Psych M.D. - Peripheral Nervous System


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Term:Peripheral Nervous System (PNS)
Definition (Myers): the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body. (pg.65)
Definition (alternative): That portion of the nervous system that is outside the brain and spinal cord. The peripheral nervous system (PNS) is one of the two major divisions of the nervous system. The other is the central nervous system (CNS) which is made up of the brain and spinal cord. The nerves in the peripheral nervous system (PNS) connect the central nervous system (CNS) to sensory organs (such as the eye and ear), other organs of the body, muscles, blood vessels and glands. The peripheral nerves include the 12 cranial nerves, the spinal nerves and roots, and what are called the autonomic nerves. The autonomic nerves are concerned with automatic functions of the body. Specifically, autonomic nerves are involved with the regulation of the heart muscle, the tiny muscles lining the walls of blood vessels, and glands. "Peripheral" in anatomy and medicine (as elsewhere) is the opposite of "central." It means situated away from the center. The word "peripheral" comes from the Greek "peripheria" ("peri-", around or about + "pherein", to bear, carry). An IV (intravenous) catheter is a peripheral line. *
Contextual explanation: There are two types of cells in the peripheral nervous system. These cells carry information to (sensory nervous cells) and from (motor nervous cells) the central nervous system (CNS). Cells of the sensory nervous system send information to the CNS from internal organs or from external stimuli.
  • Sensory Nervous System - sends information to the CNS from internal organs or from external stimuli.

  • Motor Nervous System - carries information from the CNS to organs, muscles, and glands.

    • Somatic Nervous System - controls skeletal muscle as well as external sensory organs.

    • Autonomic Nervous System - controls involuntary muscles, such as smooth and cardiac muscle.

      • Sympathetic - controls activities that increase energy expenditures.

      • Parasympathetic - controls activities that conserve energy expenditures.
insert imeem widget for podcast here
Related terms and concepts: Nervous System, Central Nervous System (CNS), Sensory Neurons, Motor Neurons, Autonomic Nervous System, Somatic Nervous System
Peripheral Nervous System

Related websites: Peripheral Nervous System, Organization of the Nervous System
Edited by: Jessica



More pages