The vagus nerve is the longest cranial nerve originating from nuclei in the brainstem. It has both motor and sensory components and is one of the parasympathetic nerves. It exits the skull through the jugular foramen and gives rise to branches innervating the ear, pharynx, larynx, heart, lungs and gastrointestinal tract. Pathologies can be localized to supranuclear, nuclear, brainstem, skull base, nerve trunk or branchial divisions based on examination of voice, swallowing, autonomic and sensory functions.
The hypothalamus controls many essential functions through its connections with the pituitary gland and autonomic nervous system. It regulates homeostasis, hormone production and secretion, circadian rhythms, temperature, hunger and thirst, sleep cycles, emotions, and reproductive functions. The hypothalamus is located below the thalamus and forms part of the walls and floor of the third ventricle. It is divided into four levels - preoptic, supraoptic, tuberal, and mammillary - which contain nuclei that integrate homeostatic processes and regulate the endocrine and autonomic nervous systems.
The medulla oblongata connects the pons superiorly to the spinal cord inferiorly. It has important cranial nerve nuclei and tracts that control vital functions like breathing and heart rate. A key feature is the decussation of the pyramids, where most corticospinal fibers cross to the opposite side. The medulla also contains nuclei that relay proprioceptive and fine touch sensations from the body to the brain.
the fibers present in the cerebellar peduncles
the applied anatomy of the cerebellum
the microscopic structure of the cerebellum, mossy, and climbing fibers
The brain stem is located between the cerebrum and spinal cord, and consists of the midbrain, pons, and medulla oblongata. The midbrain connects the forebrain to the pons and cerebellum. It contains important centers for visual and auditory reflexes, and gives rise to the trochlear nerve. Key structures in the midbrain include the superior and inferior colliculi, oculomotor nucleus, red nucleus, and substantia nigra. The midbrain serves to relay motor and sensory signals between the spinal cord and forebrain.
The midbrain connects the hindbrain and forebrain. It is involved in vision, hearing, motor control and other functions. The midbrain contains several structures including the tectum, tegmentum, cerebral peduncles, cerebral aqueduct, superior and inferior colliculi, substantia nigra and red nucleus. It also contains nuclei associated with cranial nerves III, IV, V and VI. Sensory and motor tracts pass through the midbrain connecting different parts of the brain and spinal cord.
The internal capsule is a central white matter structure that contains important projection fibers connecting the cerebral cortex with deep gray matter structures. It is divided into the anterior limb, genu, posterior limb, retrolenticular and sublenticular parts. The internal capsule receives its blood supply from the middle cerebral artery, anterior cerebral artery, and anterior choroidal artery. Strokes or lesions involving the internal capsule can cause motor or sensory deficits depending on the fibers affected.
The document discusses the glossopharyngeal (CN IX) and vagus (CN X) nerves. It covers their anatomy, functions, and clinical assessment. The glossopharyngeal nerve innervates the pharynx and posterior tongue. The vagus nerve is the longest cranial nerve, innervating muscles of the pharynx and larynx, and the heart and gastrointestinal tract via parasympathetic fibers. Clinical examination focuses on motor function of soft palate, larynx, and reflexes. Lesions are localized based on involved structures and associated deficits in other cranial nerves.
The hypothalamus controls many essential functions through its connections with the pituitary gland and autonomic nervous system. It regulates homeostasis, hormone production and secretion, circadian rhythms, temperature, hunger and thirst, sleep cycles, emotions, and reproductive functions. The hypothalamus is located below the thalamus and forms part of the walls and floor of the third ventricle. It is divided into four levels - preoptic, supraoptic, tuberal, and mammillary - which contain nuclei that integrate homeostatic processes and regulate the endocrine and autonomic nervous systems.
The medulla oblongata connects the pons superiorly to the spinal cord inferiorly. It has important cranial nerve nuclei and tracts that control vital functions like breathing and heart rate. A key feature is the decussation of the pyramids, where most corticospinal fibers cross to the opposite side. The medulla also contains nuclei that relay proprioceptive and fine touch sensations from the body to the brain.
the fibers present in the cerebellar peduncles
the applied anatomy of the cerebellum
the microscopic structure of the cerebellum, mossy, and climbing fibers
The brain stem is located between the cerebrum and spinal cord, and consists of the midbrain, pons, and medulla oblongata. The midbrain connects the forebrain to the pons and cerebellum. It contains important centers for visual and auditory reflexes, and gives rise to the trochlear nerve. Key structures in the midbrain include the superior and inferior colliculi, oculomotor nucleus, red nucleus, and substantia nigra. The midbrain serves to relay motor and sensory signals between the spinal cord and forebrain.
The midbrain connects the hindbrain and forebrain. It is involved in vision, hearing, motor control and other functions. The midbrain contains several structures including the tectum, tegmentum, cerebral peduncles, cerebral aqueduct, superior and inferior colliculi, substantia nigra and red nucleus. It also contains nuclei associated with cranial nerves III, IV, V and VI. Sensory and motor tracts pass through the midbrain connecting different parts of the brain and spinal cord.
The internal capsule is a central white matter structure that contains important projection fibers connecting the cerebral cortex with deep gray matter structures. It is divided into the anterior limb, genu, posterior limb, retrolenticular and sublenticular parts. The internal capsule receives its blood supply from the middle cerebral artery, anterior cerebral artery, and anterior choroidal artery. Strokes or lesions involving the internal capsule can cause motor or sensory deficits depending on the fibers affected.
