OT1024 Neurosciences for Occupational Therapy PDF

OT1024 NEUROSCIENCES FOR OCCUPATIONAL THERAPY SHIFT 1 Organization of the Nervous System LESSON...

OT1024 NEUROSCIENCES FOR OCCUPATIONAL THERAPY SHIFT 1 Organization of the Nervous System LESSON Dr. Joselito Diaz | Date: August 14, 2023 01 TABLE OF CONTENTS LEGEND 1. Introduction # ★ Important / Take Note ✤ Textbook Information 1.1. The Nervous System ➤ Lecturer’s Verbatim ❐ Other Transes/Resources 1.2. Overview 1.3. Functional Organization of the # Nervous System 1. INTRODUCTION 1.3.1. Sensory Division The Nervous (generation of nerves and impulses) 1.3.2. Motor Division and Endocrine systems (producing hormones, 2. Anatomical Organization acting on target organs, causing change to a 2.1. Terminologies particular endocrine gland) together control and 2.1.1. Central Nervous System nervous meation of · · #smal impulses coordinate functions of all body systems. 2.1.2. Peripheral Nervous System ess mine-aroducing vemones ○ Coordinated as an interlocking system 2.2. Nervous Tissue termed the Neuroendocrine system 3. 2.2.1. Neuron Central Nervous System · nent iniii. One influences the other. 3.1. Meninges and Cerebrospinal Fluid ○ Nervous system performs short term crisis 3.2. Brain management 3.2.1. Fissures and Gyri hig Immediate critical action/movement 3.2.2. Lobes of the Cerebrum Mr. neuwen Example: swallowing (coordinating 3.2.3. Cerebral Hemisphere muscles,food [bolus] will be 3.2.4. White and Grey Matter mentis · neunerdachte transported down the stomach) 3.2.5. White Matter of the Cerebrum ○ Endocrine system regulates long term 3.2.6. Subcortical Nuclei 3.2.7. Diencephalon and Brainstem ongoing metabolic activities 3.2.8. Thalamus Digestion of the food or growth 3.2.9. Hypothalamus Secretion of digestive enzymes and 3.2.10. The Brainstem absorption 3.2.11. Medulla Long-term metabolic activities 3.2.12. Pons (digestion) 3.2.13. Midbrain The systems in the body must be in 3.2.14. Cerebellum equilibrium. 3.2.15. Cranial Nerves -tell ovaries to stimulate hormones 3.3. Spinal Cord Pituitary gland 3.3.1. Spinal Meninges ○ Master endocrine gland estrogen 3.3.2. Sectional Organization of the progesterone ★ It stimulates the other organs to produce their certain hormones (ex. ↑ Spinal Cord 1H (Initeinizing 3.3.3. Sectional Anatomy hormone) Ovaries to produce estrogen) 3.3.4. Organization of the Grey gland ○ Located in the brain xy/ in the Skull Matter ↳ Metabolism ★ Despite being the ‘master gland’, 3.3.5. Organization of the White gain under the - control of the ] hyperthyroid Matter weight · - - 3.4. Terminologies depression hypothalamus 4. Peripheral Nervous System tachycardia ○ Secretion of testosterones and other 4.1. Sensory Division of the PNS hormones 4.2. Motor Division of the PNS 4.3. 31 Pairs of Spinal Nerve 1.1. THE NERVOUS SYSTEM 4.4. Spinal Nerves 4.5. Dermatomes Main function of the Nervous System is accepting 5. Nerve Plexus information. 5.1. Cervical Plexus Nervous tissue specifically neurons are irritable 5.2. Brachial Plexus ○ Because they transmit info to effector 5.3. Lumbar and Sacral Plexuses organs 5.4. Peripheral Nerve and Nerve Plexus Exteroceptors - found in the skin 6. Autonomic Nervous System Interoceptors - found in the visceral stimuli 6.1. Sympathetic Division Anatomy ○ Memory and correlation coordination are 6.1.1. Organization part of the integrating system. 6.2. Parasympathetic Division Anatomy 6.2.1. Organization Memory, learning and intelligence can help in coordinating the information like temperature and pain modulation.. UST OT 2026 | NEUROSCIENCES FOR OCCUPATIONAL THERAPY 1 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System OVERVIEW Sensory What would be significant in the Receptors function of the nervous system is the activation of different receptors. Information is called Sensory Stimuli Fig #1. The Nervous System Pathway. or Afferent Stimuli. Sensory It depends if it would be visual, Pathways auditory, somatosensory [pain & Sensory Stimuli temperature] ○ Perceived by different receptors within the Brought to Sensory processing body (viscera), external environment (ex. centers in the brain skin) Sensory If visual, occipital lobe I ○ Bringing info if from generation of nerve Processing If auditory, primary auditory cortex impulses to CNS Centers in (located in temporal lobe) Central nervous system the Brain If processing, parietal lobe ○ Brain & spinal cord All of this info will be brought to The ○ Info would be accepted, integrated, association t Are