TOXICOLOGY?

photo credit : http://www.scienceclarified.com/Ph-Py/Poisons-and-Toxins.html#b

Toxicology is not only the study of poisons or something dangerous to our health; it is the study of substances introduced exogenously into the body and also the adverse effects of chemicals on living organisms. And all the substances are poisons; the only difference is the amount of intake or the dosage.

Terms to remember in Toxicology

Toxicants	-Substance that produce adverse biological effects of any nature -may be chemical or physical in nature -may be acute or chronic      Ex. Lead, Mercury
Toxins	-Specific proteins produce by living organisms (mushroom toxin or tetanus toxin) -Most exhibit immediate effects
Poisons	-toxicants that cause immediate or illness when experienced in very small amounts.
Organic toxins	-Substances that were originally  derived from living organisms -contain carbon and often are large mol. Can be synthesized as well as be obtained from natural sources.
Inorganic toxins	-chemicals not derived from the living organisms (minerals) -generally small mol. consisting of only few atoms (such as nitrogen dioxide)

Branches of toxicology

Clinical Toxicology	-it deals with emergencies such as overdoses, poisonings and/or attempted suicides. -deals with compound ID and quantification -signs and symptoms management -emergency care -poison control
Forensic toxicology	-medical-legal aspects -ID and quantification of poisons -establish relationship between tissue residual level and probable cause of death.
Industrial toxicology	-estimation of worker safety based on 8hr work day, 40hr work week. -engineering of safety measures -air sampling, worker sampling.
Environmental toxicology	-effects of compounds on water, wildlife. -Movement of chemicals in the environment – soil, air, water. - Residual life of chemicals in the environment.
Biochemical & Molecular Toxicology	- Determining mode of action of chemicals at the molecular level. - Effect of chemicals on DNA, cancer genes….
Descriptive toxicology	-The study of the level of exposure that causes harm to humans using the results obtained from the experiment done in animals.

LD50      -the measure for expressing and comparing the toxicity of chemicals.
                   -dose that kills half (50%) of the animals tested (LD = "lethal dose")
                          -animals are usually rats or mice, although rabbits, guinea pigs, hamsters

              Acute toxicity- short term effect due to exposure to a toxic chemical, that results in obvious health effects and even death.

             Chronic toxicity- long term exposure to a toxic chemical, or exposed to the substance continuously or repeatedly.

            Exposure - concentration of a chemical in the environment or the accumulated dose that an organism encounters.

Chemical hazards in the workplace and in the environment

Category	Examples
Inorganics	asbestos, carbon monoxide, hydrogen sulphide
Phenols	phenol, pentachlorophenol
Metals, and metalloids	arsenic, cadmium, lead, mercury, nickel, tin, etc
Hydrocarbons - aliphatic	propane, butane, pentane, hexane
Hydrocarbons - aromatic	benzene, toluene, xylene, naphthalene
Aliphatic alcohols, ketones, ethers, aldehydes and acids	ethyl alcohol (ethanol), acetone, diethyl ether, formaldehyde, acetic acid
Chlorinated volatile organic compounds	perchlorethylene (tetrachloroethene), trichloroethylene (trichloroethene), vinyl chloride
Miscellaneous organic compounds	acrylonitrile, benzidine, aniline, di-isocyanates, organophosphates
Chlorinated non volatile organic compounds	chlorinated dioxins and dibenzofurans, polychlorinated biphenyls, pesticides such as chlordane and DDT

Bored? Play a Quiz Game. More facts and trivia. Click on this links :)

http://www.funtrivia.com/trivia-quiz/SciTech/Toxic-Trivia-97601.html
http://www.funtrivia.com/trivia-quiz/SciTech/Thisll-Kill-Ya-186558.html
http://www.funtrivia.com/trivia-quiz/SciTech/Warning-Questions-May-Be-Toxic-285643.html

Here are some videos that can help us to understand more about Toxicology.

Introduction to Toxicology

Forensic toxicology and Drugs

Reference: http://www.eoearth.org/article/Toxicology
                     http://insects.about.com/od/l/g/LD50.htm
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/L/LD50.html
http://www.scienceclarified.com/Ph-Py/Poisons-and-Toxins.html#b

Introduction to Endocrinology

Endocrinology; What is it?

