Computer generated transcript

Warning!
The following transcript was generated automatically from the content and has not been checked or corrected manually.

PreClinEazy X Cardiff Medsoc The Neurovascular supply of the Brain By Rayyan Malik (OsceEazy)Neurovascular supply of the Brain Central and Peripheral Nervous System Spinal Tracts Anatomy of the Brain Vascular Supply of the Brain CSF FlowCentral & Peripheral Nervous System Nervous System CNS PNS Peripheral Nervous System (PNS): Central Nervous System (CNS): Extends from the CNS to the rest of the body. Comprises the brain and spinal cord. Acts as the command centre, processing information Divided into the sensory and motor divisions. Enables communication between the CNS and and generating responses. peripheral tissues and organs. Responsible for higher cognitive functions, emotions, and motor coordination. Peripheral Nervous System Autonomic Somatic Motor Motor Sensory Sensory Sensory Division: The PNS consists of sensory receptors that detect various stimuli. Motor Division: Responsible for executing voluntary and involuntary movements. Two main Motor subdivisions: Somatic Nervous System (SNS): Controls voluntary muscle movements. Sympathetic Parasympathetic Autonomic Nervous System (ANS): Regulates involuntary functions like heart rate, digestion, respiratory rate. SyFight or Flight | ParasympaRest & DigestSpinal Tracts DCLM Pathway 1. Primary afferent neuron (1st order) carry impulses to the Medulla on the IPSILATERAL SIDE (same side) of the body 2. 2nd order neurons (internal arcuate fibres) DECUSSATES AT MEDULLA at the medial lemniscus and synapses at the thalamus 3. 3rd order neurons (thalamo-cortical neurons) ascend from the thalamus and through the internal capsule and terminate at the somatosensory cortex. Spinothalamic Tracts 1. Primary afferent neuron (1st order) enter the spinal cord and synapses at tip of the dorsal horn onto substantia gelatinosa (SG) 2. Spinothalamic neuron (2nd order) from SG decussates onto the opposite side by passing through the anterior white commissure. Travels up via the anterior/lateral path CONTRALATERALLY and synapses in the thalamus 3. Thalamocortical neurons (3rd order) ascend through the internal capsule and terminate at the primary somatosensory cortex (post-central gyrus) Corticospinal Tracts 1. UMN descends from the cortex 2. Synapses in the ventral horn of spinal cord and becomes LMN 3. LMN excites then muscles 90% of fibers decussate at the medulla and enter the contralateral, lateral corticospinal tract. 10% of the pyramidal fibers DON'T decussate at the medulla and remain ipsilateral and enter the ventral/anterior corticospinal. SPINAL TRACTS - SUMMARY LATERAL SPINOTHALAMIC ANTERIOR SPINOTHALAMIC • Origin: Free Nerve Endings • Origin: Free Nerve Endings • Function: Pain and Temperature • Function: Pressure and Light touch • Decussation: Cross at level of spinal cord entry • Decussation: Crosses at level (or 1-2 level above) LATERAL CORTICOSPINAL DORSAL COLUMN LEMINICUS • Origin: Meissner's Corpuscles, Pacinian Corpuscles, • Origin: Motor Cortex Muscle spindles, Tendon organs • Function: Motor Function • Function: Discriminative touch, Vibration, • Decussation: Crosses at Medullary Pyramids (medulla) Proprioception • Decussation: Crosses at medial lemniscus (Medulla)Anatomy of the Brain Functional Areas of the Brain Parietal lobe Frontal lobe Occipital lobe Temporal lobe Functions of 4 Lobes Frontal Lobe Parietal Lobe Temporal Lobe Occipital Lobe • Motor: contralateral voluntary Sensory function Auditory function Visual function movement Awareness of somatic Awareness of pitch, frequency Analysis and recognition of sensation (pain, light and location of sound visual stimulus (colour, • Frontal eye fields: voluntary shape, movement) eye movement. touch, temperature, Heschl's gyrus: tucked into the • Prefrontal cortex: memory, vibration and superior-medial surface of learning, personality, proprioception) temporal lobe behaviour, decision making, Wernicke’s area: motor planning comprehension of written and spoken language (receptive • Broca’s area: speech production aphasia) (usually found on the left side, expressive aphasia) Primary olfactory cortex: awareness of smell Functional Areas of the Brain Motor Primary Motor PRECENTRAL GYRUS – IMMEDIATELY ANTERIOR function cortex TO