What is the typical mammal? Breifly explain about cranial nerves
Typical mammal is endothermic ("warm-blooded"), have four-chambered heart, diaphragm, hair or fur. Females secrete "milk" from a specialized gland or glands to feed infants. Twelve pairs of cranial nerves are present in all mammals. They emerge directly from the brain. A cranial nerve could comprise of one or many fibers. A cranial nerve with many fibers is called mixed nerve. The cranial nerves are as follows: Olfactory Nerve: The olfactory nerve is a special sensory organ. Its function is to know and distinguish smell. Optic Nerves: This too comes under the category of special sensory organ. Its function is to impart vision. Oculomotor Nerve: It performs and controls most of the eye movements like bating of eyelid, blinking, dilation of pupil etc. Trochlear Nerve:& Its function is to control the movement of the eye ball Like moving the eye ball up and down. Trigeminal Nerve: It receives sensation from the face and transmits it to the brain. Abducens Nerve: It is related to the retina Facial Nerve: Its function is to control the expressions of the face. It also performs the function of taste and the salivary glands. Vestibucochlear& Nerve: It controls the balance and the movement of the body.It also senses sounds. Glossopharyngeal Nerve:& It receives signals of taste from the one third of the tongue located at the end. It also senses hot or cold, and pain. Palantine tonsils will also transmit certain sensation to the brain. Vagus nerves: It transmits special taste sense. It controls the voice muscles. Accessory Nerve: It controls the neck muscles and also performs certain functions of the vagus nerves. For example, it helps in shrugging the neck. Hypoglossal nerve:& Its function includes swallowing and formation of speech.