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.
Heartworm disease is only spread through the bite of a mosquito. Inside a dog, a heartwormâs lifespan is five to seven years. Adult heartworms look like strands of cooked spaghetti, with males reaching about 4 to 6 inches in length and females reaching about 10 to 12 inches in length.The number of worms living inside an infected dog is called the worm burden.his is about one month longer than in dogs. The presence of microfilariae in a catâs bloodstream is uncommon. Only 20 percent of cats with heartworm disease have microfilariae in the bloodstream, compared to 80 to 90 percent of dogs with heartworm disease.