Лист за преговор: Neural Pathways and Body Regulation

📋 Course Outline

1. Autonomic Nervous System & Organization
2. Neurotransmitters & Receptors
3. Sensory Receptors & Pathways
4. Cerebral Cortex & Language
5. Cerebellum & Motor Control
6. Basal Ganglia & Movement Disorders
7. Visual & Auditory Pathways
8. Spinal Cord & Reflexes
9. Blood-Brain Barrier & CSF
10. Temperature Regulation & Fever

📖 1. Autonomic Nervous System & Organization

🔑 Key Concepts & Definitions

• Autonomic Nervous System (ANS): A division of the peripheral nervous system that controls involuntary physiological functions, including heart rate, digestion, and respiratory rate.

• Sympathetic Nervous System: A branch of ANS responsible for "fight or flight" responses, increasing heart rate, dilating bronchi, and inhibiting digestion.

• Parasympathetic Nervous System: A branch of ANS promoting "rest and digest" activities, decreasing heart rate, constricting bronchi, and stimulating digestion.

• Dual Innervation: Most organs receive nerve fibers from both sympathetic and parasympathetic systems, often with antagonistic effects, allowing fine regulation of organ function.

• Autonomic Ganglia: Clusters of nerve cell bodies outside the central nervous system where preganglionic fibers synapse with postganglionic fibers.

• Neurotransmitters: Chemical messengers such as acetylcholine (ACh) and norepinephrine (NE) that transmit signals across synapses in the ANS.

📝 Essential Points

• The ANS maintains homeostasis by regulating involuntary functions via a balance of sympathetic and parasympathetic activity.

• Preganglionic neurons originate in the central nervous system (brainstem and spinal cord), synapsing in autonomic ganglia with postganglionic neurons that innervate target organs.

• Sympathetic fibers originate from thoracolumbar spinal segments (T1-L2), while parasympathetic fibers originate from craniosacral regions (brainstem nuclei and S2-S4).

• The sympathetic nervous system primarily uses norepinephrine as a neurotransmitter at effector sites, except in sweat glands where ACh is used.

• The parasympathetic nervous system predominantly uses acetylcholine at both pre- and postganglionic synapses.

• The ANS's effects are modulated by receptor types: adrenergic (for NE) and cholinergic (for ACh), with subtypes such as alpha and beta adrenergic receptors.

• Clinical relevance includes conditions like autonomic neuropathy, orthostatic hypotension, and dysautonomia.

💡 Key Takeaway

The autonomic nervous system intricately balances sympathetic and parasympathetic inputs to regulate involuntary organ functions, enabling the body to adapt to changing physiological needs through complex neural and chemical signaling pathways.

📖 2. Neurotransmitters & Receptors

🔑 Key Concepts & Definitions

• Neurotransmitter: Chemical messenger released by neurons that transmits signals across a synapse to target cells, such as other neurons, muscles, or glands.
• Receptor: Protein on the cell surface or within the cell that binds specific neurotransmitters, initiating a cellular response.
• Ionotropic Receptor: Ligand-gated ion channel receptor that directly controls ion flow across the membrane upon neurotransmitter binding.
• Metabotropic Receptor: G-protein-coupled receptor that indirectly influences cellular activity through second messenger systems after neurotransmitter binding.
• Agonist: Substance that binds to a receptor and activates it, mimicking the effect of the natural neurotransmitter.
• Antagonist: Substance that binds to a receptor but does not activate it, blocking the action of agonists or natural neurotransmitters.

📝 Essential Points

• Neurotransmitters are classified into amino acids (e.g., glutamate, GABA), monoamines (e.g., dopamine, norepinephrine, serotonin), and peptides.
• Receptors are divided into ionotropic (fast, direct ion channel control) and metabotropic (slow, involve second messenger cascades).
• The binding of neurotransmitters to ionotropic receptors causes rapid changes in membrane potential, crucial for synaptic transmission.
• Metabotropic receptors modulate cellular activity over longer periods, affecting gene expression, enzyme activity, or ion channel states indirectly.
• Specific neurotransmitter-receptor interactions underpin many physiological processes, including mood regulation, muscle contraction, and sensory perception.
• Drugs can target neurotransmitter systems by acting as agonists, antagonists, or modulators, influencing neural activity and treating disorders.

