Nervous System Flashcards
What does the Somatic Nervous System do?
Relays information to and from skin and skeletal muscles. Voluntary. Division of PNS.
What are the two parts of the nervous system?
Central Nervous System (CNS) and the Peripheral Nervous System (PNS).
What does the Autonomic Nervous System do?
Relays information to internal organs. Involuntary. Division of PNS.
What does the Sympathetic Nervous System do?
Controls organs in times of stress. Division of Autonomic Nervous System.
What does the Parasympathetic Nervous System do?
Controls organs when body is at rest. Division of the Autonomic Nervous System.
What is a neuron?
Basic functional cell of nervous system. Transmits impulses (up to 250 mph)
Dendrite
Receive stimulus and carries impulses toward the cell body.
Cell body with nucleus
Nucleus and most of cytoplasm.
Axon
Fibre which carries impulses away from cell body.
Schwann Cells
Cells which produce myelin or fat layer in the PNS.
Myelin sheath
Dense lipid layer which insulated the axon - makes the axon look grey.
Node of Ranvier
Gaps or nodes in the myelin sheath.
How do impulses travel?
From dendrite to cell body to axon.
What are the 3 types of neurons?
Sensory Neurons
Motor Neurons
Interneurons
What do sensory neurons do?
Bring messages to CNS.