Association Cortices for integration coordination would be occurring Conscious Will tell you it will be activating now ○ If info is significant, it is stored in the brain and as memory. through Motor Pathways by assigning Subconscious different skeletal muscles needed to Info coming inside and outside of Motor the body are correlated and be able to react to the particular Centers coordinated action would be done. stimuli Somatic Those that will go to the muscle This will be transmitted to Effector / Nervous fibers, organs (muscles, glands, etc.). System ○ Ex. car coming at to you Efferent fibers or motor nerve to VIsual/auditory stimuli when activate different skeletal muscles. crossing the street ○ Skeletal muscle - How much more time will it Autonomic Those that will be going to the Nervous involuntary muscle, would include take for the car to reach System you? smooth and cardiac muscle. As well - info goes to brain and as activation of different glands. memory [if you slow down, ○ Visceral effectors (smooth you might get hit] - muscles, glands, cardiac correlation is done muscle, adipocytes, etc.) Both stimuli will tell you the time on when the vehicle will pass by if you ANS Scenario: don’t move - activates muscles to Car coming and you are in the middle yNs move backward to not get hit. of the street, skeletal muscles will not only be activated [move- forward or 1.2. OVERVIEW OF NEURAL INTEGRATION - backward] since there is an impending danger, there could be ANS - dilatation of pupils to see better Brain and Central integration center Spinal Cord Info will be received by the CNS through the 1) sensory nerve by activation of different receptors sensory (afferent pathway) Stimuli Processing, integration, correlation would be happening in the CNS, then the appropriate action would be done Transmitted to our effector organs through the motor nerves (efferent pathway) 1) Sensory (afferent pathway) : activation of diff. receptors 2) CNS : processing integration , glandular cells correlation pathway) > hr bp Fig #2. Neural Integration body temp , transmitted respiration b) (efferent : , motor Blood FlON regulation - Metabolism I digestion pupil dilation contractivity UST OT 2026 | Neurosciences for Occupational Therapy 2  OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System MOTOR DIVISION (EFFERENT) (skin , body) Visceral motor division / Autonomic NS (no conscious control) ○ Info going to smooth and cardiac muscles (diff glandular epithelium) ○ Innervates the cardiac and smooth muscles (Involuntary) ○ 2 Divisions Sympathetic division ○ fight or flight [emergency] ○ Increase in heart rate ○ Shut down action of intestine (muscles , glands) Parasympathetic division ○ Resting motor ○ Vegetative sensory ○ Reduction in heart rate Outer-CNS-inner ○ Activity of gastrointestinal tract AFFerent efferent Somatic motor division Fig #3. Afferent and Efferent Pathways - The brain is protected by the ○ Information going to the muscles. skull, meninges and CSF. ○ Innervates the skeletal muscles (Voluntary) 2. ANATOMICAL ORGANIZATION OF THE NERVOUS SYSTEM 1.3. FUNCTIONAL ORGANIZATION OF THE NERVOUS SYSTEM GNS P brain spinal cord motor Sensory A visceral somatic um am sensory sensory ,umd durn CNS Brain SC pimotor Sensory VsI -SMD I VMD JSD i SD PD CNS peripherally = PNS laterally : Fig #4. Functional Organization of the Nervous System Structured peripherally = CNS ○ Brain and Spinal Cord ○ Composed of interneurons (association neurons) Fig #5. Anatomical Organization of the Nervous System - Structured laterally = PNS 2.1. TERMINOLOGIES SENSORY DIVISION (AFFERENT) Visceral Sensory Division CENTRAL NERVOUS SYSTEM ○ Info coming from the internal viscera ○ ex. feeling of hunger, urinate, etc. 2 Areas ○ Found in the different internal organs. ○ Grey Matter Somatic Sensory Division Located on the surface of the brain ○ Info or sensory coming from skin Composed of neuronal cell body ○ Ex. pain, temperature, touch = coming from the Neuron is diff from other muscle, ligaments, tendons (proprioception) cells in the body, contain ○ Found in skin and joints. processes (dendrites [receiving info] and axons PN) Somatic [myelinated]) I kin Neural cortex - Grey matter on the surface of the brain UST OT 2026 | Neurosciences for Occupational Therapy 3 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System Cerebral cortex and ○ 98% nervous tissue concentrated in brain cerebellar cortex and spinal cord Where cell body of the Nervous tissue contains two basic cell types neuron would be