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Nithin Kumar

1. Human growth and development involves changes in size, shape, and maturity over time. It can be characterized by growth curves that track changes in dimensions like height. 2. The first documented recording of a child's growth was made by Philibert Gueneau de Montbeillard, who measured his son Francois' height every six months from birth to age 18. 3. Growth is defined as an increase in size, while development refers to increases in functional abilities. Growth curves like distance and velocity curves reveal distinct growth phases from infancy to adulthood.

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INTRODUCTION TO HUMAN GROWTH & DEVELOPMENT Dr. Nithin Kumar
INTRODUCTION Human growth and development are characterized and defined by the way in which we change in size, shape, and maturity relative to the passage of time. It has been more common for the size of children to be assessed for reasons of classification and organization that requires assessment at certain ages for specific reasons. However, the first longitudinal record we have of the growth of a child was the result of a desire to apply scientific method to the natural world. Patterns of Human Growth 2
GROWTH DEFINITION It is the process of physical maturation resulting an increase in size of the body and various organs. It occurs by multiplication of cells and an increase in in intracellular substance. It is quantitative changes of the body. 3
DEVELOPMENT DEFINITION It is the process of functional and physiological maturation of the individual. It is progressive increase in skill and capacity to function. It is related to maturation and myelination of the nervous system. It includes psychological, emotional and social changes. It is qualitative aspects. 4
HISTORICAL BACKGROUND 5 How it all 恢艶乙温稼
AGE OF ENLIGHTENMENT in 18th century France, Between the death of Louis XIV & emergence of Napoleon Bonaparte (1715- 1799) a movement away from religious and monarchical authority and toward a more liberal and empirical attitude. natural scientists and philosophers believed that peoples habits of thought were based on irrationality, polluted by religious dogma, superstition, and over- adherence to historical precedent and irrelevant tradition. The way to escape from this is to seek for true knowledge in every sphere of life, to establish the truth and build on it, thereby literally enlightening Peoples minds 6
GEORGES-LOUIS LECLERC(COMPTE DE BUFFON (1707 88) interested in mathematics, natural science, and silviculture, the cultivation of trees. premier horticulturist and arborist in France and was appointed by King Louize XVth as the director of the Jardin du Roi king invited him to write a compendium on the herbs of France But Buffon decided such a compendium would be too narrow and instead started working on a broader project that was to include all that was known of natural history. - Histoire Naturelle, Ge卒ne卒rale et Particulie`re Ending up with 36 volumes by the time of his death in 1788 This included 15 volumes on quadrupeds, 9 on birds, 5 on minerals and 7 Supplementary Volumes. 7
BERNARD GERMAIN DE LAPEAUDE appointed as a sub-demonstrator in the Jardin in 1785 further added 8 volumes to Histoire Naturelle, Ge卒ne卒rale et Particulie`re These 8 volumes included 2 on reptiles, 5 on fish, and 1 on Cetacea. However, it is the supplement to volume 14, published in 1778, that is particularly interesting to us. As it contained record of the growth of a boy, Francois Gueneau De Montbeillard (1759-1847). 8
PHILIBERT GUENEAU DE MONTBEILLARD (1720 85) He would take an empirical interest in the growth of his own son had been measuring the height of Francois about every 6 months from his birth until he was 18 years of age. Was a close friend of Buffon and their common interest in the natural sciences resulted in De Montbeillard being invited as a co-author Buffon wished to include this primary evidence of the course of human growth 9
RICHARD E. SCAMMON (1883 1952) Translated the measurements of De Montbeillard into SI units. He published his results in 1930 in the American Journal of Physical Anthropology under the title of The first seriatim study of human growth Thus, for the first-time people in the English-speaking world were able to look upon the pattern of growth exhibited by Francois Gueneau De Montbeillard in the form of a chart. 10
