2.3 Overview of the Nervous System and the Neuron
3 min read•december 19, 2022
Megan Revello
Dalia Savy
Haseung Jun
Megan Revello
Dalia Savy
Haseung Jun
Vocabulary
Nervous System
The is our body’s speedy electrochemical messaging system. It is made up of both the peripheral and central nervous systems. The (CNS) is composed of our brain🧠 and 🦴, while our (PNS) connects our sensory and motor neurons to the CNS.
CNS
As mentioned above, the CNS is composed of just the brain and ! The brain's neurons work in that send messages quickly.
A is an often created by a signal neural pathway in our . Reflexes are so quick and automatic because the message is received and responded to before our brain even has time to respond. The in the enable this reflexive response.
The is also a highway🛣️ connecting the and the brain.
PNS
The can be broken down further into the autonomic and somatic systems. The is in charge of controlling of our skeletal muscles💪 - like covering your eye during an eye exam at the doctor. The then controls all automatic functions of our internal organs - like your heart beating❤️ and your lungs breathing. The automatic comes into play especially in . It can increase your or in such situations.
The can be broken down further into two other systems, the sympathetic and parasympathetic. The is our . When you get nervous before an exam your heart may race, and your breathing may become more rapid - this is thanks to the , which prepares us for action🏃. On the other hand, the returns us to a calm and neutral state once the stimuli that triggered our original arousal has subsided.
💡Sympathetic = "Fight or Flight"
💡Parasympathetic = "Rest and Digest"
Image Courtesy of Lecturio
Image courtesy to Wikimedia Commons
Image courtesy to Wikimedia Commons
Neurons
Sensory neurons, sometimes referred to as afferent neurons, are what carry incoming into the brain and (CNS). The is then processed by in the brain and and then a message or response is carried back out through our motor, or efferent, neurons in our muscles and glands.
Sneak peek into the next key topic
Image Courtesy of CNS
How do signals occur? How does our brain know what to do? Basically, must occur for a message to continue to travel down the axon of a neuron, which is the messenger. This only occurs if the neuron’s threshold has been met - meaning it has received enough stimulation🔋 from the original sending neuron. If this threshold is met, the occurs and the message travels down the axon via a process of depolarization. If the threshold is not met, nothing happens. Neurons have an all-or-none response - they either fire or they don’t.
Once the message has passed through the axon, it reaches the terminal branches. The contain which are then released. These cross the between neurons and are gathered in by of a new neuron, continuing the 📩.
The is where two neurons meet and are released into it. There is both an , which relays quick🐆 messages to another cell, and a , which sends messages slowly🦥 to another cell.
Key Terms to Review (34)
Action Potential
: Action potential is an electrical charge that travels along an axon when a neuron transmits information.Arousal System
: The arousal system refers to physiological responses that prepare us for action or alertness, often in response to stimuli such as stress or excitement.Automatic Response
: An automatic response is a bodily reaction that occurs without conscious thought, often in response to a specific stimulus.Autonomic Nervous System
: The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions such as heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal.Axon of a Neuron
: The axon is the long, slender projection of a neuron that conducts electrical impulses away from the neuron's cell body.Blood Pressure
: Blood pressure is the force exerted by circulating blood on the walls of blood vessels. It's one of the principal vital signs that health professionals measure to assess a person's physical health.Central Nervous System
: The central nervous system (CNS) consists of the brain and spinal cord. It is responsible for processing information received from all parts of the body.Chemical Synapse
: A chemical synapse is a type of synapse that uses neurotransmitters, which are chemical messengers, to transmit signals from one neuron (nerve cell) to another.Communication Process
: The communication process in psychology refers to the exchange of information, ideas, thoughts, and emotions between individuals or groups. It involves a sender transmitting an idea to a receiver.Dendrites
: Dendrites are the branched projections of a neuron that act to conduct the electrical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project.Depolarization Process
: The depolarization process refers to the change in a cell’s membrane potential, making it more positive and initiating an action potential.Electrical Synapse
: An electrical synapse is a type of synapse in which electrical current freely flows from one cell into another through structures called gap junctions.Fight-or-Flight Responses
: This is an automatic physiological reaction to stressful or threatening situations. It prepares the body for physical action - either fighting off danger or fleeing from it.Heart Rate
: The number of times your heart beats per minute.Interneurons
: Interneurons are neurons located entirely within the central nervous system that act as intermediaries between sensory neurons and motor neurons.Motor (Efferent) Neurons
: Motor neurons, also known as efferent neurons, carry information from the central nervous system to muscles and glands causing them to contract or secrete substances respectively.Nerves