located ○ Neurons = functional units Cortex - located on the Only cells that can transmit surface of the brain information in the form of electrical Nuclei - Collection of neuron cell current at their cell membranes bodies in the interior of CNS Receive and process information Grey matter embedded Convert info to another cell within the white matter. Contains processes in the form of ○ White Matter axon and dendrites. Composed of axons ○ Neuroglia = “nerve glue” (SUPPORTING Organized into tracts and columns CELLS) It is color white because of the provide physical support for presence of myelin sheath neurons Myelin sheath is made up Represent 90% of a cells in brain of fats that’s why it’s white. Astrocytes, oligodendrogliomas, ★ Tracts (bundles of CNS axons) schwann cells Bundle of axons that share More abundant than the two type of common origin and cell destination Astrocytes can replicate neurons. Ex. corticospinal tracts, There can be tumors coming from starts with the cortex, ends the neuroglia. with spinal cord; Spinothalamic tract to the thalamus Also known as fasciculus (arcuate fasciculus / fasciculus cuneatus) and lemniscus (these terms will denote that certain parts are tracts) ★ Columns Several tracts that are located in a distinct area White matter is divided into anterior, dorsal, lateral column (in the spinal cord) Tracts in a distinct area in CNS Fig #6. Neuron PERIPHERAL NERVOUS SYSTEM NEURON PNS The neuron is the functional unit of the nervous ○ Grey matter in PNS system Ganglia (sing. ganglion) Cell body is lined up on the grey matter Grey matter located Dendrites receive information from another cell or outside CNS receptor and transmit the message to the cell body Ex: Semilunar ○ Single or thousands of dendrites ○ White matter "nerve" The cell body contains the nucleus, mitochondria Nerves and other organelles typical of eukaryotic cells Bundle of axons ○ From dendrites with a lot of info, cell body Ex. median nerve, ulnar processes info and only a single action nerve sciatic nerve would be created and transmitted to the axon ★ CNS it is called Tracts (Lemniscus and Fasiculus); The axon conducts messages away from the cell PNS is Nerves body ○ Neuron always has one axon 2.2. NERVOUS TISSUE ○ Activation is greater than inhibitory Specialized tissue for rapid conduction of ○ Inhibitory = no nerve impulse would be electrical impulses that convey information generated from one part of the body to another UST OT 2026 | Neurosciences for Occupational Therapy 4 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System ○ Surrounded by: meninges (connective tissue covering - There would be meningeal space where cerebrospinal fluid the is located. Cerebrospinal fluid BRAIN (3 vesicle) ○ Forebrain (cerebral hemisphere) Cerebrum Diencephalon (interbrain) ○ Midbrain (most superior) ○ Hindbrain (most inferior) Fig #7. Parts of the Neuron Pons (inferior) - A neuron only have one axon. There could be tons of dendrites but Medulla (inferior) - the axon is only one. Cerebellum (derivative of - hindbrain) SPINAL CORD (31 segments) ⑧ ○ 8 - Cervical segments ○ 12 - Thoracic segments ○ 5 - Lumbar segments ○ 0 5 - Sacral segments ○ 0 - - 1 - Coccygeal segment 3) segments Controls the action of the tail Start of the spinal cord is the foramen magnum region. - Anything above the foramen magnum is part of the medulla and below that would be the cervical spinal Fig #8. Neuron. Pyramidal in Shape cord Cerebellum is located dorsal of the brain stem Brain is )not a hollow organ (has a cavity within) ○ Vesicles (lateral ventricles, 3rd ventricles, sylvian aqueduct, 4th ventricles) - Central canal - spinal cord cavity it is a hollow organ Cerebrospinal fluid - within ventricles Meninges - connective tissue surrounding the brain ○ Within meninges is subarachnoid space which contains CSF. Fig #9. Oligodendrocytes 3. CENTRAL NERVOUS SYSTEM Consists of the brain located within the skull and the spinal cord located within the vertebral foramen Integration and command center of the body ○ We know the the brain and spinal cord are important as they are encased in a boney structure ○ Brain - cranium cavity : ventricles ○ Spinal cord - vertebral column Fig #10. The Midsagittal Section of the CNS - It contain cavities inside Covered by meninges and surrounded by called VENTRICLES;Diencephalon connecting to the spinal cord is cerebrospinal fluid the brainstem. ○ It is within the bone structure that’s why it is important UST OT 2026 | Neurosciences for Occupational Therapy 5 