💡 Key Takeaway

Neurotransmitters and their receptors form the fundamental communication system of the nervous system, with ionotropic receptors mediating rapid responses and metabotropic receptors regulating longer-term cellular functions. Understanding these interactions is essential for grasping neural signaling and pharmacological interventions.

📖 3. Sensory Receptors & Pathways

🔑 Key Concepts & Definitions

• Sensory Receptors: Specialized structures that detect specific types of stimuli (e.g., mechanical, chemical, thermal, electromagnetic) and convert them into neural signals.
• Receptor Potential: The change in membrane potential in sensory receptors in response to a stimulus, which can initiate nerve impulses.
• Afferent Pathways: Neural pathways that carry sensory information from receptors to the central nervous system (CNS).
• Modalities: Different types of sensory information (e.g., touch, temperature, pain, proprioception).
• Receptor Specificity: The property by which receptors respond primarily to particular types of stimuli.
• Sensory Coding: The process by which sensory receptors translate stimulus intensity, duration, and modality into neural signals.

📝 Essential Points

• Sensory receptors are classified based on the type of stimulus they detect: mechanoreceptors (touch, pressure), thermoreceptors (temperature), nociceptors (pain), chemoreceptors (chemical stimuli), and photoreceptors (light).
• Receptor potential magnitude correlates with stimulus intensity; if it reaches threshold, it triggers action potentials in afferent neurons.
• Different receptors have distinct structures and locations, influencing their response properties and adaptation rates (e.g., rapid vs. slow adapting receptors).
• Sensory information is transmitted via afferent fibers that differ in diameter and conduction velocity, affecting the speed and precision of sensation.
• The dorsal column-medial lemniscal pathway transmits fine touch, vibration, and proprioception; the spinothalamic pathway transmits pain and temperature.
• Sensory pathways undergo processing in the CNS, including synaptic relay in the spinal cord and thalamus, before reaching the somatosensory cortex for perception.
• Receptor specificity and receptive fields determine the spatial resolution and discrimination ability of sensory systems.

💡 Key Takeaway

Sensory receptors are specialized structures that transduce specific environmental stimuli into neural signals, which are then conveyed through distinct afferent pathways to the brain for perception, with their structure and function finely tuned to the modality and intensity of the stimulus.

📖 4. Cerebral Cortex & Language

🔑 Key Concepts & Definitions

• Cerebral Cortex: The outer layer of the brain involved in higher cognitive functions, including language, perception, and voluntary movement.

• Broca's Area: Located in the posterior inferior frontal gyrus; responsible for speech production and language expression.

• Wernicke's Area: Situated in the posterior superior temporal gyrus; involved in language comprehension.

• Aphasia: A language disorder resulting from brain damage, affecting speech, comprehension, or both.

• Lateralization of Language: The tendency for language functions to be predominantly localized in one hemisphere, usually the left.

• Arcuate Fasciculus: A bundle of nerve fibers connecting Broca's and Wernicke's areas, facilitating language processing.

📝 Essential Points

• The cerebral cortex is essential for language, with specific regions dedicated to different aspects: Broca's area for speech production and Wernicke's area for comprehension.

• Language lateralization is typically left hemisphere dominance in right-handed individuals, but can vary.

• Damage to Broca's area causes expressive aphasia, characterized by slow, halting speech with preserved comprehension.

• Damage to Wernicke's area results in receptive aphasia, characterized by fluent but nonsensical speech and impaired comprehension.

• The arcuate fasciculus disruption leads to conduction aphasia, where patients can understand and produce speech but cannot repeat words.

• Language functions are complex and involve multiple interconnected regions; lateralization and individual variability exist.

• Neuroplasticity allows some language recovery after injury, especially in children.

💡 Key Takeaway

The cerebral cortex's language centers, primarily Broca's and Wernicke's areas, work together through neural pathways like the arcuate fasciculus to enable speech comprehension and production; damage to these regions results in distinct aphasic syndromes, highlighting the specialized and lateralized nature of language in the brain.

📖 5. Cerebellum & Motor Control

🔑 Key Concepts & Definitions

• Cerebellum: A brain structure located at the posterior of the brain, essential for coordination, precision, and timing of movements, as well as motor learning.

• Motor Control: The regulation and coordination of movement by the central nervous system, involving planning, initiation, and execution of voluntary and involuntary movements.

