Transcript Growth and Development

Growth and Development
An Introduction
Stages of the Human Lifespan


1.
2.
3.
Each stage of the human lifespan is
associated with an approximate age and
certain developmental milestones.
Prenatal (conception – 9 months). There are 3
sub-stages occurring during this period
Germinal stage (week 3 – middle of week 4)
Embryonic stage (middle of week 4 – week 10)
Foetal stage (week 11 – birth)
Stages of the human lifespan

1.
2.

1.
2.
Infancy & toddlerhood (birth – 3 years)
Infancy (birth – 18 months)
Toddlerhood ( 18 months – 3 years)
Childhood (3 years – 12 years)
Early childhood (3 – 6 years)
Late childhood (6 –12 years)
Defining Growth




Growth
– an increase in the size and number of
cells in the body.
- is quantitative ie: it can be measured.
- involves change in weight, height,
specialized cells that make up body
systems etc
How does growth occur?



Growth involves production
and replacement of cells, as
well as an increase in cell size.
New cells are formed by a cell
division process known as
mitosis.
Cells are able to perform
different functions as they
differentiate this creates cells
with specialized characteristics
eg: bone cells, nerve cells.
Body Systems & Structures



Each system is made up of
various types of tissues
designed to carry out a
specific function.
Skeletal System – supportive
structure of body , bones
linked by joints to enable
movement.
Circulatory System – moves
blood & it’s contents
throughout the body.
Consists of heart & blood
vessels – these range in size
from tiny capillaries to veins &
much larger arteries.
Body Systems & Structures cont…



Muscular System- muscles
are attached to skeleton by
various types of connective
tissue. Muscles enable
movement.
Respiratory System- works
with the circulatory system, the
lungs restore O2 to blood to
enable it to be transported to
all body cells.
Endocrine System –
produces & releases hormones
that act on various parts of the
body. It consists of a series of
glands that release hormones
at receptor sites.
Body Systems & Structures cont…..


Nervous System – transports neural impulses
(messages) around the body.
Nerve cells are arranged to form 2 main parts of
the nervous system. The 1st is CNS (central
nervous system) = brain & spinal cord, and the
2nd is PNS (peripheral nervous system) =
connects rest of the body to the CNS.
Body Systems & Structures cont…



Digestive System – responsible for the
breakdown of food into elements that can
be used by cells in the body.
Food passes through the mouth,
oesophagus, stomach & intestine.
Other organs assist in the breakdown &
absorption eg: liver, pancreas
Body Systems & Structures cont….

Reproductive
System – production
and storage of
gametes (sperm &
ova) to enable
fertilization to occur.
When does growth occur?


1.
2.
Obviously not all growth occurs at once.
There are 4 important periods of growth
during the human lifespan
Most rapid – between conception and 1st
birthday ie: from 2 cells to fully functioning
infant with countless differentiated cells.
Slow & steady growth from approx 12 months
to puberty.
Periods of Growth cont…


3. Adolescent growth spurt is rapid and lasts
for about 2 yrs. Timing is different for boys (12
– 13yrs) and girls (11 – 12yrs). It is important to
recognize that individual variation with timing of
growth is normal.
4. After growth spurt of puberty, growth slows
down again. An individual reaches maximum
height and physical development consolidates.
What happens after a person’ height is
reached in early adulthood?


Growth continues as
cells are constantly dying
and need to be replaced.
Repair & replacement
continues, but as we age
this process slows down.
Eventually the body
declines as replacement
rate diminishes.
Interrelationship between
growth & development



It is useful to understand that the terms growth and
development are often used interchangeably, this is not
correct.
It could be said that in order to grow we need to develop,
and that if we are to develop we need to grow eg: to be
able to walk, the nervous system must have developed
sufficiently. At the same time, leg muscles & skeleton
must have grown to appropriate size & strength to
support weight of upper body when activity is
performed.
We continue to grow & develop from conception to
death.
What is development?



Development is the gradual changes that occur
in our physical, social, emotional & intellectual
states & abilities.
Development is lifelong.
Development is qualitative – the quality
improves or becomes more complex, eg:
Intellectual development involves changes in a
person’s perceptions & thinking; we can’t
actually “see” this. It is not easily measured.
Physical development
Physical Development





Changes that relate to our size & shape and therefore our body
structure.
Motor development is a type of physical development – in order to
move, we use our motor skills. (the word “motor” refers to movement).
As we grow & develop we gain greater control over muscles & joints
in our body enabling a huge range of movements.
Gross motor skills – ability to control movement of larger muscle
groups ie: leg & arm muscles for activities such as jumping, running,
etc.
Fine motor skills – ability to control movement of smaller muscle
groups. Precise movements such as writing, drawing, playing a
musical instrument, turn the pages of a book, etc
Social Development