THE DISTANCE CURVE OF GROWTH Scammon produced the height-for-age curve known as a height distance curve Growth is not a linear process term distance to describe height achieved it is easy to visualize and understand the fact that a childs height at any age is a reflection of how far that child has progressed toward adulthood. 11
THE DISTANCE CURVE OF GROWTH 1. growth is a continuous process. 2. growth is not a linear process i. e., we do not gain the same amount of height during each calendar year. 3. this growth curve has five distinct phases corresponding to relatively rapid growth in infancy steady growth in childhood a short period of rapid growth during the juvenile period a second period of rapid growth during adolescence very slow growth as the individual nears adulthood. 4. growth represents a most dramatic increase in size. Eg: Francois De Montbeillard grew from about 50 cm at birth to over 186 cm at adulthood. 5. we stop growing and reach our adult height, during our late teenage years. Observation from distance curve of growth 12
THE DISTANCE CURVE OF GROWTH The fact that this growth curve shows constant pattern eg: polynominal, sigmoidal, allows us to apply mathematical models to the pattern of growth. These models are, in fact, parametric functions that contain constants or parameters. Once we have found an appropriate function that fits the raw data, we can analyze the parameters and by so doing learn a good deal about the biological process responsible for growth. Consequently, they can be used in research into human growth. 13
VELOCITY GROWTH CURVE & GROWTH SPURTS
The rate of change of size with time is called growth velocity DArcy Thompson a famous British natural scientist & mathematical biologist published a book titled On Growth and Form in 1917 He wrote, An organism is so complex a thing, and growth so complex a phenomenon, that for growth to be so uniform and constant in all the parts as to keep the whole shape unchanged would indeed be an unlikely and an unusual circumstance. Rates vary, proportions change, and the whole configuration alters accordingly. While the distance curve, showed a continuous succession of varying magnitudes, the curve of the rate of change of height with time, shows a succession of varying velocities. 15
16
Distinct increase in growth rate or growth velocity is termed growth spurt Following birth, two relatively distinct increases in growth rate occur at 6-8 years juvenile or mid-growth spurt at 11-18 years adolescent growth spurt 17
Another growth spurt occurs prior to birth between 20 and 30 weeks of gestation There is increase in height as well as weight Observed through intra-uterine ultrasound measurements of fetuses and extra- uterine anthropometric measurements of pre-term infants Corresponds to rapid accumulation of fat during this period. Why?? Fat is a more efficient source of energy than protein or carbohydrate This significant source of energy is required by the infant during immediate post-natal period 18
Pre-natal spurt and juvenile growth spurt may vary in magnitude, but they seem to occur at similar ages both within and between the sexes. Adolescent growth spurt demonstrates sexual dimorphism in both magnitude and timing Males enter their adolescent growth spurt almost two years later than females Changes includes extra height, muscle mass and fat distribution Males demonstrate rapid increases in muscle mass and females accumulate greater amounts of fat. 19
OTHER PATTERNS OF GROWTH
OTHER PATTERNS OF GROWTH Pattern of growth in height is only one of several patterns of growth that are found within the body Neural tissue (brain and head), lymphoid tissue (thymus, lymph nodes, intestinal lymph masses), reproductive tissue (testes, ovaries, epididymis, prostate, seminal vesicles, Fallopian tubes) as well as some major organ systems (respiratory, digestive, urinary). Research on the growth of neural tissue must be targeted at fetal and infant ages Research on the growth of reproductive tissue on adolescent or teenage years when growth is at a maximum. 21
GROWTH VS MATURITY
Growth is defined as an increase in size while maturity or development is an increase in functional ability. All children who live in normal environmental circumstances will have a similar pattern of growth. Getting taller, heavier, fatter, and more muscular as well as changes in our body proportions till we reach adulthood. We become more mature, when we experience an increase in our functional capacity with advancing age with increasing ability to undertake physical exercise in terms of both magnitude and duration 23
