Foundations Practical - Week 1 to 8: Difference between revisions

From Embryology
mNo edit summary
Line 63: Line 63:
* '''Stage''' - Carnegie stage, a historic staging system for human embryonic period from fertilization, between week 1 to 8 (GA 3-10) of development.  
* '''Stage''' - Carnegie stage, a historic staging system for human embryonic period from fertilization, between week 1 to 8 (GA 3-10) of development.  
* '''Tissue''' - A group of cells that perform a similar function.
* '''Tissue''' - A group of cells that perform a similar function.
----


{{FoundationLab}}
{{FoundationLab}}

Revision as of 09:30, 21 April 2013

The Embryonic Period

Development of Organs and Tissues

You have now been through the earliest stages of embryonic development. From the original simple trilaminar embryo all the organs and tissues will now begin to develop, details of these processes require more time than we currently have available. What we will now look at are the changes in the external embryo appearance during this period.

Human Carnegie stage 1-23.jpg

Key features to note are:

  • changes in overall size (CRL)
  • surface bulges that reflect organ development
  • development of the upper and lower limbs
  • development of the head

This page is about getting an overview of the external changes that occur during the embryonic period. In order to observe and understand the internal changes occuring in organ development is beyond the scope of this current practical.

Changes in Overall Size

In the first 8 weeks the embryo grows from 0.1 mm to about 3 cm in length.

Actual Size 5cm ruler.jpg

Enlarged Size Stage1 size with ruler.jpg

During this time the embryo size is also measured from "crown" to "rump" or the Crown Rump Length (CRL).

Stage13 crown rump length.jpg

Surface Bulges Reflect Organ Development

Stage13 surface bulges.jpg

Surface of the Stage 13 Embryo showing surface features reflecting surface and internal development. Carnegie stage 13



Links: Embryonic Development | Carnegie stage 13


Placentation

During this period the parts of the conceptus not contributing to the embryo will contribute the fetal component of the placenta and the embryonic/fetal membranes.

Gray0032.gif Placental membranes.jpg


This topic will also be covered in detail in BGD.

Timeline Overview

Human development timeline graph 01.jpg


Human development timeline graph icon.jpg
 ‎‎Human Timeline
Page | Play

Terms

  • CRL - Acronym for Crown Rump Length, a staging measurement of embryo and fetal size.
  • Crown Rump Length - (CRL) A staging measurement of embryo and fetal size. Measures length from the top curvature (crown) to bottom curvature (rump) in mm.
  • Gestational Age - (GA) Clinical age from last menstrual period (LMP) about 2 weeks before fertilization occurs. Gestational Age, not Fertilization Age is generally used clinically.
  • Organ - A collection of tissues joined in a structural unit to serve a common function.
  • Stage - Carnegie stage, a historic staging system for human embryonic period from fertilization, between week 1 to 8 (GA 3-10) of development.
  • Tissue - A group of cells that perform a similar function.



Foundsmall.jpg

Foundations Practical: Introduction | Week 1 and 2 | Week 3 and 4 | Week 1 to 8 | Week 9 to 36 | Neonatal | Critical Periods | Additional Resources | Quiz


Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers


Cite this page: Hill, M.A. (2024, March 28) Embryology Foundations Practical - Week 1 to 8. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Foundations_Practical_-_Week_1_to_8

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G