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.
1 All of these diseases are transmitted by parasites. Heartworm disease is spread by mosquitoes; Lyme disease, ehrlichiosis, and anaplasmosis are carried by ticks. 2  Testing takes only a few minutes and requires only a small sample of your dogâs blood.  Sometimes, follow-up testing is recommended.