Hormones: Substances made in the body by cells or organs that control the function of cells or organs.
- Embryo and Fetal Development In the First Trimester.
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An example is estrogen, which controls the function of female reproductive organs. Placenta: Tissue that provides nourishment to and takes away waste from the fetus. Sperm: A cell produced in the male testes that can fertilize a female egg. Surfactant: A substance produced by cells in the respiratory system that contributes to the elasticity of the lungs and keeps them from collapsing.
Human Fetal growth and development upto second trimester
Ultrasound Exam: A test in which sound waves are used to examine internal structures. During pregnancy, it can be used to examine the fetus.
Uterus: A muscular organ located in the female pelvis that contains and nourishes the developing fetus during pregnancy. It is not intended as a statement of the standard of care, nor does it comprise all proper treatments or methods of care. Please check for updates at www.
Fetal development: The 1st trimester - Mayo Clinic
Women's Health Care Physicians. If you have further questions, contact your obstetrician—gynecologist. Copyright All rights reserved. Now what do you do? Our checklist will help you get through your first trimester and pave the way for the rest of your pregnancy Experts answer your top questions about your developing baby's movements, from when she'll start kicking to how often you should feel her kick. Chances are you have no idea you're pregnant yet-but your body is already hard at work. Watch as the egg undergoes its wondrous transformation to embryo.
At this point, your baby is awake and asleep at very specific times of the day. Find out about his sleep patterns, and what they mean. You'll start feel your baby's fluttering movements called quickening between now and 22 weeks.
Women's Health Care Physicians
Get ready, mama: Feeling him kick is one of the most magical parts of being pregnant. Ultrasound: A Trimester-by-Trimester Guide Find out what to expect at your first and second trimester ultrasound appointments, what you can learn from those ultrasounds, and why you might need an ultrasound or a few in the third trimester. Embryo to Fetus: Weeks 9 to 12 of Pregnancy You're well into your first trimester at this point, and your baby is growing bigger and bigger each day. Your First Trimester Diet Eating well now and throughout your pregnancy is crucial.
Growing Big: Weeks 31 to 34 of Pregnancy Your baby now weighs about three pounds, roughly the size of a melon. Take Quiz. Is it normal to lose weight during my first trimester? See the Incredible Ultrasound Image of Twins Kissing in Utero These expectant parents were so surprised when an ultrasound photo captured their twin daughters cuddling and kissing in the womb.
These include heavy metals, polycyclic aromatic hydrocarbons PAH , volatile hydrocarbons, aldehydes, aromatic amines, and nitrosamines. Below we describe the effects of maternal smoking on the fetal testis and also the fetal human liver, as the liver may be the organ most affected by xenotoxins derived from the mother.
Protection of the fetus from xenotoxicants in smoke and from environmental sources is through maternal metabolism, placental metabolism, and metabolism by the fetus itself Fig.
First Trimester (0 – 12 Weeks)
This means that the fetal liver is exposed to the highest concentrations of maternally-derived xenochemical. The most important metabolic hepatic enzymes are the phase 1 and phase 2 enzymes.
These act to detoxify xenobiotics through oxidation, reduction, and hydrolysis reactions phase 1 and through conjugation reactions phase 2 , which normally inactivate the compound and increase excretion rates. This data shows that, as a model, the smoke-exposed fetus is likely to be of significant use in identifying xenotoxin-dependent mechanisms of developmental deregulation. How exogenous chemicals reach the fetus. Maternal intake of chemicals, including pollutants and drugs, occurs via multiple routes of exposure, with maternal biotransformation metabolism, modification, conjugation, sulphation in the gastro-intestinal tract, liver and placenta.
The fetus will be exposed to xenochemicals through the feto-maternal interface at the placenta. Testosterone levels were slightly, but not significantly, reduced by maternal smoking but the reduction in hCG may leave the fetus more susceptible to other perturbations which affect Leydig cell function. Of these transcripts, only one, desert hedgehog DHH , was significantly reduced by maternal smoking. It remains to be determined, however, whether and how a reduction in fetal DHH levels would affect testis development in utero and post-natally.
Whether maternal smoking affects other developmental pathways in the testis is unknown and awaits global analysis of transcript expression in the different cohorts. By the nature of the subject, studies on the human fetal testis are largely confined to what can be observed or measured directly, along with insights that can be gained from the phenotype of natural mutations.
It is likely that more comprehensive and detailed study of the effects of maternal smoking, including for example epigenetic changes, will identify mechanisms by which xenotoxicants can affect fetal development and the testes in particular. The authors declare that they have no conflicts of interest concerning this article. Journal page Archives Sommaire. Article Article Outline.
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