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Questions and Answers
Questions and Answers
Which of the following accurately describes the arrangement of gray and white matter in the spinal cord compared to the brain?
Which of the following accurately describes the arrangement of gray and white matter in the spinal cord compared to the brain?
- Both the brain and spinal cord have gray matter on the outer side and white matter on the inner side.
- Both the brain and spinal cord have white matter on the outer side and gray matter on the inner side.
- The spinal cord has gray matter on the inner side and white matter on the outer side, which is reversed in the brain. (correct)
- The brain has gray matter in the center, while the spinal cord has gray matter surrounding the white matter.
How does the myelin sheath contribute to nerve impulse transmission?
How does the myelin sheath contribute to nerve impulse transmission?
- It slows down the transmission of nerve impulses by providing insulation.
- It accelerates the transmission of nerve impulses, allowing for faster communication. (correct)
- It blocks nerve impulses, forcing the signal to jump between nodes of Ranvier.
- It has no significant role in nerve impulse transmission.
Which of the following describes the primary function of the Autonomic Nervous System (ANS)?
Which of the following describes the primary function of the Autonomic Nervous System (ANS)?
- Regulating involuntary actions of internal organs like heart rate and digestion. (correct)
- Relaying sensory information from the skin to the brain.
- Coordinating balance and posture.
- Controlling voluntary movements of skeletal muscles.
What unique structural feature is present within the neuron's cell body (cyton)?
What unique structural feature is present within the neuron's cell body (cyton)?
How do sensory, motor, and association neurons work together to respond to a stimulus?
How do sensory, motor, and association neurons work together to respond to a stimulus?
Considering the function of the medulla oblongata, which of the following scenarios would be directly affected by damage to this region of the brain?
Considering the function of the medulla oblongata, which of the following scenarios would be directly affected by damage to this region of the brain?
Which statement accurately contrasts natural reflexes and conditioned reflexes?
Which statement accurately contrasts natural reflexes and conditioned reflexes?
How does the central canal contribute to the function of the spinal cord?
How does the central canal contribute to the function of the spinal cord?
What is the primary role of the cerebral hemispheres?
What is the primary role of the cerebral hemispheres?
How does the structure of the cerebrum maximize its functional capacity?
How does the structure of the cerebrum maximize its functional capacity?
Which of the following accurately describes the function of the thalamus and hypothalamus?
Which of the following accurately describes the function of the thalamus and hypothalamus?
What best describes the role of the Nodes of Ranvier in neuron function?
What best describes the role of the Nodes of Ranvier in neuron function?
Considering the structure of a typical neuron, what is the functional significance of dendrites?
Considering the structure of a typical neuron, what is the functional significance of dendrites?
What is the functional importance of meninges?
What is the functional importance of meninges?
How do nerves contribute to the function of the nervous system?
How do nerves contribute to the function of the nervous system?
Which of the following accurately describes the composition of a nerve?
Which of the following accurately describes the composition of a nerve?
What is the primary role of cerebrospinal fluid (CSF) within the central nervous system?
What is the primary role of cerebrospinal fluid (CSF) within the central nervous system?
How does the location of the cerebellum contribute to its function?
How does the location of the cerebellum contribute to its function?
What is the role of the synaptic cleft in neuronal communication?
What is the role of the synaptic cleft in neuronal communication?
What is the primary function of the spinal cord?
What is the primary function of the spinal cord?
Questions and Answers
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Flashcards
Flashcards
Neuron
Neuron
The unit of the nervous system, also known as a nerve cell, responsible for transmitting information.
Synapse
Synapse
The point of contact between the terminal branches of an axon of one neuron and the dendrites of another neuron, separated by a fine gap.
Myelin Sheath
Myelin Sheath
The white insulating sheath that surrounds the axon of a neuron.