The document discusses the glossopharyngeal (CN IX) and vagus (CN X) nerves. It covers their anatomy, functions, and clinical assessment. The glossopharyngeal nerve innervates the pharynx and posterior tongue. The vagus nerve is the longest cranial nerve, innervating muscles of the pharynx and larynx, and the heart and gastrointestinal tract via parasympathetic fibers. Clinical examination focuses on motor function of soft palate, larynx, and reflexes. Lesions are localized based on involved structures and associated deficits in other cranial nerves.
The cerebellum is located behind the brain stem and is divided into three lobes - anterior, posterior, and flocculonodular. It receives input from the spinal cord, vestibular system, and cerebral cortex. The cerebellar cortex consists of molecular, purkinje, and granular layers. Purkinje cells are the sole output, projecting to deep cerebellar nuclei which connect to motor and premotor areas. The cerebellum is involved in coordination, precision of movement, and maintaining balance and posture.
The document discusses the blood supply of the brain. It begins by describing the two pairs of arteries that supply the brain - the vertebral and internal carotid arteries. These arteries are interconnected to form the circle of Willis at the base of the brain. The vertebrobasilar system arises from the vertebral arteries and forms the basilar artery, which divides into the posterior cerebral arteries. The internal carotid system gives rise to the anterior and middle cerebral arteries. These arteries and their branches supply different regions of the brain. The circle of Willis provides an important anastomosis between the two systems to ensure adequate blood flow to the brain.
The document discusses the thalamus and its functions. It begins with objectives and physiological anatomy of the thalamus. It then discusses the internal structure of the thalamus including its white and grey matter. Next, it covers the connections of the thalamus including its sensory, motor, visceral, and integrative nuclei. It lists the functions of the thalamus such as acting as a sensory relay center and in arousal, perception, emotions, and motor integration. Finally, it discusses some applied aspects including thalamic syndrome, Korsakoff's syndrome, and frontal lobotomy.
The vagus nerve is:
- The longest and most widely distributed of the cranial nerves.
- A mixed nerve that is mostly motor and innervates structures in the head, neck, thorax, and abdomen.
- Involved in motor function of the pharynx and larynx, and parasympathetic function like regulating heart rate and smooth muscle of organs.
- Assessed clinically by having a patient say "ah" and observing for symmetry of soft palate movement.
The document provides an overview of the midbrain, including its:
1. Anatomy, with descriptions of its major parts like the cerebral peduncles, substantia nigra, and corpora quadrigemina.
2. Internal structures seen on transverse sections at different levels, such as the cerebral aqueduct, oculomotor and trochlear nerve nuclei.
3. Connections of structures like the superior colliculus and red nucleus.
4. Functions including roles in visual, auditory, and motor pathways through the brainstem.
The third ventricle is a midline cavity situated between the two thalami and hypothalamus. It extends from the lamina terminalis anteriorly to the cerebral aqueduct posteriorly. The third ventricle has anterior, posterior, roof, floor and lateral walls formed by surrounding structures like the thalamus, hypothalamus, pineal gland and others. It has recesses that extend into surrounding structures like the infundibular recess into the pituitary stalk. The pineal gland is a small reddish-grey structure located between the superior colliculi that secretes the hormone melatonin and is involved in biological functions like sleep-wake cycles.
The main arterial supply to the upper limb begins with the subclavian artery. It arises from the brachiocephalic trunk on the right side and directly from the aorta on the left. The subclavian artery passes lateral to the anterior surface of the cervical pleura and becomes the axillary artery at the outer border of the first rib. It gives off several branches that supply the neck, thorax and upper limb including the vertebral, internal thoracic, and thyrocervical trunks. The internal thoracic artery supplies the anterior chest wall and is often used in coronary bypass grafts.
The internal capsule is divided into superior and inferior parts. It is located medially between the caudate nucleus and thalamus, and laterally between the lentiform nucleus. It contains ascending and descending tracts that connect the cortex to lower brain structures. The internal capsule has anterior, genu, posterior, retrolentiform, and sublentiform parts that contain different tracts. We need to learn about the internal capsule because it is important for understanding the pathways involved in motor and sensory functions.
This document discusses the anatomy and functions of the corpus callosum. It describes the corpus callosum as the wide bundle of neural fibers beneath the cortex that connects the left and right cerebral hemispheres. It summarizes that the corpus callosum is divided into five regions - the splenium, body, genu, rostrum, and isthmus. It also briefly discusses the blood supply, development, and functions of the different regions of the corpus callosum.
The internal capsule is a bundle of fibers that passes through the basal ganglia and connects the cerebral cortex with lower brain structures. It is divided into the anterior limb, genu, posterior limb, retrolenticular part, and sublenticular part. The internal capsule contains thalamocortical fibers, corticopontine fibers, corticonuclear fibers, and corticospinal fibers. It receives its blood supply from the lenticulostriate arteries of the middle cerebral artery, the anterior cerebral artery, and the anterior choroidal artery. Damage to specific parts of the internal capsule can cause motor or sensory deficits on the opposite side of the body.
The pterygopalatine ganglion is the largest parasympathetic ganglion in the head and neck. It is located in the pterygopalatine fossa, an important neurovascular junction of the deep face. The ganglion receives sensory roots from the maxillary nerve and autonomic roots from the greater superficial petrosal and deep petrosal nerves. It gives off several branches that innervate structures like the nasal cavity, palate, and pharynx.
