Exercise 19 The Brain Cranial Nerves Ventricles of
![Exercise 19 The Brain & Cranial Nerves Exercise 19 The Brain & Cranial Nerves](https://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-1.jpg)
Exercise 19 The Brain & Cranial Nerves
![Ventricles of the Brain Figure 12. 5 Ventricles of the Brain Figure 12. 5](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-2.jpg)
Ventricles of the Brain Figure 12. 5
![Fiber Tracts in White Matter Figure 12. 10 a Fiber Tracts in White Matter Figure 12. 10 a](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-3.jpg)
Fiber Tracts in White Matter Figure 12. 10 a
![Basal Nuclei Figure 12. 11 a Basal Nuclei Figure 12. 11 a](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-4.jpg)
Basal Nuclei Figure 12. 11 a
![Basal Nuclei Figure 12. 11 b Basal Nuclei Figure 12. 11 b](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-5.jpg)
Basal Nuclei Figure 12. 11 b
![Meninges • Three connective tissue membranes lie external to the CNS – dura mater, Meninges • Three connective tissue membranes lie external to the CNS – dura mater,](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-6.jpg)
Meninges • Three connective tissue membranes lie external to the CNS – dura mater, arachnoid mater, and pia mater • Functions of the meninges – Cover and protect the CNS – Protect blood vessels and enclose venous sinuses – Contain cerebrospinal fluid (CSF) – Form partitions within the skull
![Meninges Figure 12. 23 a Meninges Figure 12. 23 a](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-7.jpg)
Meninges Figure 12. 23 a
![Dura Mater • Leathery, strong meninx composed of two fibrous connective tissue layers • Dura Mater • Leathery, strong meninx composed of two fibrous connective tissue layers •](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-8.jpg)
Dura Mater • Leathery, strong meninx composed of two fibrous connective tissue layers • The two layers separate in certain areas and form dural sinuses
![Dura Mater • Three dural septa extend inward and limit excessive movement of the Dura Mater • Three dural septa extend inward and limit excessive movement of the](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-9.jpg)
Dura Mater • Three dural septa extend inward and limit excessive movement of the brain – Falx cerebri – fold that dips into the longitudinal fissure – Falx cerebelli – runs along the vermis of the cerebellum – Tentorium cerebelli – horizontal dural fold extends into the transverse fissure
![Dura Mater Figure 12. 24 Dura Mater Figure 12. 24](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-10.jpg)
Dura Mater Figure 12. 24
![• The middle meninx, which forms a loose brain covering • It is • The middle meninx, which forms a loose brain covering • It is](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-11.jpg)
• The middle meninx, which forms a loose brain covering • It is separated from the dura mater by the subdural space • Beneath the arachnoid is a wide subarachnoid space filled with CSF and large blood vessels • Arachnoid villi protrude superiorly and permit CSF to be absorbed into venous blood Arachnoid Mater
![Arachnoid Mater Figure 12. 23 a Arachnoid Mater Figure 12. 23 a](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-12.jpg)
Arachnoid Mater Figure 12. 23 a
![Pia Mater • Deep meninx composed of delicate connective tissue that clings tightly to Pia Mater • Deep meninx composed of delicate connective tissue that clings tightly to](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-13.jpg)
Pia Mater • Deep meninx composed of delicate connective tissue that clings tightly to the brain
![Cerebrospinal Fluid (CSF) • Watery solution similar in composition to blood plasma • Contains Cerebrospinal Fluid (CSF) • Watery solution similar in composition to blood plasma • Contains](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-14.jpg)
Cerebrospinal Fluid (CSF) • Watery solution similar in composition to blood plasma • Contains less protein and different ion concentrations than plasma • Forms a liquid cushion that gives buoyancy to the CNS organs • Prevents the brain from crushing under its own weight • Protects the CNS from blows and other trauma • Nourishes the brain and carries chemical signals throughout it
![Choroid Plexuses • Clusters of capillaries that form tissue fluid filters, which hang from Choroid Plexuses • Clusters of capillaries that form tissue fluid filters, which hang from](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-15.jpg)
Choroid Plexuses • Clusters of capillaries that form tissue fluid filters, which hang from the roof of each ventricle • Have ion pumps that allow them to alter ion concentrations of the CSF • Help cleanse CSF by removing wastes
![Choroid Plexuses Figure 12. 25 a Choroid Plexuses Figure 12. 25 a](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-16.jpg)
Choroid Plexuses Figure 12. 25 a
![Blood-Brain Barrier • Protective mechanism that helps maintain a stable environment for the brain Blood-Brain Barrier • Protective mechanism that helps maintain a stable environment for the brain](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-17.jpg)
Blood-Brain Barrier • Protective mechanism that helps maintain a stable environment for the brain • Bloodborne substances are separated from neurons by: – Continuous endothelium of capillary walls – Relatively thick basal lamina – Bulbous feet of astrocytes
