Lifespan Development Flashcards
How many stages of lifespan development are there and what are they ?
Infancy ( birth - 2), childhood ( 2-10), adolescence ( 10 - 20), early adulthood ( 20-40), middle aged ( 40-65), old age ( 65+ )
Pre-natal dev: 1st trimester
Embryological and foetal development
Major organ systems laid down as ectoderm-mesoderm-endoderm
Prenatal dev:2nd trimester
13-27 weeks
Organs and organ systems develop
Foetus looks like human by 6 months
Prenatal dev: 3rd trimester
Rapid foetal growth
Major organ systems fully functioning
Deposit adipose tissue
Prenatal organ development
Placenta -
Brain and spinal cord -
Placenta - dev from conception in womb
Connected to baby by umbilical cord
Brain and spinal - form at weak 2
Week 3 is heart and foetal circulation
Week 4 is lungs
Discuss foetal critical time periods and risks if exposed to harmful agents
Minor/major birth defects and occur.
Exposure during pre-embryonic ( weeks 1-2 ) period may cause spontaneous abortion
During embryonic ( weeks 3-8 ) severe birth defects may occur
Sometimes defects may be reversible.
Discuss foetal circulation before birth
Babies blood receives O2 from mother in placenta
Umbilical vein carries O2 blood back to liver and some goes through ductus venosus and enters inferior vena cava ( IVC )
ductus venosus provides “short cut” from umbilical vein to IVC
High O2 blood from placenta mixes with low O2 blood in IVC. high pressure so moves into right atrium.
Right atrium - right ventricle through pulmonary artery to lungs ( fluid sacs as baby in uterus )
High resistance in lungs cause high pressure in pulmonary artery.
Therefore high in right atrium and ventricle so blood enters left atrium from right atrium through foramen ovale.
Then enters left ventricle and squeezed into aorta.
Aorta - umbilical artery, then returns to placenta.
Foetal circulation before birth
Hypoxic pulmonary vasoconstriction -
Alveolus in lungs causes arterioles to constrict, therefore high resistance in lungs ( has smooth muscle )
* baby in utero therefore lungs are sacs of fluid which lack O2 due to this fluid
Foetal circulation before birth
Foram ovale -
Allows blood to move from right to left atrium.
Foetal circulation before birth
Foram ovale -
Allows blood to move from right to left atrium.
Foetal circulation before birth
Ductus arteriosis -
Allows blood from pulmonary artery to aorta ( moves from high pressure to low pressure )
Foetal circulation before birth
Ductus arteriosis -
Allows blood from pulmonary artery to aorta ( moves from high pressure to low pressure )
Foetal circulation before birth
Why is blood dawn to the placenta ?
Key foetal adaptions:
Drawn to placenta bc placenta has low resistance
Umbilical vein
Ductus venosus
Foramen ovale
Ductus arteriosis
Umbilical artery
What changes happen immediately at birth to foetal circulation?
Infant first breath - lungs expand and fill with air. Blood will flow to lungs as no longer restricted ( low pressure allowing blood to flow towards )
Blood enters pulmonary system and increases O2 levels, meaning ductus arteriosis constricts
High pressure in left atrium, therefore foramen ovale closes
Cord is clamped
Ductus venosus remains but lack of blood causes it to close hours later
Describe the respiratory system in infancy
Soft and cartilaginous rib cage till around 3yrs
Less type 1 muscle fibres - fatigue quickly
Poorly developed intercostal muscles
Small airway diameter -increased airway resistance
Airway prone to collapse due to little cartilage support
Poorly developed cilia so prone to infection
Decreased alveoli at birth ( 150 mil )
Infants - higher resting metabolic rate so require high O2 levels
All means they’re more vulnerable and at higher risk
Describe muskoskeletal system at infancy
Born with 300 bones - some will fuse eg. Skull
Bones are soft at birth and will ossify over time
Small and watery muscle fibres - weakness and fatigue is common.
Describe neurological system at infancy
Brain is 1/4 of total infant weight
Lower centres of brain are most developed - medulla and brain stem
Involuntary functions - ‘flexural tones’ - curled up
Posses primitative reflex eg rooting reflex - to feed and grasping reflex
Neurone and nerves are present, just need to learn what to do.
Physical growth of a infant
1/3 of adult height
There are 3 phases of growth
Weight will increase before height
Growth stages:
Bones - muscles - hands - fest - legs - arms
Genetic factors that influence growth and development
Sex
Physical status
Race
Environmental factors influencing growth and development
Family
Religion
Community
Food availability- poorly nourished child more likely to have infections and not attain full height potential
Explain physical growth stages from infancy to adolescence
Double weight by 4-6months and triple it by 1 year
1st 6 months - 2lb weight gain per month, and after that 1lb per month
Factors will influence this
Childhood: slow steady physical growth
Refine motor skills
Adolescence: rapid hormonal changes
Puberty - 10-14 girls
12-16 boys
Explain muscoskeletal system in adolescence
Accelerated skeletal growth - closure of epiphyseal plates
Increased strength and endurance of skeletal muscle
Testosterone has a greater effect than oestrogen, therefore leading to significant difference in muscle mass between genders.
Describe the neurological system during adolescence
Sex hormones will affect CNS
Leads to increased sex drive and sexual behaviour - triggered by testosterone and oestrogen