Do you Know ?

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Duration of pregnancy

Though pregnancy begins at conception, it is more convenient to date from the first day of a woman's last menstrual period (LMP), or from the date of conception (if known). Starting from one of these dates, the expected date of delivery (EDD) can be calculated. Counting from the LMP, pregnancy usually lasts between 37 and 42 weeks, with the EDD at 40 weeks, 38 weeks after conception. 40 weeks is a little more than nine months and six days, which forms the basis of Naegele's rule for estimating date of delivery. Gestation peroid in humans is around 42 weeks (between 259 and 294 days since LMP).

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tanx ........................

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Blood is a specialized bodily fluid (technically a tissue). It is composed of blood cells suspended in a liquid called blood plasma. Plasma, which comprises 55% of blood fluid, is mostly water (90% by volume), and contains dissolved proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), platelets and blood cells themselves. The blood cells present in blood are mainly red blood cells (also called RBCs or erythrocytes) and white blood cells, including leukocytes and platelets (also called thrombocytes).

Blood performs many important functions within the body including:

* Supply of oxygen to tissues (bound to hemoglobin which is carried in red cells)
* Supply of nutrients such as glucose, amino acids and fatty acids (dissolved in the blood or bound to plasma proteins
* Removal of waste such as carbon dioxide, urea and lactic acid
* Immunological functions, including circulation of white cells, and detection of foreign material by antibodies
* Coagulation, which is one part of the body's self-repair mechanism
* Messenger functions, including the transport of hormones and the signaling of tissue damage
* Regulation of body pH (the normal pH of blood is in the range of 7.35 - 7.45)
* Regulation of core body temperature
* Hydraulic functions

Blood accounts for 7% of the human body weight. One microliter of blood contains 4.7 to 6.1 million (male), 4.2 to 5.4 million (female) erythrocytes, 4,000-11,000 leukocytes, 200,000-500,000 thrombocytes.

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Blood Circulation

Blood is circulated around the body through blood vessels by the pumping action of the heart. In humans, blood is pumped from the strong left ventricle of the heart through arteries to peripheral tissues and returns to the right atrium of the heart through veins. It then enters the right ventricle and is pumped through the pulmonary artery to the lungs and returns to the left atrium through the pulmonary veins. Blood then enters the left ventricle to be circulated again.

Arterial blood carries oxygen from inhaled air to all of the cells of the body, and venous blood carries carbon dioxide, a waste product of metabolism by cells, to the lungs to be exhaled. However, one exception includes pulmonary arteries which contains the most deoxygenated blood in the body, while the pulmonary veins contain oxygenated blood.

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Blood Donation Facts

1. Blood is collected only after proper medical examination.
2. All adult males and females in the age range of 18 to 60 years can safely donate blood.
3. Blood donation is completely safe and painless.
4. Out of your total body blood - 5 l -500 ml at a time is taken and that too is restored by your body in 48 hours.
5. It takes only 15 minutes for blood donation. These 15 min will be most precious for someone, because your gift of blood will be a gift of life for him/her.
6. After blood donation, you can perform your routine duties with out any harm.
7. You can safely donate blood once in 3 months.

The donor is also asked about medical history and given a short physical examination to make sure that the donation is not

hazardous to their health. Donors are examined for signs and symptoms of diseases that can be transmitted in a blood transfusion, such as HIV, malaria, and viral hepatitis.

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The donor's blood type must be determined if the blood will be used for transfusions. The collecting agency usually identifies whether the blood is type A, B, AB, or O and the donor's Rh (D) type and will screen for antibodies to less common antigens. More testing, including a crossmatch, is usually done before a transfusion. Group O is often cited as the "universal donor" but this only refers to red cell transfusions. For plasma transfusions the system is reversed and AB is the universal donor type.

The most common method is collecting the blood from the donor's vein into a container. The collected blood is typically separated into parts, usually red blood cells and plasma, since most recipients need only a specific component for transfusions. The blood is usually stored in a plastic bag that also contains sodium citrate, phosphate, dextrose, and sometimes adenine. This combination keeps the blood from clotting and preserves it during storage.

Donors are usually kept at the donation site for 10-15 minutes after donating since most adverse reactions take place during or immediately after the donation. Blood centers typically provide light refreshments such as tea and biscuits or a lunch allowance to help the donor recover.

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that interesting

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The main railway stations in Kerala

Thiruvananthapuram-Kochuveli-Varkala- Attingal- Paripally- Kollam- Oachira- Kayamkulam- Mavelikkara- Chengannur - Tiruvalla - Changanassery - Kottayam - Ettumanoor - Piravom - Mulanthuruthy - Tripunithura - Ernakulam town - Aluva - Angamali - Chalakkudy - Irinjalakkuda - Thrissur - Vadakkancherry - Shornur - Karakkad - Patambi - Pallipuram - Kuttipuram - Tirur - Tanur - Prappanangadi - Kadalundy - Feroke - Kozhikode - Koyilandy - Payyoli- Mahe - Talassery - Kannur - Payyannur - Nileswaram - Kanganghad - Kasarkode - Mangalore.

Palakkad/Coimbatore route take diversion from Shornur.

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Vainu Poppu Solar Observatory, Kavalur : It is the biggest solar observatory, situated 35 km from Tiruppathur and 25 km from Yelagiri, a popular hill station. On Saturdays from 4 to 6 pm, one can visit the Observatory without prior permission. A large variety of deer roam around the Observatory.

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Liquefied Petroleum Gas (LPG) is a mixture of hydrocarbons, which are in gaseous state at ambient temperature and pressure but these are liquefied under pressure for easy storage, handling and transportation in pressurized vessels. It is obtained through Crude Oil refining or from Natural Gas through fractionation. Butane and Propane are the main constituent hydrocarbon's in LPG. Others present in traces or small fractions are Iso-butane, butylene, n-butane, propylene etc.

LPG is a blend of Butane and Propane readily liquefied under moderate pressure. LPG vapour is heavier than air; thus it normally settles down in low-lying places. Since LPG has only a faint scent, a mercaptan odorant is added to help in its detection. In the event of an LPG leak, the vapourisation of liquid cools the atmosphere and condenses the water vapour contained in it to form a whitish fog, which is easy to observe. LPG in fairly large concentrations displaces oxygen leading to a nauseous or suffocating feeling.

LPG is one of the safest, economical, eco friendly healthy cooking fuels for all. Besides domestic usage, LPG is often used as an efficient source of energy in various industrial and commercial applications.