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Questions and Answers
What is the primary role of the brain within the central nervous system?
What is the primary role of the brain within the central nervous system?
Which component is NOT part of the peripheral nervous system?
Which component is NOT part of the peripheral nervous system?
What is a function of sensory organs and receptors?
What is a function of sensory organs and receptors?
What is the function of ascending nerve tracts?
What is the function of ascending nerve tracts?
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What term describes a cluster of nerve cell bodies outside the central nervous system?
What term describes a cluster of nerve cell bodies outside the central nervous system?
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What does the term 'innervation' refer to?
What does the term 'innervation' refer to?
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Which of the following describes a reflex?
Which of the following describes a reflex?
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What is the function of a nerve?
What is the function of a nerve?
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Which lobe of the brain is primarily responsible for controlling skilled motor functions?
Which lobe of the brain is primarily responsible for controlling skilled motor functions?
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What is the primary function of the cerebellum?
What is the primary function of the cerebellum?
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Which type of nerve fibers primarily convey information controlling voluntary movements?
Which type of nerve fibers primarily convey information controlling voluntary movements?
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How many pairs of cranial nerves originate from the under surface of the brain?
How many pairs of cranial nerves originate from the under surface of the brain?
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The 31 pairs of spinal nerves are grouped based on what criteria?
The 31 pairs of spinal nerves are grouped based on what criteria?
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What type of nerve fibers carry instructions from the autonomic nervous system to organs and glands?
What type of nerve fibers carry instructions from the autonomic nervous system to organs and glands?
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What is the designation for the first four lumbar nerves?
What is the designation for the first four lumbar nerves?
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Which part of the nervous system is responsible for receiving external stimuli such as touch?
Which part of the nervous system is responsible for receiving external stimuli such as touch?
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What is the role of dendrites in a neuron?
What is the role of dendrites in a neuron?
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What distinguishes white matter from gray matter in the nervous system?
What distinguishes white matter from gray matter in the nervous system?
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Which part of the brain is primarily responsible for thought, judgment, and memory?
Which part of the brain is primarily responsible for thought, judgment, and memory?
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What structure is responsible for protecting the brain and spinal cord?
What structure is responsible for protecting the brain and spinal cord?
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What is the function of neurotransmitters?
What is the function of neurotransmitters?
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Which part of the neuron conducts impulses away from the cell body?
Which part of the neuron conducts impulses away from the cell body?
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Which of the following structures is NOT part of the central nervous system?
Which of the following structures is NOT part of the central nervous system?
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What is the role of glial cells in the nervous system?
What is the role of glial cells in the nervous system?
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Study Notes
Nervous System Terminology
- The nervous system is responsible for coordinating all bodily functions by receiving and transmitting messages throughout the body.
Overview of Structures, Combining Forms, and Functions of the Nervous System
- Brain (cerebr/o, encephal/o): Coordinates all body activities, receiving and translating messages.
- Spinal Cord (myel/o): Transmits nerve impulses between the brain, limbs, and lower body.
- Nerves (neur/i, neur/o): Receive and transmit messages to and from all body parts.
-
Sensory Organs and Receptors: Receive external stimuli and transmit these signals to sensory neurons. Examples include:
- Eyes (oculo)
- Ears (oto)
- Nose (naso)
- Skin (touch; dermato)
- Tongue (taste; lingua)
Structures of the Nervous System
- The major structures of the nervous system include:
- Nerves
- Brain
- Spinal cord
- Sensory organs
Divisions of the Nervous System
- Two primary divisions:
- Central nervous system (CNS):
- Brain
- Spinal cord
- Peripheral nervous system (PNS):
- 12 pairs of cranial nerves extending from the brain
- 31 pairs of peripheral spinal nerves extending outwards from the spinal cord
- Central nervous system (CNS):
The Nerves
- Nerve: One or more bundles of neuronal extensions that connect the brain and spinal cord to other body parts.
- Tract: A bundle or group of nerve fibers located within the brain or spinal cord.
- Ascending Nerve Tracts: Carry nerve impulses towards the brain.
- Descending Nerve Tracts: Carry nerve impulses away from the brain.
- Ganglion: A nerve center made up of a cluster of nerve cell bodies outside the central nervous system.
- Innervation: The supply of nerves to a specific body part.
- Reflex: An automatic, involuntary response to change, internal or external to the body. Examples include changes in heart rate, breathing, coughing, sneezing, responses to painful stimuli, and deep tendon reflexes.
- Plexus: A network of intersecting spinal nerves (plural, plexuses). This also relates to a network of intersecting blood or lymphatic vessels.
- Receptors: Sites in sensory organs (eyes, ears, skin, nose, taste buds) that receive external stimuli.
