Growth and Development
What is the universal standard for classifying sexual maturity?
"Tanner" stages of maturity
What is the peak height velocity of boys? Approximately how much do they add to their height?
13.5 years, add 20cm
At puberty there's a difference of _____ years between boys and girls
2 years
When does peak bone mineral density occur in the hips and the lumbar spine?
20 years of age
When does puberty begin on average for girls?
9 for African American Girls 10 for caucasian girls 3% of African American girls and 1% of caucasian girls develop breasts and pubic hair by age 3 48% of African American girls and 15% of caucasian girls have entered puberty by age 8
When does primary teeth erupt?
From 6 months of age to 2 year
Infancy
From the end of four weeks of the neonatal period until two years of age. Infancy is characterized by tremendous growth increased coordination and mental development
Menarche
The onset of menstruation
What is the important difference between boys and girls from birth to maturity?
The rate of maturity. Girls mature faster than boys.
When is puberty in girls complete?
When females have reached sexual maturity(~2 yeaes after menarche when a mature ova has been developed)
In which season do children grow faster in weight?
autumn and winter
The peak height velocity is highest in ________-__________ children and lowest in ______-________ children
early-maturing children late-maturing children
In which season do children grow faster in height?
spring and summer
What are the five types of skeletal development?
1. Average Children 2. Early Maturers- tall in childhood but not as adults 3. Early Maturers and genetically tall 4. Late Maturers- small in childhood, average as adults 5. Late maturers and genetically short
What are some ways of preventing osteoporosis?
1. Decreasing the rate of bone loss during adult life 2. Maximizing bone mineral accumulation during the growing years
Factors influencing growth and maturation
1. Genetical Control 2. Nutrition 3. Secular Trends 4. Season and Climate 5. Differences between races
What are the stages of postnatal growth?
1. Neonatal period 2. Infancy 3. Childhood. 4. Adolescence. 5. Adulthood.
What are the indices of maturity
1. Radiological (skeletal) Age 2. Dental Age 3. Growth Curves 4. Sexual Age 5. Neural Age
The reproductive organs remain in less than ___% of their final wait until the onset puberty
10%
What is the average age of the onset of growth acceleration in boys in North America?
11 years +/- 1.5 years
What is the peak height velocity of girlss? Approximately how much do they add to their height?
11.5 years, add 16cm
At what age does menarche usually occur?
12.8-13.0 (+/- 1) years of age in caucasians girls 12.2-12.5 (+/- 1) years of age in African American girls 95% range is 11.0-15.0 years of age
Cross-sectional studies in the USA show that girls with a mean takeoff age of 9 have reached their final height by ___ to ___ years of age
14-15 years of age
During the growth spurt, girls may add ______kg to the weight
16kg
Cross-sectional studies in the USA show that boys with a mean takeoff age of 11 have reached their final height by ___ to ___ years of age
17-18 years of age
Between ______ and _____ the average height of American and Wast European children between the ages _____ and _____ increased by more than ______ an inch per decade, a total of more than _____ inches
1880 and 1950 ages 5 and 7 1/2 an inch per decades a total of more than 4 inches
There has been an upward trend in adult height of _____cm per decade since 1880
1cm
Peak height velocity may occur as much as _____ years earlier or later than the average, within each sex.
2 years
At every chronological age up to full maturity, the radiological age of girls is in advance of that of boys by a factor of ______% or more
20%
During the growth spurt, boys may add ______kg to the weight
20kg
What is the growth in weight from when an individual an is born to maturity?
20x
The brain at birth is about ____%of its adult weight.
24%
What is the difference in time between the peak height velocity and peak weight velocity?
3 months, the individual shoots up and fills out later
Half way through the fetal period, the skeleton of girls is already ______ weeks more advanced than the boys' skeleton
3 weeks
What is the growth in weight from when an individual is an ovum to when he/she is born?
3x10^9
At birth, there is a ___ to ____ week difference in maturity between boys and girls
4 weeks to 6 weeks
What is the growth in weight from when an individual an is born to 2 years of age?
