what is the immediate response of human body soon after a poisoning.what type of reactions take place?

One cannot generalize, except that it depends on the poison, and the dose.

Rattlesnake venom, lead, mustard gas, and poision ivy all evoke different reactions, and those reactions depend on the dose.

It depends upon the type of poison.

For some of the symptoms, see
http://www.emedicinehealth.com/poisoning/page3_em.htm

The immediate response of the human body after poisoning can vary depending on the specific substance that was ingested, inhaled, or absorbed. However, I can provide you with a general overview of the common reactions that can occur.

1. Gastrointestinal Effects: Many toxic substances can cause symptoms like nausea, vomiting, diarrhea, abdominal pain, or cramping. These reactions result from the body's attempt to quickly eliminate the toxic substance.

2. Respiratory Distress: Inhalation of toxic substances can lead to respiratory symptoms such as coughing, difficulty breathing, or chest pain. This occurs as the body tries to expel or protect itself from the harmful substance.

3. Cardiovascular Effects: Some poisonous substances can affect the heart and blood vessels. Symptoms may include an increased or irregular heart rate, low blood pressure, or abnormal heart rhythms.

4. Neurological Symptoms: Depending on the type and severity of the poisoning, the nervous system can be affected. Common neurological symptoms include dizziness, confusion, headache, seizures, or unconsciousness.

It is important to note that the immediate response to poisoning can vary greatly, and it may be necessary to seek immediate medical attention. To accurately determine the specific reactions that take place, it's essential to consult a healthcare professional or poison control center, as they can provide guidance and advice specific to the situation.