Podcast
Questions and Answers
What role do glial cells serve in the nervous system?
What role do glial cells serve in the nervous system?
- They provide structure and support to neurons. (correct)
- They transmit signals between neurons.
- They facilitate muscle contractions.
- They replicate and communicate like neurons.
Which part of the neuron is primarily responsible for sending signals to other neurons?
Which part of the neuron is primarily responsible for sending signals to other neurons?
- Axon (correct)
- Cell body
- Nucleus
- Dendrites
What is the primary characteristic of neurons regarding replication?
What is the primary characteristic of neurons regarding replication?
- Neurons can replicate under certain conditions.
- Neurons replicate constantly.
- Neurons replicate during any stage of life.
- Neurons do not replicate. (correct)
Where in the body is the central nervous system located?
Where in the body is the central nervous system located?
What function does the endoplasmic reticulum serve in a neuron?
What function does the endoplasmic reticulum serve in a neuron?
Which division of the nervous system is responsible for the 'rest and digest' response?
Which division of the nervous system is responsible for the 'rest and digest' response?
What are neurotransmitters?
What are neurotransmitters?
Which part of the neuron receives signals from other neurons?
Which part of the neuron receives signals from other neurons?
What neurotransmitter is primarily responsible for inhibitory signaling in the nervous system?
What neurotransmitter is primarily responsible for inhibitory signaling in the nervous system?
What process is primarily responsible for the elimination of neurotransmitters from the synapse?
What process is primarily responsible for the elimination of neurotransmitters from the synapse?
Which neurotransmitter is linked to the mood regulation and organ function?
Which neurotransmitter is linked to the mood regulation and organ function?
Selective serotonin reuptake inhibitors (SSRIs) are primarily used to treat which conditions?
Selective serotonin reuptake inhibitors (SSRIs) are primarily used to treat which conditions?
What type of neurons release glutamate?
What type of neurons release glutamate?
What is the primary function of the sodium/potassium pump in neurons?
What is the primary function of the sodium/potassium pump in neurons?
What is the resting membrane potential of a neuron?
What is the resting membrane potential of a neuron?
What is the primary role of the sodium-potassium pump in neurons?
What is the primary role of the sodium-potassium pump in neurons?
Which ions are primarily involved in generating action potentials in neurons?
Which ions are primarily involved in generating action potentials in neurons?
What triggers the opening of ligand-gated channels?
What triggers the opening of ligand-gated channels?
Where do graded potentials primarily occur in a neuron?
Where do graded potentials primarily occur in a neuron?
How does the ionic movement contribute to the action potential in neurons?
How does the ionic movement contribute to the action potential in neurons?
What occurs during hyperpolarization of a neuron?
What occurs during hyperpolarization of a neuron?
What occurs to the membrane potential when a neuron is depolarized?
What occurs to the membrane potential when a neuron is depolarized?
What causes repolarization in a neuron after depolarization?
What causes repolarization in a neuron after depolarization?
What is meant by the term 'polarized membrane' in relation to neurons?
What is meant by the term 'polarized membrane' in relation to neurons?
What is a characteristic of graded potentials?
What is a characteristic of graded potentials?
What triggers the release of neurotransmitters in neurons?
What triggers the release of neurotransmitters in neurons?
Which of the following channels opens in response to mechanical pressure?
Which of the following channels opens in response to mechanical pressure?
What role do negatively charged proteins play inside the neuron?
What role do negatively charged proteins play inside the neuron?
What are the types of membrane ion channels mentioned?
What are the types of membrane ion channels mentioned?
What is the threshold voltage that must be reached to generate an action potential?
What is the threshold voltage that must be reached to generate an action potential?
Which ions are primarily involved in the depolarization of the neuron during an action potential?
Which ions are primarily involved in the depolarization of the neuron during an action potential?
What happens during the absolute refractory period?
What happens during the absolute refractory period?
How does the sodium-potassium pump affect membrane potential after an action potential?
How does the sodium-potassium pump affect membrane potential after an action potential?
What is the nature of propagation of an action potential down a myelinated axon?
What is the nature of propagation of an action potential down a myelinated axon?
What must the membrane potential be to allow a second action potential to occur during the relative refractory period?
