The nervous system controls everything you do, for example, breathing, walking, what you think and what you feel. This system consists of the brain, spinal cord and all the nerves of the body. The brain is the control center and the spinal cord is the main highway that connects with him. Nerves transmit messages to the body and from the brain to interpret and act accordingly.
nerve tissue
Nerve tissue
Nerve tissue is composed of interconnected neurons. Between the Blutkapillaren glial cells connect with other neurons and glial cells. Through these nerve cells is associated nerve tissue from other tissue types identifiable. Nerve tissue is mainly in the brain, spinal cord and peripheral nerves to find, but also at the gut (→ Enteric Nervous System) and in the retina are net related nerve cells.
In the living organism has the nerve tissue the color pink to white. In the gray matter outweigh nerve cells. The white matter consists of cable railways, the myelinhaltigen nerve fibers. In the white matter, networking is low.
Nerve tissue leads selectively excitement of receptors on the success of organs. The gray matter processed, the white heads.
nervous system pictures building
Building
Schedule a nerve cell . Basic building block of the nervous system is the nerve tissue. It consists of interconnected nerve cells (neurons), whose cell body as Somata or Perikarya and their survival rates than nerve fibers (axons and dendrites) respectively.
At higher organisms, the nerve tissue from a network of neurons and glial cells many places to dock. The latter support the activity of nerve cells, without directly to the transmission of stimuli to be involved.
Cephalopods and vertebrates nervous systems
Cephalopods and vertebrates
Especially highly centralized systems are the nerves of cephalopods and vertebrates. They are a great many functions of the nervous system and muscles of the centrally controlled. It therefore speaks of a central nervous system. This consists of the brain and the spinal cord.
The outside of the central nervous system underlying neural structures to be counted peripheral nervous system. The peripheral nervous system is divided into the somatic nervous system and the vegetative nervous system (including visceral or autonomous nervous system, consisting of sympathetic, and enteric nervous system Parasympathikus) broken. The vegetative nervous system is primarily concerned with controlling the activities of the outside of consciousness expiring body functions.
Arthropod nervous system
Arthropod
Schematic construction of a knitting head of nervous system
In the arthropod is already in the training of higher processing centers in the form of several nerve knots (ganglia). These ganglia are two nerves like knitting heads together, so we here of a knitting nervous talking head. For most of these animals is particularly great Oberschlundganglion trained. It already assumes the functions of a "brain", especially the processing of sensory stimuli. The ganglia of body segments often control the movements of the leg and wing muscles largely autonomous. The knitting head nerve systems (with the exception of the upper pharyngeal Gang Lions) below the digestive system. Therefore, one speaks also of abdominal Mark.
Evolution
Evolution
In the course of evolution and with the higher development of individual departments of the animal kingdom is a clear trend towards concentration and associated specialization of parts of the nervous system noted. While in primitive animals, yet some individual neurons fall special functions (eg pacemaker neurons, the clock for elementary body movements of worms pretend), to perform highly complex nervous systems of up to several billions of interconnected neurons in specific tasks.
In nervous systems with Zentralganglien the conduction of neurons in Afferenzen (from the sensors to the brain) and Efferenzen (from effectors to the brain, muscles, for example) are divided.
nervous
Nervous
Overview of the human nervous system
The term nervous system (Systema nervosum lat) is the totality of nerve cells in an organism and describes how they arranged and connected. It is an organ system of higher animals, which has the task to provide information on the environment and the organism record, process and reactions of the organism action to optimal to react to changes. The nervous realized one of the basic properties of life, the irritability (irritability).
Subscribe to:
Posts (Atom)
