Human development and its stages Cognitive development

1. HUMAN GROWTH, DEVELOPMENT
& COMMUNITY BASED
REHABILITATION
DR. AYESHA KARIM
LECTURE 1

2. FORMING A NEW LIFE

4. CONCEPTION
“occurs when a sperm cell from a fertile man swims
up through the vagina and into the uterus of a
woman and joins with the woman’s egg cell as it
travels down one of the fallopian tubes from the
ovary to the uterus”.

5. MULTIPLE BIRTHS
 Fertilization of two ova
 By splitting of one fertilized ovum

6. DIZYGOTIC TWINS
Twins who happen to be born at the same time
but they arise from two separate eggs fertilized
by two separate sperm, just like ordinary
siblings.
 The two eggs form two zygotes, hence the
terms dizygotic and bi ovular.
 Also known as Fraternal twins.

7. MONOZYGOTIC TWINS
Twins are formed when one zygote, created with one
egg and one sperm, splits into two, leading to two
embryos. Each of those embryos then develops as
a separate fetus.
 also known as identical twins, because they
share practically identical genes.
 Monozygotic twins have same sex, share
physical characteristics and even may have
similar personalities

9. DETERMINATION OF SEX
 During conception, each receives 23 chromosomes
from mother and 23 from father. Forming 23 pair of
chromosomes.
 22 pair of autosomes
 1 pair of sex chromosomes
 A child receiving X chromosome from father will be
a female.
 A child receiving Y chromosome from father will be
a male.

10. PHENOTYPE AND GENOTYPE
 Phenotype:
“the set of observable characteristics of an individual
resulting from the interaction of its genotype with
the environment”.
e.g. hair color, height etc
 Genotype:
“the inherited instructions of an organism it carries
within its genetic code”.

11. PHENOTYPE AND GENOTYPE
 Not all organisms with the same genotype look or
act the same way because appearance and
behavior are modified by environmental and
developmental conditions.
 Likewise, not all organisms that look alike
necessarily have the same genotype

12. PRENATAL DEVELOPMENT
 The process of prenatal(before birth)development
occurs in three main stages:
 Germinal stage
 Embryonic period
 Fetal period

13. PRENATAL DEVELOPMENT
 Germinal stage:
“The first two weeks after conception”.
(cell division, differentiation, implantation)
 Embryonic period:
“The period from third week through the eighth
week”
(rapid growth and development of systems and
organs)
 Fetal period:
“The time from the ninth week until birth”.
(increased detail of body parts and increase in
body size)

14. PRENATAL DEVELOPMENT

15. PRENATAL DEVELOPMENT
 In the second week of prenatal life, the rapidly
growing blastocyst flattens into so called the
embryonic disk.
 The embryonic disk soon acquires three layers:
 Ectoderm (outer layer)
 Skin, hair, nails, teeth, nervous system, sensory
organs.
 Mesoderm (middle layer)
 muscles, skeleton, circulatory system
 Endoderm (inner layer)
 digestive system, liver, pancrease, salivary glands
and respiratory system

16. EMBRYONIC DISK

17. WHAT CAN FETUS DO?
 All of the fetus’s senses will be stimulated
naturally during the course of pregnancy,
except for vision.
 The fetus has the ability to detect stimuli from
as early as 8 weeks, in the case of touch.
 The older fetus learns, while in the womb, to
recognize certain sounds or tastes, and this
prepares them for life after birth.

18. BIRTH DEFECTS AND DISEASES
 Birth defects are structural or functional
abnormalities present at birth that cause physical or
mental disability.
 They are the leading cause of death for infants
during the first year of life.
 Birth defects may be caused by genetic
problems, problems with chromosomes, or
environmental factors.

19. ENVIRONMENTAL INFLUENCES ON PRENATAL
DEVELOPMENT
 Mother’s nutrition
 Physical activity
 Smoking
 Alcohol intake
 Drugs
 Environmental hazards
 External influences may affect father’s sperm

20. GROWTH AND DEVELOPMENT

21. LIFE STAGES
 Growth and development begins at birth and ends
at death.
 During an entire lifetime, individuals have needs
that must be met.
 Health care workers need to be aware of the
various stages and needs of the individual to
provide quality health care.

