest skeletal fate 01.jpg\|600px]]

Z8600021: Created page with "{{ANAT2341Lab10}} ==Week 4== During week 4 a number of features appear visible on the embryo surface: * At the level of the body heart, liver, somite bulges and limb buds ap..."

2012-10-02T04:40:53Z

Created page with "{{ANAT2341Lab10}} ==Week 4== During week 4 a number of features appear visible on the embryo surface: * At the level of the body heart, liver, somite bulges and limb buds ap..."

New page

{{ANAT2341Lab10}}

==Week 4==

During week 4 a number of features appear visible on the embryo surface:
* At the level of the body heart, liver, somite bulges and limb buds appear.
* At the level of the head sensory placodes and pharyngeal arches appear.

==Carnegie Stage 12 to 14==
===Week 4===
[[Carnegie_stage_11|Stage 11]]

[[File:Stage11_sem13c.jpg]] [[File:Stage11_sem20c.jpg]]

This is a scanning EM of the embryo superior dorsal view showing the paired otic placodes sinking into the surface at the level of the hindbrain between day 24 and day 25

[[Carnegie_stage_12|Stage 12]]

[[File:Stage12_sem1c.jpg]] [[File:Stage12 bf2c.jpg]][[File:Stage12_bf1c.jpg]]

[[File:Stage12 sem4.jpg|300px]] [[File:Stage12 sem5.jpg|300px]]

===Week 5===
[[Carnegie_stage_13|Stage 13]]

[[File:Stage13_sem1c.jpg]] [[File:Stage13_bf1c.jpg]] [[File:Stage13_sem2c.jpg]]

==Sensory Placodes==
{|
| [[File:Stage14_sem2l.jpg|300px]]

[[Carnegie_stage_14|Stage 14]]
|

Sensory placodes develop as small patches of ectodermal thickenings.

The placodes are laterally paired and contribute key components to sensory structures of the ear, eye and nose.

Named by the sensory system and components they will form: otic placode, lens placode and nasal placode.

The links below are to '''additional information''' providing background about each of the sensory systems. Only hearing is covered in today's class.

{{Template:Hearing Links}}

{{Template:Vision Links}}

{{Template:Smell Links}}

:'''Taste Links:''' [[Sensory - Taste Development|Introduction]]
|}

===Stage 13===

Identify the structure and position of the otic vesicle (otocyst) relative to other head structures.

[[File:Stage 13 image 051.jpg|500px]]

[[File:Stage 13 image 052.jpg|500px]]

[[File:Stage 13 image 053.jpg|500px]]

[[File:Stage 13 image 054.jpg|500px]]

[[File:Stage 13 image 055.jpg|500px]]

==Pharyngeal Arches==
[[File:Head arches cartoon.jpg]]
[[File:Pharyngeal arch structure cartoon.gif]]

===Stage 13 Pharyngeal Arches===

[[File:Stage13 pharyngeal arch excerpts.gif]]

[[:File:Stage 13 image 055.jpg|A6L]]  [[:File:Stage 13 image 056.jpg|A7L]]  [[:File:Stage 13 image 057.jpg|B1L]]  [[:File:Stage 13 image 058.jpg|B2L]]  [[:File:Stage 13 image 059.jpg|B3L]]  [[:File:Stage 13 image 060.jpg|B4L]]  [[:File:Stage 13 image 061.jpg|B5L]]  [[:File:Stage 13 image 062.jpg|B6L]]

Look through the above cross-sections of the stage 13 embryo observing and identifying structures of the face and ear visible at this stage.

