Nervous tissue. Nervous tissue or nerve tissue is the main tissue component of the two parts of the nervous system; the brain and spinal cord of the central nervous system (CNS), and the branching peripheral nerves of the peripheral nervous system (PNS), which regulates and controls bodily functions and activity.
Transmission. Mosquitoes carry the parasite that causes heartworm disease from animal to animal. The life cycle of a heartworm begins when a mosquito bites an infected animal carrying heartworm microfilariae in its blood.If that mosquito bites another cat or dog, it transmits the larvae to that animal.The larvae mature into adult worms in the heart and lungs of the host animal.he life cycle of a heartworm begins when a mosquito bites an infected animal carrying heartworm microfilariae in its blood. If that mosquito bites another cat or dog, it transmits the larvae to that animal. The larvae mature into adult worms in the heart and lungs of the host animal.
The larvae enter a new animal's body when it is bitten by an infected mosquito. Larvae mature and migrate to the pet's heart. Worms in the heart mate and produce microfilariae (6-7 months after infection in dogs, 8 months in cats). An important part of a complete heartworm prevention program is testing. All dogs should be tested for heartworm infection before starting a preventive program.