• Purkinje Cells: Large neurons in the cerebellar cortex that serve as the primary output neurons, integrating input from various sources and sending inhibitory signals to deep cerebellar nuclei.

• Deep Cerebellar Nuclei: The output centers of the cerebellum, including the dentate, emboliform, globose, and fastigial nuclei, which project to motor and premotor areas.

• Climbing Fibers: Axons originating from the inferior olive that form powerful excitatory synapses with Purkinje cells, crucial for motor learning.

• Mossy Fibers: Afferent fibers from various sources that synapse onto granule cells, which in turn influence Purkinje cells via parallel fibers.

📝 Essential Points

• Cerebellar Anatomy & Pathways:

  • The cerebellum receives afferent input via mossy and climbing fibers.
  • Mossy fibers excite granule cells; granule cells send parallel fibers to Purkinje cells.
  • Climbing fibers directly synapse onto Purkinje cells, providing potent excitatory input.
  • Purkinje cells project inhibitory signals to the deep cerebellar nuclei, which send output to motor pathways.

• Function in Motor Control:

  • The cerebellum compares intended movement (via cortical commands) with actual movement (via proprioceptive feedback).
  • It adjusts ongoing movements and facilitates motor learning by modifying synaptic strength, especially at parallel fiber-Purkinje cell synapses.

• Role in Coordination and Balance:

  • Coordinates voluntary movements, ensuring smooth execution.
  • Maintains balance and posture through connections with vestibular nuclei and spinal cord.

• Clinical Correlations:

  • Damage causes ataxia: uncoordinated, clumsy movements.
  • Lesions can lead to intention tremor, dysmetria, and gait disturbances.
  • The cerebellum does not initiate movement but refines and smooths it.

• Motor Learning:

  • Involves long-term depression (LTD) at parallel fiber-Purkinje cell synapses, a key mechanism for adapting motor responses.

💡 Key Takeaway

The cerebellum acts as the brain's "error corrector" for movement, integrating sensory feedback with motor commands to ensure smooth, coordinated actions and facilitate motor learning. Damage to this structure results in characteristic coordination deficits known as ataxia.

📖 6. Basal Ganglia & Movement Disorders

🔑 Key Concepts & Definitions

• Basal Ganglia: A group of subcortical nuclei including the caudate nucleus, putamen, globus pallidus, subthalamic nucleus, and substantia nigra, involved in regulating voluntary movement, motor control, and motor learning.

• Dopamine: A neurotransmitter produced in the substantia nigra pars compacta, crucial for modulating basal ganglia activity; deficits are linked to Parkinson's disease.

• Direct Pathway: Facilitates movement by disinhibiting the thalamus, involving striatal neurons that inhibit the globus pallidus internus (GPi), leading to increased thalamic activity.

• Indirect Pathway: Inhibits movement by increasing inhibitory output to the thalamus via a circuit involving the striatum, globus pallidus externus (GPe), subthalamic nucleus, and GPi.

• Parkinson's Disease: A neurodegenerative disorder characterized by loss of dopaminergic neurons in the substantia nigra, leading to bradykinesia, rigidity, resting tremor, and postural instability.

• Huntington's Disease: An autosomal dominant neurodegenerative disorder marked by degeneration of the striatum, causing chorea, cognitive decline, and psychiatric symptoms.

📝 Essential Points

• The basal ganglia modulate movement by balancing the direct and indirect pathways, which respectively facilitate and inhibit movement.

• Dopamine from the substantia nigra modulates these pathways: it excites the direct pathway (via D1 receptors) and inhibits the indirect pathway (via D2 receptors), promoting movement.

• In Parkinson's disease, loss of dopaminergic neurons results in decreased activity of the direct pathway and increased activity of the indirect pathway, leading to increased inhibitory output to the thalamus and decreased cortical excitation.

• Clinical features of Parkinson's disease include resting tremor, rigidity, bradykinesia, and postural instability; treatment often involves dopamine replacement (e.g., levodopa).

• Huntington's disease involves degeneration of GABAergic neurons in the striatum, leading to decreased inhibition of the thalamus and subsequent hyperkinetic movements (chorea).

• Other movement disorders include dystonia (sustained muscle contractions), Tourette syndrome (tics), and hemiballismus (violent flinging movements due to subthalamic nucleus lesions).

• Treatment strategies target neurotransmitter systems: dopamine antagonists for hyperkinetic disorders, dopamine precursors or agonists for hypokinetic disorders.