Node of Ranvier
Node of Ranvier
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Neuroscience
Neuroscience
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Sensory Neuron
Sensory Neuron
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Motor Neuron
Motor Neuron
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Nerve
Nerve
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Central Nervous System (CNS)
Central Nervous System (CNS)
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Peripheral Nervous System (PNS)
Peripheral Nervous System (PNS)
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Dura Mater
Dura Mater
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Arachnoid
Arachnoid
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Pia Mater
Pia Mater
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Cerebrum
Cerebrum
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Cerebellum
Cerebellum
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Medulla Oblongata
Medulla Oblongata
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Reflex
Reflex
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Reflex Arc
Reflex Arc
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Natural Reflex
Natural Reflex
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Conditioned Reflex
Conditioned Reflex
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Flashcards
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Study Notes
Study Notes
- The nervous system comprises the brain, spinal cord, sense receptors, and nerves
- The human brain averages 100 billion neurons
Neuron Structure
- The neuron is the nervous system's functional unit
- Neurons consists of the cell body, dendrites, and axon
Cell Body (Perikaryon/Cyton)
- Contains a well-defined nucleus surrounded by granular cytoplasm
- Lacks a centrosome, thus nerve cells cannot divide
Dendrites
- Branched cytoplasmic extensions of the cell body
- Conduct nerve impulses to the cyton
Axon
- A long process extending from the cell body
- Surrounded by a myelin sheath (white insulating layer) and an outer neurolemma
- Nodes of Ranvier are gaps in the myelin sheath
- Axon terminals connect to other neurons via a synaptic cleft
Synapse
- The point of contact between an axon's terminal branches and another neuron's dendrites, separated by a fine gap
- Acetylcholine, a chemical, is released at the synapse
Nervous System Function
- The nervous system transmits signals at speeds up to 100 meters per second
- Neuroscience studies the nervous system
Neuron Types
- Sensory neurons carry impulses from receptors to the brain
- Motor neurons carry impulses from the brain to effectors
- Association neurons interconnect sensory and motor neurons
Nerves
- Bundles of nerve fibres (axons)
- Emerge from the brain and spinal cord, branching to all body parts
- Three types exists: sensory, motor, and mixed nerves
- Ganglia is a collection of cytons or cell bodies
Divisions of the Nervous System
- Central Nervous System (CNS): brain and spinal cord within the vertebral column
- Peripheral Nervous System (PNS): nerves emerging from and entering the brain and spinal cord
Peripheral Nervous System Subdivisions
- Somatic Nervous System (SNS): conveys information to skeletal (voluntary) muscles
- Autonomic Nervous System (ANS): controls involuntary actions of internal organs via ganglia and nerves
The Brain
- A delicate organ protected by the brain box or cranium
Brain Coverings
- The brain is protected by three membranous coverings called meninges
- Dura mater: the outermost tough, fibrous membrane
- Arachnoid: the thin, delicate middle layer providing a web-like cushion
- Pia mater: the innermost, highly vascular membrane
- Meningitis: inflammation of the meninges
Brain Parts
- The brain has three main external parts: cerebrum, cerebellum, and medulla oblongata
Cerebrum
- The largest portion of the brain, divided into cerebral hemispheres with convoluted surfaces (ridges and grooves)
- Contains an outer cortex of gray matter (cell bodies) and an inner medulla
- Interior white matter due to axons
Cerebellum
- Located at the base of the brain, under the cerebrum
- Has furrows, an outer cortex of gray matter, and central white matter
- Functions to maintain body balance and coordinate muscular activity
Medulla Oblongata
- The lowest part of the brain, located at the skull's base and continuous with the spinal cord
- Controls internal organ activities (e.g., heart rate, breathing)
Brain Regions
- Forebrain: cerebrum (intelligence, memory, voluntary actions), diencephalon (thalamus relays impulses, hypothalamus controls body temperature and the pituitary)
- Midbrain: A small tubular region involved in reflexes (eyes and ears)
- Hindbrain: cerebellum (coordinates balance), pons (carries impulses and coordinates muscular movements), medulla oblongata (controls internal organs)
The Spinal Cord
- Extends from the brain's medulla down the backbone, ending at the second lumbar vertebra
- Arrangement of interior white and gray matter is reversed from that in the brain
- A central canal runs the length of the cord, continuous with brain cavities and filled with cerebrospinal fluid
Spinal Cord Functions
- Controls reflexes below the neck
- Conducts sensory impulses from the skin and muscles to the brain
- Conducts motor responses from the brain to muscles of the trunk and limbs
Peripheral Nervous System (PNS)
- Nerves carrying impulses to and from the CNS
- 12 pairs of cranial nerves emerge from the brain
- 31 pairs of spinal nerves emerge from the spinal cord
Autonomic Nervous System (ANS)
- Nerves and ganglia controlling involuntary actions
- Includes sympathetic (prepares for action) and parasympathetic (restores normal conditions) sections for heart rate, salivation, pupil control
Reflexes
- Involuntary actions are automatic responses to a stimulus
- The reflex arc is the shortest route for an impulse, from receptor to effector
Types of Actions
- Voluntary Actions
- Involuntary Actions
Types of Reflexes
- Natural Reflexes: innate, require no previous learning (e.g., blinking, knee jerk)
- Conditioned Reflexes: acquired during lifetime (e.g., salivation at the sight of food)
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