: Nerves are bundles of fibers that transmit impulses between different areas within our bodies. They act as communication lines connecting various regions with our brain or spinal cord.Nervous System
: The nervous system is a complex network of nerves and cells that transmit signals between different parts of the body. It's divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).Neural Networks
: Neural networks are interconnected groups of neurons that form complex pathways in the brain, allowing for advanced processing and transmission of information.Neurotransmitters
: Neurotransmitters are chemical messengers that transmit signals across a synapse from one neuron (nerve cell) to another 'target' neuron, muscle cell, or gland cell.Parasympathetic Nervous System
: The parasympathetic nervous system is one of three divisions of the autonomic nervous system. Sometimes called the rest and digest system, it conserves energy as it slows heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in gastrointestinal tract.Peripheral Nervous System
: The peripheral nervous system (PNS) is the part of the nervous system that consists of the nerves and ganglia outside of the brain and spinal cord.Reflex
: A reflex is an involuntary and nearly instantaneous movement in response to a stimulus.Rest and Digest State
: The rest and digest state is when our bodies are calm and relaxed, focusing on maintenance tasks like digestion and growth.Sensory (afferent) neurons
: These are nerve cells within the nervous system responsible for converting external stimuli from the organism's environment into internal electrical impulses.Sensory Information
: Sensory information refers to the data received through our senses (sight, smell, touch, taste, and hearing) that is then transmitted to the brain for processing.Somatic Nervous System
: The somatic nervous system is a part of the peripheral nervous system that controls voluntary movements of skeletal muscles.Spinal Cord
: The spinal cord is a long bundle of nervous tissue that extends from the base of your brain down your back. It carries messages between your brain and body.Sympathetic Nervous System
: The sympathetic nervous system is part of autonomic nervous system responsible for initiating "fight or flight" response during stressful situations.Synapse
: A synapse is a tiny gap at which nerve cells (neurons) communicate with each other. Information from one neuron flows to another neuron across this small space.Synaptic gaps
: The synaptic gap, also known as synaptic cleft, is a tiny space between two neurons where communication occurs through the exchange of neurotransmitters.Terminal Branches of a Neuron
: Terminal branches are the ends of axons that form junctions with other cells and transmit messages to those cells.Threshold Stimulation
: Threshold stimulation is the minimum level of stimulation required to activate a particular neuron, leading to an action potential or nerve impulse.Voluntary Movements
: These are movements that individuals consciously control, such as walking, talking, or picking up an object.2.3 Overview of the Nervous System and the Neuron
3 min read•december 19, 2022
Megan Revello
Dalia Savy
Haseung Jun
Megan Revello
Dalia Savy
Haseung Jun
Vocabulary
Nervous System
The is our body’s speedy electrochemical messaging system. It is made up of both the peripheral and central nervous systems. The (CNS) is composed of our brain🧠 and 🦴, while our (PNS) connects our sensory and motor neurons to the CNS.
CNS
As mentioned above, the CNS is composed of just the brain and ! The brain's neurons work in that send messages quickly.
A is an often created by a signal neural pathway in our . Reflexes are so quick and automatic because the message is received and responded to before our brain even has time to respond. The in the enable this reflexive response.
The is also a highway🛣️ connecting the and the brain.
PNS
The can be broken down further into the autonomic and somatic systems. The is in charge of controlling of our skeletal muscles💪 - like covering your eye during an eye exam at the doctor. The then controls all automatic functions of our internal organs - like your heart beating❤️ and your lungs breathing. The automatic comes into play especially in . It can increase your or in such situations.
The can be broken down further into two other systems, the sympathetic and parasympathetic. The is our . When you get nervous before an exam your heart may race, and your breathing may become more rapid - this is thanks to the , which prepares us for action🏃. On the other hand, the returns us to a calm and neutral state once the stimuli that triggered our original arousal has subsided.
💡Sympathetic = "Fight or Flight"
💡Parasympathetic = "Rest and Digest"
Image Courtesy of Lecturio
Image courtesy to Wikimedia Commons
Image courtesy to Wikimedia Commons
Neurons
Sensory neurons, sometimes referred to as afferent neurons, are what carry incoming into the brain and (CNS). The is then processed by in the brain and and then a message or response is carried back out through our motor, or efferent, neurons in our muscles and glands.
Sneak peek into the next key topic
Image Courtesy of CNS
How do signals occur? How does our brain know what to do? Basically, must occur for a message to continue to travel down the axon of a neuron, which is the messenger. This only occurs if the neuron’s threshold has been met - meaning it has received enough stimulation🔋 from the original sending neuron. If this threshold is met, the occurs and the message travels down the axon via a process of depolarization. If the threshold is not met, nothing happens. Neurons have an all-or-none response - they either fire or they don’t.
