ch 3 Flashcards
What are the two major types of cells in the nervous system?
Neurons and glial cells.
What is the primary function of neurons?
Neurons are responsible for communication within the nervous system, using electrical and chemical signals to transmit information.
What is the main role of glial cells in the nervous system?
Glial cells provide support, insulation, and protection for neurons, and they assist in maintaining homeostasis in the brain.
What are dendrites, and what do they do?
Dendrites are branches of neurons that receive input from other neurons and sensory receptors.
What is the function of the axon in a neuron?
The axon carries signals away from the cell body toward other neurons or effector cells.
What is the myelin sheath, and why is it important?
The myelin sheath is a fatty layer covering segments of the axon that insulates the neuron and speeds up neural impulses.
What happens at the axon terminal?
The axon terminal releases neurotransmitters that allow the neuron to communicate with other neurons across a synapse.
How do neurons communicate with each other?
Neurons communicate using both electrical impulses (action potentials) and chemical signals (neurotransmitters).
What are synapses?
Synapses are small gaps between neurons where neurotransmitters are released to transmit signals to the next neuron.
What is neuroplasticity?
Neuroplasticity is the brain’s ability to reorganize and form new neural connections in response to experience or injury.
What is the blood-brain barrier (BBB), and which cells are involved in its formation?
The BBB is a protective barrier that prevents harmful substances from entering the brain. Astroglial cells are involved in creating it.
What is an action potential?
An action potential is a sudden, rapid increase in electrical charge that travels down a neuron’s axon when a threshold voltage is reached.
What are astrocytes, and what function do they serve?
Astrocytes are glial cells that help create the blood-brain barrier and regulate blood flow in response to neuronal activity.
What is the sodium-potassium pump, and what role does it play in neurons?
The sodium-potassium pump is a protein that moves sodium ions out of the neuron and potassium ions into it, helping to maintain the resting potential.
How do glial cells contribute to the myelin sheath?
Oligodendroglia in the central nervous system and Schwann cells in the peripheral nervous system form the myelin sheath around axons.
What neurotransmitter is involved in mood regulation and sleep?
Serotonin is involved in mood regulation, sleep, and appetite.
What is the difference between excitatory and inhibitory neurotransmitters?
Excitatory neurotransmitters trigger action potentials in the postsynaptic neuron, while inhibitory neurotransmitters prevent action potentials.
What is the role of dopamine in the brain?
Dopamine is involved in controlling voluntary movement, mood, and reward mechanisms.
What is the function of GABA?
GABA is the main inhibitory neurotransmitter in the brain, helping to reduce neural activity and promote relaxation.
What is neuroplasticity, and why is it important?
Neuroplasticity refers to the brain’s ability to change and adapt by forming new neural pathways, allowing for learning and recovery after injury.
What is multiple sclerosis (MS), and how does it affect neurons?
MS is a disease that involves the degradation of the myelin sheath on neurons, leading to impaired signal transmission and symptoms like muscle weakness.
How do action potentials travel faster along myelinated neurons?
Action potentials jump from one node of Ranvier (gaps in the myelin sheath) to the next, speeding up conduction through saltatory conduction.
What is synaptic plasticity?
Synaptic plasticity refers to changes in the strength or number of synapses due to experience, learning, or injury, affecting how neurons communicate.
What is acetylcholine’s role in the nervous system?
Acetylcholine is involved in stimulating muscles, attention, arousal, memory, and motor control.
What happens during the refractory period of a neuron?
During the absolute refractory period, the neuron cannot fire another action potential, while during the relative refractory period, it can fire with a stronger-than-usual stimulus.
What is glutamate, and what is its primary function in the brain?
Glutamate is the most common excitatory neurotransmitter in the brain, playing a key role in learning and memory formation.
How do sodium and potassium ions contribute to a neuron’s resting potential?
Sodium ions are kept outside the neuron, while potassium ions are inside, creating a negative charge inside the neuron, which maintains the resting potential.
What happens when neurotransmitters are released into the synaptic cleft?
Neurotransmitters bind to receptors on the postsynaptic neuron, causing either excitatory or inhibitory effects, depending on the type of neurotransmitter.
What is the corpus callosum, and what is its function?
The corpus callosum is a bundle of axons that connects the two hemispheres of the brain, allowing communication between them.
What is an example of brain lateralization in humans?
In most people, language areas such as Broca’s and Wernicke’s areas are located in the left hemisphere of the brain.
What are interneurons, and what is their function?
Interneurons act as connectors, communicating between sensory and motor neurons, and also among themselves within the nervous system.
What are sensory neurons responsible for?
Sensory neurons detect stimuli from the environment (such as light, sound, touch) and send this information to the brain and spinal cord.
What do motor neurons do?
Motor neurons carry signals from the brain and spinal cord to muscles and glands, enabling movement and other responses.
What is saltatory conduction?
Saltatory conduction is the process by which action potentials jump from one node of Ranvier to the next in myelinated neurons, speeding up signal transmission.
What is a neurotransmitter receptor?
A neurotransmitter receptor is a protein on the postsynaptic neuron’s membrane that binds to neurotransmitters, enabling communication between neurons.
What is the role of ependymal cells?
Ependymal cells line the brain’s ventricles and produce cerebrospinal fluid, which cushions the brain and spinal cord.
What is hyperpolarization in a neuron?
Hyperpolarization is when the inside of a neuron becomes more negative than its resting potential, making it less likely for the neuron to fire an action potential.
What is synaptic pruning?
Synaptic pruning is the process of eliminating weaker synaptic connections, allowing stronger and more efficient connections to thrive, which is important for brain development and plasticity.
What is the blood-brain barrier (BBB)?
The BBB is a selective barrier formed by astrocytes that prevents harmful substances from entering the brain while allowing essential nutrients to pass through.
What is the function of microglia in the nervous system?
Microglia act as the brain’s immune cells, cleaning up debris from dead or damaged neurons and protecting the brain from infections