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System 3.1. MENINGES AND CEREBROSPINAL FLUID ○ Drainage from The meninges are 3 connective tissue membranes brain to internal that lie external to the brain and the spinal cord jugular vein ○ Dura mater, arachnoid mater, ○ Venous drainage subarachnoid space, pia mater Arachnoid mater ○ Cover and protect the CNS ○ web-like structures, there are also ○ Hold cerebrospinal fluid (CSF) processes. ○ Prevents harmful substances from entering Subarachnoid space "true space" CSF ○ CSF and large vessels of the brain Pachymeninx (tough membrane) is also called Dura ○ Large arteries and veins ANEURYSM -> -present in all humans mater Pia mater Leptomeninx is also called Pia Mater ○ thinnest covering ○ adherent to the brain and the spinal cord THE CEREBROSPINAL FLUID The CSF is the extracellular fluid found in the ventricles of the brain and subarachnoid space ○ Surrounds the brain and spinal cord in the subarachnoid space Subarachnoid hemorrhage (Stroke in Subarachnoid Space) ○ Cushions and protects the CNS from trauma ○ Provides mechanical buoyancy and support the brain Brain = around 1kg (we do not feel the weight because it is floating in water, anything floating in water is light) ○ Nourishes the CNS and removes metabolites Fig #12. Illustration of Meninges Choroid plexus B ○ Produces CSF ○ Located within ventricles (primarily the lateral ventricles and some in the 3rd and 4th ventricles) ○ Flow is from lateral ventricle - 3rd ventricle - sylvian aqueduct - 4th ventricle - subarachnoid space - very little to central canal ○ Foramina of luschka & Foramina of Magendie opening in 4th ventricle for CSF to flow into subarachnoid space (within spinal cord) -lateral opening Fig #11. Meninges epidural - Skull & dura - Dura mater - subdural dura & arachnoid ○ 2 layers - Periosteal layer (closer to the periosteum of the skull Meningeal layer (adjacent to the arachnoid mater) The 2 layers would separate in some areas to form: Dural sinuses UST OT 2026 | Neurosciences for Occupational Therapy 6  Right & Left Longitude in t = OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System 3.2. BRAIN Fig #13 arachnoid mater drain into venous system Fig #15. The Human Brain re Arachnoid granulation / Pacchonian bodies invaginate in ○ Drain CBS fluid into venous blood / dural - input sinuses (occurs in pacchionian bodies) outpacketing - & output of AG ↳ drainage If pus build up in the paccionian of arachnoid bodies there would be blockage granulation causing meningitis. of arachnoid ~○ Hydrocephalus Arachnoid granulation / pacchionian bodies is unable to drain CBS Accumulation of CBS in ventricles CIF · Fig #14 Fig #16. Cerebral Hemisphere Sacular aneurysm ○ Abnormalities in the blood vessel Gyration ○ Weakening of the walls of the large arteries ○ Folded so that it will increase surface area in the brain to accommodate more neurons Subarachnoid hemorrhage ○ Grey matter would contain neurons ○ Rupture of cerebral artery ○ Polymicrogyria - Seen in individuals who ○ Secondary to a ruptured aneurysm have autism spectrum disorder. ○ Fatal ○ Pacchonian bodies would be unable to drain CSF causing hydrocephalus SRUIl Dural Dura mater - trauma Injection accum Epidural space , , Arachnad UST OT 2026 | Neurosciences for Occupational Therapy 7  -contralateral OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System primary motor cortex I FISSURES AND GYRI ○ Frontal lobe - beneath the frontal bone encompassing ( ○ Parietal lobe - beneath parietal bone ○ Occipital lobe - beneath occipital bone ○ Temporal lobe - beneath temporal bone Limbic lobe ○ For emotions and memory formation, personality development ○ Limbus - would be a circle ○ Located in the cingulum frontal part of the temporal lobe and parietal lobe -most primitive part of brain CEREBRAL HEMISPHERE contralateral parietal lobe primary somatosensory e Front Fig #17 is less neurons elevated Gyrus - ↳ in portion ○ Grey matter polymicrogyria -> autism ○ The ridges ○ The vertical lines in the right image not smooth ○ Increases surface area to accommodate , more neurons ○ If smooth, there will be no space for neurons Fissures (deep groove) and Sulci (groove) LOBES OF THE CEREBRUM Surface contains gyri and sulci or fissures ○ Longitudinal fissure separates two Fig #19. The Cerebral Hemisphere cerebral hemispheres Even if they appear similar, the right and left The main “hati” cerebral have different functions ○ Central sulcus of Rolando separates the Left Cerebral Hemisphere frontal and