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