The figure shows three boys and three girls who are of the same ages within sex. Even though they are the same age they demonstrate vastly different degrees of maturity. The boy and girl on the left are relatively immature compared to those on the right as depicted by their indicators of maturity or maturity indicators There is obvious development of secondary sexual characteristics (breast and pubic hair in girls and genitalia and pubic hair in boys), in addition to dramatic changes in body shape, increases in muscularity in males and increases in body fat in females 24
The end-point of growth is the size we attain by adulthood The end-point of maturity is when we are functionally able to successfully procreate. Not simply to be able to produce a viable sperm or egg, but to produce an offspring who themselves may also procreate Thus, successful maturation requires not just biological maturity but also psycho-social and behavioral maturity. 25
Because size is governed by factors other than the process of maturation, we cannot use an absolute size to determine maturation. Use the appearance and relative size of structures rather than their absolute size to reflect maturity. Also, use of various maturity indicators are secondary sexual development, skeletal maturity, and dental maturity 26
CONTROL OF GROWTH
Growth and development is both complex and extensive. Genetic, epigenetic, and environmental factors has an influence Environment has the potential to alter genetic blueprint we are born with affecting our ability to achieving a particular adult size and shape. This environmental factor will affect primarily the endocrine system 28
The anterior lobe or adenohypophysis of pituitary gland releases the major hormones controlling human growth and development; growth hormone, thyroid stimulating hormone, prolactin, the gonadotrophins (luteinizing and follicle stimulating hormone), and adrenocorticotropic hormone Normal growth is a result of a complex and at times exquisite relationship between the nervous and endocrine systems. Growth hormone release of insulin-like growth factor 1 (IGF-1) from the liver. 29
IGF-1 directly affects skeletal muscle fibers and cartilage cells in the long bones to increase the rate of uptake of amino acids and incorporate them into new proteins and thus contributes to growth in length during infancy and childhood. At adolescence, the gonadal hormones or sex steroids (testosterone in boys, and estrogen in girls) affects the growth spurt Hence, diagnosis of growth disorders becomes a complex and engrossing series of investigations that increasingly requires an appreciation of both genetic, environmental and endocrine mechanisms. 30
GROWTH REFERENCE CHARTS
In order to assess the normality or otherwise of the growth of children we use growth reference charts. These charts depict both the average height to be expected throughout the growing years (typically from birth to 18 years), and the range of normal heights, in the form of percentile or centile distributions 32
CANALIZATION
Growth of children without any environmental constrain exhibits a pattern more or less parallel to a particular centile or within some imaginary canal. This phenomenon is termed canalization or homeorrhesis. This pattern is genetically determined This genetic potential for adult stature and the process of growth, in an unconstrained environment, takes us inevitably toward that target. 34
CATCH-UP GROWTH
36
Waddington equates growth to the movement of a ball rolling down a valley floor. The sides of the valley keep the ball rolling steadily down the central course (point A). If an insult occurs, it tends to push the ball out of its groove or canal and force it up the side of the valley (point B) The magnitude of the loss of velocity will depend on the severity and duration of the insult. Alleviation of the insult will result in a rapid return to the valley floor at an increased velocity (point C) Having reached the floor normal growth velocity is resumed (point D) 37
38 Growth chart of a girl who has suffered from celiac syndrome. Condition there is an abnormality of the lining of the gut and food cannot be absorbed Malnourished growth retardation On diagnosis the child is switched to a gluten-free diet which alleviates the malabsorption. Rapid recovery of height velocity She demonstrates complete catch-up growth within 1-2 years.
