Nervous System Flashcards
What are Neurons?
Specialized cells that transmit electrical impulses throughout the body
What are Nerves?
Bundles of neurons
What are the 2 subsections of our nervous system?
- Central nervous system (CNS)
2. Peripheral nervous (PNS)
What are the 2 main components of the central nervous system?
- Brain
2. Spinal cord
Purpose of the central nervous system?
Responsible for analyzing and interpreting data that your peripheral nervous system (nerves outside of brain and spine) collects
What are the 2 types of Neurons used by both Nervous systems?
- Afferent
2. Efferent
General principle of Afferent systems
Carry things to a central point
General principle of Efferent systems
Carry things away from a central point
What is the Peripheral nervous system?
Part of the nervous system that consist of nerves outside of the brain and spinal cord
In the Peripheral system, the afferent parts are called
Sensory neurons
How are sensory neurons activated?
Via external stimuli
What do afferent neurons do in the Central nervous system?
They carry data into special parts of the brain
In the Peripheral system, the efferent parts are called
Motor neurons
What are the 2 subsystems on the Efferent(motor neurons) side of the Peripheral Nervous System?
- Somatic Nervous System
2. Autonomic Nervous
What does the Somatic system control?
Controls the things you think about doing
What is the Reflex Loop?
The process of afferent nerves send signals to the spinal cord and the spinal cord sending signals back to the muscles without the brain’s involvement.
What does the Autonomic System do?
Carries signals from the Central Nervous System that drive bodily functions without thinking about them (digestion, heart beating, breathing, etc.)
What are the 2 divisions of the Autonomic Nervous System?
- Sympathetic Division
2. Parasympathetic Division
What does the Sympathetic Division do?
Interprets “stress” and Prepares body for action.
How does the Sympathetic Division prepare the body for action?
Increases heart rate, increases blood pressure, dilation of pupils, stimulates adrenal cortex, shuts off blood supply to digestive and reproductive systems, enhances senses
How many pairs of nerves does the Sensory-somatic nervous system consist of?
12 cranial pairs
31 spinal pairs
Associated Ganglia
What is a ganglia?
A structure containing a number of nerve cell bodies
How does the integrative sensory function work?
Uses sensory information to make decisions by joining sensory input with memories already stored in the brain.
Anatomy of a Neuron
Dendrites, axon, nodes of Ranvier, Myelin
What are dendrites?
Branches that extend from the neuron
What is the axon and its function?
The trunk of the neuron and transmits signals to other neurons
What is Myelin and its function?
fatty material that intermittently covers the axon which acts as insulation
What are the nodes of Ranvier and their function?
Pieces of exposed axon between the Myelin that allow the signal to hope from node to node, increasing speed of signal travel
What is Saltatory Conduction
The hopping of electricity from node to node on the neural axon
What is a Synapse
Place where the axons branches come into contact with the next cell’s dendrites.
How fast are neurotransmissions?
90 metres per second
