Pathology semester 1 Flashcards
What is lifespan development
life span development refers to age relate changes that occur from birth, throughout a person’s life, into and during old age.
What are the 6 stages of life span development
infancy- birth 2 years, childhood- 2-4 years, adolescence- 10-20 years, early adulthood- 20-40 years, middle age- 40-65 years, older age 65+
how many trimesters are there for prenatal development
3
prenatal development- first trimester
embryological and foetal development where the beginnings of all major organ systems appear, being laid down as ectoderm- mesoderm- endoderm (3 layers of cells
prenatal development- second trimester
development of organs and organ systems. Body shape and proportions change, the foetus looks distinctively like a human by 6 months
prenatal development- third trimester
Rapid foetal growth and deposition of adipose tissue. major organ systems are fully functioning in the early stage of this trimester
Development of organs (from conception)
placenta (start at 1 weeks), brain and spinal cord (start at week 2), heart and foetal circulation (start at week 3), lungs (start at week 4)
importance of placenta before birth
baby sticks capillaries into placenta blood to gain nutrients from mother. Baby gets oxygenated through this blood
foetal circulation step 1 (umbilical vein and ductus venosus)
umbilical vein carries blood back to the mother, the ductus venous allows blood to travel from the UV to the inferior vena cava. This is a large vein that picks up oxygenated blood
foetal circulation step 2 (where does blood go from inferior vena cava)
the blood then goes into the right atrium, some of the blood is squeezed into the right ventricle and then out via the pulmonary artery to the lungs
foetal circulation step 3 (hypoxic pulmonary vasoconstriction)
in the lungs there are sacks filled with fluid, meaning there isn’t much oxygen. This causes hypoxic pulmonary vasoconstriction, this is where the alveolus helps to constrict the arteriole, increasing the resistance of the arteriole and therefore the lungs.
foetal circulation step 4 (pressure un PA and RA)
The pressure in the PA is very high (due to resistance in lungs), therefore there is a large amount of pressure in the right side of the heart. The pressure in the RA becomes higher than the pressure in the LA, causing blood to move to the LA via the foramen ovale
foetal circulation step 5 (blood from PV going to LA)
There is blood going from the PV going into the LA, this blood then goes into the LV and is squeezed into the aorta. Some of the blood in the PA goes directly into the aorta due to the pressure being higher in the PA than the aorta, via the ductus arteriosus, the aorta then distributes blood to the foetal tissue
foetal circulation step 7(what do the foramen ovale and ductus arteirosus allow)
they allow a right to left shunt to bypass the lungs. the advantageous because blood doesn’t need to go to the lungs as the baby isn’t breathing. The foetus relies on oxygen from the maternal circuit in the placenta
foetal circulation step 8 (umbilical artery)
the umbilical artery then brings blood back to the placenta, the placenta has a low resistance, making blood divert towards it.
immediate changes at birth
changes occur when the infant takes its first breath and the lungs expand. Blood rushes into the pulmonary system causing the constriction of the ductus arteriosus
pressure rushes into the LA causing the foramen ovale to close
the cord is clamped- leading to umbilical artery and vein shrivelling up as they are no longer necessary, the ductus venous remains viable for several hours, but lack of blood from the placenta causes it to close
respiratory system in infancy
the rib cage is soft/ cartilaginous, poorly developed intercostal muscles and have less type 1 muscle twitch fibres, angle of insertion for diaphragm is horizontal, preferential nasal breathing, airways diameters are small and there increase airway resistance and increase WOB, poorly developed cilia- less wafting, about 150 million alveoli (instead of 400), collateral ventilation does not exist at birth- less tubes to alveoli takes 3 years to fully develop, they have a higher resting metabolic rate (requires more oxygen
musculoskeletal system in infancy
born with 300 bones, some of which fuse (adults have 206 bones)
bones are soft at birth, cartilaginous and ossify over time
muscle fibres are small- fatigue easily
body fat is laid down until 9-12 years old
neurological system in infancy- brain
brain is a quarter of total baby’s weight
the lower centre of brains are most developed
Physical growth from birth
At birth 1/3 of adult heigh, growth is in 3 phases, body parts grow at different stages, weight. increases before height
Factors influencing growth and development- genetic
genetic factors determine characteristics such as sex, physical status and race
Factors influencing growth and development- environmental factors
They affect an individual’s growth and development, e.g. family, religion, school. Poorly nourished children is more likely to have infection than a well fed child and may not attain his or her potential height
factors affecting physical growth- traits
traits and characteristics inherited at the time of conception
factors affecting physical growth- birth
single or multiple birth, normal or abnormal delivery, conditions of care at the time of delivery, care of mother and baby
factors affecting physical growth- health
physical as well as mental health of the mother during pregnancy
factors affecting physical growth- nutrition
nutrition received by the child after birth
physical growth- weight
most infants double their birth weight at 4-6 months and triple it by 1 year, first 6 months, average weight gain 2lb per month, second 6 months, weight gain is approx 1lb per month, the average 1 year old boy weighs 10kg, girl weighs 9.5 kg
Growth- childhood
from 2-10 years, period of slow steady physical growth, refinement of motor skills, mental development through school
growth- adolescence
from 10-20 years, begins puberty (10-14 years girls and 12-16 years boys), a time of rapid hormonal change which affects male and females differently
musculoskeletal systems in adolescence
accelerated bone deposition and skeletal growth with the closure of epiphyseal plates, increase strength and endurance of skeletal muscle, testosterone has a greater effect than oestrogen leading to significant different in muscle mass between male and females
neurological systems in adolescence
sex hormones affect the CNS, there is an increase sex drive and sexual behaviours by the increase in testosterone and oestrogen
cardiorespiratory systems in adolescence
the pressure of increased level of testosterone causes blood volume to increase, testosterone stimulates the disproportionate growth of the larynx and a thickening of the vocal cord- deepening voice
growth after puberty
background secretion of hormones maintains the sex specific differences between males and females, both continue to grow at a slower pace up until 18-21 years, the boundary between adolescent and maturity is hazy as it has physical as well as emotional and behavioural components, adolescence is over physically when growth stops (physical maturity)
Neurological systems in infancy- muscles and positions
normal exhibits flexural tone- curled up, difficult to fully extend joints
posses primitive reflexes
all neurones are nerves are present- just need to be told what to do
transient exuberance- dendrites find correct pathways and forming connections through learning
