Questions and Answers
The ______ is responsible for higher functions such as thinking and memory.
cerebrum
The ______ coordinates movement and balance.
cerebellum
The ______ controls basic life functions like breathing and heart rate.
brainstem
Neuroplasticity is the ability of the nervous system to ______ and adapt in response to experience.
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The nervous system maintains internal balance through ______ mechanisms.
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The nervous system is composed of the central nervous system (CNS) and the ______ nervous system.
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The components of the central nervous system (CNS) are the brain and ______.
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Neurons transmit signals away from the cell body through the ______.
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The temporary reversal of the electrical potential across a neuron's membrane is called ______.
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In the autonomic nervous system, the ______ division prepares the body for 'fight or flight' responses.
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Sodium channels open during the ______ phase of action potential.
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Neurotransmitters that promote a response are known as ______ neurotransmitters.
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The somatic nervous system is part of the ______ nervous system.
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The ______ is the long projection that transmits signals away from the cell body.
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The insulating layer around the axon is called the ______ sheath.
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During an action potential, the rapid influx of ______ ions causes depolarization.
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______ is involved in muscle activation and memory as a key neurotransmitter.
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The ______ nervous system manages involuntary functions.
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Saltatory conduction refers to action potentials jumping between ______ of Ranvier.
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The ______ nervous system consists of all neural tissue outside the CNS.
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The ______ period prevents a neuron from immediate re-firing after an action potential.
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Study Notes
Physiology of the Nervous System
Overview
- The nervous system coordinates and regulates body functions through electrical and chemical signals.
- Composed of the central nervous system (CNS) and peripheral nervous system (PNS).
Central Nervous System (CNS)
- Components: Brain and spinal cord.
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Functions:
- Integrates sensory information.
- Controls motor responses.
- Responsible for higher cognitive functions (thinking, memory, emotion).
Peripheral Nervous System (PNS)
- Components: Somatic nervous system and autonomic nervous system.
-
Functions:
- Connects CNS to limbs and organs.
- Carries sensory information to the CNS and motor commands from the CNS.
Neurons
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Structure:
- Dendrites: Receive signals.
- Cell body: Contains nucleus.
- Axon: Transmits signals away from the cell body.
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Types:
- Sensory neurons: Relay sensory information to the CNS.
- Motor neurons: Convey commands from the CNS to muscles.
- Interneurons: Connect neurons within the CNS.
Action Potential
- Definition: A temporary reversal of the electrical potential across a neuron's membrane.
-
Phases:
- Depolarization: Sodium channels open, sodium ions rush in.
- Repolarization: Potassium channels open, potassium ions exit.
- Hyperpolarization: Membrane potential becomes more negative temporarily.
- Propagation: Action potentials travel along the axon via saltatory conduction in myelinated fibers.
Synaptic Transmission
-
Process:
- Action potential reaches axon terminal.
- Release of neurotransmitters into synaptic cleft.
- Bind to receptors on post-synaptic neuron, generating a response.
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Types of Neurotransmitters:
- Excitatory (e.g., glutamate) and inhibitory (e.g., GABA).
Autonomic Nervous System (ANS)
-
Divisions:
- Sympathetic: Prepares body for 'fight or flight' responses.
- Parasympathetic: Promotes 'rest and digest' functions.
- Regulation: Controls involuntary functions (heart rate, digestion).
Brain Regions
- Cerebrum: Higher functions (thinking, memory, voluntary movement).
- Cerebellum: Coordination of movement and balance.
- Brainstem: Controls basic life functions (breathing, heart rate).
Neuroplasticity
- Definition: The ability of the nervous system to change and adapt in response to experience.
- Importance: Essential for learning, memory formation, and recovery from injury.
Homeostasis
- Role of the Nervous System: Maintains internal balance by regulating physiological processes through feedback mechanisms.
Key Points
- The nervous system operates via complex networks of neurons and synapses.
- Electrical impulses and chemical signals are fundamental to communication within the nervous system.
- Understanding these processes is crucial for the study of behavior, cognition, and health.
Overview of the Nervous System
- Coordinates body functions via electrical and chemical signals.
- Composed of the central nervous system (CNS) and the peripheral nervous system (PNS).
Central Nervous System (CNS)
- Components: Consists of the brain and spinal cord.
-
Functions:
- Integrates sensory information from the body.
- Controls motor responses to stimuli.
- Responsible for higher cognitive functions, including thinking, memory, and emotions.
Peripheral Nervous System (PNS)
- Components: Divided into the somatic and autonomic nervous systems.
-
Functions:
- Connects the CNS to limbs and organs.
- Transmits sensory information to the CNS and motor commands from the CNS.
Neurons
-
Structure:
- Dendrites: Receive incoming signals.
- Cell body: Contains the nucleus, processes information.
- Axon: Transmits signals away from the cell body.
-
Types:
- Sensory neurons: Convey sensory information to the CNS.