What must the membrane potential be to allow a second action potential to occur during the relative refractory period?
What is primarily responsible for the rapid entry of sodium ions into neurons when the threshold is reached?
What is primarily responsible for the rapid entry of sodium ions into neurons when the threshold is reached?
What role does excess potassium play during the generation of action potentials?
What role does excess potassium play during the generation of action potentials?
Study Notes
Nervous Tissue
- Nervous tissue is composed of two types of cells: neurons and glial cells.
- Neurons are responsible for communication within the nervous system.
- Glial cells provide structure and support to neurons, but cannot communicate.
Neuron Anatomy
- Cell Body houses organelles such as the nucleus, nucleolus, ribosomes, and endoplasmic reticulum.
- Dendrites receive signals from other neurons.
- Axon begins at the axon hillock and sends signals to other neurons.
Nervous Systems
- The Central Nervous System (CNS) includes the brain and spinal cord, which are housed within the cranial cavity and vertebral cavity.
- The Peripheral Nervous System (PNS) comprises the nerves outside the brain and spinal cord, lacking bony protection.
Communication within the Nervous System
- Communication depends on electrical signaling which occurs due to the movement of ions.
- Ion movements generate action potentials, leading to the release of neurotransmitters.
Membrane Potentials
- The cell membrane acts as a barrier to ionic movement.
- This difference in charge is called the resting membrane potential
- Resting membrane potential of a neuron is -70 mV.
Maintaining Resting Membrane Potential
- Sodium-Potassium Pump: pumps 3 sodium ions out of the cell and 2 potassium ions into the cell, creating a relatively negative internal environment.
- Unequal Distribution of Ions: Sodium ions are more concentrated outside the cell, while potassium ions are more concentrated inside the cell.
- Leak Channels: Potassium ions exit the cell through leak channels, further contributing to the negative charge inside the cell.
Changes in Resting Membrane Potential
- Depolarization: The charge difference decreases, making the interior of the cell less negative.
- Hyperpolarization: The charge difference increases, making the interior of the cell more negative.
- Repolarization: A return to a polarized state after depolarization occurs.
Membrane Channels
- Ligand-Gated Channels: Open and close due to the binding of a molecule (ligand).
- Mechanically-Gated Channels: Open and close in response to pressure or distortions in cell membranes.
Graded Potentials
- Small changes in the resting membrane potential that vary in size.
- Caused by mechanically-gated and ligand-gated membrane channels.
- Occur along dendrites and the cell body.
- May hyperpolarize when excess potassium exits.
- Sodium-Potassium pumps restore the membrane potential back to -70mV.
Action Potentials
- Occur when a threshold of -55mV is reached.
- Triggered by opening voltage-gated sodium and potassium channels.
- Sodium ions rapidly enter the neuron, depolarizing it.
- Potassium ions exit the neuron, repolarizing it.
Refractory Period
- Occurs after an action potential is generated.
- Absolute Refractory Period: No new action potential can be generated.
- Relative Refractory Period: A new action potential can be generated only with a stronger stimulus.
Propagation of an Action Potential
- Action potential travels down the axon in a sequence.
- Sodium ions enter one section of the axon, depolarizing it, and triggering the depolarization of the next section.
Myelinated Axons
- Myelinated axons are wrapped in a myelin sheath, which speeds up the conduction of action potentials.
- This is called saltatory conduction.
Neurotransmitters
- Chemicals that relay messages from neurons.
- Examples include:
- Glutamate: Learning and memory
- GABA: Principal inhibitory neurotransmitter
- Glycine: Spinal cord
- Dopamine: Reward system
- Norepinephrine: Mood and regulation of organ function
- Epinephrine: Adrenaline
- Neurotransmitters have specific receptors on the postsynaptic neuron.
- They are eliminated from the synapse via reuptake.
Serotonin
- Serotonin reuptake inhibitors (SSRIs) are used to treat anxiety and depression.
- SSRIs block the reuptake of serotonin, increasing its concentration in the synapse.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores the structure and function of nervous tissue, focusing on neurons and glial cells. It covers neuron anatomy, including the cell body, dendrites, and axon, and distinguishes between the central and peripheral nervous systems. Test your knowledge of how communication within the nervous system occurs through electrical signaling.