4x
At what age has the brain reached 90% of its adult weight and the body reached 25% of its adult weight?
5 years old
The difference of _____ years between an early maturing girl and late maturing boy is possible.
6
The neonatal body is only about __% of its adult weight.
6%
What is the average age of the onset of growth acceleration in girls in North America?
9 years +/- 1 year
osteoporosis
A condition of the bones where they become thin and brittle due to decreased mineral content, makes them susceptible to fracture.
When is the critical time for bone mineral accumulation?
Adolescence
Which of the following three populations have the greatest average growth tempo? European, African, Asiatic
Africans and Asiatics
At what age do girls and boys get back to being about the same height and weight?
Age 14
Radiological age
Age determined by a series of changes in bone that tells you the progress an individual's skeleton has made towards adult conditions
When does peak velocity of bone mineral content occur in boys and girls? What does this suggest about about the density of bone before the peak velocity of bone mineral content?
Approximately one year after peak height velocity. This means that there's a short period during which long bone weakens after peak height velocity, resulting in an increased risk of fractures
Which of the following three populations have the shortest average height? European, African, Asiatic
Asiatic
Why are the average male's legs longer than the average female's?
Because during the two years of additional growth boys have before their growth spurt, their legs grow relatively faster than their trunk.
Why do boys end up being taller than girls?
Because they have two more years of growth before their growth spurt. After the growth spurt, individuals have a rapid slowing of growth.
The need for________ during peak linear growth is substantial and so is an adequate level of ___________ ___
Calcium Vitamin D- Effects of sunshine and diet
What are some changes that occur during puberty?
Changes in: 1.reproductive organs 2.secondary sex characteristics 3.body size and shape 4.relative proportions of fat, muscle and bone
Why is the chronological age of a child an unreliable guide to assess how far an individual child has progressed towards maturity?
Children mature at different rates Measurements of height and weight are only partially useful
The bones the face grow faster than the _________ ________
Cranial vault "at adolescence the face emerges from underneath the skull"
At all ages, which part of the body are more advanced than the other?
Dimensions of the head are more developed than the trunk the peripheral parts of limbs are more developed than the central parts
What are of average ages of menarche of the three following populations? European, African, Asiatic
European- 12.8 years of age African and Asiatic- 12.5 years of age
True/False Children are now growing slower and stopping growing later
False Children are now growing faster and stopping growing earlier
True/False Ectomorphic boys, on average, tend to mature earlier than other and have an early adolescent growth spurt
False Mesomorphic boys, on average, tend to mature earlier than other and have an early adolescent growth spurt
True/False Populations do not differ in their average adult size and their tempo of growth and as well as their shape.
False Populations do differ in their average adult size and their tempo of growth and as well as their shape.
True/False Mental and psychological development is much more closely related to chronological age than radiological age
False Radiological age and mental and psychological development are much are closely related
True/False Early Maturing boys are greatly handicapped in competition with early maturing boys
False, Late Maturing boys are greatly handicapped in competition with early maturing boys
True/False: Menarche is more closely related to chronological age than it is to radiological age
False, Menarche is more closely related to radiological age than chronological age
True or False: Skeletal maturity and dental maturity are closely related in the individual
False, they're not
When does primary dentition occur?
From 6 years of age to 13
Neonatal Period
From birth to the end of four weeks
Which gender has their growth spurt earlier? Girls/Boys? At what age?
Girls have their growth spurt earlier, at age 9-10. As a result ,girls tend to be taller and heavier than boys at this age.
Longitudinal data
Growth curve is derived from a single individual or firm repeated measurements on the same group of individuals over a period of many years
Compare the body ratios of an infant to an adult
Head Height to total height -Infants 1:4 -Adults 1:7.5 Leg Length to total height -Infants 1:3 -Adults 1:2
Velocity curve
Increments in growth are plotted against time to show the variation in the rate of growth the time
Why do individuals in warmer regions have longer limbs?
It enables her/him to lose more heat per unit volume
What disadvantage do late maturing children in sport have when competing with early maturing children?
