Nervous System Part 1

Flashcard 1

Q: What are the primary functions of the nervous system?

A: Sensory input (detects changes), integration (processes information), and motor output (activates responses).

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Flashcard 2

Q: What are neurons?

A: Specialized cells that transmit electrical impulses to communicate with other cells.

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Flashcard 3

Q: What is the function of neuroglia?

A: To support, nourish, protect, and insulate neurons.

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Flashcard 4

Q: What role do neurotransmitters play in neural communication?

A: They transmit signals across synapses from one neuron to another or to other target cells.

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Flashcard 5

Q: How is the nervous system organized?

A: Into the Central Nervous System (CNS) and Peripheral Nervous System (PNS).

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Flashcard 6

Q: What does the CNS consist of?

A: The brain and spinal cord.

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Flashcard 7

Q: What is the PNS, and what is its function?

A: The Peripheral Nervous System, which connects the CNS to the rest of the body, facilitating communication.

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Flashcard 8

Q: Describe the sensory (afferent) division of the PNS.

A: It carries signals from sensory receptors to the CNS.

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Flashcard 9

Q: Describe the motor (efferent) division of the PNS.

A: It transmits signals from the CNS to muscles and glands.

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Flashcard 10

Q: What are the two subdivisions of the motor division?

A: Somatic Nervous System (voluntary control) and Autonomic Nervous System (involuntary control).

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Flashcard 11

Q: What does the somatic nervous system control?

A: Voluntary movements of skeletal muscles.

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Flashcard 12

Q: What is the role of the autonomic nervous system?

A: Controls involuntary actions of smooth muscles, cardiac muscles, and glands.

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Flashcard 13

Q: Name the types of neuroglia found in the CNS.

A: Microglia, oligodendrocytes, astrocytes, and ependymal cells.

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Flashcard 14

Q: What are the types of neuroglia in the PNS?

A: Schwann cells and satellite cells.

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Flashcard 15

Q: What is the role of microglia?

A: Act as phagocytes, cleaning up cellular debris and pathogens in the CNS.

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Flashcard 16

Q: What is the function of oligodendrocytes?

A: Form the myelin sheath around CNS axons.

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Flashcard 17

Q: What do astrocytes do in the CNS?

A: Provide structural support, regulate nutrients, and maintain the blood-brain barrier.

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Flashcard 18

Q: What is the function of ependymal cells?

A: They produce and circulate cerebrospinal fluid in the CNS.

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Flashcard 19

Q: How do Schwann cells function in the PNS?

A: They produce myelin sheaths around peripheral nerves, aiding in impulse conduction.

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Flashcard 20

Q: Describe the structure of a neuron.

A: Consists of a cell body, dendrites, and an axon.

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Flashcard 21

Q: What is the purpose of dendrites?

A: They receive signals and conduct impulses toward the cell body.

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Flashcard 22

Q: What is the function of the axon?

A: Conducts impulses away from the cell body toward other neurons or effectors.

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Flashcard 23

Q: What is a myelin sheath?

A: An insulating layer that surrounds axons, speeding up impulse transmission.

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Flashcard 24

Q: What are nodes of Ranvier?

A: Gaps in the myelin sheath where ion exchange occurs, aiding rapid signal conduction.

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Flashcard 25

Q: Define resting membrane potential.

A: The stable, negative charge of a neuron at rest, typically around -70 mV.

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Flashcard 26

Q: What creates the resting membrane potential?

A: The unequal distribution of ions, with more sodium ions outside and more potassium ions inside the cell.

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Flashcard 27

Q: What is depolarization in a neuron?

A: The process by which the inside of a neuron becomes less negative, initiating an action potential.

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Flashcard 28

Q: Define action potential.

A: A rapid change in membrane potential that propagates along the neuron.

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Flashcard 29

Q: What is the "all-or-none" principle?

A: An action potential either fully occurs if the threshold is met, or it does not occur at all.