         Endocrinology is the study of hormones including diseases and conditions related or associated with hormonal imbalance. The endocrine system which is a finely integrated system continually communicate through feedback inhibition and stimulation to control all aspects of metabolism, growth and reproduction. Through this, it is possible to characterize an underlying  abnormality and provide treatment.

Questions regarding growth and development can now be addressed by studying  the changing pattern of hormones. It is a known truth that the endocrine system regulates our mood, growth and maturity, tissue function, metabolism as well as sexual and reproductive function.

For sure it will tickle our mind and imagination for what seems to be a dry, boring subject is a wonderful subject very interesting and educational.

Figure 1

Photo credit: 

http://webs.ashlandctc.org/mflath/KEY%20ENDOCRINE%20OBJECTIVES.htm

Major Endocrine Glands and Hormones

glands	HORMONES	GLAND/HORMONE FUNCTION	SOME DISORDERS
Hypothalamus (Lower middle of the brain)	Growth hormone-releasing hormone (GHRH) Thyrotropin-releasing hormone (TRH) Corticotropin-releasing hormone (CRH) Gonadotropin-releasing hormone (GnRH) Prolactin-(PRL) Antidiuretic Hormones- (ADH)	Communicates with both nervous and endocrine systems. Stimulates (GHRH, TRH, CRH, GnRH) or inhibits (PIF) hormone production in the pituitary Water balance	Precocious puberty (early GnRH production) Kallman syndrome (inadequate GnRH production)
Pituitary (below hypothalamus, behind sinus cavity)	Prolactin Growth Hormone ACTH TSH LH, FSH	Milk production Bone growth Stimulates cortisol Stimulates thyroid Regulation of testosterone and estrogen, fertility	Hypopituitarism    Empty Sella Syndrome    Galactorrhea Acromegaly or Gigantism (excess GH) Growth Hormone Deficiency (GHD) Cushing disease (excess ACTH) Hyper/Hypothyroidism (TSH) Loss of menstrual period Loss of sex drive Infertility
Thyroid (butterfly shaped, Lies flat against windpipe in the throat)	T4 (thyroxine) T3 (triiodothyronine) calcitonin	Metabolism Regulate blood in calcium	Thyroid diseases (including hypo and hyperthyroidism)
Parathyroid (located above or next to thyroid)	Parathyroid Hormone (PTH)  or Parathormone		Hyperparathyroidism Hypoparathyroidism
Adrenal    (2 organs on top of kidneys)	Epinephrine Norepinephrine Aldosterone  Cortisol	Blood pressure regulation stress reaction Salt, water balance Stress reaction	Pheochromocytopenia(MEN2) Conn syndrome Cushing syndrome Addisons disease
Ovaries (located on the pelvis)	Estrogen Progesterone	Female sexual characteristics	Polycystic ovary syndrome (PCOS)
Testes (located in the groin)	Testosterone	Male sexual characteristics	Hypogonadism
Pancreas (located behind the stomach)	Insulin Glucagon Somatostatin	Glucose regulation	Diabetes mellitus MENI Zollinger-Ellison syndrome
Pineal (lower side of the brain)	Melatonin	Helps control sleep patterns

Did you know that Nervous system and Endocrine system work together?

You might wonder how this is possible? For our information, the endocrine and nervous system work together to attain a normal body function. The endocrine system in charge of the body processes of cell growth and development of different body organs of the body while breathing and movement of the body are controlled by the nervous system.

The hypothalamus which is the linked of the nervous system to the endocrine system via pituitary gland allows the release of hormones and is then circulated to different body organs. Here, we can see that the two major vital systems of our body work hand in hand to promote maintain a normal body function, our bodies normal function.

For us to understand more, please watch this video!

http://www.youtube.com/watch?v=PMrPlCDGUwo

Reference:
http://www.blurtit.com/q1085214.html
http://wiki.answers.com/Q/How_does_the_nervous_and_endocrine_systems_work_together
http://labtestsonline.org/understanding/conditions/endocrine/start/2
Donald F. Calbreath, Clinical Chemistry a Fundamental Textbook
Henry's Clinical Diagnosis and Management by Laboratory Methods 21st Edition