SUMMARY & CONCLUSION
Introduction to the study of human growth and development. Curve of human growth has been changing as we evolve There is less of environmental constrains on us now, but it is still there Infancy and adolescence are the two major stages where adjustment to final size and shape is still occurring More than 50% of infants exhibit either catch-up or catch-down growth, which has direct bearing on the final size, shape, morbidity, and perhaps mortality Timing of the adolescent growth spurt is also important in terms of healthy and successful survival. 40
We are the survivors and use various survival strategies to survive and propagate our species. One of the most powerful of these strategies is the plasticity of our growth and development. In subsequent chapters you will learn how that plasticity is inherited, controlled, and expressed It is a fascinating story about the most fundamental biological phenomena of our species. 41
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intro to human growth and development.pptx

  • 2. INTRODUCTION Human growth and development are characterized and defined by the way in which we change in size, shape, and maturity relative to the passage of time. It has been more common for the size of children to be assessed for reasons of classification and organization that requires assessment at certain ages for specific reasons. However, the first longitudinal record we have of the growth of a child was the result of a desire to apply scientific method to the natural world. Patterns of Human Growth 2
  • 3. GROWTH DEFINITION It is the process of physical maturation resulting an increase in size of the body and various organs. It occurs by multiplication of cells and an increase in in intracellular substance. It is quantitative changes of the body. 3
  • 4. DEVELOPMENT DEFINITION It is the process of functional and physiological maturation of the individual. It is progressive increase in skill and capacity to function. It is related to maturation and myelination of the nervous system. It includes psychological, emotional and social changes. It is qualitative aspects. 4
  • 6. AGE OF ENLIGHTENMENT in 18th century France, Between the death of Louis XIV & emergence of Napoleon Bonaparte (1715- 1799) a movement away from religious and monarchical authority and toward a more liberal and empirical attitude. natural scientists and philosophers believed that peoples habits of thought were based on irrationality, polluted by religious dogma, superstition, and over- adherence to historical precedent and irrelevant tradition. The way to escape from this is to seek for true knowledge in every sphere of life, to establish the truth and build on it, thereby literally enlightening Peoples minds 6
  • 7. GEORGES-LOUIS LECLERC(COMPTE DE BUFFON (1707 88) interested in mathematics, natural science, and silviculture, the cultivation of trees. premier horticulturist and arborist in France and was appointed by King Louize XVth as the director of the Jardin du Roi king invited him to write a compendium on the herbs of France But Buffon decided such a compendium would be too narrow and instead started working on a broader project that was to include all that was known of natural history. - Histoire Naturelle, Ge卒ne卒rale et Particulie`re Ending up with 36 volumes by the time of his death in 1788 This included 15 volumes on quadrupeds, 9 on birds, 5 on minerals and 7 Supplementary Volumes. 7
  • 8. BERNARD GERMAIN DE LAPEAUDE appointed as a sub-demonstrator in the Jardin in 1785 further added 8 volumes to Histoire Naturelle, Ge卒ne卒rale et Particulie`re These 8 volumes included 2 on reptiles, 5 on fish, and 1 on Cetacea. However, it is the supplement to volume 14, published in 1778, that is particularly interesting to us. As it contained record of the growth of a boy, Francois Gueneau De Montbeillard (1759-1847). 8
  • 9. PHILIBERT GUENEAU DE MONTBEILLARD (1720 85) He would take an empirical interest in the growth of his own son had been measuring the height of Francois about every 6 months from his birth until he was 18 years of age. Was a close friend of Buffon and their common interest in the natural sciences resulted in De Montbeillard being invited as a co-author Buffon wished to include this primary evidence of the course of human growth 9
  • 10. RICHARD E. SCAMMON (1883 1952) Translated the measurements of De Montbeillard into SI units. He published his results in 1930 in the American Journal of Physical Anthropology under the title of The first seriatim study of human growth Thus, for the first-time people in the English-speaking world were able to look upon the pattern of growth exhibited by Francois Gueneau De Montbeillard in the form of a chart. 10
  • 11. THE DISTANCE CURVE OF GROWTH Scammon produced the height-for-age curve known as a height distance curve Growth is not a linear process term distance to describe height achieved it is easy to visualize and understand the fact that a childs height at any age is a reflection of how far that child has progressed toward adulthood. 11