parietal lobes Rolandic Fissure - - ○ Would be the “dominant one” I non-dominant ○ Lateral Sylvian fissure separates the ○ Majority of humans have a left dominant temporal lobe from the frontal and parietal - - ↑imaginary" hemisphere lobes ○ Contains the language areas ○ Line drawn from the parieto-occipital -> seen in medial ○ Left-handed does not = dominant right sulcus down to the preoccipital notch surface of brain hemisphere (95% have left hemisphere) delineate the occipital lobe from the ○E ⑲Dinam Broca's area (language area / motor line temporal and parietal lobes parietal a occipital speech) Located in theE frontal lobe Movement that would control the mouth, tongue, pharynx, and larynx dominant in order to produce sound ○E Wernicke's area (interpretation language) understanding Located at the temporal lobe at the Language superior temporal gyrus; most -temporal lobe language " - auditory" posterior Responsible for interpretation of language (written or oral language; all types) Language areas are located in the dominant hemisphere Majority of people would have their language areas located in the left cerebral hemisphere Frontal lobe Fig #18. Lateral View of the Lobes of Cerebrum ○ Broca’s area speech are a -> ○ Motor speech area Brain divided in 4 lobes ○ Primary motor cortex -activate all skeletal muscles UST OT 2026 | Neurosciences for Occupational Therapy 8 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System Responsible for the activation of ○ Example situation: muscles on the contralateral side of Connecting right temporal and left the body temporal lobe Parietal lobe Example: Corpus callosum ○ Primary sensory cortex Projection fibers Interpretation of pain, temperature, ○ Connects the brain / cerebral cortex to light touch, and conscious the subcortical nuclei, brainstem and proprioception coming from the spinal cord nuclei contralateral side of the body Example: Left somatosensory cortex would interpret information from the right side of the body Temporal lobe ○ Primary auditory cortex ○ Primary olfactory cortex Occipital lobe ○ Processing of visual information Insula ○ Underlying grey matter beneath the separated lips of the lateral sylvian fissure ○ Gustatory cortex is located here Sense of taste WHITE AND GREY MATTER common impairment basal ganglia : in disease Parkinson's Fig #21 SUBCORTICAL NUCLEI Fig #20. Coronal Section showing the White and Gray Matter Embedded in the white matter would be the different subcortical nuclei The brainstem has no cortex but instead it has the different brainstem nuclei WHITE MATTER OF THE CEREBRUM Association fibers ○ connections from gyrus to gyrus and from lobe to lobe within the same cerebral hemisphere ○ Example: Superior longitudinal fasciculus - connects frontal lobe to temporal lobe Fig #22 Commissural fibers Thalamus ○ Connections that occur between ○ All sensory information before they reach homologous areas of the two the cerebral cortex would have to pass hemispheres through the thalamus (relaying station) UST OT 2026 | Neurosciences for Occupational Therapy 9 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System ○ 3rd ventricle Coordinates the activities of the cerebral cortex, Medial to the thalamus basal nuclei and cerebellum ○ Caudate, putamen, globus pallidus interna Olfaction/smell - do not pass thalamus & externa Part of the basal ganglia (responsible for execution of motor processes and would have some executive functioning) Subcortical Nuclei ○ Embedded within the white matter ○ Are also called nuclei in the spinal cord (the grey matter there DIENCEPHALON AND BRAINSTEM Diencephalon / Interbrain ○ Connecting the 2 cerebral hemispheres ○ The structure between the right and left cerebral hemispheres Diencephalon is composed of: ○- Epithalamus ↑ melatonin (sleep hormones) Includes the pineal gland ○ -- Hypothalamus will Wake you. ○- Subthalamus Part of the basal ganglia pathway ○- Thalamus The largest Fig #24 HYPOTHALAMUS Controls somatic motor activities at the subconscious level wake Controls autonomic function sleep Coordinates activities of the endocrine and nervous systems Secretes hormones ○ That will cause activation of the pituitary gland (not part of the hypothalamus, just connected); the secretion of the different releasing hormones will cause the pituitary gland to secrete stimulating hormones ○ may also produce hormones that may go directly into the blood/vascular system which includes: 1st Thalamus Vasopressin or antidiuretic hormone : Fig #23 cortex primary auditory