The document provides information about the brainstem, which consists of the medulla, pons, and midbrain. It describes the gross anatomy and internal features of the medulla, including nuclei, tracts, and blood supply. Specific conditions that can affect the medulla, such as raised intracranial pressure and lateral/medial medullary syndromes, are also discussed. The pons is then covered, outlining its anterior and posterior surfaces, nuclei including the pontine nuclei, and blood supply from the basilar artery.
The cerebellum has three main parts - the vermis, two hemispheres, and four lobes. It receives sensory input from the spinal cord, brainstem, and cerebral cortex. There are three layers in the cerebellar cortex - molecular layer, purkinje cell layer, and granular layer. The cerebellum is connected to the brainstem via three cerebellar peduncles and plays a role in motor coordination and balance.
The brainstem is located between the cerebrum and spinal cord. It consists of the midbrain, pons, and medulla oblongata. The midbrain connects the pons and cerebrum and contains the superior and inferior colliculi. The pons connects to the cerebellum via peduncles and contains pontine nuclei and cranial nerve nuclei. The medulla oblongata connects to the spinal cord and contains cranial nerve nuclei, the inferior olives, and tracts such as the gracile and cuneate fasciculi.
The pons lies between the medulla oblongata and midbrain, connecting them. It contains motor and sensory nuclei for cranial nerves 5-8 and helps transmit signals between the cerebellum and cerebral cortex. The pons has anterior and posterior surfaces and contains fibers, nuclei, and tracts that process sensory information and coordinate motor functions. Damage to different areas can cause deficits like hemiplegia, hearing loss, or facial paralysis.
The white matter of the cerebrum contains three main types of nerve fibers: commissural fibers, association fibers, and projection fibers. Commissural fibers such as the corpus callosum connect the two cerebral hemispheres. Association fibers like the superior longitudinal bundle connect different regions within the same hemisphere. Projection fibers including those in the internal capsule connect the cerebral cortex to lower brain centers. The internal capsule specifically contains fibers that project to and from the cortex and plays an important role in motor function. Damage to the internal capsule can thus cause contralateral hemiplegia.
The document provides an overview of the divisions and structures of the brain, including the forebrain (telencephalon and diencephalon), midbrain, and hindbrain (metencephalon and myelencephalon). Key structures discussed include the cerebral hemispheres, thalamus, hypothalamus, pons, cerebellum, and medulla oblongata. Common neurological conditions like headaches, stroke, and Horner's syndrome are also briefly mentioned.
The internal carotid artery has 7 segments from its origin at the common carotid artery bifurcation to where it enters the cranium. Each segment has unique anatomic features and branches. The segments are named cervical, petrous, lacerum, cavernous, clinoid, ophthalmic, and communicating. The petrous, cavernous, and ophthalmic segments each have important branches including the vidian artery, meningohypophyseal trunk, and ophthalmic artery respectively.
This document summarizes the anatomy of the circle of Willis and cerebral blood supply. It describes the circle of Willis as a polygonal anastomotic channel at the base of the brain supplied by the internal carotid and vertebral arteries. It then discusses the branches and functions of the circle of Willis, cortical and central arteries, lenticulostriate arteries, and the blood-brain barrier. Finally, it provides details on the regional arterial supply of different brain regions and applied anatomy related to various neurological syndromes.
The vagus nerve is the longest cranial nerve. It originates in the brainstem and travels through the head and neck, thorax, and abdomen. It is a mixed nerve that carries both sensory and motor fibers. In the head and neck, it innervates muscles of the pharynx and larynx. It gives off several branches including the superior and recurrent laryngeal nerves, as well as cardiac branches. The vagus nerve plays an important role in parasympathetic functions such as slowing heart rate and increasing digestive activity. Injury to it can cause hoarseness, difficulty swallowing, and other issues.
The cerebellum is located behind the brain stem and is divided into three lobes - anterior, posterior, and flocculonodular. It receives input from the spinal cord, vestibular system, and cerebral cortex. The cerebellar cortex consists of molecular, purkinje, and granular layers. Purkinje cells are the sole output, projecting to deep cerebellar nuclei which connect to motor and premotor areas. The cerebellum is involved in coordination, precision of movement, and maintaining balance and posture.
The document discusses the blood supply of the brain. It begins by describing the two pairs of arteries that supply the brain - the vertebral and internal carotid arteries. These arteries are interconnected to form the circle of Willis at the base of the brain. The vertebrobasilar system arises from the vertebral arteries and forms the basilar artery, which divides into the posterior cerebral arteries. The internal carotid system gives rise to the anterior and middle cerebral arteries. These arteries and their branches supply different regions of the brain. The circle of Willis provides an important anastomosis between the two systems to ensure adequate blood flow to the brain.
The document discusses the thalamus and its functions. It begins with objectives and physiological anatomy of the thalamus. It then discusses the internal structure of the thalamus including its white and grey matter. Next, it covers the connections of the thalamus including its sensory, motor, visceral, and integrative nuclei. It lists the functions of the thalamus such as acting as a sensory relay center and in arousal, perception, emotions, and motor integration. Finally, it discusses some applied aspects including thalamic syndrome, Korsakoff's syndrome, and frontal lobotomy.
The vagus nerve is:
- The longest and most widely distributed of the cranial nerves.
- A mixed nerve that is mostly motor and innervates structures in the head, neck, thorax, and abdomen.