[[File:Pharyngeal_arch_cartilages.jpg]]

==Structures derived from Arches==

{| width="100%"
|-bgcolor="CEDFF2"
| width="15%" |
''' Arch'''
| width="20%" |
'''Nerve'''
| width="22%" |
'''Muscles'''
| width="25%" |
'''Skeletal'''
| width="18%" |
'''Artery'''
|-
|
<center>1 (maxillary/mandibular)</center>
|
<center>trigeminal (V)</center>
|
mastication (temporalis, masseter, medial pterygoid, lateral pterygoid)
|
Meckel's cartilage mandible modelmalleus, incus
|
maxillary(terminal branches)
|-bgcolor="F5FAFF"
|
<center>2 (hyoid)</center>
|
<center>facial (VII)</center>
|
facial expression (buccinator, platysma, stapedius, stylohyoid, digastric posterior belly)
|
Reichert's cartilage stapes, styloid process, lesser cornu of hyoid, upper part of body of hyoid bone
|
stapedial (embryonic) corticotympanic (adult)
|-
|
<center>3</center>
|
<center>glossopharyngeal (IX)</center>
|
stylopharyngeus
|
greater cornu of hyoid, lower part of body of hyoid bone
|
common carotid, internal carotid (root)
|-bgcolor="F5FAFF"
|
<center> 4 and 6 </center>
|
<center>superior laryngeal and recurrent laryngeal branch of vagus (X)</center>
|
intrinsic muscles of larynx, pharynx; levator palati
|
thyroid, cricoid, arytenoid, corniculate and cuneform cartilages
|
4 - aortic arch, right subclavian 6 - ductus arteriosus, pulmonary (roots)
|}

==Structures derived from Pouches==
{| width="100%"
|-bgcolor="CEDFF2"
| width="83" |
'''Pouch'''
|
'''Overall Structure'''
|
'''Specific Structures'''
|-
| width="83" |
<center>1</center>
|
tubotympanic recess
|
tympanic membrane, tympanic cavity, mastoid antrum, auditory tube
|-bgcolor="F5FAFF"
| width="83" |
<center>2</center>
|
intratonsillar cleft
|
crypts of palatine tonsil, lymphatic nodules of palatine tonsil
|-
| width="83" |
<center>3</center>
|
inferior parathyroid gland, thymus gland
|
|-bgcolor="F5FAFF"
| width="83" |
<center>4</center>
|
superior parathyroid gland, ultimobranchial body
|
|-
| width="83" |
<center>5</center>
|
becomes part of 4th pouch
|
|}

==Additional Information==
{|
| [[File:Cranial neural crest skeletal fate 01.jpg|600px]]
| '''Cranial neural crest contribution to skeletal structures'''

The embryo figure shows colonization of the head and pharyngeal arches by diencephalic, anterior and posterior mesencephalic, and rhombencephalic neural crest cells (NCCs), as indicated by the colour code. The diagram is representative human embryos, although the NCC migratory pathways might differ slightly in different species. The skull drawings show contributions of NCC populations to cranial skeletal elements of humans, based on NCC fate-mapping studies and on extrapolation of avian and mouse data to known homologues in the human.

Some bones, including the squamosal (SQ), alisphenoid (AS), and pterygoid (PT), are shown with mixed contribution from different NCC populations. Note that in mammals the frontal (FR) and parietal (PA) bones have been reported to be of neural crest and mesodermal origin, respectively.

(text modified from original figure legend)
|}

{|
|
* '''BA1-BA3''' - pharyngeal arches 1 - 3
* '''di''' - diencephalon
* '''FNP''' - frontonasal process
* '''HY''' - hyoid bone
* '''IN''' - incus
* '''MA''' - malleus
|
* '''mes''' - mesencephalon
* '''MX''' - maxillary bone
* '''NA''' - nasal bone
* '''R1–R7''' - rhombomeres 1 – 7
* '''ST''' - stapes
* '''ZY''' - zygomatic bone
|}

Review article<ref><pubmed>14523380</pubmed>| [http://www.nature.com/nrn/journal/v4/n10/full/nrn1221.html Nat Rev Neurosci.]</ref>

==References==

<references/>

{{ANAT2341Lab10}}

{{Glossary}}
{{Footer}}