chapter 16 neurology

Sphenopalatine ganglion neuralgia: “XX” refers to the sphenoid bone, and “XX” relates to the palatine bones. A XX is a neural structure, and “neuralgia” means pain. This is another way to describe an XX XX XX.

Sphenopalatine ganglion neuralgia: “spheno” refers to the sphenoid bone, and “palatine” relates to the palatine bones. A ganglion is a neural structure, and “neuralgia” means pain. This is another way to describe an ice cream headache.

Introduction

There is a continuous XX of information between

the XX, XX XX, and XX XX

Many subtle forms of interaction, feedback, and

regulation link higher centers with the various

components of the brain stem.

Introduction

There is a continuous flow of information between

the brain, spinal cord, and peripheral nerves.

Many subtle forms of interaction, feedback, and

regulation link higher centers with the various

components of the brain stem.

Think about pathways we have talked about motor and sensory. Motor think XX. Sensory think XX.

Think about pathways we have talked about motor and sensory. Motor think ventral. Sensory think dorsal. 

Nerve pathways, called tracts,

connect the XX andXX

Ascending (XX) pathways

Descending (XX) pathways

Tract XX often indicates its XX and

XX

Nerve pathways, called tracts,

connect the CNS and PNS

Ascending (sensory) pathways

Descending (motor) pathways

Tract name often indicates its origin and

destination

There are no XX in the CNS. Nerves XX and XX at the level of the XX XX along the vertebral bodies. Instead, the CNS has XX, which are either XX XX (sensory) or XX XX (motor).

There are no nerves in the CNS. Nerves begin and end at the level of the intervertebral foramen along the vertebral bodies. Instead, the CNS has tracts, which are either ascending afferent (sensory) or descending efferent (motor).

Ascending = XX = XX
Descending =XX = XX

Ascending = afferent = sensory.
Descending = efferent = motor.

We name tracts based on their direction. For example, “corticospinal” — “spinal” as the suffix indicates its XX, so it is XX. “Spinoreticular” or “spinotectal” — when “spino-” is the prefix, that indicates XX, XX, sensory pathways.

We name tracts based on their direction. For example, “corticospinal” — “spinal” as the suffix indicates it is descending, so it is motor. “Spinoreticular” or “spinotectal” — when “spino-” is the prefix, that indicates ascending, afferent, sensory pathways.

If you see the term “bulbar,” it refers to the brainstem. So “corticobulbar” is also XX, XX, XX, even though “spinal” is not in the word.

If you see the term “bulbar,” it refers to the brainstem. So “corticobulbar” is also descending, efferent, motor, even though “spinal” is not in the word.

Sensory and Motor Pathways

Sensory pathways

The XX column pathway

The XX pathway

The XX pathway

Sensory and Motor Pathways

Sensory pathways

The posterior column pathway

The spinothalamic pathway

The spinocerebellar pathway

Sensory pathways usually contain three neurons:

First-order neuron — to the XX

Second-order neuron — an XX located in either the

XX XX or the XX XX

Third-order neuron — carries information from the

XX to the XX XX

Sensory pathways usually contain three neurons:

First-order neuron — to the CNS

Second-order neuron — an interneuron located in either the

spinal cord or the brain stem

Third-order neuron — carries information from the

thalamus to the cerebral cortex

As you think about sensory pathways, if we say “posterior column,” just by its anatomical location you would know it is probably XX—and it is. If you see terms like “spinothalamic” or “spinocerebellar,” those are XX XX XX pathways. 

As you think about sensory pathways, if we say “posterior column,” just by its anatomical location you would know it is probably sensory—and it is. If you see terms like “spinothalamic” or “spinocerebellar,” those are ascending afferent sensory pathways. 

The first-order neuron carries information from the XX into the XX, entering the spinal cord. After a synapse, the second-order neuron ascends to the tXX, where another synapse occurs. Then, the third-order neuron travels from the XX to the XX.When we think of the sensory association cortex, that is the XX XX—sensory equals XX XX

The first-order neuron carries information from the environment into the CNS, entering the spinal cord. After a synapse, the second-order neuron ascends to the thalamus, where another synapse occurs. Then, the third-order neuron travels from the thalamus to the cortex.When we think of the sensory association cortex, that is the postcentral gyrus—sensory equals postcentral gyrus.