  • 12. THE DISTANCE CURVE OF GROWTH 1. growth is a continuous process. 2. growth is not a linear process i. e., we do not gain the same amount of height during each calendar year. 3. this growth curve has five distinct phases corresponding to relatively rapid growth in infancy steady growth in childhood a short period of rapid growth during the juvenile period a second period of rapid growth during adolescence very slow growth as the individual nears adulthood. 4. growth represents a most dramatic increase in size. Eg: Francois De Montbeillard grew from about 50 cm at birth to over 186 cm at adulthood. 5. we stop growing and reach our adult height, during our late teenage years. Observation from distance curve of growth 12
  • 13. THE DISTANCE CURVE OF GROWTH The fact that this growth curve shows constant pattern eg: polynominal, sigmoidal, allows us to apply mathematical models to the pattern of growth. These models are, in fact, parametric functions that contain constants or parameters. Once we have found an appropriate function that fits the raw data, we can analyze the parameters and by so doing learn a good deal about the biological process responsible for growth. Consequently, they can be used in research into human growth. 13
  • 14. VELOCITY GROWTH CURVE & GROWTH SPURTS
  • 15. The rate of change of size with time is called growth velocity DArcy Thompson a famous British natural scientist & mathematical biologist published a book titled On Growth and Form in 1917 He wrote, An organism is so complex a thing, and growth so complex a phenomenon, that for growth to be so uniform and constant in all the parts as to keep the whole shape unchanged would indeed be an unlikely and an unusual circumstance. Rates vary, proportions change, and the whole configuration alters accordingly. While the distance curve, showed a continuous succession of varying magnitudes, the curve of the rate of change of height with time, shows a succession of varying velocities. 15
  • 16. 16
  • 17. Distinct increase in growth rate or growth velocity is termed growth spurt Following birth, two relatively distinct increases in growth rate occur at 6-8 years juvenile or mid-growth spurt at 11-18 years adolescent growth spurt 17
  • 18. Another growth spurt occurs prior to birth between 20 and 30 weeks of gestation There is increase in height as well as weight Observed through intra-uterine ultrasound measurements of fetuses and extra- uterine anthropometric measurements of pre-term infants Corresponds to rapid accumulation of fat during this period. Why?? Fat is a more efficient source of energy than protein or carbohydrate This significant source of energy is required by the infant during immediate post-natal period 18
  • 19. Pre-natal spurt and juvenile growth spurt may vary in magnitude, but they seem to occur at similar ages both within and between the sexes. Adolescent growth spurt demonstrates sexual dimorphism in both magnitude and timing Males enter their adolescent growth spurt almost two years later than females Changes includes extra height, muscle mass and fat distribution Males demonstrate rapid increases in muscle mass and females accumulate greater amounts of fat. 19
  • 21. OTHER PATTERNS OF GROWTH Pattern of growth in height is only one of several patterns of growth that are found within the body Neural tissue (brain and head), lymphoid tissue (thymus, lymph nodes, intestinal lymph masses), reproductive tissue (testes, ovaries, epididymis, prostate, seminal vesicles, Fallopian tubes) as well as some major organ systems (respiratory, digestive, urinary). Research on the growth of neural tissue must be targeted at fetal and infant ages Research on the growth of reproductive tissue on adolescent or teenage years when growth is at a maximum. 21
  • 23. Growth is defined as an increase in size while maturity or development is an increase in functional ability. All children who live in normal environmental circumstances will have a similar pattern of growth. Getting taller, heavier, fatter, and more muscular as well as changes in our body proportions till we reach adulthood. We become more mature, when we experience an increase in our functional capacity with advancing age with increasing ability to undertake physical exercise in terms of both magnitude and duration 23
  • 24. The figure shows three boys and three girls who are of the same ages within sex. Even though they are the same age they demonstrate vastly different degrees of maturity. The boy and girl on the left are relatively immature compared to those on the right as depicted by their indicators of maturity or maturity indicators There is obvious development of secondary sexual characteristics (breast and pubic hair in girls and genitalia and pubic hair in boys), in addition to dramatic changes in body shape, increases in muscularity in males and increases in body fat in females 24