22. LIFE STAGES
 Infancy: birth to 1 year
 Early childhood: 1-6 years
 Late childhood: 6-12 years
 Adolescence: 12-20 years
 Early adulthood: 20-40 years
 Middle adulthood: 40-65 years
 Late adulthood: 65 years and up

23. GROWTH AND DEVELOPMENT
 Growth:
Implies a physical change, usually resulting from
either an increase in cell number or cell size.
 Development:
A change or modification in a person’s capacity to
function; the enhancement of a skill.

24. GROWTH AND DEVELOPMENT
 Pattern is more important.
Growth in young people occurs in the following
pattern:
 Relatively rapid growth during infancy with a
gradual deceleration until about the fourth year of
life
 A slow but uniform period of growth until puberty
 A prominent adolescent growth spurt.
 A relatively gradual decrease in the rate of growth
until completion of maturity, usually after age 20.

25. GROWTH AND DEVELOPMENT TYPES
 Physical: Body Growth
 Mental: Mind Development
 Emotional: Feelings
 Social: Interactions and relationships with others
 All four types above occur in each stage

26. FACTORS AFFECTING GROWTH
 Genetic factors.
 Maternal illnesses during pregnancy. e.g.
Diabetes
 Maternal and family socio-economic
disadvantages during and after pregnancy.
 Maternal and family social/emotional problems
during childhood

27. DEVELOPMENT

28. BRAIN GROWTH & DEVELOPMENT
 Nearly one half of the brain’s postnatal growth
is achieved by the end of the first year.
 New cortical cells are added.
 More connecting links are created, and cells
become larger.
 Myelination of brain cells.
 Pattern of myelination results as:
 cephalad to caudal direction.

29. DEVELOPMENT
 Motor
 Speech /Language
 Cognitive
 Social /Emotional

30. MOTOR DEVELOPMENT
 Occurs in a cephalo-caudal, proximo-distal
pattern.
 First achieves postural control of the head
through control of the neck muscles.
 Develops control of the shoulders, upper back,
lower back, hips etc
 The major accomplishments of the first year of
life are the ability to stand, and the capacity for
a Pincer grasp.

31. SPEECH & LANGUAGE DEVELOPMENT
The development of speech and language skills also
follow predictable patterns.
 Infant communication: Proto-conversations, in
which parent and infant take turns responding
through facial gestures.
 Cooing: the infant makes vowel sounds
 Babbling: the infant makes consonant sounds.
Arises prior to six months

32. SPEECH & LANGUAGE DEVELOPMENT
 Jargon: speech-like sounds which include vowels,
consonants, and prosody (the music of language)
without actually using words. Arises prior to one
year.
 Single words. Usually arise by age one.
 Two and three word sentences. Usually arise by
age two

33. COGNITIVE DEVELOPMENT
 Piaget divided child cognitive development into four
stages:
 Sensori motor stage (0 to 2 years)
 The Preoperational stage (2 to 7 years )
 The concrete operational stage (7 to 11 or 12
years)
 The stage of formal operations

34. SENSORI MOTOR STAGE (0 TO 2 YEARS)
 About their own body movements
 To coordinate two or more movements or activities
to reach a goal
 The major cognitive development of the first two
years of life is the acquisition of object
permanence.

35. THE PREOPERATIONAL STAGE (2 TO 7 YEARS
)
 "Operations" was a word Piaget coined to refer
to ‘mental schemes’ or ‘mental strategies’.
 Establish cause and effect relationships
between two events called transductive
reasoning. E.g.?
 Egocentrism (inability to differentiate between
self and others)
 Can not apprehend more than one concept. E.g.
width or height

36. THE CONCRETE OPERATIONAL STAGE (7 TO
11 OR 12 YEARS)
The child learns operations such as:
 Subtraction
 Multiplication
 Addition
 Division
 Serial Ordering

37. THE CONCRETE OPERATIONAL STAGE (7 TO
11 OR 12 YEARS)
b. The child learns to conserve volume.
 Piaget considered this to be the major
achievement of this age group.
 There is a decline of egocentrism. (inability to
differentiate between self and others)
 Children at this stage are now able to imagine how
others would perceive various situations.
 The child is unable to understand hypothetical
situations.

38. THE STAGE OF FORMAL OPERATIONS
 Adolescent must start to think about imaginary
things and possible occurrences.
 Adolescents learn how to
 Use strategies for solving problems.
 Accept a proposition that may be completely
ridiculous and make arguments or conclusions
from this proposition.
 Understand abstractions (justice, liberty, etc.).
 Think about their own thinking.