Ascending (sensory) pathways and tracts in the spinal cord:

We have the XX XX medially and the XX XX. Think about the gracilis muscleXX XX carries ascending afferent sensory information from below the diaphragm XX XX is the opposite; it carries ascending afferent sensory information from above the diaphragm.The dorsal root ganglion, dorsal horn, and dorsal root are all purely XX, while the ventral side is purely XX.The posterior spinocerebellar tract fits the anatomical orientation. The anterior spinocerebellar tract and the lateral and anterior spinothalamic tracts are also XX. Even if the wording is confusing, “spino-” indicates XX, XX XX pathways.

Ascending (sensory) pathways and tracts in the spinal cord:

We have the fasciculus gracilis medially and the fasciculus cuneatus. Think about the gracilis muscle—fasciculus gracilis carries ascending afferent sensory information from below the diaphragm. Fasciculus cuneatus is the opposite; it carries ascending afferent sensory information from above the diaphragm.The dorsal root ganglion, dorsal horn, and dorsal root are all purely sensory, while the ventral side is purely motor.The posterior spinocerebellar tract fits the anatomical orientation. The anterior spinocerebellar tract and the lateral and anterior spinothalamic tracts are also sensory. Even if the wording is confusing, “spino-” indicates ascending, afferent sensory pathways.

The posterior column, spinothalamic, and spinocerebellar sensory pathways:

The first-order neuron carries information into the XX. It then synapses in the XX XX (part of the brainstem, or myelencephalon). After this synapse, the pathway decussates (crosses over). The second-order neuron then XXto the XX. After another synapse, the third-order neuron travels to the XX XX—specifically the XX gyrus, where the body map is located.

The posterior columns carry XX (XX) touch, vXX, XX, and body position sensation, typically from the opposite side of the body after crossing.

The posterior column, spinothalamic, and spinocerebellar sensory pathways:

The first-order neuron carries information into the CNS. It then synapses in the medulla oblongata (part of the brainstem, or myelencephalon). After this synapse, the pathway decussates (crosses over). The second-order neuron then ascends to the thalamus. After another synapse, the third-order neuron travels to the cerebral cortex—specifically the postcentral gyrus, where the body map is located.

The posterior columns carry fine (soft) touch, vibration, pressure, and body position sensation, typically from the opposite side of the body after crossing.

In the sensory cortex, certain areas have more representation depending on how much innervation they have. For example, the XX, XX, and XX have much larger areas of sensation due to their high level of XX input. This is represented by the cortical XX

In the sensory cortex, certain areas have more representation depending on how much innervation they have. For example, the hands, lips, and tongue have much larger areas of sensation due to their high level of sensory input. This is represented by the cortical homunculus.

First second third order neurons are XX issues XX XX XX

First second third order neurons are sensory issues, ascending afferent sensory.

The spinocerebellar pathway has no XX XX neuron. It stops at the XX, so it does not reach XX XX. This pathway carries information about XX XX (XX), including input from Golgi tendon organs, muscle spindle fibers, and joint capsules.For identifying sensory pathways: posterior column, spinothalamic, and spinocerebellar tracts are all XX. The key difference is that spinocerebellar pathways handle XX below the level ofXX . When thinking about cerebellar pathways, remember—they stop at the XX.

The spinocerebellar pathway has no third-order neuron. It stops at the cerebellum, so it does not reach conscious awareness. This pathway carries information about body position (proprioception), including input from Golgi tendon organs, muscle spindle fibers, and joint capsules.For identifying sensory pathways: posterior column, spinothalamic, and spinocerebellar tracts are all sensory. The key difference is that spinocerebellar pathways handle proprioception below the level of consciousness. When thinking about cerebellar pathways, remember—they stop at the cerebellum.

