Week 6 - Exercise in Special Populations Flashcards
Process of conception
Conception occurs when a sperm penetrates an ovum
- 23 chromosomes of the sperm + 23 chromosomes of the ovum = zygote
- 23rd pair is sex
- 22 pairs autosomal
Sex is determined by the sperm
XX = female; XY = male
The rate of multiple births has doubled in Canada since the 1990s
3/1000 births are multiples
- Identical vs. fraternal
– Identical ⅓ — identical genes, single egg and sperm
– Fraternal ⅔ — 50% shared genes; regular siblings; 2 sperm and ova - Increased maternal age
- Assisted Human Reproduction
– Fertility drugs
– Cryopreservation — IVF labs
– Artificial insemination
Pregnancy
a physical condition in which a woman’s body is nurturing a developing embryo or fetus
Prenatal Development
Prenatal development, or gestation, is the process that transforms a zygote into a newborn
length of pregnancy
40 weeks (±2) or 10 months
1st trimester
weeks 1-12
2nd trimester
weeks 13-24
3rd trimester
weeks 25+
Milestones of prenatal development
No period in human lifespan where more changes occur at a faster rate than the prenatal period
Germinal Stage
first two weeks, including conception to implantation
Conception
Day 1
- Sperm and ovum unite, forming a zygote containing genetic instructions for the development of a new and unique human being.
Implantation
Days 10-14
- The zygote burrows into the lining of the uterus. Specialized cells that will become the placenta, umbilical cord, and embryo are already formed.
NOTE: mom and baby blood NEVER mix due to function of placenta
Embryonic Stage
Weeks 3-8
includes organogenesis
Organogenesis
All the embryo’s organ systems form during the six-week period following implantation
Weeks 9-12
Fingerprints; grasping reflex; facial expressions; swallowing and rhythmic “breathing” of amniotic fluid; urination; genitalia alternating periods of physical activity and rest
Weeks 13-16
Hair follicles; responses to mother’s voice and loud noises; 8 to 12 centimetres long, crown to rump; weighs 25 to 100g
Weeks 17-20
Fetal movements felt by mother; heartbeat detectable with stethoscope; lanugo (hair) covers body; eyes respond to light introduced into the womb; eyebrows; fingernails; 13-17 cm long, crown to rump; weights 140-300g
Weeks 21-24
Vernix (oily substance) protects skin; lungs produce surfactant (vital to respiratory function); viability becomes possible, although most born now do not survive
Weeks 25-28
Recognition of mother’s voice; regular periods of rest and activity; 35-38 cm long, crown to heel; weighs 660-1000g; good chance of survival if born now
Weeks 29-32
Very rapid growth; antibodies acquired from mother; fat deposited under skin; 39-43 cm long, crown to heel; weighs 1.2-1.7 kg; excellent chance of cervical if born now
Weeks 33-36
Movement to head-down position for birth; lungs mature; approx. 44-48 cm long, crown to heel; weighs about 1.9-2.6 kg; virtually 100% chance of survival if born now
Weeks 37+
Full-term status; about 49 cm long, crown to heel; weighs about 3kg
Low birth weight (LBW)
- Newborn weight below 2500g
- Preterm most common
- Small-for-date / small for gestational age