Social development is concerned with changes
in the way we interact with those around us as
we move through the life span.
We become socialised – the process of
acquiring values, attitudes & behaviours through
interacting with others.
The ways that we interact change slowly over
time ie; think about the way young people
communicate with each other in early primary
school compared to the way they do in
secondary school.
Emotional Development


Emotional development deals with our
feelings & moods and the ways which we
express, understand and control them.
As a very young child we only know how
to express such basic emotions as
happiness & sadness. Over time the range
of emotions we identify and express
increases.
Intellectual Development


Intellectual development (also known as cognitive
development) refers to the ways in which we are able to
think & reason.
As young children we understand the world in
“concrete” terms (things that we can see & feel). As we
get older we are able to understand things without
actually having to see them – they are referred to as
“abstract” concepts. eg: young children need blocks or
counters to be able to add numbers, but by the time they
are in secondary school they can deal with more abstract
concepts such as algebra I in maths and forming
hypotheses in science.
Summary of types of development
Physical development
Changes in our
Size
Shape
Overall body structure
Social development
Changes in our ability to interact with
 Family
Friends
Authority figures, etc
Emotional development
Changes in our
 feelings & moods
How and when these are expressed
Intellectual development
Changes in our
Ways of thinking
Ability to solve problems
Reasoning abilities
Principles of Development

1.




There are a number of principles or “rules” that apply
to our understanding of how development occurs in
humans.
Development requires change.
Obviously development involves change. The major
changes that occur over the lifespan are:
Changes in physical size, such as height & weight
Changes in body proportions ie: an infant’s head
makes up a larger proportion of the overall body mass
than an adult’s
Changes to features. Some appear, some disappear
eg: types of speech & language used, baby teeth
Principles of Development cont...



2. Early development is essential for late development.
What occurs during the early stages of our development
sets the foundation for all future development,
The earliest development begins at conception. Cells
divide & differentiate in order to form certain body
structures to perform vital functions eg: brain. The first 3
months are referred to as the “critical period” and are the
most important. During these weeks, if anything interferes
with this formation, problems can occur with development,
both now & in the future eg: consumption of alcohol can
affect brain development, leading to learning & behavioural
problems during childhood.
Principles of Development cont….





3. Development equals maturation plus learning.
Maturation – process whereby a person gradually
realises their genetic potential. It is commonly used to
describe development because it has a lot to do with the
way we function.
Learning involves relatively permanent acquisition (or
modification) of certain behaviours, usually through
interaction with the environment.
We are born with a set of behaviours that are reflexes
9not learned). They help us to adapt to our new
environment outside the uterus eg:sucking reflex. Most
behaviours from this point on are learned.
Maturation influences the ability to learn ie: if we are
not mature enough to learn, then we are not ready to
learn.
Principles of Development
cont….

4. The general pattern of development is
predictable.
Principles of Development cont….
Principles of Development


1.
Development through the lifespan is predictable. We
all experience the same general pattern of
development.
There are 2 laws that indicate the directions of
development that humans follow:
Cephalocaudal law – development occurs from top of
body, down to the bottom ie: from head to toes eg: an
infant learning to crawl must first be able to raise head
& upper body, using neck first, then arms. Very little
leg movement initially. Gradually control will be gained
over leg muscles and eventually the infant will be able
to coordinate these muscles so that crawling is
possible.
Principles of Development


2. Proximodistal Law – development takes place from
the centre (inside) of the body and extends outward to
the body’s periphery eg: crawling (again) – musvle
development is at first in the trunk of the body – these
muscle are important for breathing, digestive processes,
etc. Once these muscles are developed, legs & arms
follow.
Another aspect of the predictable nature of
development is evident during the adolescent growth
spurt. At puberty most adolescents experience a rapid
increase in height & weight (growth) as well as other
changes.
Principles of Development



Percentile charts – over many years data has been
collected about height & weight from birth to adulthood.
This data has been compiled into what is referred to as
“norms” (or normal range).
A percentile chart is a graph representing these “norms”
for growth in height & weight for a given population.
On these charts a series of lines allows the individual to
be compared o “normal” development statistically. Most
people progress at around the 50th percentile ie: approx
50% of people are this height/weight (the average). The
other lines indicate whether an individual is above or
below what is considered to be average.
Principles of Development

Percentile Charts
Principles of Development




5. There are individual differences in
development.
Although we all follow a general pattern, there is
also individual variation.
Differences relate to rate & timing of
development eg: a commonly asked question is
“When did your child start to walk?”
Genetic influences are mainly responsible for
these variations, but environmental factors also
need to be considered eg; prolonged illness.
Summary of The Principles of
Development
Development requires change
Early development is essential for later
development
Development equals maturation plus
learning
The general pattern of development
is predictable
There are individual differences in
develoment
Physical size
Body proportions
Some features appear & others
disappear

Later development is based on
foundations that have been established &
consolidated during early development

Maturation – gradually realising genetic
potential
Learning – relatively permanent
acquisition (& modification) of behaviours

Cephalocaudal Law
Proximodistsl Law

Rate
timing
