Nervous System part 3

Flashcard 1

Q: What are the three main functions of the nervous system?

A: Sensory input, integration/processing, and motor output.

Flashcard 2

Q: What are the two main cell types in the nervous system?

A: Neurons and neuroglia.

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### Neuron Structure and Function

Flashcard 3

Q: Describe the structure of a neuron.

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

Flashcard 4

Q: What is the role of dendrites?

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

Flashcard 5

Q: What is the function of the axon?

A: To transmit impulses away from the cell body.

Flashcard 6

Q: What is the function of the myelin sheath?

A: It insulates the axon, speeding up the transmission of nerve impulses.

Flashcard 7

Q: What are nodes of Ranvier?

A: Gaps in the myelin sheath that facilitate rapid impulse conduction through saltatory conduction.

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### Neuroglia Types and Functions

Flashcard 8

Q: List the types of neuroglia in the CNS.

A: Astrocytes, oligodendrocytes, microglia, and ependymal cells.

Flashcard 9

Q: What is the primary function of astrocytes?

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

Flashcard 10

Q: Describe the function of Schwann cells in the PNS.

A: They produce the myelin sheath around peripheral axons.

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### Membrane Potential and Action Potentials

Flashcard 11

Q: What is the resting membrane potential of a neuron?

A: Approximately -70 mV, with the inside of the neuron more negative than the outside.

Flashcard 12

Q: Define depolarization.

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

Flashcard 13

Q: What is an action potential?

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

Flashcard 14

Q: What occurs during repolarization?

A: The membrane potential returns to a negative value after an action potential.

Flashcard 15

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

A: An action potential occurs fully if the threshold is reached; otherwise, it does not occur at all.

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### Synapses and Neurotransmitters

Flashcard 16

Q: What is a synapse?

A: The junction between two neurons where neurotransmitters transmit signals.

Flashcard 17

Q: Name an excitatory neurotransmitter and its role.

A: Glutamate; it increases the likelihood of an action potential in the postsynaptic neuron.

Flashcard 18

Q: What is the role of GABA as a neurotransmitter?

A: It is inhibitory, decreasing the likelihood of an action potential.

Flashcard 19

Q: How is neurotransmitter action stopped?

A: Through reuptake or enzymatic breakdown to prevent continuous stimulation.

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### Nervous System Divisions

Flashcard 20

Q: What are the two main divisions of the nervous system?

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

Flashcard 21

Q: What does the CNS include?

A: The brain and spinal cord.

Flashcard 22

Q: Describe the PNS and its components.

A: It consists of cranial and spinal nerves that connect the CNS to the body, including sensory and motor divisions.

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### CNS - Spinal Cord Structure and Function

Flashcard 23

Q: How many segments does the spinal cord have?

A: 31 segments, each with a pair of spinal nerves.

Flashcard 24

Q: Name the primary functions of the spinal cord.

A: To transmit impulses to and from the brain and house spinal reflexes.

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### Meninges

Flashcard 25

Q: What are the three layers of the meninges?

A: Dura mater, arachnoid mater, and pia mater.

Flashcard 26

Q: What is the role of the dura mater?

A: It is the tough outer layer, containing blood vessels and forming a sheath around the spinal cord.

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### Brain Structure - Cerebrum and Lobes

Flashcard 27

Q: What are the four lobes of the cerebrum?

A: Frontal, parietal, temporal, and occipital lobes.

Flashcard 28

Q: What is the function of the cerebrum?

A: Responsible for sensory processing, motor control, and higher mental functions like reasoning and memory.

Flashcard 29

Q: What is the cerebral cortex?

A: The outer layer of gray matter involved in processing and containing neuron cell bodies.

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### Brainstem and Functions

Flashcard 30

Q: What are the three parts of the brainstem?

A: Midbrain, pons, and medulla oblongata.

Flashcard 31

Q: Describe the function of the medulla oblongata.

A: It regulates vital functions like heart rate, blood pressure, and breathing.

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### Cranial Nerves

Flashcard 32

Q: How many cranial nerves are there?

A: Twelve pairs.

Flashcard 33

Q: What is the function of the optic nerve (Cranial Nerve II)?

A: Vision.

Flashcard 34

Q: What does the vagus nerve (Cranial Nerve X) control?

A: It controls muscles related to speech, heart rate, and digestion.

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### Spinal Reflexes and Reflex Arcs

Flashcard 35

Q: What is a reflex arc?

A: The pathway of a reflex, involving a sensory neuron, interneuron, and motor neuron.

Flashcard 36

Q: Give an example of a simple reflex.

A: The patellar (knee-jerk) reflex.

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### Ventricles and Cerebrospinal Fluid (CSF)

Flashcard 37

Q: What are the brain ventricles?

A: Connected cavities filled with CSF, providing protection and nutrients to the CNS.

Flashcard 38

Q: Where is cerebrospinal fluid (CSF) produced?

A: In the choroid plexuses of the ventricles.

Flashcard 39

Q: What is the function of CSF?

A: It cushions the brain and spinal cord and transports nutrients and wastes.

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### Limbic System

Flashcard 40

Q: What is the primary role of the limbic system?

A: To control emotional responses and behavior related to survival.

Flashcard 41

Q: Name a key structure in the limbic system associated with emotion.

A: The amygdala.

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### Diencephalon - Thalamus and Hypothalamus

Flashcard 42

Q: What is the function of the thalamus?

A: To relay sensory information to the cerebral cortex.

Flashcard 43

Q: How does the hypothalamus maintain homeostasis?

A: By regulating functions like body temperature, hunger, and endocrine activity.

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### Autonomic Nervous System (ANS)

Flashcard 44

Q: What are the two divisions of the autonomic nervous system?

A: Sympathetic (fight or flight) and parasympathetic (rest and digest).

Flashcard 45

Q: Which neurotransmitter is mainly associated with the sympathetic division?

A: Norepinephrine.

Flashcard 46

Q: Which neurotransmitter is mainly associated with the parasympathetic division?

A: Acetylcholine.

Flashcard 47

Q: Describe the effects of the sympathetic nervous system on the heart and lungs.

A: Increases heart rate and dilates bronchioles.

Flashcard 48

Q: Describe the effects of the parasympathetic nervous system on digestion.

A: Increases digestive activities, such as peristalsis and glandular secretion.

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### Nerve Plexuses

Flashcard 49

Q: What is a nerve plexus?

A: A network of intersecting nerves that control muscles and skin of specific body regions.

Flashcard 50

Q: Name the three main nerve plexuses.

A: Cervical, brachial, and lumbosacral plexuses.

Flashcard 51

Q: What does the phrenic nerve control, and which plexus

is it part of?

A: It controls the diaphragm and is part of the cervical plexus.

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### Sympathetic vs. Parasympathetic Pathways

Flashcard 52

Q: Where do sympathetic fibers originate?

A: From the thoracic and lumbar regions of the spinal cord (T1-L2).

Flashcard 53

Q: Where do parasympathetic fibers originate?

A: From the brainstem and sacral spinal cord.

Flashcard 54

Q: What are autonomic ganglia?

A: Structures where preganglionic neurons synapse with postganglionic neurons.