human nervous system - Encyclopedia Britannica
Human nervous system, the series of cells and nerve tracts that conduct stimuli from sensory receptors in the periphery to receptors in the brain and spinal cord and then conduct impulses back to other body parts.
Nervous system | Definition, Function, Structure, & Facts | Britannica
2024年10月30日 · Nervous system, organized group of cells specialized for the conduction of electrochemical stimuli from sensory receptors. The nervous system allows for the almost instantaneous transmission of electrical impulses from one region of the body to another.
Human body systems | Muscle, Skeletal, Respiratory, Circulatory ...
The muscle and skeletal systems, for example, act together to move the body. The skeletal system also protectively houses internal organs, such as the brain, heart, and lungs, while the muscle system aids in breathing and interacts with the nervous system to coordinate sensory and muscle responses.
Human nervous system - Receptors, Signals, Pathways | Britannica
Human nervous system - Receptors, Signals, Pathways: Receptors are biological transducers that convert energy from both external and internal environments into electrical impulses. They may be massed together to form a sense organ, such as the eye or ear, or they may be scattered, as are those of the skin and viscera.
Central nervous system | Description, Anatomy, & Function
2024年11月12日 · central nervous system, system of nerve tissue in vertebrates that consists of the brain and spinal cord. The central nervous system controls both voluntary movements, such as those involved in walking and in speech, and involuntary movements, such …
Functions of the human nervous system - Encyclopedia Britannica
The human nervous system differs from that of other mammals chiefly in the great enlargement and elaboration of the cerebral hemispheres. Much of what is known of the functions of the human brain is derived from observations of the effects of disease, from the results of experimentation on animals, particularly monkeys, and from neuroimaging ...
Human body | Organs, Systems, Structure, Diagram, & Facts
2024年11月12日 · The nine major organ systems in the human body are the integumentary system, the musculoskeletal system, the respiratory system, the circulatory system, the digestive system, the excretory system, the nervous system, the …
Human nervous system - Brain, Spinal Cord, Neurons | Britannica
The central nervous system consists of the brain and spinal cord, both derived from the embryonic neural tube. Both are surrounded by protective membranes called the meninges, and both float in a crystal-clear cerebrospinal fluid.
Human nervous system - Reflex Actions, Motor Pathways, Sensory …
It consists of an afferent (or sensory) nerve, usually one or more interneurons within the central nervous system, and an efferent (motor, secretory, or secreto-motor) nerve. Most reflexes have several synapses in the reflex arc.
Human nervous system - Peripheral Nerves, Sensory-Motor …
Human nervous system - Peripheral Nerves, Sensory-Motor Pathways, Reflexes: The peripheral nervous system is a channel for the relay of sensory and motor impulses between the central nervous system on one hand and the body surface, skeletal muscles, and …