Embryology - Upper Body

Question 1

When does the limb bud appear?

Answer 1

26 days intrauterine

Question 2

When does the hand plate appear?

Answer 2

4-5 weeks

Question 3

When do fingers appear?

Answer 3

47 days

Question 4

Humerus: Primary centre of ossification?

Answer 4

Shaft

Question 5

Humerus: Secondary centres of ossification?

Answer 5

Proximal:
head, greater tubercle and lesser tubercle (6-20yrs)
Distal:
trochlea, capitulum, medial and lateral epicondyles (2-18yrs)

Question 6

What is the hand order of ossification?

Answer 6

Distal phalanges, metacarpals, proximal phalanges, middle phalanges (5 months prenatal), carpals (3 months-6yrs postnatal), bases and then heads of metacarpals by about 14-15 yrs.

Question 7

When does the clavicle appear?

Answer 7

5th-10th prenatal week

Question 8

Clavicle: primary ossification centre

Answer 8

7th-11th prenatal week

Question 9

Clavicle: secondary ossification centres

Answer 9

medial end 16-21 yrs

lateral end 19-20yrs

Question 10

Scapula: primary ossification centre

Answer 10

Surgical neck 7-8 weeks prenatal
Corocoid process appears within the first year
These two parts fuse 14-15yrs