- Involved in motor function of the pharynx and larynx, and parasympathetic function like regulating heart rate and smooth muscle of organs.
- Assessed clinically by having a patient say "ah" and observing for symmetry of soft palate movement.
The document provides an overview of the midbrain, including its:
1. Anatomy, with descriptions of its major parts like the cerebral peduncles, substantia nigra, and corpora quadrigemina.
2. Internal structures seen on transverse sections at different levels, such as the cerebral aqueduct, oculomotor and trochlear nerve nuclei.
3. Connections of structures like the superior colliculus and red nucleus.
4. Functions including roles in visual, auditory, and motor pathways through the brainstem.
The third ventricle is a midline cavity situated between the two thalami and hypothalamus. It extends from the lamina terminalis anteriorly to the cerebral aqueduct posteriorly. The third ventricle has anterior, posterior, roof, floor and lateral walls formed by surrounding structures like the thalamus, hypothalamus, pineal gland and others. It has recesses that extend into surrounding structures like the infundibular recess into the pituitary stalk. The pineal gland is a small reddish-grey structure located between the superior colliculi that secretes the hormone melatonin and is involved in biological functions like sleep-wake cycles.
The main arterial supply to the upper limb begins with the subclavian artery. It arises from the brachiocephalic trunk on the right side and directly from the aorta on the left. The subclavian artery passes lateral to the anterior surface of the cervical pleura and becomes the axillary artery at the outer border of the first rib. It gives off several branches that supply the neck, thorax and upper limb including the vertebral, internal thoracic, and thyrocervical trunks. The internal thoracic artery supplies the anterior chest wall and is often used in coronary bypass grafts.
The internal capsule is divided into superior and inferior parts. It is located medially between the caudate nucleus and thalamus, and laterally between the lentiform nucleus. It contains ascending and descending tracts that connect the cortex to lower brain structures. The internal capsule has anterior, genu, posterior, retrolentiform, and sublentiform parts that contain different tracts. We need to learn about the internal capsule because it is important for understanding the pathways involved in motor and sensory functions.
This document discusses the anatomy and functions of the corpus callosum. It describes the corpus callosum as the wide bundle of neural fibers beneath the cortex that connects the left and right cerebral hemispheres. It summarizes that the corpus callosum is divided into five regions - the splenium, body, genu, rostrum, and isthmus. It also briefly discusses the blood supply, development, and functions of the different regions of the corpus callosum.
The internal capsule is a bundle of fibers that passes through the basal ganglia and connects the cerebral cortex with lower brain structures. It is divided into the anterior limb, genu, posterior limb, retrolenticular part, and sublenticular part. The internal capsule contains thalamocortical fibers, corticopontine fibers, corticonuclear fibers, and corticospinal fibers. It receives its blood supply from the lenticulostriate arteries of the middle cerebral artery, the anterior cerebral artery, and the anterior choroidal artery. Damage to specific parts of the internal capsule can cause motor or sensory deficits on the opposite side of the body.
The pterygopalatine ganglion is the largest parasympathetic ganglion in the head and neck. It is located in the pterygopalatine fossa, an important neurovascular junction of the deep face. The ganglion receives sensory roots from the maxillary nerve and autonomic roots from the greater superficial petrosal and deep petrosal nerves. It gives off several branches that innervate structures like the nasal cavity, palate, and pharynx.
The document provides information about the brainstem, which consists of the medulla, pons, and midbrain. It describes the gross anatomy and internal features of the medulla, including nuclei, tracts, and blood supply. Specific conditions that can affect the medulla, such as raised intracranial pressure and lateral/medial medullary syndromes, are also discussed. The pons is then covered, outlining its anterior and posterior surfaces, nuclei including the pontine nuclei, and blood supply from the basilar artery.
The cerebellum has three main parts - the vermis, two hemispheres, and four lobes. It receives sensory input from the spinal cord, brainstem, and cerebral cortex. There are three layers in the cerebellar cortex - molecular layer, purkinje cell layer, and granular layer. The cerebellum is connected to the brainstem via three cerebellar peduncles and plays a role in motor coordination and balance.
The brainstem is located between the cerebrum and spinal cord. It consists of the midbrain, pons, and medulla oblongata. The midbrain connects the pons and cerebrum and contains the superior and inferior colliculi. The pons connects to the cerebellum via peduncles and contains pontine nuclei and cranial nerve nuclei. The medulla oblongata connects to the spinal cord and contains cranial nerve nuclei, the inferior olives, and tracts such as the gracile and cuneate fasciculi.
The pons lies between the medulla oblongata and midbrain, connecting them. It contains motor and sensory nuclei for cranial nerves 5-8 and helps transmit signals between the cerebellum and cerebral cortex. The pons has anterior and posterior surfaces and contains fibers, nuclei, and tracts that process sensory information and coordinate motor functions. Damage to different areas can cause deficits like hemiplegia, hearing loss, or facial paralysis.
The white matter of the cerebrum contains three main types of nerve fibers: commissural fibers, association fibers, and projection fibers. Commissural fibers such as the corpus callosum connect the two cerebral hemispheres. Association fibers like the superior longitudinal bundle connect different regions within the same hemisphere. Projection fibers including those in the internal capsule connect the cerebral cortex to lower brain centers. The internal capsule specifically contains fibers that project to and from the cortex and plays an important role in motor function. Damage to the internal capsule can thus cause contralateral hemiplegia.
