Nervous System and Neurons Flashcards
Nervous System
Responds to stimuli by controlling actions of the body through electrochemical messages
Central Nervous System (CNS)
Consists of brain and spinal cord - is the coordinating system
Peripheral Nervous System (PNS)
Consists of nerves that carry information between organs and CNS - divided into somatic and autonomic
PNS: Somatic
Relay information about environment and control voluntary actions (skeletal muscle, bone, skin, etc.)
PNS: Autonomic
Controls internal organs (heart, etc.) and involuntary actions
Types of Cells: Glial
Non-conducting cells that are important for structural support and metabolism
Types of Cells: Neurons
Functional units of NS, divided into three types: sensory, motor, and interneurons
Sensory Neurons
Sense and relay information about the environment to the CNS for processing - located in clusters called ganglia
Motor Neurons
Relay information to the effectors
Interneurons
Link neurons together - integrate sensory and motor neurons
Parts of Neurons: Dendrite
Receives information by conducting nerve impulses toward the cell body
Parts of Neurons: Axon
Projects nerve impulses away from the cell body
Parts of Neurons: Myelin Sheath
Covers the axon, insulates neurons, and prevents loss of charged ions - made up of special glial cells called schwann cells
Parts of Neurons: Nodes of Ranvier
Areas between sections of myelin sheath that nerve impulses jump to and from, speeding up process (myelinated axons are faster)
Parts of Neurons: Neurilemma
Surrounds axon and promotes regeneration of damaged axons