💡 Key Takeaway

The basal ganglia regulate voluntary movement through a delicate balance of excitatory and inhibitory pathways modulated by dopamine; disruptions in this system lead to characteristic movement disorders such as Parkinson's and Huntington's disease.

📖 7. Visual & Auditory Pathways

🔑 Key Concepts & Definitions

• Visual Pathway: The neural route from the retina to the visual cortex, involving the optic nerve, optic chiasm, optic tracts, lateral geniculate nucleus (LGN), optic radiations, and visual cortex.
• Auditory Pathway: The neural route from the cochlea to the auditory cortex, involving the cochlear nerve, cochlear nuclei, superior olivary complex, lateral lemniscus, inferior colliculus, medial geniculate nucleus (MGN), and auditory cortex.
• Optic Chiasm: The crossing point where fibers from the nasal half of each retina cross to the opposite side, enabling binocular vision.
• Lateral Geniculate Nucleus (LGN): A relay nucleus in the thalamus that processes visual information before projecting to the visual cortex.
• Auditory Cortex: The region in the temporal lobe responsible for processing auditory information.
• Gating: The regulation of sensory signals at various relay points, such as the thalamus, to modulate perception.

📝 Essential Points

• Visual Pathway:

  • Visual signals originate in the retina, where photoreceptors convert light into neural signals.
  • The optic nerve carries signals to the optic chiasm, where fibers from nasal retina cross, allowing for binocular vision.
  • Post-chiasmal fibers project to the LGN of the thalamus, which acts as a relay and processing center.
  • From the LGN, signals travel via the optic radiations to the primary visual cortex in the occipital lobe.
  • Lesions at different points cause specific visual deficits (e.g., homonymous hemianopia with cortical lesions).

• Auditory Pathway:

  • Sound waves are transduced into neural signals by hair cells in the cochlea.
  • The cochlear nerve transmits signals to the cochlear nuclei in the brainstem.
  • From there, signals project to the superior olivary complex (for binaural processing), then to the lateral lemniscus, inferior colliculus, and MGN of the thalamus.
  • The auditory cortex in the temporal lobe processes the signals.
  • Pathways are tonotopically organized, preserving frequency information.

• Key Features:

  • Both pathways involve relay stations that process and modulate signals.
  • The optic chiasm's crossing allows for the integration of visual fields.
  • The auditory pathway emphasizes binaural processing for sound localization.
  • Damage at different levels results in characteristic deficits (e.g., visual field cuts, deafness).

💡 Key Takeaway

The visual and auditory pathways are complex, relay-based systems that process sensory information from peripheral organs to specialized cortical areas, with specific anatomical crossings and relay stations that determine the nature of sensory deficits following lesions. Understanding their anatomy and function is essential for localizing neurological damage and interpreting clinical signs.

📖 8. Spinal Cord & Reflexes

🔑 Key Concepts & Definitions

• Spinal Cord: The elongated, cylindrical structure within the vertebral column that transmits nerve signals between the brain and the body, and contains neural circuits responsible for reflexes.
• Reflex Arc: The neural pathway that mediates a reflex action, typically consisting of a sensory receptor, afferent neuron, integration center, efferent neuron, and effector.
• Gray Matter: The butterfly-shaped region in the spinal cord composed mainly of neuronal cell bodies, dendrites, and unmyelinated axons; involved in processing and integrating information.
• White Matter: The outer region of the spinal cord composed mainly of myelinated axons that form ascending and descending tracts for signal transmission.
• Reflex: An involuntary, rapid response to a stimulus, mediated by the spinal cord or brain, essential for protective and homeostatic functions.
• Monosynaptic Reflex: A reflex involving a single synapse between the sensory neuron and motor neuron, such as the stretch (myotatic) reflex.
• Polysynaptic Reflex: A reflex involving one or more interneurons between sensory input and motor output, allowing for more complex responses.