- Motor neurons: Send commands from the CNS to muscles.
- Interneurons: Facilitate communication within the CNS.
Action Potential
- Definition: A brief reversal of electrical potential across a neuron's membrane.
-
Phases:
- Depolarization: Sodium channels open, allowing sodium ions to enter.
- Repolarization: Potassium channels open, letting potassium ions exit.
- Hyperpolarization: Temporary increase in negativity of the membrane potential.
- Propagation: Move along the axon through saltatory conduction, which occurs in myelinated fibers.
Synaptic Transmission
-
Process:
- Action potential reaches the axon terminal and triggers neurotransmitter release.
- Neurotransmitters cross the synaptic cleft and bind to receptors on the post-synaptic neuron, generating a response.
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Types of Neurotransmitters:
- Excitatory (e.g., glutamate) facilitate action potential generation.
- Inhibitory (e.g., GABA) decrease the likelihood of action potentials.
Autonomic Nervous System (ANS)
-
Divisions:
- Sympathetic: Activates 'fight or flight' responses during stress.
- Parasympathetic: Encourages 'rest and digest' processes.
- Regulation: Governs involuntary functions such as heart rate and digestion.
Brain Regions
- Cerebrum: Manages higher cognitive functions, including voluntary movement and reasoning.
- Cerebellum: Coordinates movement, balance, and posture.
- Brainstem: Regulates essential life functions like breathing and heart rate.
Neuroplasticity
- Definition: Ability of the nervous system to adapt and change in response to experiences.
- Importance: Critical for processes such as learning, memory formation, and recovery from injuries.
Homeostasis
- Role of the Nervous System: Maintains internal balance by regulating physiological processes through feedback mechanisms.
Key Points
- The nervous system relies on intricate networks of neurons and synapses for communication.
- Electrical impulses and chemical signals serve as fundamental mechanisms for nervous system operation.
- Understanding these neural processes is vital for exploring behavior, cognition, and health.
Neuron Structure
- Neurons serve as the basic units of the nervous system.
- The cell body (soma) houses the nucleus and key organelles necessary for neuron function.
- Dendrites are branching structures that receive incoming signals from other neurons.
- The axon is a long projection that transmits electrical signals away from the soma toward other neurons or tissue.
- Myelin sheath is an insulating layer around the axon that enhances the speed of signal transmission.
- Nodes of Ranvier are gaps in the myelin sheath where the regeneration of action potentials occurs.
- Axon terminals release neurotransmitters, facilitating communication with other neurons.
Signal Transmission
- Neurons maintain a resting potential of approximately -70 mV, indicating a negative charge inside relative to the outside.
- Action potential occurs when a neuron depolarizes and reaches a threshold level of -55 mV.
- Following depolarization, Na+ ions rapidly enter the neuron, making the inside more positive.
- Repolarization happens as K+ ions exit the neuron, restoring the negative charge.
- There is a refractory period during which the neuron cannot fire again immediately after an action potential.
- Saltatory conduction refers to the process where action potentials leap between nodes of Ranvier, significantly increasing conduction speed.
Neurotransmitters
- Neurotransmitters are chemical messengers that enable signal transmission across synapses.
- Key neurotransmitters include:
- Acetylcholine: Essential for muscle activation and memory processes.
- Dopamine: Linked to pleasure, reward pathways, and motor control functions.
- Serotonin: Regulates mood, sleep cycles, and appetite.
- Norepinephrine: Affects attention, response actions, and the state of arousal.
- GABA: The primary inhibitory neurotransmitter, helping to decrease neuronal excitability.
Central Vs Peripheral Nervous System
- The central nervous system (CNS) consists of the brain and spinal cord and is crucial for processing and integrating sensory information.
- The peripheral nervous system (PNS) includes all neural tissue outside the CNS.
- The PNS is classified into two main divisions:
- Somatic nervous system: Governs voluntary movements of skeletal muscles.
- Autonomic nervous system: Regulates involuntary physiological functions, further divided into:
- Sympathetic nervous system: Prepares body for 'fight or flight' responses.
- Parasympathetic nervous system: Promotes 'rest and digest' activities.
Functional Organization Of Neural Circuits
- Neural circuits consist of interconnected neurons that process specific types of information.
- Types of neural circuits include:
- Converging circuits: Multiple inputs converge to produce a single output, useful for integrating sensory information.
- Diverging circuits: One input spreads to multiple outputs, amplifying signals.
- Reverberating circuits: Neurons stimulate each other in a loop, engaged in rhythmic activities like breathing.
- Parallel after-discharge circuits: Input traveling through various pathways leads to a single complex output, enabling sophisticated processing.
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Description
Explore the intricate workings of the nervous system in this quiz. Learn about the central and peripheral nervous systems, their components, and functions. Test your knowledge on neurons and their roles in transmitting signals throughout the body.