Sensory and Motor Pathways

Motor pathways

The XX pathway

The XX tracts

The XX tracts

The medial and lateral pathways

Motor pathways usually contain XX XX

Somatic nervous system (SNS)

XX XX neuron — within CNS

XX XX neuron — from CNS to effector

Autonomic nervous system (ANS)

XX neuron

XX neuron

Sensory and Motor Pathways

Motor pathways

The corticospinal pathway

The corticobulbar tracts

The corticospinal tracts

The medial and lateral pathways

Motor pathways usually contain two neurons

Somatic nervous system (SNS)

Upper motor neuron — within CNS

Lower motor neuron — from CNS to effector

Autonomic nervous system (ANS)

Preganglionic neuron

Ganglionic neuron

Motor (XX, XX) pathways originate from the XX gyrus. When you look at them, you see the XX pathway. The Babinski reflex—where you run an object along the bottom of the foot—can be positive or negative, and the corticospinal tract takes time to fully develop.“Corticospinal” indicates it is motor because “-spinal” is at the end, showing a XX pathway. “Corticobulbar” means cortex to brainstem (“bulbar”), so that is also a XX pathway. There are medial and lateral motor pathways as well.For motor pathways, instead of first-, second-, and third-order neurons, we use XX XX neurons and XX XX neurons. The upper motor neuron is located within the XX, and the lower motor neuron extends from the XX to the XX (muscle).

Motor (descending, efferent) pathways originate from the precentral gyrus. When you look at them, you see the corticospinal pathway. The Babinski reflex—where you run an object along the bottom of the foot—can be positive or negative, and the corticospinal tract takes time to fully develop.“Corticospinal” indicates it is motor because “-spinal” is at the end, showing a descending pathway. “Corticobulbar” means cortex to brainstem (“bulbar”), so that is also a motor pathway. There are medial and lateral motor pathways as well.For motor pathways, instead of first-, second-, and third-order neurons, we use upper motor neurons and lower motor neurons. The upper motor neuron is located within the CNS, and the lower motor neuron extends from the CNS to the effector (muscle).

Where does your spinal cord end, XX and XX. So it ends at L2, so this is still XX XX XX.

Where does your spinal cord end, L1 and L2. So it ends at L2, so this is still upper motor neuron.

Motor pathways:

The corticospinal and corticobulbar tracts are XX, XX motor pathways.The medial pathways include the XX, XXl, and XX tracts—all of which are also XX. When a pathway involves the cerebral cortex, it is associated with XX control of movement.If a pathway is beneath the level of XX, it is more automatic. For example, the rubrospinal tract (from the red nucleus) is XX, and “-spinal” as a suffix indicates a motor pathway operating below the level of XX.

Motor pathways:

The corticospinal and corticobulbar tracts are descending, efferent motor pathways.The medial pathways include the vestibulospinal, tectospinal, and reticulospinal tracts—all of which are also descending. When a pathway involves the cerebral cortex, it is associated with conscious control of movement.If a pathway is beneath the level of consciousness, it is more automatic. For example, the rubrospinal tract (from the red nucleus) is descending, and “-spinal” as a suffix indicates a motor pathway operating below the level of consciousness.

Somatic motor control:

The basal nuclei include the XX, XX, and XX XX. The hypothalamus (don’t confuse it with the hippocampus) controls functions like XX, XX, XX, and XX XX.The cerebellum operates XX the level of XX, helping with coordination and balance. The thalamus and the mesencephalon (midbrain) include the XX with the corpora quadrigemina.The cerebral cortex is responsible for XX planning and awareness. Information coming into the body is XX, while conscious awareness of that information is XX

Somatic motor control:

The basal nuclei include the caudate, putamen, and globus pallidus. The hypothalamus (don’t confuse it with the hippocampus) controls functions like eating, sleeping, drinking, and sexual behavior.The cerebellum operates below the level of consciousness, helping with coordination and balance. The thalamus and the mesencephalon (midbrain) include the tectum with the corpora quadrigemina.The cerebral cortex is responsible for conscious planning and awareness. Information coming into the body is sensation, while conscious awareness of that information is perception.

Higher-Order Functions

Higher-order functions have the following

characteristics:

They are performed by the XX XX

They involve XX XX and

communication between areas within the cerebral cortex

and between the cerebral cortex and other areas of the

brain.

They involve both XX and XX information

XX.