Once the message has passed through the axon, it reaches the terminal branches. The contain which are then released. These cross the between neurons and are gathered in by of a new neuron, continuing the 📩.
The is where two neurons meet and are released into it. There is both an , which relays quick🐆 messages to another cell, and a , which sends messages slowly🦥 to another cell.
Key Terms to Review (34)
Action Potential
: Action potential is an electrical charge that travels along an axon when a neuron transmits information.Arousal System
: The arousal system refers to physiological responses that prepare us for action or alertness, often in response to stimuli such as stress or excitement.Automatic Response
: An automatic response is a bodily reaction that occurs without conscious thought, often in response to a specific stimulus.Autonomic Nervous System
: The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions such as heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal.Axon of a Neuron
: The axon is the long, slender projection of a neuron that conducts electrical impulses away from the neuron's cell body.Blood Pressure
: Blood pressure is the force exerted by circulating blood on the walls of blood vessels. It's one of the principal vital signs that health professionals measure to assess a person's physical health.Central Nervous System
: The central nervous system (CNS) consists of the brain and spinal cord. It is responsible for processing information received from all parts of the body.Chemical Synapse
: A chemical synapse is a type of synapse that uses neurotransmitters, which are chemical messengers, to transmit signals from one neuron (nerve cell) to another.Communication Process
: The communication process in psychology refers to the exchange of information, ideas, thoughts, and emotions between individuals or groups. It involves a sender transmitting an idea to a receiver.Dendrites
: Dendrites are the branched projections of a neuron that act to conduct the electrical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project.Depolarization Process
: The depolarization process refers to the change in a cell’s membrane potential, making it more positive and initiating an action potential.Electrical Synapse
: An electrical synapse is a type of synapse in which electrical current freely flows from one cell into another through structures called gap junctions.Fight-or-Flight Responses
: This is an automatic physiological reaction to stressful or threatening situations. It prepares the body for physical action - either fighting off danger or fleeing from it.Heart Rate
: The number of times your heart beats per minute.Interneurons
: Interneurons are neurons located entirely within the central nervous system that act as intermediaries between sensory neurons and motor neurons.Motor (Efferent) Neurons
: Motor neurons, also known as efferent neurons, carry information from the central nervous system to muscles and glands causing them to contract or secrete substances respectively.Nerves
: Nerves are bundles of fibers that transmit impulses between different areas within our bodies. They act as communication lines connecting various regions with our brain or spinal cord.Nervous System
: The nervous system is a complex network of nerves and cells that transmit signals between different parts of the body. It's divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).Neural Networks
: Neural networks are interconnected groups of neurons that form complex pathways in the brain, allowing for advanced processing and transmission of information.Neurotransmitters
: Neurotransmitters are chemical messengers that transmit signals across a synapse from one neuron (nerve cell) to another 'target' neuron, muscle cell, or gland cell.Parasympathetic Nervous System
: The parasympathetic nervous system is one of three divisions of the autonomic nervous system. Sometimes called the rest and digest system, it conserves energy as it slows heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in gastrointestinal tract.Peripheral Nervous System
: The peripheral nervous system (PNS) is the part of the nervous system that consists of the nerves and ganglia outside of the brain and spinal cord.Reflex
: A reflex is an involuntary and nearly instantaneous movement in response to a stimulus.Rest and Digest State
: The rest and digest state is when our bodies are calm and relaxed, focusing on maintenance tasks like digestion and growth.Sensory (afferent) neurons
: These are nerve cells within the nervous system responsible for converting external stimuli from the organism's environment into internal electrical impulses.Sensory Information
: Sensory information refers to the data received through our senses (sight, smell, touch, taste, and hearing) that is then transmitted to the brain for processing.Somatic Nervous System
: The somatic nervous system is a part of the peripheral nervous system that controls voluntary movements of skeletal muscles.Spinal Cord
: The spinal cord is a long bundle of nervous tissue that extends from the base of your brain down your back. It carries messages between your brain and body.Sympathetic Nervous System
: The sympathetic nervous system is part of autonomic nervous system responsible for initiating "fight or flight" response during stressful situations.Synapse
: A synapse is a tiny gap at which nerve cells (neurons) communicate with each other. Information from one neuron flows to another neuron across this small space.Synaptic gaps
: The synaptic gap, also known as synaptic cleft, is a tiny space between two neurons where communication occurs through the exchange of neurotransmitters.Terminal Branches of a Neuron
: Terminal branches are the ends of axons that form junctions with other cells and transmit messages to those cells.Threshold Stimulation
: Threshold stimulation is the minimum level of stimulation required to activate a particular neuron, leading to an action potential or nerve impulse.Voluntary Movements
: These are movements that individuals consciously control, such as walking, talking, or picking up an object.
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