The document provides an overview of the divisions and structures of the brain, including the forebrain (telencephalon and diencephalon), midbrain, and hindbrain (metencephalon and myelencephalon). Key structures discussed include the cerebral hemispheres, thalamus, hypothalamus, pons, cerebellum, and medulla oblongata. Common neurological conditions like headaches, stroke, and Horner's syndrome are also briefly mentioned.
The internal carotid artery has 7 segments from its origin at the common carotid artery bifurcation to where it enters the cranium. Each segment has unique anatomic features and branches. The segments are named cervical, petrous, lacerum, cavernous, clinoid, ophthalmic, and communicating. The petrous, cavernous, and ophthalmic segments each have important branches including the vidian artery, meningohypophyseal trunk, and ophthalmic artery respectively.
This document summarizes the anatomy of the circle of Willis and cerebral blood supply. It describes the circle of Willis as a polygonal anastomotic channel at the base of the brain supplied by the internal carotid and vertebral arteries. It then discusses the branches and functions of the circle of Willis, cortical and central arteries, lenticulostriate arteries, and the blood-brain barrier. Finally, it provides details on the regional arterial supply of different brain regions and applied anatomy related to various neurological syndromes.
The vagus nerve is the longest cranial nerve. It originates in the brainstem and travels through the head and neck, thorax, and abdomen. It is a mixed nerve that carries both sensory and motor fibers. In the head and neck, it innervates muscles of the pharynx and larynx. It gives off several branches including the superior and recurrent laryngeal nerves, as well as cardiac branches. The vagus nerve plays an important role in parasympathetic functions such as slowing heart rate and increasing digestive activity. Injury to it can cause hoarseness, difficulty swallowing, and other issues.
The vagus nerve is the longest cranial nerve and is a mixed nerve with both sensory and motor functions. It originates in the brainstem and exits the skull through the jugular foramen before descending through the neck. The vagus nerve innervates many structures in the head, neck, thorax and abdomen. It has both parasympathetic and sympathetic functions and is important for speech, swallowing, heart rate and digestion. Injuries to branches of the vagus nerve can cause hoarseness, dysphagia and changes to heart rate.
The glossopharyngeal nerve, vagus nerve, and cranial portion of the accessory nerve are collectively known as the vagal system. They originate from common brainstem nuclei and exit the skull through the jugular foramen together. The glossopharyngeal nerve innervates parts of the throat and tongue. The vagus nerve is the longest cranial nerve and innervates parts of the heart, lungs and digestive system. The accessory nerve innervates muscles of the neck and shoulder. Injuries to these nerves can cause issues like difficulty swallowing, impaired taste, and muscle weakness.
VAGUS NERVE ANATOMY IN HEAD AND NECK AND ITS BRANCHESVaishnawiRai
The vagus nerve is the longest cranial nerve. It has both sensory and motor functions and provides parasympathetic innervation to many organs. It exits the skull through the jugular foramen and descends in the neck giving off branches like the superior and recurrent laryngeal nerves. In the thorax, it gives cardiac branches and in the abdomen it supplies the stomach, liver and intestines. Stimulation of its auricular branch can increase appetite. Damage can cause voice and swallowing issues due to involvement of structures like the larynx. It is sometimes surgically severed (vagotomy) to treat peptic ulcers.
The document provides information on the functional anatomy of the brainstem, including its three main parts - medulla, pons, and midbrain. It discusses the structures, functions, blood supply, and clinical correlates of each region. Key points include that the brainstem connects the spinal cord to the forebrain, contains important reflex centers, and cranial nerve nuclei. It describes nuclei and tracts at different levels, and clinical syndromes that can result from lesions in different areas, such as lateral medullary syndrome and Dejerine's anterior bulbar palsy.
This document provides an overview of the nerve supply of the head and neck region. It begins with an introduction to the nervous system, including the central and peripheral nervous systems. It then discusses the 12 cranial nerves in detail, including their origin, course, structures supplied, and clinical correlations. For each cranial nerve, it provides summaries of key branches and their functions. The document also briefly discusses the spinal nerves and covers topics such as neurons, neuroglial cells, and the development of the nervous system. Overall, the document concisely summarizes the anatomy and clinical relevance of the major nerves involved in innervating the head and neck.
The facial nerve has both sensory and motor components. It has nuclei in the pons that control muscles of facial expression, lacrimal and salivary glands, and taste sensation on the anterior tongue. The facial nerve exits the skull through the stylomastoid foramen and divides into branches that innervate muscles of the face, scalp and neck including the orbicularis oculi and orbicularis oris. It also communicates with adjacent cranial and spinal nerves to coordinate movements between branchial arches.
The document provides information on the anatomy and structure of the spinal cord. It discusses the following key points:
- The spinal cord is surrounded by three meningeal coverings - dura mater, arachnoid mater, and pia mater. It has cervical and lumbar enlargements.
- Spinal nerves arise in pairs from the spinal cord. Each nerve has a dorsal root containing a ganglion and a ventral root.
- The spinal cord has gray matter on the outside containing nuclei and white matter on the inside. It also contains ascending and descending tracts that connect to the brain.
- Ascending tracts like the anterior and lateral spinothalamic tracts transmit sensory information from
This document provides an overview of the structure and function of the brainstem and spinal cord. It begins by outlining the learning objectives which are to analyze various parts of the brainstem including cranial nerves, tracts, and nuclei. It then provides detailed descriptions of the internal structures and connections of the medulla, pons, midbrain, diencephalon, and spinal cord white matter. Key structures like cranial nerve nuclei, ascending and descending tracts, and neuronal circuits are defined.
