Session 2.pdf

DPT 542 Functional Neurosciences. Session 2 Overview of Brain Structures and Functions Learning Objective 3 Describe the organization of the nervous system and function of each component Describe the organization of the nervous system Identify major components of Nerv...

DPT 542 Functional Neurosciences. Session 2 Overview of Brain Structures and Functions Learning Objective 3 Describe the organization of the nervous system and function of each component Describe the organization of the nervous system Identify major components of Nervous System Locate components and describe key anatomical features Define functions of each component Structural Organization of Nervous System Nervous System Central Nervous Peripheral Nervous System (CNS) System (PNS) Spinal Nerves Cranial Nerves Brain Spinal Cord (31 Pairs) (12 Pairs) Functional Cognition Organization Perception Action Sensory systems Motor system From: http://academic.kellogg.edu/herbrandsonc/bio201_mckinley/Nervous%20System.htm Regions of the Central Nervous System (CNS) Cerebrum Cerebral cortex Limbic system Basal ganglia Diencephalon Hypothalamus Thalamus Brainstem Midbrain Pons Medulla (oblongata) Cerebellum Spinal cord Embryologic Development Embryologic Nomenclature is important to know Directional Terms  Directional terms- cerebrum Anterior/ Rostral Dorsal/Superior Midline Lateral Lateral sulcus Ventral/Inferior Posterior/ Caudal Lateral View Ventral (Inferior) View Match the view? Superior View Medial View Inferior View Lateral View Identify major components of Nervous System Locate components and describe key anatomical features Define functions of each component Cerebrum (Cerebral Cortex) A. Lobes B. Topographical regions and structures Question: The cerebrum develop from what part of a 5 week old fetus? Slide 5!!  Cerebrum Fig. 2-10 Cerebral Hemispheres Divided in two by Falx Cerebri Longitudinal Fissure Each hemisphere contains Five (5) Lobes Frontal Parietal To halves connected by Temporal the corpus callosum Occipital Insular (not shown) Cerebrum is characterized by numerous sulci and gyri How do the 4 primary cerebral Lobes get their Names? What is the difference between a sulcus and a fissure? Primary Surface Anatomic features Central sulci Lateral Fissure (Sylvian fissure) Pre central gyrus Post central gyrus Insular lobe-lateral view What type of section? i Insular lobe/cortex  Main functions of lobes Frontal – Parietal – Temporal – Occipital – Insula – General Organization of Function in the Brain? Structures associated with initiation and execution of movement Motor system function are more Anterior Rostral in the cerebrum, or ventral in the spinal cord Structures associated with processing sensory information Sensory system information are more Posterior Caudal in the cerebrum or more dorsal in the spinal cord. Major tip! Go back and look at were the lobes are located Slide 13 and what their functions are Slide 17! When you learned about the spinal cord and nerve roots how were they located for sensory and motor? Limbic System Functions H - Homeostasis O - Olfaction M - Memory E - Emotion Basal Ganglia Functions: What part of the developing nervous system do basal ganglia evolve from? Diencephalon Thalamus Hypothalamus What is the developmental name of this structure? Thalamus Means “inner chamber” or “bedroom” in Greek Major relay nuclei (station) for sensory information and motor information from cortex, basal ganglia, cerebellum, limbic system Hypothalamus Mid-Sagittal (medial) view What is the view? Inferior (Ventral) view Brainstem Functions ? Major through way for sensory and motor pathways Nuclei for all CN III-XII Major inputs to visceral function (Autonomic Nervous System) Connection to Cerebellum Regional terms Midbrain Pons Medulla Base Tegmentum Tectum What are the developmental structures? Anterior to Posterior Regions of the Brainstem Base (basis or Basal) Tegmentum Tectum  Anterior/Rostal What is the view? Hypothalamus Midbrain Pons Medulla Cerebellum Posterior/ Caudal  Function? Cerebellum Posterior fossa Spinal Cord PNS to CNS Reflex control at the spinal level Grey Matter White mater Learning Objective 4: Describe the major brain supportive structures Meninges Ventricular system Major Blood supply Blood Brain Barrier Clinical Applications Intercranial Mass Hydrocephalous Blumenfeld Chapter 5 This information is covered in Anatomy. Make a link between skull, its compartments and Brain structures.  