📝 Essential Points

• The spinal cord functions as both a conduit for nerve signals and a center for reflex activity.
• Reflexes are rapid, involuntary responses that help maintain posture, protect tissues, and regulate physiological functions.
• The reflex arc components include:
  • Receptor: Detects stimulus.
  • Afferent neuron: Transmits impulse to the spinal cord.
  • Integration center: Usually in the gray matter, processes the information.
  • Efferent neuron: Carries response from the spinal cord to the effector.
  • Effector: Muscle or gland that responds.
• Stretch reflex (e.g., knee-jerk): Monosynaptic, involves muscle spindles and maintains muscle tone.
• Withdrawal reflex: Polysynaptic, involves interneurons, and causes limb withdrawal from painful stimuli.
• Reflexes can be tested clinically to assess the integrity of the nervous system (e.g., deep tendon reflexes).
• The spinal cord contains tracts:
  • Ascending tracts: Carry sensory information to the brain.
  • Descending tracts: Carry motor commands from the brain to the spinal cord.
• Reflex modulation can occur via descending pathways, allowing voluntary control or inhibition.

💡 Key Takeaway

The spinal cord acts as a vital communication highway and reflex center, enabling rapid involuntary responses that protect the body and help maintain homeostasis, with reflexes serving as essential diagnostic tools for nervous system health.

📖 9. Blood-Brain Barrier & CSF

🔑 Key Concepts & Definitions

• Blood-Brain Barrier (BBB): A selective permeability barrier formed by endothelial cells lining CNS blood vessels, restricting the passage of substances from blood to brain tissue to maintain CNS homeostasis.

• Cerebrospinal Fluid (CSF): Clear, colorless fluid produced mainly by the choroid plexus in ventricles, providing cushioning, nutrient transport, and waste removal for the brain and spinal cord.

• Endothelial Cells: Cells lining blood vessels; in the BBB, they are tightly joined by tight junctions, limiting paracellular permeability.

• Tight Junctions: Specialized connections between endothelial cells that prevent free passage of substances between cells, crucial for BBB integrity.

• Transport Mechanisms: Include passive diffusion, facilitated diffusion, active transport, and receptor-mediated transcytosis, enabling selective movement of molecules across the BBB and into CSF.

• Choroid Plexus: A network of capillaries and epithelial cells in ventricles responsible for CSF production; features fenestrated capillaries and tight junctions in epithelial cells.

📝 Essential Points

• Structure of the BBB: Composed of endothelial cells with tight junctions, basement membrane, pericytes, and astrocyte end-feet, forming a highly selective barrier.

• Function of the BBB: Protects the CNS from toxins, pathogens, and fluctuations in blood composition; regulates the entry of nutrients and removal of waste.

• Transport across the BBB: Small lipophilic molecules diffuse freely; polar molecules require specific transporters; large molecules typically cross via receptor-mediated transcytosis.

• CSF Circulation: CSF is produced by the choroid plexus, flows through ventricles, around the brain and spinal cord in the subarachnoid space, and is absorbed into venous blood via arachnoid villi.

• Composition of CSF: Similar to plasma but with lower protein content and fewer cells; maintains a stable environment for neural tissue.

• Clinical Relevance:

  • Disruption of BBB: Can lead to neuroinflammation, infections, or tumors.
  • CSF Analysis: Used in diagnosis of infections (meningitis), hemorrhage, multiple sclerosis, and other neurological conditions.
  • Drug Delivery: The BBB limits CNS drug access; strategies include modifying drugs to cross or bypass the barrier.

💡 Key Takeaway

The blood-brain barrier is a highly selective interface that protects the CNS by regulating substance entry, while the CSF provides a supportive environment for neural tissue; understanding their structure and function is crucial for diagnosing and treating neurological diseases.

📖 10. Temperature Regulation & Fever

🔑 Key Concepts & Definitions

• Thermoregulation: The physiological process that maintains core body temperature within a narrow, optimal range (~98.6°F or 37°C) despite environmental changes.
• Hypothalamus: The brain region that acts as the body's thermostat, integrating signals and initiating responses to regulate temperature.
• Set Point: The target temperature maintained by thermoregulatory mechanisms; can be altered during fever.
• Fever (Pyrexia): An elevation of body temperature above the normal range due to a reset of the hypothalamic set point, usually in response to infection or inflammation.
• Pyrogens: Substances (e.g., cytokines like IL-1, IL-6, TNF-alpha) that induce fever by acting on the hypothalamus to increase the set point.
• Heat Production & Loss: The balance between metabolic heat generation (via muscle activity, metabolism) and heat dissipation (via vasodilation, sweating, radiation).

