GROWTH & DEVELOPMENT Flashcards
What is the equation for BMI
(Weight/height)^2
What influences change in size?
- Hypertrophy- increase in cell size
- Hyperplasia- division of cells, increase in number of cells
- Accretion- increase in intracellular substance
List 4 elements of growth
- Changes in form, proportion and shape
- baby 4 heads tall, adult 8 heads tall
- Stature of growth increases while centre of gravity drops - Differential timing
- Not homogenous
- mass processes at a different rate than height - Alterations of composition
- muscle mass and fat mass (+/-)
- subtraction = thymus gland around puberty
- substitution= cartilage to bone (ossification)
What is hypertrophy?
Increase in cell size
What is hyperplasia?
Division of cells
Increase in number of cells
What is accretion?
Increase in intracellular substance
Explain differentiation
A series of orderly and irreversible stages that every organism undergoes from the start to the end of life.
Transformation from an undifferentiated state to a highly organised mature state
Translocation
Change in position
Maturation
Process of progression to a mature state (internal processes)
Adaption
The result of the body’s accommodation or adjustment to the immediate environment (external process)
What are the 3 modes of adaption?
Give examples
- Long-term: skin colour
- Short-term: weight gain
- Pharmacological: natural or pharmacologically induced, training..?
What are the lifespan development stages?
Pre-natal Birth Post-natal Childhood Adolescence Adulthood Senescence Death
What are unique aspects of human growth and development?
- Long time to maturity- 20-25% of lifespan is spent growing (first 2-3 decades)
- Experience a resurgence of rapid growth at adolescence- 50% of bone mass is accrued in the 2 years bordering PHV
Why is the there a long human growth period?
- Long period of infant dependency
- An extended childhood growth period from childhood to adolescence
- Resurgence of rapid growth during adolescence leading to sexual and physical maturity
What is anthropometry?
Techniques used to describe and measure growth
What techniques are used to measure growth?
- Size: height, lengths, breadths, circumferences etc.
- Composition: weight, % fat, % lean etc.
- Shape and Proportion: physique type, somatotype
- Maturation: maturational age (skeletal, somatic, Tanner stages)
What is allometry?
Allometry describes the relationship between various dimensions of growth
E.g. during growth height changes at a different rate from weight or bone mass accrual
What’s similar between both boys and girls prior to puberty (around 10 years old)?
Prior to puberty growth for both boys and girls is fairly similar in terms of height and weight gain per year
Height = 5-6 cm/year Weight= 2.5kg/year
Which gender begins puberty earlier?
Girls and as a result also reach PHV earlier
Around which ages do both boys and girls reach PHV?
Girls: 11-12 years old
Boys: 13-14 years old
What happens during the adolescent growth spurt with regards to PHV?
The velocity of linear growth can more than double over the childhood growth rate.
Over this period the PHV:
Girls = 9-10cm/year at the age of 12
Boys= 11-16cm/year from the age of 14-16
What is auxology?
A branch of developmental biology. The study of growth and development