![Blood-Brain Barrier: Functions • Selective barrier that allows nutrients to pass freely • Is Blood-Brain Barrier: Functions • Selective barrier that allows nutrients to pass freely • Is](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-18.jpg)
Blood-Brain Barrier: Functions • Selective barrier that allows nutrients to pass freely • Is ineffective against substances that can diffuse through plasma membranes • Absent in some areas (vomiting center and the hypothalamus), allowing these areas to monitor the chemical composition of the blood • Stress increases the ability of chemicals to pass through the blood-brain barrier
![Cranial Nerves • Twelve pairs of cranial nerves arise from the brain • They Cranial Nerves • Twelve pairs of cranial nerves arise from the brain • They](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-19.jpg)
Cranial Nerves • Twelve pairs of cranial nerves arise from the brain • They have sensory, motor, or both sensory and motor functions • Each nerve is identified by a number (I through XII) and a name • Four cranial nerves carry parasympathetic fibers that serve muscles and glands
![Cranial Nerves Figure 13. 5 a Cranial Nerves Figure 13. 5 a](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-20.jpg)
Cranial Nerves Figure 13. 5 a
![Summary of Function of Cranial Nerves Figure 13. 5 b Summary of Function of Cranial Nerves Figure 13. 5 b](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-21.jpg)
Summary of Function of Cranial Nerves Figure 13. 5 b
![Cranial Nerve I: Olfactory • Arises from the olfactory epithelium • Passes through the Cranial Nerve I: Olfactory • Arises from the olfactory epithelium • Passes through the](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-22.jpg)
Cranial Nerve I: Olfactory • Arises from the olfactory epithelium • Passes through the cribriform plate of the ethmoid bone • Fibers run through the olfactory bulb and terminate in the primary olfactory cortex • Functions solely by carrying afferent impulses for the sense of smell
![Cranial Nerve I: Olfactory Figure I from Table 13. 2 Cranial Nerve I: Olfactory Figure I from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-23.jpg)
Cranial Nerve I: Olfactory Figure I from Table 13. 2
![Cranial Nerve II: Optic • Arises from the retina of the eye • Optic Cranial Nerve II: Optic • Arises from the retina of the eye • Optic](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-24.jpg)
Cranial Nerve II: Optic • Arises from the retina of the eye • Optic nerves pass through the optic canals and converge at the optic chiasm • They continue to the thalamus where they synapse • From there, the optic radiation fibers run to the visual cortex • Functions solely by carrying afferent impulses for vision
![Cranial Nerve II: Optic Figure II Table 13. 2 Cranial Nerve II: Optic Figure II Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-25.jpg)
Cranial Nerve II: Optic Figure II Table 13. 2
![Cranial Nerve III: Oculomotor • Fibers extend from the ventral midbrain, pass through the Cranial Nerve III: Oculomotor • Fibers extend from the ventral midbrain, pass through the](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-26.jpg)
Cranial Nerve III: Oculomotor • Fibers extend from the ventral midbrain, pass through the superior orbital fissure, and go to the extrinsic eye muscles • Functions in raising the eyelid, directing the eyeball, constricting the iris, and controlling lens shape • Parasympathetic cell bodies are in the ciliary ganglia
![Cranial Nerve III: Oculomotor Figure III from Table 13. 2 Cranial Nerve III: Oculomotor Figure III from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-27.jpg)
Cranial Nerve III: Oculomotor Figure III from Table 13. 2
![Cranial Nerve IV: Trochlear • Fibers emerge from the dorsal midbrain and enter the Cranial Nerve IV: Trochlear • Fibers emerge from the dorsal midbrain and enter the](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-28.jpg)
Cranial Nerve IV: Trochlear • Fibers emerge from the dorsal midbrain and enter the orbits via the superior orbital fissures; innervate the superior oblique muscle • Primarily a motor nerve that directs the eyeball
![Cranial Nerve IV: Trochlear Figure IV from Table 13. 2 Cranial Nerve IV: Trochlear Figure IV from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-29.jpg)
Cranial Nerve IV: Trochlear Figure IV from Table 13. 2
![Cranial Nerve V: Trigeminal • Composed of three divisions: ophthalmic (V 1), maxillary (V Cranial Nerve V: Trigeminal • Composed of three divisions: ophthalmic (V 1), maxillary (V](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-30.jpg)
Cranial Nerve V: Trigeminal • Composed of three divisions: ophthalmic (V 1), maxillary (V 2), and mandibular (V 3) • Fibers run from the face to the pons via the superior orbital fissure (V 1), the foramen rotundum (V 2), and the foramen ovale (V 3) • Conveys sensory impulses from various areas of the face (V 1) and (V 2), and supplies motor fibers (V 3) for mastication
![Cranial Nerve V: Trigeminal Figure V from Table 13. 2 Cranial Nerve V: Trigeminal Figure V from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-31.jpg)
Cranial Nerve V: Trigeminal Figure V from Table 13. 2
![Cranial Nerve VI: Abdcuens • Fibers leave the inferior pons and enter the orbit Cranial Nerve VI: Abdcuens • Fibers leave the inferior pons and enter the orbit](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-32.jpg)