oxin/toxin THALAMUS - dadaan muna here bago brain Produces emotions and behavioral drives ○ Part of the limbic system Final relay point for ascending sensory information ○ The hunger center, and thirst center; All sensory information (pain, touch, temperature, activation in each means you are hungry or proprioception, visual, auditory) has to pass thirsty through the thalamus before it reaches the primary ○ Satiety center will tell you that you are full somatosensory cortex and needs to stop eating Only one sensation will reach the cerebral cortex In cases of morbid obesity, there without passing through the thalamus–the sense of could be problems in the satiety smell or olfaction part of limbic system (not passing through thalamus) center such that even though the Smell would be a very primitive sensation (oldest of individual has eaten a lot, the all special senses) center is not activated Regulates body temperature UST OT 2026 | Neurosciences for Occupational Therapy 10 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System ○Located within the hypothalamus are the different internal thermoreceptors Tells the body if it's too cold = THE BRAINSTEM -> cardiorespiratory centers shivers (an autonomic function that Composed superiorly of the pons, and the medulla we are not aware of) Too hot = Three functions activation of the sympathetic (N 3-12 ○ 1. Serves as a conduitrfor the ascending nervous system that causes and descending tracts connecting the sweating to regulate body 1 cerebral h. : spinal cord to the higher centers in the temperature 2 dincephalon : forebrain The suprachiasmatic nucleus of the Connecting the diencephalon to the hypothalamus will awaken the brain spinal cord and cerebral and body telling us to wake up hemispheres Coordinates circadian cycles of activity The information going to the spinal Would be the origin of the autonomic nervous cord would have to pass through system the brainstem ○ Hypothalamus spinal tract - origin of the All information coming from the sympathetic and parasympathetic nervous body for it to reach the cerebral system hemisphere, would have to pass ★ Infundibulum - where the pituitary gland is located through the brainstem ○ 2. Contains important reflex centers associated with control of respiration and the cardiovascular system (centers are located in the medulla and pons) ○ 3. Contains important nuclei of cranial nerves III through XII Olfactory nerve (CN I) arises from the- cerebral hemisphere (N9-12 Optic nerve (CNII) will be arising from the -diencephalon Oculomotor nerve (CNIII) to Hypoglossal nerve (CN XII) arises from the- brainstem Fig #25 Fig #27 Located within the brainstem are reticular formation, and some of these forms the cardiovascular and respiratory centers primarily located in the medulla Fig #26 and pons UST OT 2026 | Neurosciences for Occupational Therapy 11 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System ○ Cardiovascular center is located in the medulla ○ Respiratory center is located both in the pons and medulla If there are any disruption, it will cause the individual to go to cardiorespiratory arrest MEDULLA Most inferior Connects the brain with the spinal cord Contains relay stations, reflex centers and cranial nerve nuclei Fig #29. The Medulla Oblongata in Posterolateral and Anterior View ○ at the level of pyramidal decussation would be at the level of the foramen magnum PONS ○ Olivary nuclei complex ○ Cardiovascular and respiratory rhythmicity Sensory and motor nuclei for four cranial nerves centers ○ CN V, VI, VII, VIII Reticular formation begins in the medulla oblongata ○ Trigeminal, Abduscence, Facial, and extends into more superior portions of the Vestibulocochlear brainstem Nuclei that help controlC respiration ○ A cluster of nuclei located within the Nuclei and tracts linking the cerebellum with the brainstem and diencephalon and has brain stem, cerebrum and spinal cord specific functions Ascending, descending and transverse tracts Ascending Reticular Activating System (ARAS) - necessary to maintain consciousness Fig #30. Pons Fig #28. The Medulla Oblongata UST OT 2026 | Neurosciences for Occupational Therapy 12 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System Fig #31. Pons There is an enlargement laterally – brought by the transverse fibers which is the major area wherein the cerebral hemisphere would connect with the cerebellum Located here are the different pontine nuclei that would link the cerebellum with the cerebrum; brainstem and spinal