The hypoglossal nerve originates in the hypoglossal nucleus of the medulla and innervates the muscles of the tongue. It exits the skull through the hypoglossal canal and descends through the neck. Lesions can occur at the supranuclear, nuclear, or peripheral levels. Supranuclear lesions of the corticobulbar tract cause contralateral tongue weakness without atrophy. Nuclear lesions in the medulla result in ipsilateral tongue paresis, atrophy and fasciculations. Peripheral lesions of the hypoglossal nerve cause ipsilateral tongue paresis through the hypoglossal canal.
MRI is the best imaging modality for evaluating cranial nerves due to its high contrast resolution. It can visualize cranial nerves as dark structures against the bright CSF. CT is useful for evaluating bony structures. The 12 cranial nerves were described in detail, including their anatomy, pathways, and imaging appearance. Common pathologies that can involve cranial nerves include tumors such as schwannomas and meningiomas, inflammation such as optic neuritis, and infections.
Cranial nerves Not directly associated with the eyeOthman Al-Abbadi
The cranial nerves do not directly relate to the eye, except for the optic nerve (CN II). The 12 pairs of cranial nerves originate from the brain and leave the cranial cavity through openings. The olfactory (CN I), optic (CN II), and vestibulocochlear (CN VIII) nerves are entirely sensory. The facial (CN VII) nerve contains motor, sensory, and parasympathetic components. The glossopharyngeal (CN IX) and vagus (CN X) nerves are mixed nerves containing motor, sensory and parasympathetic fibers. The hypoglossal nerve (CN XII) is a pure motor nerve that supplies the muscles of the tongue.
The document provides an overview of the peripheral nerves, with a focus on the spinal nerve roots and major plexuses. It discusses:
1) Spinal nerve roots exit the spinal cord and form 31 spinal nerves that innervate the body. Dorsal roots carry sensory information and ventral roots carry motor signals.
2) The major plexuses include the cervical, brachial, and lumbosacral plexuses. The brachial plexus forms the nerves of the upper extremities and the lumbosacral plexus forms the nerves of the lower extremities.
3) Common peripheral nerve injuries are also summarized, including median nerve entrapment at the carpal tunnel causing carpal
Cranial nerve 9,10,11 - By Dr Piyush, MMCH. AQUIBEJAZ
The cranial nerves IX, X, and XI were summarized. The glossopharyngeal nerve (CN IX) emerges from the medulla and has sensory and motor branches that innervate structures in the pharynx, tongue, and carotid body. The vagus nerve (CN X) is a mixed nerve with extensive distribution from the head and neck to the abdomen. It emerges from the medulla and has branches throughout its course. The accessory nerve (CN XI) has a cranial and spinal root, with the spinal root innervating the sternocleidomastoid and trapezius muscles.
This document provides information on spinal anatomy and spinal anesthesia. It describes the basic spinal anatomy including the vertebrae, spinal cord, meninges, and spinal nerves. It then discusses spinal anesthesia, including the indications, contraindications, procedure, advantages, disadvantages, mechanism of action, uptake and elimination of spinal anesthetics. It also covers factors that determine the distribution of spinal anesthetics such as characteristics of the local anesthetic solution, patient characteristics, injection technique, and characteristics of spinal fluid.
This document describes the various tracts within the spinal cord. It discusses both descending and ascending tracts. The descending tracts include the pyramidal tract, rubrospinal tract, reticulospinal tracts, vestibulospinal tract, olivospinal tract, and hypothalamo-spinal tract. The ascending tracts include the spinothalamic tracts, fasciculus gracilis and cuneatus tracts, and spinocerebellar tracts. Intersegmental tracts like the dorsolateral fasciculus are also mentioned. The pathways, origins, courses and terminations of each tract are delineated in detail.
The vagus nerve is the 10th cranial nerve that passes through the head and neck. It is the longest nerve of the parasympathetic nervous system. The vagus nerve emerges from the medulla, passes through the jugular foramen, and descends in the neck giving off several branches that supply structures in the head and neck like the pharynx, larynx, outer ear, and meninges. It is a mixed nerve responsible for motor, sensory, and parasympathetic functions. Injuries and irritation of its branches can cause issues like hoarseness, cough, or dysphagia.
Ascending, descending, and medulla oblongata is important anatomical structures for coordinations in physiology, embryology, and psychological activities in humans
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
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Our backs are like superheroes, holding us up and helping us move around. But sometimes, even superheroes can get hurt. That’s where slip discs come in.
These lecture slides, by Dr Sidra Arshad, offer a simplified look into the mechanisms involved in the regulation of respiration:
Learning objectives:
1. Describe the organisation of respiratory center
2. Describe the nervous control of inspiration and respiratory rhythm
3. Describe the functions of the dorsal and respiratory groups of neurons
4. Describe the influences of the Pneumotaxic and Apneustic centers
5. Explain the role of Hering-Breur inflation reflex in regulation of inspiration
6. Explain the role of central chemoreceptors in regulation of respiration
7. Explain the role of peripheral chemoreceptors in regulation of respiration
8. Explain the regulation of respiration during exercise
9. Integrate the respiratory regulatory mechanisms
10. Describe the Cheyne-Stokes breathing
Study Resources:
1. Chapter 42, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 36, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 13, Human Physiology by Lauralee Sherwood, 9th edition
Histololgy of Female Reproductive System.pptxAyeshaZaid1
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Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
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6. INTRODUCTION
• The Longest and most widely distributed Cranial Nerve
• Same nuclei of origin as for 9th cranial nerve.