📝 Essential Points

• Normal Body Temperature Regulation:
  • The hypothalamus receives input from peripheral thermoreceptors (skin) and central thermoreceptors (brain).
  • Responses to cold include shivering, vasoconstriction, and increased metabolic activity.
  • Responses to heat include vasodilation, sweating, and behavioral adaptations.
• Fever Pathophysiology:
  • Triggered by pyrogens that stimulate the hypothalamus to raise the set point.
  • The body perceives current temperature as too low and initiates heat-generating responses.
  • Once pyrogens are cleared, the set point returns to normal, and heat loss mechanisms are activated, often causing chills initially.
• Clinical Significance of Fever:
  • Often indicates infection, inflammation, or immune response.
  • Mild fever can be beneficial by enhancing immune function.
  • High or prolonged fever can be dangerous, leading to dehydration, seizures, or tissue damage.
• Therapeutic Interventions:
  • Antipyretics (e.g., acetaminophen, NSAIDs) reduce fever by inhibiting prostaglandin synthesis in the hypothalamus.
  • Cooling measures may be used in severe hyperthermia or heat stroke.
• Heat Stroke & Hyperthermia:
  • Characterized by dangerously high body temperatures (>104°F or 40°C).
  • Can cause multi-organ failure; requires immediate cooling and supportive care.
• Environmental & Behavioral Factors:
  • Clothing, ambient temperature, hydration, and activity influence thermoregulation.
  • Behavioral responses include seeking shade, removing clothing, or increasing fluid intake.

💡 Key Takeaway

Thermoregulation is a complex, finely tuned process centered in the hypothalamus that maintains body temperature within a narrow range; fever results from a hypothalamic set point reset due to pyrogens, serving as an immune response indicator but potentially causing harm if uncontrolled.

📊 Synthesis Tables

Feature	Sympathetic Nervous System	Parasympathetic Nervous System
Origin	Thoracolumbar spinal segments (T1-L2)	Craniosacral regions (brainstem nuclei, S2-S4)
Neurotransmitter at effector sites	Norepinephrine (NE), ACh in sweat glands	Acetylcholine (ACh)
Receptor types	Adrenergic (alpha, beta), cholinergic (muscarinic)	Cholinergic (muscarinic, nicotinic)
Effect on heart rate	Increases	Decreases
Effect on bronchi	Dilation (except in parasympathetic)	Constriction
Innervation of organs	Often dual; antagonistic effects	Often dual; antagonistic effects

Neurotransmitter & Receptor Types	Function	Example Effect
Acetylcholine (ACh)	Binds to cholinergic receptors; fast synaptic transmission	Muscle contraction, parasympathetic responses
Norepinephrine (NE)	Binds to adrenergic receptors; modulates sympathetic responses	Increased heart rate, vasoconstriction
Ionotropic Receptors	Rapid response; ligand-gated ion channels	Glutamate receptors in excitatory synapses
Metabotropic Receptors	Slow response; G-protein coupled	Muscarinic ACh receptors, adrenergic receptors

⚠️ Common Pitfalls & Confusions

1. Confusing sympathetic and parasympathetic origins (thoracolumbar vs. craniosacral).
2. Assuming neurotransmitter exclusivity; e.g., NE always in sympathetic, ACh always in parasympathetic.
3. Overlooking dual innervation and antagonistic effects on organs.
4. Misidentifying receptor types; e.g., thinking all ACh receptors are nicotinic.
5. Ignoring receptor subtypes (alpha vs. beta adrenergic) and their distinct effects.
6. Confusing ionotropic and metabotropic receptor mechanisms regarding speed and function.
7. Overgeneralizing neurotransmitter effects without considering receptor distribution.

✅ Exam Checklist

• Describe the organization and function of the autonomic nervous system.
• Differentiate between sympathetic and parasympathetic pathways, including origins and neurotransmitters.
• Explain the roles of adrenergic and cholinergic receptors in autonomic signaling.
• Identify the types of sensory receptors and their modalities.
• Trace the pathway of sensory information from receptors to the brain.
• Outline the functions of Broca's and Wernicke's areas in language.
• Describe the neural basis of aphasia and lateralization of language.
• Summarize the roles of the cerebellum and basal ganglia in motor control.
• Explain the visual and auditory pathways from sensory organs to cortex.
• Describe the reflex arc and spinal cord organization.
• Outline the blood-brain barrier structure and function.
• Summarize mechanisms of temperature regulation and fever response.
• Recognize common pitfalls in neural pathway and receptor identification.