They are not part of the programmed “wiring” of the brain;

therefore, the functions are subject to XX and XX over time. A.K.A — XX

Higher-Order Functions

Higher-order functions have the following

characteristics:

They are performed by the cerebral cortex.

They involve complex interconnections and

communication between areas within the cerebral cortex

and between the cerebral cortex and other areas of the

brain.

They involve both conscious and unconscious information

processing.

They are not part of the programmed “wiring” of the brain;

therefore, the functions are subject to modification and

adjustment over time. A.K.A — learning

When dealing with motor function, we consider both XX and XX processing, which is also part of XX. The brain can change its wiring (neuroplasticity), and when this happens, it can lead to XX XX or damage that disrupts those axonal pathways.

When dealing with motor function, we consider both conscious and unconscious processing, which is also part of learning. The brain can change its wiring (neuroplasticity), and when this happens, it can lead to false memories or damage that disrupts those axonal pathways.

Integrative Regions of the Cerebral Cortex

Cortical areas that act as centers for complex

sensory stimuli and motor responses

General interpretive area

Receives information from all sensory association areas

Only present in one hemisphere, usually the left

Speech center

Regulates patterns of breathing and vocalization

Prefrontal cortex

Coordinates information from the secondary and special

association areas of the cortex

Performs abstract intellectual functions

Integrative Regions of the Cerebral Cortex

Cortical areas that act as centers for complex

sensory stimuli and motor responses

General interpretive area

Receives information from all sensory association areas

Only present in one hemisphere, usually the left

Speech center

Regulates patterns of breathing and vocalization

Prefrontal cortex

Coordinates information from the secondary and special

association areas of the cortex

Performs abstract intellectual functions

Broca’s area is the XX XX area of the face (organized from feet to face). The gnostic (general interpretive) area is XX area, which is the sensory language area.Broca’s area is the XX center that regulates patterns of XX and XX. Wernicke’s area is responsible for XX and XX language.These areas are usually located in the left hemisphere, though they can sometimes be on the right. Females often show greater neuroplasticity, meaning if one side is damaged, the other side can take over more efficiently, even after puberty.The XX cortex is the anterior part of the brain and is involved in higher-level processing.

Broca’s area is the motor speech area of the face (organized from feet to face). The gnostic (general interpretive) area is Wernicke’s area, which is the sensory language area.Broca’s area is the speech center that regulates patterns of breathing and vocalization. Wernicke’s area is responsible for understanding and interpreting language.These areas are usually located in the left hemisphere, though they can sometimes be on the right. Females often show greater neuroplasticity, meaning if one side is damaged, the other side can take over more efficiently, even after puberty.The prefrontal cortex is the anterior part of the brain and is involved in higher-level processing.

The XX area is Broca’s area, and the XX XX (XX) area is Wernicke’s area.

The speech area is Broca’s area, and the general interpretive (gnostic) area is Wernicke’s area.

If someone has Broca’s aphasia, they cannot XX well, but they do XX what is being said.If someone has Wernicke’s aphasia, they can XX (and swallow normally), but their speech may not make sense, and they do not XX what is being said.People with Broca’s aphasia know what they want to say. They can hear and understand language (including written words), but they struggle to XX the sounds needed to XX.

If someone has Broca’s aphasia, they cannot speak well, but they do understand what is being said.If someone has Wernicke’s aphasia, they can speak (and swallow normally), but their speech may not make sense, and they do not understand what is being said.People with Broca’s aphasia know what they want to say. They can hear and understand language (including written words), but they struggle to produce the sounds needed to speak.

Higher-Order Functions

Memory

Process of accessing XX XX OF information

acquired through XX

Short-term memories last XX to XX

Long-term memories can last for XX and are

stored in the XX XX

Memory consolidation— conversion from a XX-

term memory to a XX-term memory

The XX body and the XX

(limbic system) are essential to memory

consolidation

Higher-Order Functions

Memory

Process of accessing stored bits of information

acquired through experience

Short-term memories last seconds to hours

Long-term memories can last for years and are

stored in the cerebral cortex

Memory consolidation— conversion from a short-

term memory to a long-term memory

The amygdaloid body and the hippocampus

(limbic system) are essential to memory

consolidation

Short-term memories may not XX XX at all, while long-term memories can last an XX XX. Over time, short-term memories can consolidate into XX XX memories. These memories can also XX if there are changes in XX XX.The amygdala is involved in emotions such as fear, aggression, and sexual behavior.

