L21: Childhood Growth Flashcards
What is measuring children important
- measurement allows to provide a sensitive indication of health in child related
- growth rates are well defined in healthy children with adequate nutrition
What do changes in growth rate indicate
A health problem in the child
What are the typical body portions of babies like
Large head
Small mandible
Short neck
Limbs short
How can we measure
Arm span
Sitting height
Name the conditions that involve alterations to the normal body proportions
Short trunk dysplasia Short limb dysplasia Rhizomelic dysplasia Mesomelic dysplasia Acromelic dysplasia Asymmetry
What is short trunk dysplasia
When the trunk does not grow much
What is short limb dysplasia
When the both limbs do not grow much
What is rhizomelic dysplasia
Arms and thighs do not grow well
What is mesomelic dysplasia
Forearm and leg do not grow well
What is acromelic
Hands and feet do not grow well
What is asymmetry
Differences in one side/half of the body
What chart do we use to compare the growth of a patient against white children
Growth charts
What is the normal range of height between
3rd and 97th percentile
What are the components of the infancy, childhood and puberty model
Infancy component
Childhood component
Puberty component
What is the infancy component
This is driven by nutrition where there is a rapid decelerating growth in the first years
What is the childhood component
Growth and thyroid hormone are important
What is the puberty component
Pubertal hormone i.e oestrogen and testosterone are important which causes a growth spurt
When does the growth spurt stop
When the fusion of epihyseal stop
What hormone causes epihyseal fusion
Oestrogen
How is oestrogen produced in males
Testosterone is converted to oestrogen by aromatase in adipose tissue
Which gender is taller than the other
Males
What is the first sign of puberty in females
Breast development
What is the first sign of puberty in males
Increased in testicular volume
What are the determinants of growth
Parental phenotype and genotype Quality and duration of pregnancy Nutrition Specific system and organ integrity Psycho-social environment Growth promoting hormones
How can we estimate the growth of a male using the heights from parents
(Mothers height + fathers height + 12.5) / 2
How are females height calculated using the heights from parents
(Mothers height + father’s height - 12.5)/ 2
Where does growth occurs
At growth plates where chondrogenesis happens
What factors affect the growth plate
Calcium
Phosphate
Nutrition
Which factors can inhibit growth at the growth plate
Inflammatory cytokines
Acidosis
Toxins
What are the ways in which we can classify growth retardation
1) primary growth plate abnormality
2) secondary growth disorders
3) idiopathic short stature
What are categories of primary growth plate abnormalities that can occur
Osteochondrodyplasias (skeletal dysplasia)
chromosomal abnormalities
What are osteochondrodysplasia
Genetic abnormalities of cartilage and bone growth that lead to abnormal size of the skeleton and disproportion of the long bones, spines, head.
What are the chromosomal abnormalities that can occur
Turners syndrome (45,X)
What doe secondary growth disorders include
Malnutrition
Chronic disease
Intra uterine growth retardation
Endocrine disorders
Give an example of a endocrine disorder that can cause growth retardation
GH and IGF-1 deficiency
Describe the the growth hormone regulation axis
1) hypothalamus secreted GHRH to the anterior pituitary gland
2) anterior pituitary gland releases GH to the liver or GH stimulates directly the bone
3) liver produced IGF-1 that acts on the bone for growth
4) IGF-1 and GH inhibit the anterior pituitary and hypothalamus later on
What are the causes of IGF deficiency
- GH deficiency due to hypothalamic dysfunction or pituitary GH deficiency
- GH insensitivity: signalling cascade is disrupted or primary defects of IGF1 synthesis
- IGF1 resistance- due to defects of IGF-1 receptors or post receptor defect
How is IGF1 transported in the serum
Via:
ALS
IGF-BP3
What are the 3 causes of idiopathic short stature
1) familial short stature
2) constitutional delay of growth and puberty with normal height prediction
3) overlap of familial and constitutional delay
How can we asses patients with GH deficiency
Take an x-ray of their left hand and look for a delayed bone age
What is psychosocial short startup
It is the emotional rejection inside a family so when the child is removed from the stressful environment they can grow