CENTRAL SULCUS MUSCLE MOVEMENT area Primary Sensory Broca’s area Cortex LEFT HEMISPHERE, FRONTAL LOBE PRODUCTION Somatosensory Association OF SPEECH area SUPERIOR TEMPORAL GYRUS OF TEMPORAL Higher Auditory area mental LOBE HEARING functions LEFT HEMISPHERE, POSTERIOR SUPERIOR Visual area TEMPORAL LOBE COMPREHENSION OF SPEECH OCCIPITAL LOBE VISION POSTCENTRAL GYRUS – IMMEDIATELY POSTERIOR TO Association area Wernicke’s area CENTRAL SULCUS RECEIVES INFORMATION ABOUT SENSATION OF PAIN, TOUCH, TEMPERATURE, PROPRIOCEPTION Question 2 Hippocampus A 60-year-old patient presents with progressive memory loss, A personality changes, and difficulty with language comprehension. On neurological examination, the patient B Amygdala exhibits fluent but meaningless speech with impaired repetition and comprehension. MRI of the brain shows C Broca’s Area atrophy in the left posterior temporal and inferior parietal lobes. Wernicke’s Area D Which anatomical structure is primarily affected in this E Angular Gyrus patient's condition? Question 1 A 60-year-old patient presents with progressive memory loss, A Hippocampus personality changes, and difficulty with language comprehension. On neurological examination, the patient Amygdala B exhibits fluent but meaningless speech with impaired repetition and comprehension. MRI of the brain shows Broca’s Area C atrophy in the left posterior temporal and inferior parietal lobes. D Wernicke’s Area Which anatomical structure is primarily affected in this patient's condition? Angular Gyrus E Wernicke's area, located in the left hemisphere of the brain, encompasses the posterior part of the superior temporal gyrus. It is responsible for language comprehension and is often associated with fluent but empty speech and impaired repetition and comprehension when damaged or affected by atrophy, as seen in this patient.Arterial Supply of the Brain Anterior Communicating Artery Middle Cerebral Anterior Artery Cerebral Artery Internal Carotid Posterior Communicating Posterior Artery Circle of Willis Cerebral Artery Basilar Artery Posterior Inferior Cerebellar Artery Vertebral ArteryBasilar artery: REMEMBER stroke symptoms Vertebral artery: Supplies pons and superior, relating to loss of sensation are Supplies the medulla and the inferior anterior and inferior cerebellum and posterior aspect of cerebellum contralateral to brain injury. Arterial Supply of the Brain ACA: MCA: PCA: Supplies medial frontal and parietal Supplies lateral frontal, temporal and Supplies the occipital lobe, lobe temporal lobe, the thalamus and parietal lobe, basal ganglia the midbrain Wernicke’s and Broca’s area Question 2 A 55-year-old patient with a history of hypertension presents Basilar Artery A with a sudden loss of consciousness and left-sided weakness. A CT angiogram of the brain reveals a large thrombus blocking B Vertebral Artery a major artery. The clot has occluded one of the arteries that forms the Circle of Willis. Anterior cerebral artery (ACA) C Which artery is most likely to be affected in this case, leading D Middle Cerebral artery (MCA) to the described symptoms? E Posterior cerebral artery (PCA) Question 2 Basilar Artery A 55-year-old patient with a history of hypertension presents A with a sudden loss of consciousness and left-sided weakness. A CT angiogram of the brain reveals a large thrombus blocking B Vertebral Artery a major artery. The clot has occluded one of the arteries that forms the Circle of Willis. C Anterior cerebral artery (ACA) Which artery is most likely to be affected in this case, leading Middle Cerebral artery (MCA) D to the described symptoms? E Posterior cerebral artery (PCA) 🔑 KEY FACT Most common site for blood clots/ischemic stroke = Middle Cerebral Artery Most common site for brain aneurysms = Anterior Cerebral ArteryCSF Flow Question 3 Ahmed, a 55-year-old male, presents with hydrocephalus. It is A Subarachnoid Space found that this is due to narrowing of the interventricular foramen. B 4 Ventricle In which region will CSF likely to build up? C 3 Ventricle Lateral Ventricle D E Choroid Plexus Question 3 Ahmed, a 55-year-old male, presents with hydrocephalus. It is A Subarachnoid Space found that this is due to narrowing of the interventricular foramen. B 4 Ventricle In which region will CSF likely to build up? C 3 Ventricle Lateral Ventricle D E Choroid Plexus CSF