• Both Motor and Sensory segments
• One of the Parasympathetic cranial nerve
• Despite its clinical importance , it is difficult to evaluate bedside.
7.
8. • General Somatic Afferent – Touch, Pain & Temperature – Spinal nucleus of Vth
• Special Visceral Afferent - Taste buds of the Epiglottis – Nucleus Tractus
Solitarius
• Special Visceral Efferent- Motor/ Brachiomotor – Nucleus Ambigious
• General Visceral Afferent – Dorsal nucleus of Vagus
• General Visceral Efferent - Secretomotor fibres – Dorsal nucleus of Vagus
20. COURSE
• The six to eight rootlets of the vagus nerve emerge from the posterior sulcus of
the lateral medulla oblongata dorsal to the inferior olive in close association with
the glossopharyngeal nerve.
• These vagal rootlets form a single trunk that leaves the skull by way of the jugular
foramen in a dural sheath that also contains the spinal accessory nerve
21.
22.
23. JUGULAR FORAMEN
• Cavity formed by the petrous part of the temporal bone (A) and occipital bone (P)
• It lies lateral to the occipital condyles, Medial to it lies the Hypoglossal canal
• Foramen is divided by a fibro-ossesous bridge that connects the jugular spine on
the petrous part of the temporal bone and jugular process of the occipital bone,
into 2 parts
• Antero- Medial – Pars Nervosa (9th,Jacobsens nerve, Inferior petrosal sinus)
• -- Pars Vascularis ( Jugular Bulb, Xth ,Arnolds nerve, X1th )
24.
25.
26. GENERAL SENSORY AFFERENT
• The auricular ramus (nerve of Arnold) of the Vagus nerve is given off; this branch
then traverses the mastoid process and innervates the skin of the concha of the
external ear, External acoustic meatus, tympanic cavity
• At this point the Vagus also gives off the meningeal ramus, which runs to the
dura mater of the posterior fossa
27.
28. SPECIAL VISCERAL AFFERENT
• Within the nodose ganglion are cells whose fibers carry taste sensation from the
epiglottis, hard and soft palates, and pharynx.
• The axons of these ganglion cells terminate in the nucleus solitarius of the
medulla.
29. SPECIAL VISCERAL EFFERENT
• Pharyngeal ramus, which forms the pharyngeal plexus with the glossopharyngeal
nerve and sends motor fibers to the muscles of the pharynx and the soft palate
(except the stylopharyngeus and tensor veli palatini muscles).
• The superior laryngeal nerve arises from the vagus near the nodose ganglion and
divides into a predominantly motor external ramus (to the cricothyroid muscle)
and an internal ramus (which pierces the thyrohyoid membrane and sends
sensory fibers to the larynx).
30.
31. • In the neck, the vagus nerve proper descends within a sheath common to the
internal carotid artery and the internal jugular vein.
• Within the neck, the vagus gives off the cardiac rami, which follow the carotid
arteries down to the aorta and contribute fibers to the cardiac plexus.
• At the root of the neck, the recurrent laryngeal nerves are given off and pursue
different courses on the two sides.
• The right recurrent laryngeal nerve bends upward behind the subclavian artery to
ascend in the tracheoesophageal sulcus, whereas the left recurrent laryngeal
nerve passes beneath the aortic arch to attain this sulcus
34. INTO THE THORAX
• The vagus nerve enters the thorax, crossing over the subclavian artery on the
right side and traveling between the left common carotid and subclavian arteries
on the left side.
• The right nerve then passes downward near the brachiocephalic trunk and
trachea and behind the right brachiocephalic vein and superior vena cava to the
posterior lung root
• The left nerve travels between the left common carotid and subclavian artery,
passes over the aortic arch, and reaches the left lung root.
36. INTO THE ABDOMINAL VISCERA
• Right Vagus – Celiac plexus – Adrenals, Kidney, Intestine, Pancreas & Spleen
• Left Vagus- Hepatic Plexus – Liver & Gall Bladder.
37.
38. GENERAL VISCERAL AFFERENT
• General visceral sensations from the oropharynx, larynx, and linings of the
thoracic and abdominal viscera have their cells of origin in the nodose ganglion,
which also projects to the nucleus solitaries (nucleus parasolitarius).
• These include sensations from Esophageal, Celiac, Hepatic Plexus
• Internal Laryngeal nerve – Above the vocal cord
• Recurrent laryngeal nerve- Below the vocal cord
• Aortic arches & Carotid bodies.
46. EXAMINATION OF VAGUS
• MOTOR FUNCTIONS
• AUTONOMIC FUNCTIONS
• SENSORY FUNCTIONS
• REFLEXES
• DISORDERS OF THE FUNCTION
47. EXAMINATION OF MOTOR FUNCTIONS.
• 1) Character of voice & Ability to swallow- Branchiomotor function assessment
• 2) Soft Palate – Palate & Uvula.
• 3) Examination of Pharynx.
• 4) Assessment of Vocal Cords.
48. DISORDERS OF FUNCTION OF MOTOR PART
• Voice & Swallowing
• Acute Unilateral lesions – Nasal Quality & Dysphagia, marked for liquids –
Velopharyngeal insufficiency
49. • Soft Palate
• Unilateral weakness – Levator veli palatini and musculus uvulae, which causes
droop of the palate and flattening of the palatal arch.
