week 4 Flashcards
Detail the factors affecting pre-natal growth
most rapid phase- fertilisation to birth
3 phases
1. zygote- increace in cell number no inc in mass
2. embryo- differentiation and migration (day 4 to week 8)
3. fetus- hyperpasia in 2nd tri( 9-16 inc in length). maturation in the 3rd (17-38 increase in girth)
extrinsic factors- placenta, blood flow + nutrition. maternal anatomy, size, nutrition.
intrinsic factors- genes, hormone function.
teratogens- (TORCH infections)
Describe the endocrinological regulation of postnatal growth and understand the Karlsberg ICP model of growth
different factors are important at different times.
useful to think about from diagnostic point of view.
1st years of life genetics start to show.
Define canalisation and explain the principles of catch-up and catch-down growth
from 1950s
reckons you stay within 1-2 centiles of where you are born. can be normal to cross them though, so slightly outdates.
essentially think about centile crossing and it might be bad.
catch - down- getting appropriately smaller
catch-up- getting appropriately bigger.
Identify social influences on growth
Describe body composition changes (symetrical vs non symetrical) and gender differences during growth
asymmetrical- normal size head but small body
symmetric- generally small
large for gestational age- maternal DM2.
Describe the physiological processes of skeletal growth
osteogenesis 6-7 weeks.
intramembrinaous ossification - skull + clavicle. woven bone formed without cartilage.
1. mesenchymal cells develop into osteoblasts.
2. blasts secrete osteoid, then mature into osteocytes.
3. trabeculae give the woven spongyness, alls blood supply
4. fibrous periosetum forms on the surface.
endochondral ossification. - cartiladgenous model of bone is made by chondrocites.
1. hyaline cartiladge formed first.
2. chondroblasts calficy and die in the middle.
3. blood penetrates and delivers osteoblasts.
4. cavity develops, bone growth continues on the ends of the bone.
Understand the importance of monitoring growth in childhood
key element of childs health
should be considered whenever children are seen
essential for prescribing. + overall health. can indicate a variety of conditions. monitoring of conditions. indicate social concerns.
Understand what is meant by faltering growth, short stature, underweight, overweight and obesity and how to recognise these
faltering growth- fall in weight of two or more major centile lines
short stature- height below the 2nd centile
underweight- bmi under 2nd centile
overweight- above 91st centile
obesity bmi over 98th centile.
how to describe growth chart measurements
if within a quater of a space on the centile then they are on the centile
if more than one quarter centile space above of below then they are between the centiles.
Detail the factors that prepare the foetal lung for normal postnatal gaseous exchange, including the stimuli for lung growth and the production and role of pulmonary surfactant
4 stages
ebryonic
pseudoglandular
canalicular
saccular
alveolar
surfactant produced at 24-26 weeks
stiff lungs in reduced surfactant. needs to be matured by glucocorticoids, thyroid and insulin.
Describe the role of foetal lung liquid secretion and the mechanism by which the liquid is removed at birth. additionally what cells are responsible for its secretion.
clamping of placenta gives stimulus to breathe and cough it up. cooling also stimulates this.
big breathing effort is stimmed by hypoxia
some absorbed into lymphatics. air replaces.
Explain the functional adaptations of foetal haemoglobin that promote oxygen transfer from maternal to foetal blood and its developmental changes
2 alpha chains and two gamma chains, higher affinity for O2.
in pregnant women there is a sig inc in 2-3DPG. this means that mother haemoglobin is more willing to give the oxygen molecules.
Describe the anatomical and functional adaptations in the foetal circulation
large surface area in the chorion.
goes from umbilical vein via the liver.
though the IVC then into the foramen ovale and into the left atrium.
high resistance in the pulmonary vessels reducing flow.
ductus arteriosus is also present from the aorta reducing global sats
Describe the peri-natal (Transition) and post-natal changes in circulation and understand the consequences if these fail (Patent ductus arteriosus and pulmonary hypertension)
post natlly- pulmonary vascular resistance falls. lungs expand. pulmmonary stretch receptors fire. 8-10x more blood flow.
FO closes due to big rise in venous return to left atrium (because of pulm vasc resistance falling) RA + LA pressure equalises and flap is pushed closed.
ductus arteriosis closes due to bidirectional flow + o2 rise.
Describe the process of neonatal metabolic adaptation
insulin has less effect on blood glucose in the fetus. BUT it is the dominant hormone in 3rd tri. builds some fat. creates an anabolic environment.
must go from anabolic state in utero- to a catabolic state (or neutral) when born. (glucagon, cortisol, GH)
gluconeogenic hormones are switched on by catecholamine surge at birth. allowing the ability to create glucose between feeds.
baba diet is 50% fat- breast milk contains enzymes that will help digest it.
mcadd - what is it and what enzymes are deficient.
Outline the theory of neurodevelopment
progressive attainment of skills that involve both mental and muscular activity.
genes and environment affect the brain during critical period of development.
neuronal - proliferation, migration, organisation
myelineation.
Apply your understanding of developmental milestones in a clinical scenario
sitting crawling, walking running. - to know.
know transfer of object across midline(6mo) near pincer grasp (9mo)
smile by 6 weeks- concerning for vision if not
Detail the normal patterns of development for gross motor function, fine motor function and vision, speech and hearing, and social development
innate
incremental
progressive
responsive to stimuli
interdependent
Recognise causes of delayed development
failure to acquire a particular developmental skill when 95% of their peers would have done so.
global- delay in 2 or more areas of development- usually due to brain structure (genetic, asphyxial, infection, trauma)
or due to severe neglect
specific delays are due to specific areas of brain
Recognise the differences in pharmacokinetics for the paediatric patient and the implications for prescribing
body fat differences, increased in toddlers etc.
lack of data on medications in children.
behavioural issues.
discuss distribution of drugs in the child. additionally are hydrophobic and lipophobic drugs more readily absorbed or not.
less plasma proteins
increased competition, meaning that there can be higher free drug amounts seen.
blood brain barrier is incomplete in the newborn- inc crossing (inc meningitis)
give an overview of GFR in babies