Flow in the Brain CSF produced by choroid plexus in the Lateral Ventricles Interventricular Foramen 3 Ventricle Cerebral Aqueduct 4 Ventricle Foramen of Magendie Foramen of Lushka Subarachnoid Space Spinal Canal Mnemonic: Losing In Tennis Causes Frustration Sometimes CSF Flow in the Brain CSF produced by choroid plexus in the Lateral Ventricles Interventricular Foramen 3 Ventricle Cerebral Aqueduct 4 Ventricle Foramen of Magendie Foramen of Lushka Subarachnoid Space Spinal Canal Mnemonic: Losing In Tennis Causes Frustration Sometimes Question 4 A 45-year-old male presents to the emergency department A Subarachnoid Space with severe headaches, nausea, and blurred vision. On examination, you note papilledema and positive Brudzinski's B 4 Ventricle sign. An MRI scan reveals hydrocephalus. C 3 Ventricle Lead in: Where is the main site of CSF Production in the brain? Lateral Ventricle D E Choroid Plexus Question 4 A 45-year-old male presents to the emergency department A Subarachnoid Space with severe headaches, nausea, and blurred vision. On examination, you note papilledema and positive Brudzinski's B 4 Ventricle sign. An MRI scan reveals hydrocephalus. C 3 Ventricle Lead in: Where is the main site of CSF Production in the brain? Lateral Ventricle D E Choroid Plexus CSF is constantly being produced by choroid plexus (ependymal cells) in the lateral ventricles. (500ml/day)Bonus S2 Type SBA Questions Question 5 A 68-year-old male patient with a history of hypertension Anterior cerebral artery (ACA) A presents to the emergency department with sudden-onset weakness on the right side of his body and difficulty speaking. B Middle Cerebral artery (MCA) On examination, you observe right-sided hemiparesis and expressive aphasia. Posterior cerebral artery (PCA) C Which of the following arteries is most likely affected? D Vertebral Artery E Basilar Artery Question 5 A 68-year-old male patient with a history of hypertension A Anterior cerebral artery (ACA) presents to the emergency department with sudden-onset weakness on the right side of his body and difficulty speaking. Middle Cerebral artery (MCA) B On examination, you observe right-sided hemiparesis and expressive aphasia. Posterior cerebral artery (PCA) C Which of the following arteries is most likely affected? D Vertebral Artery Option B, "middle cerebral artery (MCA)," is correct because the MCA is Basilar Artery responsible for supplying the largest portion of the lateral part of the cerebral hemispheres, making it the most likely culprit in this ischemic stroke. In this clinical scenario, the patient's symptoms align with an MCA territory infarct. Question 6 Ahmed, a 55-year-old male, presents with hydrocephalus. It is A Subarachnoid Space found that this is due to the narrowing of the Cerebral Aqueduct. B Lateral Ventricle In which region will CSF likely to build up? C 4 Ventricle 3 Ventricle D E Choroid Plexus Question 6 Ahmed, a 55-year-old male, presents with hydrocephalus. It is A Subarachnoid Space found that this is due to the narrowing of the Cerebral Aqueduct. B Lateral Ventricle In which region will CSF likely to build up? C 4 Ventricle 3 Ventricle D E Choroid Plexus Question 7 A 62-year-old male patient presents to the emergency Anterior communicating artery A department with sudden-onset left-sided weakness and confusion. A CT scan reveals a right middle cerebral artery B Posterior communicating artery (MCA) ischemic stroke. During the evaluation, you suspect that collateral circulation may be helping to mitigate the Basilar Artery C extent of the stroke. D Superior Sagittal Sinus Which anatomical structure plays a critical role in providing collateral circulation in this patient? E Middle Meningeal Artery Question 7 A 62-year-old male patient presents to the emergency Anterior communicating artery A department with sudden-onset left-sided weakness and confusion. A CT scan reveals a right middle cerebral artery B Posterior communicating artery (MCA) ischemic stroke. During the evaluation, you suspect that collateral circulation may be helping to mitigate the Basilar Artery C extent of the stroke. D Superior Sagittal Sinus Which anatomical structure plays a critical role in providing collateral circulation in this patient? E Middle Meningeal ArteryPLEASE FILL OUT THE FEEDBACK FORM PLEASE TUNE IN TO OUR REMAINING SESSIONS THIS WEEK