• The preserved function of tensor veli palatini – prevent marked drooping of
palate.
• The palatal gag reflex may be lost on the involved side due to interruption of
motor pathway
50.
51. • Pharynx.
• Unilateral weakness of superior constrictor – “Curtain movements” with motion
the pharyngeal wall towards the non paralyzed side.
• Normal elevation of larynx may be absent on one side in U/L lesions on both
sides in B/L lesions.
52. • Vocal Cord Assessment
• A unilateral lesion of the Vagus may cause cord weakness or paralysis.
• Vocal cord dysfunction alters the character and quality of the voice and may
produce abnormalities of articulation, difficulty with respiration, and impairment
of coughing.
• Spasmodic dysphonia is a common focal dystonia that involves the vocal cords
and causes characteristic voice changes
53. EXAMINATION OF AUTONOMIC FUNCTIONS
• Orthostatic hypotension
• Abnormalities of sweating
• Dysfunction of the GI/ Genitourinary
54. ORTHOSTATIC CHANGES
• Changes in BP- Supine to Standing- Fall in SBP up to 30 & DBP up to 15
• Changes in HR- The fall in BP produces reflex Tachycardia
• Testing – Variability to deep breathing, standing & Performing Valsalva.
55. SENSORY FUNCTION
• Sensory function of the vagus nerve cannot be tested adequately because the
area of supply overlaps that of other cranial nerves (e.g., the pinna),
• Some structures are inaccessible (e.g., the meninges), and there is difficulty in
testing the epiglottis for taste function
56. REFLEX FUNCTION
• The afferent limb of the pharyngeal reflex (gag reflex) runs in the
glossopharyngeal nerve, and the efferent limb runs in the glossopharyngeal and
Vagus nerves.
• Therefore, unilateral vagal lesions depress the ipsilateral gag reflex by interrupting
the efferent arc
• Occulocardiac reflex ( Aschner Ocular Phenomenon)
• Carotid Sinus reflex.- Bradycardia, Hypotension, Vasodilatation.
• Vomiting reflex, Swallowing reflex & Hiccups.
58. LOCALIZATION OF VAGUS NERVE PATHOLOGIES
• Supranuclear lesion
• Nuclear lesions and lesions within the brainstem
• Lesions within the posterior fossa.
• Lesions affecting the vagus nerve proper
• Lesions of the superior laryngeal nerve
• Lesions of the recurrent laryngeal nerve.
59. SUPRANUCLEAR LESION
• Unilateral cerebral hemispheric lesions (lower precentral gyrus) rarely cause any
vagal dysfunction because the supranuclear control is bilateral.
• Rarely, dysphagia may occur with a unilateral precentral lesion
• . Bilateral upper motor neuron lesions result in pseudo-bulbar palsy, in which
dysphagia and spastic dysarthria are prominent. Emotional incontinence with
pathologic crying is common.
• The gag reflex may be depressed or exaggerated.
60. NUCLEAR LESIONS AND LESIONS WITHIN THE
BRAINSTEM
• Nuclear lesions result in ipsilateral palatal, pharyngeal, and laryngeal paralysis that
is usually associated with affection of other cranial nerve nuclei, roots, and long
tracts.
• Lesions of the nucleus ambiguus may occur with vascular insults (lateral
medullary or Wallenberg syndrome), tumors, syringobulbia, motor neuron
disease, and inflammatory disease
61.
62.
63.
64. LESIONS WITHIN THE POSTERIOR FOSSA
• Lesions at this location usually also involve the glossopharyngeal, spinal
accessory, and hypoglossal nerves
• Include primary (e.g., paragangliomas ) and metastatic tumors, infections (e.g.,
meningitis, otitis), carcinomatous meningitis, sarcoidosis, Guillain–Barré
syndrome, and trauma
65.
66.
67. LESIONS AFFECTING THE VAGUS NERVE PROPER
• The trunk of the Vagus nerve may be injured in the neck and thorax by tumors,
aneurysms of the internal carotid artery, trauma, and enlarged lymph nodes.
• These injuries result in complete ipsilateral vocal cord paralysis associated with
unilateral laryngeal anesthesia
• Other causes include : Neurosyphilis, Radiation Therapy, Sarcoidosis, reactivation
of herpes simplex type 1 infection, and diabetes.
68. LESIONS OF THE SUPERIOR LARYNGEAL NERVE
• Lesions of this nerve result in few clinical findings because this branch is primarily
sensory.
• The cricothyroid muscle is innervated by this branch, however, and its
involvement may result in mild hoarseness with some decrease in voice strength
69. LESIONS OF THE RECURRENT LARYNGEAL NERVE
• The recurrent laryngeal nerve is susceptible to injury throughout its intrathoracic
course by aneurysms of the aortic arch or subclavian artery, enlarged
tracheobronchial lymph nodes, mediastinal tumors, and operative damage (e.g.,
thyroidectomy).
• Unilateral recurrent laryngeal nerve injury results in hoarseness that is often
transient
• Bilateral abduction paralysis may produce severe approximation of the vocal cords
associated with airway limitation, which often necessitates tracheostomy.
Inspiratory stridor and dyspnea on exertion are common.
• Acute vocal cord paralysis may occur in patients with hereditary neuropathy with
liability to pressure palsies