Teratogens, Biology

TERATOGENS -

  • These are chemicals or drugs causing malformed foetus.
  • The production of monsters or malformed foetus is called tertogeny or teratogenesis.
  • The ability of a drug to cause foetal abnormalities when used by pragnant women is termed teratogenicity.
  • Study of malformed babies is known as teratology.
  • Teratogens may affect embryogenesis by disturbing one or more development processes.
  • They may cause over developed & under development of tissue or organs.
  • There are three main categories of teratogens -

1.       DRUGS AND CHEMICALS -

(i)       Alcohol may cause foetal alcohol syndrome (FAS). It includes deficient prenatal growth, facial abnormalities, mental retardation.

(ii)      Thalidomide may cause phocomelia i.e. hands & feet are attached close to body, resembling the flippers of a seal, ear anomalies, cardiac malformation, closed oesophagus, failure of kidney development.

(iii)     Diazepam (Valium) use increases the risk of oral cleft.

(iv)     Halucinogens - THC causes birth defects, LSD produces chromosomal & foetal abnormalities.

(v)      Quinine (Malaria), bubulphan (Leukemia), chlorambucil (Hodgkin's diseases) aminopterin (abortion) seriously harm the foetus.

(vi)      Tetracycline increases susceptibility to caries, streptomycin increase susceptibility to hearing loss.

(vii)     Epileptic woman should discontain anticonvalsant drugs (Dilantin) during pregnancy as it causes foetal hydantain syndrome (FHS) characterised by poor prenatal growth short limbs, mental retardation, facial anoma- lies, cardiovescular abnormalities.

(viii)     Many pragnent woman take progestin or estrogen to avoid abortion. Use of these hormones causes masculinization of the ext. genitilia in female foetuses.

If hormone cortisone and vit. A taken in excess during early pregnancy, cause foetal defects such as hydrocephalus (very large head).

(ix)     Tobacco smoking by pregnant women leads to poor foetal growth & increases risk of abortion, intrauterine foetal death, neonatal death and premature birth.

2.       INFECTIOUS AGENTS -

Viral, bacteria and parasitic infections may cause serious effect on foetus.

3.       RADIATION -

Exposure to ionizing radiation of 2 to 6 weeks old foetus is teratogenic. It may cause pregnancy loss, growth retardation, eye malformation and CNS defects.

May cause mutation and leukemia.

Posted Date: 10/4/2012 9:08:27 AM | Location : United States







Related Discussions:- Teratogens, Assignment Help, Ask Question on Teratogens, Get Answer, Expert's Help, Teratogens Discussions

Write discussion on Teratogens
Your posts are moderated
Related Questions
Q. Symptoms of gastro oesophageal reflux disease? Most commonly, people with GERD complain of heartburn, a painful or uncomfortable feeling in the chest, which may radiate to t

Concomitant caroid endarterectomy and CABG :   Symptoimatic or asymptomatic carotid artery disease may be present in patients undergoing CABG. It is very important to recognize thi

How light reaction effects Cell Metabolism ? Light reactions :  The light reactions are carried out by two separate assemblies of several hundred chlorophyll molecules, acces

Respiratory Insufficiency Respiratory insufficiency usually indicate inadequate exchange of oxygen and carbondioxide to meet the needs of the body during normal activities.

Eastern/Western/Venezuelan equine encephalitis This encephalitis causing group of viral diseases of wild birds including pheasants, chickens, turkeys, ducks and pigeons with a

Define Anaerobic Exercise or Energy System? Thus, exercises which are done for short bursts of time lasting only for few seconds (less than 120 sec) use only anaerobic system o

Prophylaxis   High-risk neutropenic patients, such as those undergoing allogeneic and certain autologous stem cell transplants, and those with hematologic malignancy who are exp

Tissue Culture It is an important technique for maintaining a'pm or piece of animal or plant tissue alive after their culture dishes. It is necessary to provide an environment

one disadvantage of the pyramid if a tree and grass each count as one organism

Q Are there living beings without cells? Viruses are considered the only living beings that do not have cells. Viruses are constituted by genetic material RNA or DNA enwrapped