Sciencegajab

  Common diseases in human.              • Disease causing organism à Pathogen.              • Most Parasites are pathogen              • Pathogen cause harm to host by living in /on them.              • When pathogen enters in host multiply and interfere with normal vital activity,                resulting in morphological & functional damage to the host.              • Pathogen has to adapt according to host’s body environment.  . TYPHOID FEVER:               • Pathogenà Salmonella typhi Bacteria.                     • Source of infection à contaminated water and food               • Bacteria reach to small intestine then other organ to blood.                        • Symptoms à                                   ØSustained high fever,                                   Ø weakness,                                   Ø stomach pain,                                   Ø constipation,                                   Ø headache and                                   Ø loss of appetite. 

  NEURAL CONTROL AND COORDINATION 1. The neural system Function --> coordinates and integrates @ To maintain Homoeostasis 2. The neural system and the endocrine system jointly coordinate and integrate all the activities of the organs --> in a synchronised fashion. 3. The neural system --> An organised network of point-to-point connections for a quick coordination. 4. The neural system --> composed of highly specialised cells called NEURONS 5. Neurons can detect, receive and transmit different kinds of stimuli. 6. Ganglion cells /True nerve cell evolved for the first time in coelenterates. 7. Coelenterates nerve cell derive from interstitial cell and it is polar neurons. 8. In Platyhelminthes, ladder type of nervous system consists of cerebral ganglion/brain 9. Nematodes has central, peripheral and rectal nervous system and rectal nervous system develop more in male. 10. In annelids, nervous system consists of central N. S., peripheral N.S. and sympatheti

 AIDS:  ACQUIRED IMMUNO DEFICIENCY SYNDROME. • It is deficiency of immune system, acquired during the lifetime • ‘Syndrome’ means a group of symptoms. • AIDS was first reported in 1981 • killing more than 25 million persons. • AIDS is caused by a Virus à Human Immuno deficiency Virus (HIV) • HIV à a member of retro virus family • Transmission of HIV-infection spreads only through body fluids.            Ø sexual contact with infected person,            Ø by transfusion of contaminated blood and blood products,            Ø by sharing infected needles            Ø from infected mother to her child through placenta. • Incubation period à usually 5-10 years   • After entering into host body, HIV ENTERS INTO MACROPHAGE and make viral DNA from RNA with the help of reverse transcriptase. • This viral DNA join with host DNA and direct the host infected cell to  produce virus particles. • Macrophage act as a HIV factory.  • Now virus particles attack the helper T-lymphocytes and also