cord All transverse fibers will be going to the cerebellum Fig #29. The Midbrain transmitting information into or out of the cerebellum Middle cerebral peduncle - connects the pons with the cerebellum MIDBRAIN Most superior and the structure similar to that of the spinal cord The tectum (roof) contains the corpora quadrigemina ○ Superior and inferior colliculi ○ Superior colliculus - part of the visual reflexes / vision ○ Inferior colliculus - part of the auditory Fig #30. Substantia Nigra. - Causes Parkinsons Disease and Part of the Basal Ganglia Pathway pathway The mesencephalon contains many nuclei and motor are a CEREBELLUM primary tracts ○ Red nucleus Still part of the hindbrain ex reaching an object Enbiceps : ○ Substantia nigra Main function: coordination and equilibrium Parkinson’s disease - caused by Adjusts postural muscles and tunes on-going the degeneration of the substantia movements Cerebellar problem nigra that will cause that particular Cerebellar divisions hypokinetic movement disorder ○ May be anatomically separated by fissures, ○ Cerebral peduncles forming the flocculonodular, anterior and ○ Reticular formation -> remember posterior lobes Laterally : - maintain ○ ⑳ Medial vermis and 2 cerebellar hemispheres I dixide a lobes posterior anterior laterally Connected to brainstem via superior, middle and inferior cerebellar peduncles ○ Link the cerebellum with the brainstem, diencephalon, cerebrum, and spinal cord UST OT 2026 | Neurosciences for Occupational Therapy 13 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System have motor and sensory fibers or (mixed nerves) Fig #31. Vermis, Outgrove and Primary Fissure Vermis - midline structure Out grove - lateral cerebral hemispheres Primary fissure ○ Separates anterior from posterior lobe Fig #33 Fig #32. The oldest part of the cerebellum would be the >- flocculonodular lobe ; separated from the posterior lobe to the flocculonodular fissure The cerebellum will be connected to the midbrain, Fig #34 pons, and medulla through the superior, middle and inferior cerebellar peduncles Within the white matter of the cerebellar cortex, there are grey matter called cerebellar nuclei which includes the dendrite, fastigial nucleus CRANIAL NERVES 12 pairs of cranial nerves ○ Each attaches to the ventrolateral surface of the brainstem near the associated - sensory or motor nuclei ○ 10 arises from the brainstem (CN III-CN XII) Olfactory nerve arises from the - cerebral hemisphere Optic nerve arises from the - diencephalon ○ Cranial nerves are either classified as purely motor or purely sensory, or they both Fig #35 UST OT 2026 | Neurosciences for Occupational Therapy 14 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System The cranial nerves are able to00exit or enter the skull 31 pairs of spinal nerves for each 31 spinal through different openings or foramina segments receiving into From UE. ○ Ex. Superior oblique fissure, Jugular - 8 - Cervical spinal nerves foramen - 12 - Thoracic spinal nerves - 5 - Lumbar spinal nerves 3.3. SPINAL CORD - 5 - Sacral spinal nerves The adult spinal cord ends between L1 and L2 - 1 - Coccygeal spinal nerve spiacrafter than spinal adult vertebrae column. Locate the: ○ Shallow posterior median sulcus ○ Deep anterior median fissure Shorter than vertebral column -> cavity H snape (butterfly) Fig #36. Parts of the Spinal Cord (Gray matter is in a butterfly shape) Fig #38 SPINAL MENINGES Membranes surround and protect the spinal cord Provide physical stability and shock absorption Blood vessels branching within these layers deliver oxygen and nutrients to the spinal cord Three layers (meninges): - ○ Dura mater ○ Arachnoid ~ ○ Subarachnoid ~ space (between the arachnoid and pia mater) contains cerebrospinal fluid (csf) for patients suspected with infection -○ Pia mater Fig #37. Parts of the Spinal Cord - Adult Spinal Cord ends in L1 or L2 Enlargements are composed of numerous grey matter dealing with sensory and motor control of the limbs more grey matter Cervical enlargement - nerves to the shoulder girdles and upper limbs, gains info from lower parts, white matter Lumbar enlargement – innervations to the pelvis and lower limbs ⑧ Conus medullaris is the end / tip of the spinal cord : Spinal needle spinal qnesmesial below L2/ between : (between L1 and L2 vertebrae) ex ○ - - Sacral and coccygeal segment 12 & Ly ○ Spinal cord will be shorter than the vertebral column. ○ Thoracic will have less/small gray matter ○ Cervical spinal nerves innervates the upper extremities while