Comparative anatomy of child

Question 1

What is the relationship between the cranial vault and facial skeleton in the newborn?

Answer 1

Cranial vault is disproportionately large in comparison to face

Question 2

In the newborn vs adult what is the relationship between the vertical height of orbit vs maxilla + mandible

Answer 2

Equal as newborn. 1/3 height as adult

Question 3

What bones border the anterior fontanelle?
What does it overly?
And when is it no longer palpable

Answer 3

2 parietal bones behind
2 halves of frontal bone.
Superior sagittal dural venous sinus
18 months

Question 4

What bones border the posterior fontanelle?

when does it close?

Answer 4

Occipital bone + posterior edge of two parietal bones.

6 months

Question 5

What separates the frontal bones? when does this structure disappear?

Answer 5

median metopic suture.

At 7 years

Question 6

What structure of the neonate is at full adult size?

Answer 6

Petromastoid part of temporal bone
innner ear
middle ear
mastoid antrum

Question 7

What happens to the mastoid process in the newborn?

Answer 7

Absent at birth

Grows with development of SCM

Question 8

Where are developing teeth located

Answer 8

Maxilla

Question 9

How is the mandible shaped at birth? how does it change?

Answer 9

2 halves

Cartilaginous anterior ends are separated by fibrous tissue in first year

Question 10

What is the neck like in a newborn?

Answer 10

Very short

Elongation of neck results in positional changes of covering skin

Question 11

In newborn, what is relationship between the left brachiocephalic vein and trachea?

Answer 11

Crosses very high (above jugular notch)

especially if head extended

Question 12

What does a short neck in newborn mean for relative visceral structures of neck?

Answer 12

Everything higher

• Larynx near base of tongue
• Upper border Epiglottis around C2

Everything smaller

• Larynx + trachea smaller
• Higher risk of obstruction with inflammation

Question 13

Newborn vs adult thorax shape?
Differences in ribs?
difference in thymus
DIfference in diaphragm?

Answer 13

Newborn - barrel shaped
Ribs horizontal thus ribcage is higher
Thymus is larger
Diaphragm higher -> larger abdominal volume

Question 14

Newborn vs adult

• Liver?
• Kidney?
• Adrenal?
• Pelvic cavity?

Answer 14

Liver relative to rest of abdominal structures as an adult, twice as large. Palpable inferior border
Kidneys highly lobulated, little fat
Adrenal enormous - almost size of kidney
Pelvic cavity very small, bladder fundus lies above pubic symphysis even when empty

Question 15

Newborn vs adult

Upper limb growth - where does it occur more?

Answer 15

Shoulder + wrist > elbow

Question 16

Newborn vs adult
Lower limb
- size?
- Position - how long?
- Development?
- Where does growth of lower limb proceed more rapidly?

Answer 16

Poorly developed
Maintains foetal flexion for 6 months
Becomes more robust. Undergoes extension + medial rotation
At knee > hip/ankle

Question 17

Newborn vs adult
Vertebral column
- Shape?
- Spinal cord ends at what level?

Answer 17

C-shaped. Concave ventrally.

L3, does not “rise” to L1/2 until adult years