PAEDS 108& 121 Growth

Question 1

Where do long bones grow from?

Answer 1

Epiphyseal plates

Question 2

What hormone stimulates increased apoptosis of chondrocytes?

Answer 2

Oestrogen

Question 3

What are the 4 drivers for normal growth?

Answer 3

Hormones, Nutrition, Genes and Environment

Question 4

What hormone released from the hypothalamus to act on pituitary in normal growth?

Answer 4

GnRH

Question 5

What hormones are important in growth?

Answer 5

Growth hormone, thyroid hormone, LH & FSH therefore oestrogen and other androgens

Question 6

What is the action of GH?

Answer 6

Inhibits carbohydrate and fat formation so utilisation of glucose and fat for energy
Promotes protein synthesis and chondrocyte prolferation.
Antagonises insulin, synergises with cortisol and increases IGF1 production from liver

Question 7

What is the action of Thyroid Hormone?

Answer 7

Needed for production and action of GH in long bone growth
Increases Basal Metabolic Rate (BMR)
Makes body more sensitive to catecholamines

Question 8

What are the 4 phases of growth?

Answer 8

Foetal, Infantile, Childhood and Pubertal

Question 9

What are the most important drivers in each phase of Growth?

Answer 9

Foetal and infantile : nutrition - maternal wellbeing
Childhood: Hormones but only if nutrition and happiness present
Pubertal: GH and sex hormones

Question 10

What is gonadarche?

Answer 10

Onset of puberty by increased GnRH secretion during sleep - start to develop secondary sexual characteristics

Question 11

What is adenarche?

Answer 11

increased androgen production from adrenal gland - start to develop axillary and pubic hair

Question 12

Describe a child with Marasmus?

Answer 12

Thin, flaccid skin due to reduced fat and muscle, alert and irritable but is the main childhood form of starvation/malnutrition

Question 13

Describe kwashiorkor

Answer 13

Occurs often when a child is displaced from breast feeding or trigger by an infection. Child has oedema, flaky, painful dermatitis, dry thin pigmented hair, apathy, misery and lethargy

Question 14

How many calories, roughly do infants need a day?

Answer 14

100-120kcal/kg/day

Question 15

What percentage or amount should underweight infants be fed to help them gain weight?

Answer 15

110-120% for actual weight or 130-140kcal/kg/day

Question 16

What is colostrum?

Answer 16

Mothers breast milk initially days 0-3, high protein, little fats and has anti-infective agents and growth factors

Question 17

What are the components of mature breast milk?

Answer 17

40% casein, 60% whey

There is generally more fat and lactose is the main CHO

Question 18

What is weaning?

Answer 18

The transition from exclusively milk based diet to solid foods

Question 19

Name the 5 “headings” for causes of faltering growth

Answer 19

Inadequate caloric intake
Inadequate absorption
Excessive caloric utilisation
Other medical causes
Psychosocial factors

Question 20

How would you evaluate faltering growth (4 sections)

Answer 20

Assess growth - Weight, height, head circumference
Assess nutritional status
Look for underlying disease
Look for neglect and abuse

Question 21

What do the first few breaths in life do in the lungs?

Answer 21

Push fluid from airway and alveoli and establish resting lung volume

Question 22

What two structures in the foetus allow blood to bypass the lungs?

Answer 22

Ductus arteriosus

Foramen ovale

Question 23

Where does the ductus arteriosus lie?

Answer 23

Between the pulmonary artery and aorta

Question 24

Why does blood preferentially enter the ductus arteriosus than the pulmonary arteries?

Answer 24

Due to the pulmonary arteries high vascular resistance

Question 25

Why after birth does blood flow into the pulmonary vascular system instead of the DA?

Answer 25

As the pulmonary capilliaries absorb oxygen after first few breaths the arterioles dilate and vascular resistance dramatically drops

Question 26

What causes the ductus arteriosus to close?

Answer 26

In response to oxygenated blood the smooth muscle surrounding it contracts

Question 27

What causes the foramen ovale to close?

Answer 27

Increased blood from from lungs increases the pressure in the left atrium, diminished blood from from placenta decreases pressure in the right atrium
causes septum primum to press against septum secundum

Question 28

What is brown fat for in babies?

Answer 28

for heat production - non shivering thermogenesis

Question 29

Why do babies develop anaemia within the first 5-8 weeks of life?

Answer 29

Oxygenation from lung instead of placenta increases SATS = negative feedback on EPO production –> drops to uindetectable levels

Question 30

Why do some babies develop jaundice in the first week?

Answer 30

High RBC load with shorter life span