Short-term memories may not last long at all, while long-term memories can last an entire lifetime. Over time, short-term memories can consolidate into long-term memories. These memories can also change if there are changes in neural networks.The amygdala is involved in emotions such as fear, aggression, and sexual behavior.

The reticular activating system:

We have XX information coming in through the optic nerve and the auditory (XX) nerve. This information then travels through the corona radiata (radiating crown) and the internal capsule to reach various areas of the cerebral cortex.The reticular formation—meaning “meshwork”—contains axons that help XX XX and XX.

The reticular activating system:

We have sensory information coming in through the optic nerve and the auditory (vestibulocochlear) nerve. This information then travels through the corona radiata (radiating crown) and the internal capsule to reach various areas of the cerebral cortex.The reticular formation—meaning “meshwork”—contains axons that help maintain consciousness and alertness.

Conscious states:

XX: disoriented, confused, and there are frequently hallucinations.

XX: a lot of people know this in early or late stages of dementia.

XX: you’re going to be like bipolarity—really low and then really high, so it’s kind of like a delirium.

XX XX: you’re oriented and responsive.

XX: you get really sleepy.

XX XX state: it’s unfortunate—it’s a state of consciousness where you’re conscious but unresponsive, with no evidence of cortical function; we don’t know much about this.

Conscious states:

Delirium: disoriented, confused, and there are frequently hallucinations.

Dementia: a lot of people know this in early or late stages of dementia.

Confusion: you’re going to be like bipolarity—really low and then really high, so it’s kind of like a delirium.

Normal consciousness: you’re oriented and responsive.

Somnolent: you get really sleepy.

Chronic vegetative state: it’s unfortunate—it’s a state of consciousness where you’re conscious but unresponsive, with no evidence of cortical function; we don’t know much about this.

Delirium: XX, XX, XX, XX, agitation, alternating with other conscious states, develops XX

Delirium: Disorientation, restlessness, confusion, hallucinations, agitation, alternating with other conscious states, develops quickly. 

Dementia:Progressive XX in XX XX, XX, XX, and XX

Dementia:Progressive decline in spatial orientation, memory, behavior, and language.

Confusion:Reduced XX, easily XX, easily XX by sensory stimuli, alternates between drowsiness and excitability; resembles minor form of delirium state. 

Confusion:Reduced awareness, easily distracted, easily startled by sensory stimuli, alternates between drowsiness and excitability; resembles minor form of delirium state. 

Normal consciousness: aware of XX and XX XX, well XX, XX

Normal consciousness: aware of self and external environment, well oriented, responsive 

Somnolence: Extreme XX, but will respond XX to XX

Somnolence: Extreme drowsiness, but will respond normally to stimuli 

Chronic vegetative state: XX but XX, no evidence of cortical function. 

Chronic vegetative state: conscious but unresponsive, no evidence of cortical function. 

Unconscious states:

Asleep:can be aroused by XX stimuli (light touch, sound)

Stupor: can be aroused by XX and or rXX XX

Coma: cannot be XX and does not XX to stimuli 

Unconscious states:

Asleep:can be aroused by normal stimuli (light touch, sound)

Stupor: can be aroused by extreme and or repeated stimuli 

Coma: cannot be aroused and does not respond to stimuli 

Chronic vegetative state is it consciousness yes, is it awareness no

Chronic vegetative state is it consciousness yes, is it awareness no

Common, age-related anatomical changes

in the nervous system include the following:

A XX in XX XX and XX

A reduction in the XX of XX

A decrease in XX XX to the brain

Changes in XX XX of the brain

XX and XX changes in CNS

neurons

Common, age-related anatomical changes

in the nervous system include the following:

A reduction in brain size and weight

A reduction in the number of neurons

A decrease in blood flow to the brain

Changes in synaptic organization of the brain

Intracellular and extracellular changes in CNS

neurons