To get from the embryological to the anatomical position, each limb rotates differently. This has effects on the position of the radius and its equivalent bone in the lower limb.  

Which bone in the lower limb is equivalent (developmentally homologous) to the radius of the upper limb? Explain your answer using drawing/s.

Note: This concept will be demonstrated in Weeks 3 and 4 labs using the pink baby model shown below. Please refer to the model during lab sessions to help you understand the changes in bone positions after limb rotation.

Total 18 marks 

DETAILS OF TASK:

Students are required to draw and explain the positions of the upper and lower limbs before and after limb bud rotation. The focus is on understanding and depicting how these limbs appear in the embryological position and how they transition to their orientation in the anatomical position after limb bud rotation. So the drawing(s) must include the relevant orientation of the upper and lower limbs. 

This question asks students to conceptualise the embryological position and consider the location/position of upper and lower limb bones relative to one another. An understanding of positional terms (in the embryo and adult), and bones of the limbs is required

Drawing(s) must include the following: 

1. relevant orientation of upper limbs (2 marks) and lower limbs (2 marks), BEFORE limb bud rotation 

2. relevant orientation of upper limbs (2 marks) and lower limbs (2 marks) AFTER limb bud rotation

3. correct positioning of specific bones within the limb (label all* bones of the upper and lower limb) (4 marks) - *individual carpal/tarsal names not necessary - just label as "carpals' and "tarsals" . Similarly, indicate the "group" of proximal phalanges, middle phalanges and distal phalanges as well as the "group" of metatarsals/metacarpals.

4. label the location of digit 1* in the upper AND the lower limb (4 marks)  *before and after limb bud rotation

5. the bone in lower limb that is developmentally homologous to radius should be inferred from the drawings and highlighted as correct answer (i.e answering the q ) (2 marks)

Key words: cranial (superior)/caudal (inferior) and lateral/medial

OTHER REQUIREMENTS:

• Labels required (no paragraphs - short descriptions only if necessary)
• Hand-drawn or digitally marked up  - both OK
• No more than one-page (additional pages will not be reviewed)
• Simple hand-drawn diagrams encouraged, however non-copyright images can be used eg Biorender etc. 
• Referencing not required 
• Submit on on-page and convert to PDF