Objective laws of growth and development
The processes of growth and development of the human body from birth until the attainment of full maturity proceed unevenly and are subject to a number of fundamental biological laws. Knowledge of these patterns is critically important for the correct assessment of the patient's health.
The main laws include:
- Uneven rate. The speed of growth and development processes varies at different stages of maturation.
- Heterochronicity (non-simultaneity). This is a crucial physiological pattern, the essence of which is that individual organs and functional systems of the growing body form and mature at different times.
- Sexual dimorphism. Maturation processes and morphological changes are directly determined by the biological sex of the child.
- Biological reliability. The body and its functional systems possess a genetically determined margin of safety, ensuring adaptation to external conditions.
Final growth indicators are also influenced by genetic predisposition, environmental factors, and acceleration processes.
Social age periodization
Due to the uneven course of physiological processes, hygiene identifies specific age periods. An age period is a segment of time within which the morphofunctional characteristics, developmental processes, and the body's reactions to external stimuli are identical and unambiguous.
The following social periodization is applied in the Russian Federation:
- Toddler period — from birth to 3 years.
- Preschool age — from 3 to 7 (in some cases up to 6) years.
- Early school age — from 7 (6) to 10 years.
- Middle school age — from 11 to 14 years.
- Adolescent period — from 15 to 18 years.
All hygienic, preventive, and educational measures must be differentiated taking into account the child's belonging to a specific period.
Morphofunctional characteristics: musculoskeletal system
Special attention when assessing physical development is required by the state of the musculoskeletal system, the characteristics of which change radically as the child grows.
In early school age, a key feature is the insufficient hardness of bone tissue. This is due to the fact that organic substances predominate in the child's bones, while mineral components (such as calcium, phosphorus, and magnesium) are insufficient to ensure high strength. Because of this, there is a high risk of developing deformities. The hygienic significance of this fact is enormous: continuous monitoring of correct posture during reading and writing is required (both external control by teachers and conscious self-control by the student).
Spine physiology Normally, a healthy spine has physiological curves in the sagittal plane: cervical, thoracic, and lumbar.
- Function: The curves act like a spring, providing shock absorption and protecting internal organs and the nervous system from jolts during walking, running, and jumping.
- Morphometry: The depth of the cervical and lumbar curves in normal development ranges from 3 to 5 cm (depending on the total length of the adolescent's spine).
The role of the physician and sanitary-epidemiological well-being
To ensure a safe environment in children's institutions, doctors must fulfill a number of strict requirements. The medical specialist must be able to fluently operate with medical and demographic data, analyze indicators of physical development and morbidity, and distribute children into appropriate health groups.
In addition, the physician must thoroughly know the methods for studying environmental factors that affect health. The specialist's competence includes monitoring children's nutrition, compliance with the daily routine, organization of the educational and labor processes, and physical education.
It should be remembered that the state strictly controls the sphere of sanitary legislation. Its violation entails disciplinary, administrative, and even criminal liability. At the same time, the state actively supports this sphere financially: for example, through the National Project «Education» adopted in 2005.
Briefly: answers to topical questions
What physiological curves of the spine exist in the sagittal plane and what are their normal morphometric parameters?
In the sagittal plane, there are normally 4 physiological curves of the spine: cervical and lumbar lordosis, thoracic and sacral kyphosis. The depth of the cervical and lumbar curves ranges from 3 to 5 cm (according to other data, 3–4 cm); this indicator varies depending on the total length of the spine. The main function of the curves is shock absorption, providing protection from jolts during movements.
Into which health groups are children distributed based on the results of a comprehensive health assessment?
Based on the results of medical examinations, children are distributed into 5 health groups:
- Group 1 — healthy, normally developing children without functional deviations and chronic diseases.
- Group 2 — healthy children with reduced resistance (risk group), having functional or minor morphological deviations.
- Group 3 — children under dispensary observation (exact characteristic omitted in the text).
- Group 4 — patients with chronic diseases or malformations in a state of subcompensation.
- Group 5 — patients with severe chronic diseases in a state of decompensation.
What methods are used for the practical assessment of the physical development of children and adolescents?
For the practical assessment of physical development, methods of clinical anthropometry, somatoscopy, and sanitary-statistical methods are used.
- Clinical anthropometry — includes measuring basic physical parameters using a stadiometer and medical scales.
- Somatoscopy — visual inspection, including assessment of posture, body types, and constitution.
- Sanitary-statistical methods — used to assess physical development indicators at the population level.
Which indicators belong to the main somatometric signs of physical development?
The main measured physical parameters when assessing development include height and body weight.
- Height (body length) — measured using a stadiometer.
- Body weight — determined using medical floor scales.
Also, chest circumference is additionally measured to assess proportionality and constitutional type.
To memorize the basic laws of growth, use the acronym UHPB: Unevenness, Heterochronicity, Sexual dimorphism, Biological reliability.
Class and exam questions
What is heterochronicity in a child's development?
This is an objective law of physiology, which consists of the non-simultaneous growth and maturation of various organs and functional systems of the growing organism.
Why do younger schoolchildren frequently develop spinal deformities?
At this age, organic substances predominate over minerals (calcium, phosphorus, magnesium) in the bones. Because of this, the bone tissue has insufficient hardness and easily deforms with improper posture.
What normal curves does the spine have and what is their purpose?
In the sagittal plane, the spine has cervical, thoracic, and lumbar curves. They perform a shock-absorbing function, protecting the body from jolts during movement.
How is mental health assessed when evaluating development?
It is characterized by the absence of neuropsychiatric deviations, normal functioning of the central nervous system, and harmonious mental development that fully corresponds to the age period.
What else to study on this topic
- Criteria and algorithm for distributing children into health groups.
- The impact of specific environmental factors on acceleration rates.
- Organization of daily routine and educational process in educational institutions.
- Hygienic requirements for the nutrition of children of various age groups.
- Medical-demographic indicators and morbidity analysis in pediatrics.
Master the entire topic in the "Hygiene" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on «Assessment of the physical development of children and adolescents» and 530 more pages on the subject
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- 95 video lessons for the subject
Other topics in "Chapter 10. Basics of Child and Adolescent Hygiene"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.