- Oman, officially the Sultanate of Oman, is a country in West Asia. It is located on the southeastern coast of the Arabian Peninsula, and overlooks the mouth of the Persian Gulf. It shares land borders with Saudi Arabia, the United Arab Emirates, and Yemen, while sharing maritime borders with Iran and Pakistan. The capital and largest city is Muscat. Oman has a population of nearly 4.7 million and is the 124th most-populous country. The coast faces the Arabian Sea on the southeast, and the Gulf of Oman on the northeast. The Madha and Musandam exclaves are surrounded by United Arab Emirates on their land borders, with the Strait of Hormuz (which it shares with Iran) and the Gulf of Oman forming Musandam’s coastal boundaries.
- Nervous system (Wikipedia)
In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events. Nervous tissue first arose in wormlike organisms about 550 to 600 million years ago. In vertebrates it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor nerves or efferent nerves, while those nerves that transmit information from the body to the CNS are called sensory nerves or afferent. Spinal nerves are mixed nerves that serve both functions. The PNS is divided into three separate subsystems, the somatic, autonomic, and enteric nervous systems. Somatic nerves mediate voluntary movement. The autonomic nervous system is further subdivided into the sympathetic and the parasympathetic nervous systems. The sympathetic nervous system is activated in cases of emergencies to mobilize energy, while the parasympathetic nervous system is activated when organisms are in a relaxed state. The enteric nervous system functions to control the gastrointestinal system. Both autonomic and enteric nervous systems function involuntarily. Nerves that exit from the cranium are called cranial nerves while those exiting from the spinal cord are called spinal nerves.
