Transcript Introduction & Embryology

Introduction
&
Early Embryology
Human Structure & Development
ANHB 2212
Semester 1 – 2008
Dr. Avinash Bharadwaj
[email protected]
Welcome!
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The Promise :
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An exciting unit!
All possible help during the course of the unit
Improvements… already in place
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Unit Coordinators
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Avinash Bharadwaj
Julie Hill
Lecturers
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Last year’s SPOT – both 2212 and 1102!
Assoc Prof Geoff Meyer
Yours truly
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Demonstrators/Tutors
Prerequisites other than A&HB
Units…?
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“Prescribed reading”…
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Integrated with learning resources
Available well before the actual classes
In case of difficulty (unlikely )…
… Contact me!
More About the Unit
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Learning load (?) and help
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Directed self-study
Pre-lab prep is essential
Resources, especially website
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www.lab.anhb.uwa.edu.au/anhb2212
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Some resources and features on WebCT.
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WebCT URL : http://webct.uwa.edu.au
Lab manual – available in co-op shop soon
Textbooks (“Recommended”)
Course Reader : Online, includes “prescribed” reading
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What’s in It for You?
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Wide variety of student background and goals
Integrated Structure, Function and Development
 Componets are not separable!
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Carefully selected content
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Separation in labs inevitable…
Relevance to all streams considered
Assessment designed to facilitate all streams
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Core topics…
“Other areas”
UWA Student email account
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Must be activated immediately
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Class List emails for important announcements
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Check your email regularly.
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Auto redirect to other accounts is not encouraged.
Mails coming from other accounts are likely to be auto
deleted.
ANHB computing account
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For accessing web material on G.03 computers
Now can be done through the Histology Lab.
You can do it on Thursday, Week 1 Lab!
You do not need this for computers other than in the
A&HB building.
The Unit website is “open” – needs no username or
password as of now.
Lab Allocation – OLCR
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Lab time allocations only through OLCR.
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If problems persist, see
Wendy Colangelo, Ground floor, A&HB Building.
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Adjustments done only for genuine reasons, mostly
timetable clashes.
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Mutual exchange between two students : Both must
see Wendy together!
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Allocation will settle down in a week’s time!
Communication
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Offices : Avinash : 1.77, First floor, A&HB
Julie
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: 1.75, First floor, A&HB
Email : [email protected]
[email protected]
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In general, Policy-related mails and those with
subject related questions to Avinash
Admin-related mails to Julie.
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Subject header must include : “ANHB2212”, your
name, and a word or two about the subject. E.g.
ANHB 2212 – Jane Smith – Embryology question
Teaching Strategies – Lectures
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Theme based
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Slide-show and printable versions available in
advance.
No handouts!
 Not incorporated in the lab manual.
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Recorded on Lectopia
Teaching Strategies – Labs
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Anatomy labs : “free movement”.
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Visit all tables
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Check for exhibits in the centre or on the boards.
Histology labs are “sit-down”!
For Both Labs
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Directed self study
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Pre-lab study is essential
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Attendance/worksheets : Stick to the allotted tutor.
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Roving resource persons.
Teaching Strategies – Tutorials
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Interactive, Q-A sessions.
Usually a week after the topic.
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Time to study/understand, identify ‘gaps’.
Questions not supplied in advance!
Essay writing practice during tutorials.
Attendance at Labs and Tutorials is compulsory and
recorded.
Penalties apply for absence without valid reason.
Email Julie regarding absence.
Unit Outcomes
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Detailed specific outcomes listed on the website
Do not read all at once!
Assessment carefully matched with outcomes.
In general…
Critical thinking and analysis is encouraged.
HUGE lot of guidance on the Unit website.
Correct use of language is essential 
Assessment
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Continuous assessment : 20% of total unit mark
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2x30 min tests – Weeks 5 and 9 (Tutorial hour)
MCQs, Short answer Qs, True / False Qs
End-of-semester Examination :
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Written (3 hours) : 50% of total unit mark
 MCQs, SAQs, One short essay
Lab (1.5 to 2 hours):
 25 – 30 Spot questions : 30% of total unit mark.
Actual marks are scaled to these weightages.
Other Assessment Events
Formative, do not count towards final mark.
 Short notes / Essays written during tutorials
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Pre-test in Week 1 Tutorial
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Marked and returned for feedback
Feedback to coordinators
Mock lab test (Week 8) administered as
practice. (If possible, also in Week 13).
For This Week…
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Recap (also if you have not done ANHB
1101/1102) :
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Course Reader Chapters 1, 2 and 3.
Chapter 2 : Details of mitosis and meiosis not
examinable.
Lab preparation : PowerPoint files on the Unit
website (Link given on the website).
Early Embryology
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Recap of ANHB 1101/1102 (or equivalent)
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Many facets…
Tailoring to HSD 2212
Some important concepts
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Why and How
Gross Form, Correlation
Errors in development
Structural
Embryology
Molecular
(Clinical aspects)
Real life aspects
(“non medical”)
Cellular and
Molecular
phenomena
Evolutionary
mirror
Fertilisation
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Ovum and Oöcyte
Second meiotic division
Site of fertilisation
Sperm : Acrosomal reaction
Zona pellucida
Single sperm…
Fertilisation
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Completion of meiosis II
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Polar bodies (Also dealt with in Week 11)
Restoration of diploidy
Initiation of cleavage
Chromosomal sex determination
Genetic and evolutionary implications
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Paternal and maternal chromosomes
Further mixing during next gametogenesis (crossing
over)
Cleavage
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Nuclear-cytoplasmic ratio
Division by reduction of cell volume
Planes of cleavage
Polarity…?  Inner cell mass and trophoblast
formed later
Transport through the uterine tube
Zona pellucida… retained until implantation
Blastocyst
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Inner cell mass
Trophoblast
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Invasive nature
Zona pellucida disappears
Implantation
Trilaminar Embryo
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Epiblast and Hypoblast
Hypoblast ≠ entoderm!
Primitive streak
Cell migration
Mesoderm and entoderm
Y
H
E
H
Notochord & Neural Tube
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Notochord
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Axis
Induction…
Neural plate
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Neural groove
Neural tube and crest
Divisions of Mesoderm
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Paraxial
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Intermediate
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Lateral plate
Segmentation
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Paraxial mesoderm
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“Somites”
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Each somite 
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Sclerotome
Dermomyotome
Fate of Germ Layers
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Ectoderm
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Epidermis (not skin!) ++
Mesoderm
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Muscle, Connective (including skeletal) tissues
Some epithelial structures
Parts of urogenital systems
 Endothelium of heart and blood vessels
 “Serous membranes”
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Endoderm
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Lining epithelium of digestive system
Head, Tail and Lateral Folds
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Flat three-layered embryo 
… three dimensional tube
Endoderm encloses a cavity 
…digestive system
Changes in the relative positions of certain regions
Further correlation with the development of the heart
and digestive system
The Developing Human – Three
Phases
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Early development
Embryonic phase – organogenesis
The foetal period
Differentiation, Histogenesis and Functional
development
Last Slide