Late maturing children may be deselected from age-class sports too early.
Cross-sectional data
Measurements are made of several children in each age group, and these are then combined to form a cross-sectional picture of the biggest age groups in the community at the time of the investigation
Distance curve
Measurements taken at intervals are plotted against time to produce a graph of progress
Does the body retain the same proportions throughout growth?
No, and the relative weight of given tissues and organs do not remain constant.
Is the relationship between different parts of a growing body the same as one ages?
No, different parts of the body grow at different rates
Do all parts of the body grow at the same rate?
No, they don't stop growing at the same time either
When in pubertal and growth development does menarche occur?
Occurs late in puberty, after peak height velocity is falling
Timing of which factors of growth curves are useful maturity indicators?
Peak height and weight velocities
When is the time of greatest sex differentiation since the early intra-uterine months- sexual dismorphism?
Puberty
More than 90% of adult bone mineral is present by the end of....
Skeletal maturation.
What are some secondary sex characteristics that can be used for rating maturational development?
Stages in pubic hair, breast and genital development
What did the research study in November, 2012 involving 4,131 American Boys indicate?
The average African American boy is one year ahead in pubertal development compared to the average caucasian boy
Adolescence
The period of growth and development between childhood and adult hood. It begins around the age of nine and girls and the age of 11 and the boys and ends at approximately 17 to 18 years of age.
Childhood
The period of growth and development extending from infancy to adolescence, at which time puberty begins. Childhood years are a period of relatively steady growth until preadolescence when there is a growth spurt
Adult hood
The period of life beyond adolescents and adults has reached maximum physical stature as determined by genetics nutritional and environmental factors
Growth
The progressive development of a living being or part of an organism from its earliest stage to maturity, including the attendant increases in size
What are you looking for when looking at radiographical data?
The times of appearance of primary and secondary centers of ossification and the progressive enlargement of the ossified portion of an epiphysis can be followed in detail.
Why do girls in tropical countries have a late menarche?
Their nutritional status is low
What problem does early maturing children in sport have when competing?
They may develop unrealistic expectations and have difficulty adjusting to their loss of sports advantage when their late maturing peers catch up
What are common characteristics of individuals who are more adaptive to arctic regions?
Thick-set body Short limbs
True/False Evidence shows that children who are more physically mature (on average) tend to do a bit better in mental ability tests than those who are less physically mature, but of the same age
True
True/False: Girls are ahead of boys throughout the phase of motor and sensory development and fine movements and coordination
True
True/False: Girls learn to walk, understand speech and control their bladders earlier than boys
True
True/False Children subjected to an episode of acute starvation recover more or less completely
True, provided that the adverse conditions are not too severe and do not last too long.
________________ ___ deficiency is not uncommon among childrem and adolescents, especially during the darker seasons of the yeah
Vitamin D
Puberty
When the testes, prostate gland and seminal vesicles in males suddenly enlarge or when the breasts, uterus and vagina in females suddenly enlarge
In Western European countries, the average age of menarche has _________ from ______ years in 1880 to _______ years in 1960. Why?
decreased from 16 years to 13 years better nutrition, less diseases, dominance in certain genes?
applicability of Skeletal age vs sexual age
developments in sexual maturation have limited applicability when determining an individual's progress whereas skeletal developments can be used from infancy to young adulthood to determine maturity.
Which sites are commonly used to check radiological age?
hands and wrists, where there's a large number of ossification centers
__________ is an important indicator of maturation status in females
menarche
During the four adolescent years surrounding peak height velocity, as much bone mineral content will be laid down as ...
most people lose during all of adult life. It is important to lay down as much bone mineral content as possible during this time.
Studies of twins have shown that body shape and size, fat deposition, patterns of growth are all more closely related to __________ than ________
nature(genetics) than nurture(environment)
50% of variability in bone mass in the elderly can be accounted for by...
peak skeletal mass attained during the years of growth and maturation
The growth take off age highly correlates to the ____
pubertal stage
The end of a growth spurt is followed by a ________ _____________ of growth
rapid slowing