Cranial Nerve VI: Abdcuens • Fibers leave the inferior pons and enter the orbit via the superior orbital fissure • Primarily a motor nerve innervating the lateral rectus muscle Figure VI from Table 13. 2
![• Fibers leave the pons, travel through the internal acoustic meatus, and emerge • Fibers leave the pons, travel through the internal acoustic meatus, and emerge](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-33.jpg)
• Fibers leave the pons, travel through the internal acoustic meatus, and emerge through the stylomastoid foramen to the lateral aspect of the face • Mixed nerve with five major branches • Motor functions include facial expression, and the transmittal of autonomic impulses to lacrimal and salivary glands • Sensory function is taste from the anterior two-thirds of the tongue Cranial Nerve VII: Facial
![Cranial Nerve VII: Facial Figure VII from Table 13. 2 Cranial Nerve VII: Facial Figure VII from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-34.jpg)
Cranial Nerve VII: Facial Figure VII from Table 13. 2
![Cranial Nerve VIII: Vestibulocochlear • Fibers arise from the hearing and equilibrium apparatus of Cranial Nerve VIII: Vestibulocochlear • Fibers arise from the hearing and equilibrium apparatus of](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-35.jpg)
Cranial Nerve VIII: Vestibulocochlear • Fibers arise from the hearing and equilibrium apparatus of the inner ear, pass through the internal acoustic meatus, and enter the brainstem at the ponsmedulla border • Two divisions – cochlear (hearing) and vestibular (balance) • Functions are solely sensory – equilibrium and hearing
![Cranial Nerve VIII: Vestibulocochlear Figure VIII from Table 13. 2 Cranial Nerve VIII: Vestibulocochlear Figure VIII from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-36.jpg)
Cranial Nerve VIII: Vestibulocochlear Figure VIII from Table 13. 2
![• Fibers emerge from the medulla, leave the skull via the jugular foramen, • Fibers emerge from the medulla, leave the skull via the jugular foramen,](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-37.jpg)
• Fibers emerge from the medulla, leave the skull via the jugular foramen, and run to the throat • Nerve IX is a mixed nerve with motor and sensory functions • Motor – innervates part of the tongue and pharynx, and provides motor fibers to the parotid salivary gland • Sensory – fibers conduct taste and general sensory impulses from the tongue and pharynx Cranial Nerve IX: Glossopharyngeal
![Cranial Nerve IX: Glossopharyngeal Figure IX from Table 13. 2 Cranial Nerve IX: Glossopharyngeal Figure IX from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-38.jpg)
Cranial Nerve IX: Glossopharyngeal Figure IX from Table 13. 2
![Cranial Nerve X: Vagus • The only cranial nerve that extends beyond the head Cranial Nerve X: Vagus • The only cranial nerve that extends beyond the head](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-39.jpg)
Cranial Nerve X: Vagus • The only cranial nerve that extends beyond the head and neck • Fibers emerge from the medulla via the jugular foramen • The vagus is a mixed nerve • Most motor fibers are parasympathetic fibers to the heart, lungs, and visceral organs • Its sensory function is in taste
![Cranial Nerve X: Vagus Figure X from Table 13. 2 Cranial Nerve X: Vagus Figure X from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-40.jpg)
Cranial Nerve X: Vagus Figure X from Table 13. 2
![Cranial Nerve XI: Accessory • Formed from a cranial root emerging from the medulla Cranial Nerve XI: Accessory • Formed from a cranial root emerging from the medulla](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-41.jpg)
Cranial Nerve XI: Accessory • Formed from a cranial root emerging from the medulla and a spinal root arising from the superior region of the spinal cord • The spinal root passes upward into the cranium via the foramen magnum • The accessory nerve leaves the cranium via the jugular foramen
![Cranial Nerve XI: Accessory • Primarily a motor nerve – Supplies fibers to the Cranial Nerve XI: Accessory • Primarily a motor nerve – Supplies fibers to the](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-42.jpg)
Cranial Nerve XI: Accessory • Primarily a motor nerve – Supplies fibers to the larynx, pharynx, and soft palate – Innervates the trapezius and sternocleidomastoid, which move the head and neck
![Cranial Nerve XI: Accessory Figure XI from Table 13. 2 Cranial Nerve XI: Accessory Figure XI from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-43.jpg)
Cranial Nerve XI: Accessory Figure XI from Table 13. 2
![Cranial Nerve XII: Hypoglossal • Fibers arise from the medulla and exit the skull Cranial Nerve XII: Hypoglossal • Fibers arise from the medulla and exit the skull](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-44.jpg)
Cranial Nerve XII: Hypoglossal • Fibers arise from the medulla and exit the skull via the hypoglossal canal • Innervates both extrinsic and intrinsic muscles of the tongue, which contribute to swallowing and speech
![Cranial Nerve XII: Hypoglossal Figure XII from Table 13. 2 Cranial Nerve XII: Hypoglossal Figure XII from Table 13. 2](http://slidetodoc.com/presentation_image_h/81f78e49b69b6131fcfb8e568ec4613c/image-45.jpg)
Cranial Nerve XII: Hypoglossal Figure XII from Table 13. 2
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