Anatomy and Physiology Reviewer The Nervous System
This nclexnursing is an anatomy and physiology related to the nervous system. It is a summary subject to the functions, divisions, types, and parts related to the nervous system.
The nervous system that coordinates its actions and sensory information by transmitting signals from different parts of the body called the neuron.
- Sensory input Monitor external and internal factors
- Integrating processing sensory input and initiating responses
- Homeostasis maintains homeostasis
- Mental activity include consciousness, memory, and thinking
Central Nervous System consisting primarily of the brain and the spinal cord
Peripheral Nervous System consists of nerves and ganglia.
• Sensory Division Afferent (Toward ) division. From sensory receptors to CNS.
• Motor Division Efferent (Away) Division. From CNS to effector organs.
Cells of Nervous System
Neurons transmit signals and receive stimuli from the body.
Three Parts of Neuron
• Cell body source also called soma that contains many organelles for gene expression.
• Dendrites short, highly branching cytoplasmic extension.
• Axon is a long slender projection cell extending from the neuron cell body.
Type of Neurons
Multipolar many dendrites, 1 axon
Most motor and CNS neurons
Bipolar 1 Dendrite, 1 Axon found in special organs, eyes & nose
Psuedo unipolar – 1 axon, no dendrites
Most Sensory Neurons
Neuroglia also called glial cells that do not produce electrical impulses from CNS and PNS. Has an ability to divide. More numerous.
• Astrocytes Highly branched help neural tissue repair
• Ependymal Cells Epithelial-Like circulate cerebrospinal fluid
• Microglia Small, Mobile Cells Protect CNS from infection
• Oligodendrocytes surround several axons enclose unmyelinated axons in CNS
• Schwann Cells – Single cells surrounding axons enclose unmyelinated axons in PNS. Myelin Sheaths is a lipid-rich (fatty) substance that surrounds nerve cells and the main purpose of myelin is to increase the speed at which electrical impulses.
• Unmyelinated Axons that rest in indentions of oligodendrocytes in CNS, Schwann cell in PNS.
• Myelinated Axons that have myelin sheaths wrapped around.