Class Notes (1,100,000)
CA (650,000)
Western (60,000)
Kinesiology (4,000)
3347A/B (100)
Navy (10)

Kinesiology 3347A/B Lecture Notes - Prenatal Development, Lunar Month, Gestational Age

Course Code
Kinesiology 3347A/B

This preview shows pages 1-3. to view the full 55 pages of the document.
Unit 3: Prenatal Growth
Readings: Chapter 2
o Tends to follow chronological timelines much more strictly than postnatal growth far more
Cell Theory:
o All living things are composed of cells
o The cell is the basic functional, structural and organizational unit of life
o Cells only arise from pre-existing cells
o Cells carry genetic info in the form of DNA. This material is passed from parent cell to daughter
o How we grow via hyperplasia
o Prenatal period: conception (when zygote is formed) birth (around 40 weeks)
o Gestation - carrying of an embryo/fetus; multiple (simultaneous = twins)
o Pregnancy - fertilization and development of an embryo/fetus in a female uterus
o Gestation and prenatal growth are highly species-specific
o Mice
25 day gestation
2g at birth
Growth rate = 2/25 = 0.08g/day
o Blue whale
300 day gestation
3,000,000g at birth
Growth rate = 10 kg/day

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

o Humans
259-294 day gestation (266 days on average) 37-42 weeks
~3,250g birth weight ~3.3kg
~Growth rate = 12.2g/day
Most of the mass that a human fetus accumulates is from the 4th month of pregnancy
Human Gestation:
o In utero growth and development requires 266 days
o Conceptional/ fertilizational age
o Menstrual/gestational age (relative to last menstruation of mother, 280 days) - 10 lunar months
o Lunar month = 4 weeks (28 days per month)
o Approximate DOB:
Beginning of last menstruation (b/c difficult to determine exactly when conception
happened early on)
Deduct 3 months
Add 7 days
o 95% of babies born +/- 2 weeks (of this predicted DOB)
o Weight increases several billion fold (as embryo develops)
Huge increases during prenatal period
Pediatricians guide to estimate fetal length:
o Lunar month = 28 days
o Lunar month² until 5 months
E.g., at 3 months = 3² = 9cm

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

o Multiply lunar month by 5 after 5 months
o Difficult to measure b/c curled up in the uterus
Karyotyping and Sex determination:
o Human genome, 46 chromosomes arranged in pairs
o Bottom: X and Y chromosomes = male genome
o Somatic cells
= All body cells except those involved in
46 chromosomes
44 autosomes (non-sex related
chromosomes, men and women share
between each other)
2 sex chromosomes (23rd pair)
o Similar in size and shape, same genes for same set of traits = homologues
But traits carried on the genes are often different (one from father and one from
Homologous pairs - same size and shape
One from each parent
o Karyotyped by size and shape
o Karyotyping = method used to organize and classify chromosomes
Sex Cells:
o Haploid
o 23 chromosomes
o Random assortment of traits
Contain DNA from mother or
You're Reading a Preview

Unlock to view full version