  • 25. The end-point of growth is the size we attain by adulthood The end-point of maturity is when we are functionally able to successfully procreate. Not simply to be able to produce a viable sperm or egg, but to produce an offspring who themselves may also procreate Thus, successful maturation requires not just biological maturity but also psycho-social and behavioral maturity. 25
  • 26. Because size is governed by factors other than the process of maturation, we cannot use an absolute size to determine maturation. Use the appearance and relative size of structures rather than their absolute size to reflect maturity. Also, use of various maturity indicators are secondary sexual development, skeletal maturity, and dental maturity 26
  • 28. Growth and development is both complex and extensive. Genetic, epigenetic, and environmental factors has an influence Environment has the potential to alter genetic blueprint we are born with affecting our ability to achieving a particular adult size and shape. This environmental factor will affect primarily the endocrine system 28
  • 29. The anterior lobe or adenohypophysis of pituitary gland releases the major hormones controlling human growth and development; growth hormone, thyroid stimulating hormone, prolactin, the gonadotrophins (luteinizing and follicle stimulating hormone), and adrenocorticotropic hormone Normal growth is a result of a complex and at times exquisite relationship between the nervous and endocrine systems. Growth hormone release of insulin-like growth factor 1 (IGF-1) from the liver. 29
  • 30. IGF-1 directly affects skeletal muscle fibers and cartilage cells in the long bones to increase the rate of uptake of amino acids and incorporate them into new proteins and thus contributes to growth in length during infancy and childhood. At adolescence, the gonadal hormones or sex steroids (testosterone in boys, and estrogen in girls) affects the growth spurt Hence, diagnosis of growth disorders becomes a complex and engrossing series of investigations that increasingly requires an appreciation of both genetic, environmental and endocrine mechanisms. 30
  • 32. In order to assess the normality or otherwise of the growth of children we use growth reference charts. These charts depict both the average height to be expected throughout the growing years (typically from birth to 18 years), and the range of normal heights, in the form of percentile or centile distributions 32
  • 34. Growth of children without any environmental constrain exhibits a pattern more or less parallel to a particular centile or within some imaginary canal. This phenomenon is termed canalization or homeorrhesis. This pattern is genetically determined This genetic potential for adult stature and the process of growth, in an unconstrained environment, takes us inevitably toward that target. 34
  • 36. 36
  • 37. Waddington equates growth to the movement of a ball rolling down a valley floor. The sides of the valley keep the ball rolling steadily down the central course (point A). If an insult occurs, it tends to push the ball out of its groove or canal and force it up the side of the valley (point B) The magnitude of the loss of velocity will depend on the severity and duration of the insult. Alleviation of the insult will result in a rapid return to the valley floor at an increased velocity (point C) Having reached the floor normal growth velocity is resumed (point D) 37
  • 38. 38 Growth chart of a girl who has suffered from celiac syndrome. Condition there is an abnormality of the lining of the gut and food cannot be absorbed Malnourished growth retardation On diagnosis the child is switched to a gluten-free diet which alleviates the malabsorption. Rapid recovery of height velocity She demonstrates complete catch-up growth within 1-2 years.
  • 40. Introduction to the study of human growth and development. Curve of human growth has been changing as we evolve There is less of environmental constrains on us now, but it is still there Infancy and adolescence are the two major stages where adjustment to final size and shape is still occurring More than 50% of infants exhibit either catch-up or catch-down growth, which has direct bearing on the final size, shape, morbidity, and perhaps mortality Timing of the adolescent growth spurt is also important in terms of healthy and successful survival. 40
  • 41. We are the survivors and use various survival strategies to survive and propagate our species. One of the most powerful of these strategies is the plasticity of our growth and development. In subsequent chapters you will learn how that plasticity is inherited, controlled, and expressed It is a fascinating story about the most fundamental biological phenomena of our species. 41
  • 42. 42