Why are these terms important to know? Which are potential spaces and which are real? Wow that is a big space! What inside this space? Pia mater Arachnoid Meninges Dura mater and Spaces See Blumenfeld Chapter 5 for pictures of dura mater and Reviewed in Anatomy Ventricular System  Ventricles Contain Cerebrospinal Fluid (CSF) CSF produced by the Choroid Plexus Two (2) Lateral Ventricles One in each cerebral hemisphere Third Ventricle Located in the diencephalon Fourth Ventricle Surrounded by pons, medulla, cerebellum Lateral Ventricles - Structure Frontal (anterior) Horn Extends to the Frontal Lobe of Brain Body Atrium Occipital (posterior) Horn Extends to occipital lobe of the brain Temporal (inferior) horn Extends inferiorly and anteriorly to temporal lobe Third Ventricle Slit like cavity between right and left halves of diencephalon Thalamus and Hypothalamus  Ventricles - Structure Interventricular foramen (Foramen of Monro) Communication point between lateral ventricles and third ventricle Cerebral aqueduct (aqueduct of Sylvius) Communication between the third ventricle and fourth ventricle The mean CSF volume is 150 ml, with 25 ml in the ventricles and 125 ml in choroid plexus subarachnoid spaces CSF produced in Choroid plexus Recycled through Arachnoid granulations (Arachnoid Villi) CSF is constantly being produced (between 400 to 600 ml per day) and reabsorbed.  Cerebrospinal Fluid (CSF) Flow CSF Produced in choroid plexus CSF flows to lateral ventricles Lateral ventricles through Interventricular Foramen (Foramen of Monro) into Third ventricle From third ventricle through Cerebral (Sylvian) aqueduct into the fourth ventricle From fourth ventricle through foramina of Lushka and Magendie into subarachnoid space From subarachnoid space up to arachnoid granulations and reabsorbed into the bloodstream. Major Vascular Supply to the Brain Vascular Supply Vascular Supply Vascular Supply 1 – Basilar Artery (A.) 2 – Post Communicating A. 3 – Internal Carotid A. 4 – Middle Cerebral A. 5 – Ant. Communicating A. 6 – Anterior Cerebral A. 7 – Posterior Cerebral A. 8 – Superior Cerebellar A. 9 – Vertebral Arteries  Vascular Supply 10 - Middle Cerebral A. 11 – Terminal cortical branches of Anterior Cerebral A. 12 – Terminal Cortical branches of Posterior Cerebral A. 13 – Anterior Cerebral A. 14 – Posterior Cerebral A. 15 – Post. Communicating A.  Connection between Anterior and posterior circulation Circle of Willis Why would that be important? Thomas Willis  Anterior Circle of Willis Communicating Artery Anterior Cerebral Artery (ACA) Posterior Communicating Artery Posterior Cerebral Artery (PCA) Basilar Artery Blood Brain Barrier Understand why the blood brain barrier is important for brain function. Fluid systems supporting the brain  Clinical Application 1 Inter-Cranial Mass Primary Symptoms Tumors (slowly evolving) Headache Trauma (faster evolving) Neurologic signs and symptoms Hemorrhage in potential spaces related to structures involved. Epidural Hemorrhage (EDH) Subdural Hemorrhage (SDH) See table 5.1 For list of causes of Subarachnoid Hemorrhage (SAH) secondary headache. Hemorrhagic Stroke of a cerebral artery Intracerebral or intraparenchymal Stroke (ICH)  Also see figure 5.19 CT-Scans of different Hemorrhages And effect on brain. The fluid systems of the brain allow for some compensation to smaller masses. (Non- symptomatic or impairment) With increasing size intercranial pressure increases symptoms and impairment increase Compression and destruction of adjacent areas of the brain Increasing intercranial pressure can cause shifting of brain Displacement of brain damage areas far from mass and block ventricular structures or herniation of brain structures  Clinical Application 2 Hydrocephalous Signs and symptoms Communicating Hydrocephalous Headache Excessive or poor absorption of CSF Nausea and vomiting Change in cognitive status Loss of consciousness Non communication or Obstructive Decreased vision hydrocephalous CN VI palsy Obstruction of CSF flow Due to intercranial mass. Also results in increase intercranial pressure Lumbar tap or Ventriculoperitoneal puncture procedure shunt https://healthjade.net/ventriculoperitoneal-shunt/