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Flashcard 30

Q: Explain repolarization.

A: The process of returning the neuron to its resting membrane potential after an action potential.

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Flashcard 31

Q: What is hyperpolarization?

A: When the membrane potential becomes slightly more negative than the resting potential after repolarization.

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Flashcard 32

Q: Describe continuous conduction.

A: Sequential transmission of impulses along unmyelinated axons.

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Flashcard 33

Q: What is saltatory conduction?

A: Impulse transmission in myelinated axons where impulses "jump" from one node of Ranvier to another.

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Flashcard 34

Q: What is the role of a synapse?

A: A junction where a neuron communicates with another neuron or cell.

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Flashcard 35

Q: What are excitatory neurotransmitters?

A: Chemicals that increase the likelihood of an action potential by making the postsynaptic neuron less negative.

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Flashcard 36

Q: What are inhibitory neurotransmitters?

A: Chemicals that decrease the likelihood of an action potential by making the postsynaptic neuron more negative.

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Flashcard 37

Q: What is the primary function of acetylcholine?

A: Controls skeletal muscle actions and can stimulate or inhibit autonomic responses depending on receptor types.

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Flashcard 38

Q: What role does norepinephrine play in the nervous system?

A: Associated with creating a feeling of well-being and may excite or inhibit autonomic nervous system responses.

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Flashcard 39

Q: What is the role of dopamine?

A: Produces a sense of pleasure; low levels are linked to Parkinson's disease.

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Flashcard 40

Q: Describe the function of serotonin.

A: Primarily inhibitory and associated with sleep; its activity is enhanced by SSRIs.

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Flashcard 41

Q: What is nitric oxide's role in the nervous system?

A: Acts as a vasodilator in the PNS and may play a role in memory in the CNS.

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Flashcard 42

Q: Define a reflex arc.

A: The pathway followed by nerve impulses in a reflex, typically involving a receptor, sensory neuron, interneuron, motor neuron, and effector.

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Flashcard 43

Q: What is the function of the patellar reflex?

A: Helps maintain posture by triggering the knee-jerk response upon stretching of the quadriceps tendon.

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Flashcard 44

Q: Describe the withdrawal reflex.

A: An involuntary response to pain that pulls the body part away from harmful stimuli, involving sensory, motor, and interneurons.

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Flashcard 45

Q: Explain neurotransmitter reuptake.

A: The process of neurotransmitters being reabsorbed by the presynaptic neuron for reuse, stopping their action on the postsynaptic cell.

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Flashcard 46

Q: What is a neuronal pool?

A: A group of neurons that process information and may either inhibit or excite responses in the CNS.

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Flashcard 47

Q: What is facilitation in neuronal pools?

A: A condition where a neuron becomes more responsive to stimulation after repeated excitatory input.

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Flashcard 48

Q: What is convergence in the nervous system?

A: Multiple presynaptic neurons connect to a single postsynaptic neuron, allowing it to integrate information.

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Flashcard 49

Q: Define divergence in the nervous system.

A: A single neuron branches out to communicate with multiple neurons, amplifying the signal.

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Flashcard 50

Q: What are mixed nerves?

A: Nerves that contain both sensory and motor fibers, most common in the PNS.

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Flashcard 51

Q: What are sensory (afferent) nerves?

A: Nerves that carry impulses from sensory receptors to the CNS.

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Flashcard 52

Q: What are motor (efferent) nerves?

A: Nerves that carry impulses from the CNS to effectors like muscles or glands.

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Flashcard 53

Q: Describe the structure of a nerve's connective tissue coverings.

A: Epineurium surrounds the entire nerve, perineurium surrounds nerve fascicles, and endoneurium surrounds individual nerve fibers.

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Flashcard 54

Q: What is the role of the blood-brain barrier?

A: A selective barrier maintained by astrocytes to protect the brain from harmful substances in the blood.

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