the thoracic spinal nerve innervates the abdominal muscles. UST OT 2026 | Neurosciences for Occupational Therapy 15 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System Centrum / body of the vertebra (anterior) Anterior (sensory), Posterior (motor) SECTIONAL ORGANIZATION OF THE SPINAL CORD Op - horn hOIN do we know ? the Orientation of 6 M.. if grey matter a horn is almost truching serface : POSTRIOR Fig #41. The Sectional Organization of the Spinal Cord Fig #39 Subarachnoid Space ○ Contains CSF Meningitis ○ Infection in the brain ○ Lumbar puncture is done (inserting a needle between L2 and L3 or L3 and L4 to penetrate the subarachnoid space to collect CSF) The same area to insert the spinal anesthesia ○ The spinal cord would end between L1 and L2 Centrumbray) M - Fig #42. The Sectional Organization of the Spinal Cord e norn SECTIONAL ANATOMY OF THE SPINAL CORD White matter is composed of myelinated and unmyelinated axons a Grey matter dominated by nerve cell bodies and. neuroglia Grey matter surrounds the central canal p norm Projections of grey matter called horns. Pehorn ↳ contain epidure sensory nuclei v contact synaptic Fig #40 Anterior horn Vertebral canal (center portion of the image) - ○ Where the spinal cord would be located ↳ visceral organ Spinal cord (located in-between) h motor Epidural Fat ○ Additional spinal cord protection Fig #43 Dorsal spine (posterior) ○ Palpated at the middle of the back UST OT 2026 | Neurosciences for Occupational Therapy 16 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System Fig #44 Anterior horn ○ Anterior grey matter projection Posterior horn ○ Posterior grey matter projection Lateral horn (thoracic region / at the sides) Grey commissure (black dot in the center) ○ Connects the right and left spinal cord Fig #45. Pathways horns Anterior root (root at the side of the anterior horn) & motor Posterior root (root at the side of the posterior root) sensory- -Spinal nerve "mixed nerve" 3.4. TERMINOLOGIES ○ Fusion of the anterior and posterior roots at the intervertebral foramen TERMINOLOGIES contain both motor sensory Dorsal Root contain the cell bodies of sensory ORGANIZATION OF GREY MATTER Ganglia neurons Organized into functional groups called nuclei Dorsal Root composed of sensory axons which bring Posterior horns are sensory sensory information into the spinal cord ○ Arises from dorsal root ganglia ○ Sensory neurons Spinal Nerves are mixed nerves – contain both afferent ○ Posterior grey horn contains somatic and (sensory) and efferent (motor) fibers visceral sensory nuclei Ventral Roots axons of motor neurons; control somatic ○ Would only contain neurons that would be and visceral effectors receiving sensory information ○ Arises from anterior horn Anterior horns are motor Anterior grey horns deal with somatic motor control 4. PERIPHERAL NERVOUS SYSTEM (alpha/gama motor neurons) The PNS consists of 12 pairs of cranial nerves ○ Alpha and gamma motor neurons originate from the brain and 31 pairs of nerves are ○ Contains motor neurons that would attached to the spinal cord innervate the somatic sensory system Sensory (afferent) ○ innervates skeletal muscles ○ all axons carry impulses from sensory Lateral grey horns contain visceral motor neurons receptors via the PNS to the CNS ○ Origin of the autonomic nervous system Through the sensory nerves into (preganglionic autonomic nerves) the spinal cord and to the brain (via ○ Arising would be the preganglionic fibers of the spinal nerves and cranial the sympathetic and parasympathetic nerves) nervous system Motor (efferent) Grey commissures join the lateral sides together; ○ all axons carry impulses via the PNS from axons pass from one side of the spinal cord to the CNS other through the grey commissure Mixed singing tract) ○ a mixture of sensory and motor neurons ORGANIZATION OF WHITE MATTER body-brain that carry impulses via the PNS to and from brain t spinal Divided into six columns (funiculi) containing tracts cord CNS All axons within a tract relay the same type of motor ↑ ○ most common type of nerve in the body information (sensory or motor) in the same direction tract -> descending Ascending tracts relay information from the spinal cord to the brain Descending tracts carry information from the brain to the spinal cord UST OT 2026 | Neurosciences for Occupational Therapy 17 OT1024 SHIFT #1 | LESSON #1| Organization of the Nervous System Envelopes each spinal nerve with its connective tissue ○ Perineurium piad arachnoid Envelopes each fascicle ○ Endoneurium