- Stimulus: Anything that excites (activates) a nerve and causes an impulse.
- Impulse: A wave of excitement transmitted through nerve fibers and neurons.
- Neuron: The basic cell of the nervous system, allowing different parts of the body to communicate.
Neuron Parts
- Dendrites: Root-like processes that receive impulses and conduct them to the cell body.
- Axon: Transmits impulses away from the cell body. It is protected by a myelin sheath composed of a white fatty tissue covering.
- Terminal End Fibers: Branching fibers at the end of the axon that lead impulses from the axon to the synapse.
- Synapse: The space between two neurons (or between a neuron and a receptor organ).
- Neurotransmitters: Chemical substances that transmit messages from a neuron to its target receptor.
Glial Cells
- Glial cells: Support and protect neurons. A myelin sheath is a protective covering made up of glial cells.
- The portion of nerve fibers with myelin are known as white matter.
- The portion of nerve fibers without myelin are known as gray matter.
The Central Nervous System (CNS)
- The Meninges: Membranes enclosing the brain and spinal cord.
- Cerebrospinal Fluid (CSF): A clear, colorless, and watery fluid that flows through and around the brain and spinal cord, produced by special capillaries in the brain's ventricles.
Cerebrum
- Cerebrum: Largest and uppermost part of the brain, responsible for thought, judgment, memory, emotion, motor, and sensory function.
- Cerebral Cortex: Made from gray matter. The outer layer of the cerebrum is made of elevated folds (gyri) and deep fissures (sulci).
- Gyri: Elevated folds in the cerebral cortex.
- Sulci: Fissures (grooves) in the cerebral cortex.
The Cerebral Hemispheres
- The left hemisphere controls the right side of the body.
- The right hemisphere controls the left side of the body.
- The crossover of nerve fibers occurs in the brainstem.
The Cerebral Lobes
- Frontal Lobe: Controls skilled motor functions, memory, and behavior.
- Parietal Lobe: Receives and interprets impulses from sensory receptors (in tongue, skin, and muscles).
- Occipital Lobe: Controls eyesight.
- Temporal Lobe: Controls senses of hearing and smell, and the ability to create, store, and access new information.
The Cerebellum
- Cerebellum: Second largest part of the brain, located at the back of the head below the posterior portion of the cerebrum. Coordinates movements, maintains equilibrium, and sustains posture.
The Spinal Cord
- Spinal Cord: A long, fragile tube-like structure starting from the brainstem, continuing nearly to the spinal column's bottom.
- It contains all nerves affecting the limbs and lower body parts.
- It acts as a pathway for impulses traveling to and from the brain.
The Peripheral Nervous System (PNS)
- Includes 12 pairs of cranial nerves and 31 pairs of spinal nerves.
- Contains three types of specialized peripheral nerves: autonomic, sensory, and somatic.
- Peripheral: Relating to body parts away from the center of the body.
- Autonomic Nerve Fibers: Carry instructions to organs and glands from the autonomic nervous system.
- Sensory Nerve Fibers: Receive external stimuli and transmit information to the brain (interpreting sensations).
- Somatic Nerve Fibers (Motor Nerve Fibers): Convey information controlling voluntary muscle movements.
Cranial Nerves
- 12 pairs of cranial nerves originate from the underside of the brain.
Peripheral Spinal Nerves
- 31 pairs of peripheral spinal nerves grouped based on the body regions they innervate (cervical, thoracic, lumbar, sacral); some nerves form plexuses to innervate areas. Example: the lumbar plexus.
Pathology of the Nervous System
- Cephalalgia (Headaches): Pain in the head.
- Hydrocephalus: Fluid buildup in brain's ventricles.
- Meningitis: Inflammation of the meninges (membranes surrounding the brain and spinal cord).
- Dementia: Progressive decline in mental abilities (memory, thinking, judgment). Senile dementia occurs in the elderly.
- Encephalitis: Brain inflammation.
- Alzheimer's Disease: Group of disorders affecting brain areas controlling thought, memory, and language; leading cause of dementia.
- Parkinson's Disease (PD): Chronic, degenerative central nervous disorder characterized by tremors, rigidity, and slow gait.
- Amnesia: Partial or complete inability to recall past experiences.
- Syncope (Fainting): Brief loss of consciousness due to reduced blood flow to the brain.
Strokes (CVA)
- A stroke or cerebrovascular accident is when blood flow to the brain is interrupted due to a vessel blockage or rupture.
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Description
Test your knowledge on the key structures, combining forms, and functions of the nervous system. This quiz covers elements like the brain, spinal cord, nerves, and sensory organs. Challenge yourself to understand the roles and terminologies associated with the nervous system.
