PAEDS 108& 121 Growth Flashcards
Where do long bones grow from?
Epiphyseal plates
What hormone stimulates increased apoptosis of chondrocytes?
Oestrogen
What are the 4 drivers for normal growth?
Hormones, Nutrition, Genes and Environment
What hormone released from the hypothalamus to act on pituitary in normal growth?
GnRH
What hormones are important in growth?
Growth hormone, thyroid hormone, LH & FSH therefore oestrogen and other androgens
What is the action of GH?
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
What is the action of Thyroid Hormone?
Needed for production and action of GH in long bone growth
Increases Basal Metabolic Rate (BMR)
Makes body more sensitive to catecholamines
What are the 4 phases of growth?
Foetal, Infantile, Childhood and Pubertal
What are the most important drivers in each phase of Growth?
Foetal and infantile : nutrition - maternal wellbeing
Childhood: Hormones but only if nutrition and happiness present
Pubertal: GH and sex hormones
What is gonadarche?
Onset of puberty by increased GnRH secretion during sleep - start to develop secondary sexual characteristics
What is adenarche?
increased androgen production from adrenal gland - start to develop axillary and pubic hair
Describe a child with Marasmus?
Thin, flaccid skin due to reduced fat and muscle, alert and irritable but is the main childhood form of starvation/malnutrition
Describe kwashiorkor
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
How many calories, roughly do infants need a day?
100-120kcal/kg/day
What percentage or amount should underweight infants be fed to help them gain weight?
110-120% for actual weight or 130-140kcal/kg/day
What is colostrum?
Mothers breast milk initially days 0-3, high protein, little fats and has anti-infective agents and growth factors
What are the components of mature breast milk?
40% casein, 60% whey
There is generally more fat and lactose is the main CHO
What is weaning?
The transition from exclusively milk based diet to solid foods
Name the 5 “headings” for causes of faltering growth
Inadequate caloric intake Inadequate absorption Excessive caloric utilisation Other medical causes Psychosocial factors
How would you evaluate faltering growth (4 sections)
Assess growth - Weight, height, head circumference
Assess nutritional status
Look for underlying disease
Look for neglect and abuse
What do the first few breaths in life do in the lungs?
Push fluid from airway and alveoli and establish resting lung volume
What two structures in the foetus allow blood to bypass the lungs?
Ductus arteriosus
Foramen ovale
Where does the ductus arteriosus lie?
Between the pulmonary artery and aorta
Why does blood preferentially enter the ductus arteriosus than the pulmonary arteries?
Due to the pulmonary arteries high vascular resistance
Why after birth does blood flow into the pulmonary vascular system instead of the DA?
As the pulmonary capilliaries absorb oxygen after first few breaths the arterioles dilate and vascular resistance dramatically drops
What causes the ductus arteriosus to close?
In response to oxygenated blood the smooth muscle surrounding it contracts
What causes the foramen ovale to close?
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
What is brown fat for in babies?
for heat production - non shivering thermogenesis
Why do babies develop anaemia within the first 5-8 weeks of life?
Oxygenation from lung instead of placenta increases SATS = negative feedback on EPO production –> drops to uindetectable levels
Why do some babies develop jaundice in the first week?
High RBC load with shorter life span
