PSY432 Neuroanatomy Alaon 1st Semester 2024-2025 PDF

PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA UNIT 1...

PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA UNIT 1 Organ System (ex. integumentary system) ANATOMY ○ Combinations of organs Organism (ex. monkey) Study of the structure and shape of the body and ○ Combination of organ systems. its parts and their relationship to one another. Gross Anatomy ○ Everything that can be seen. Note: Microscopic Anatomy The structural organization is present in ○ (Cytology and histology) all organisms. ○ Microscopic structure. The human being is made up of four basic elements: carbon, hydrogen, Functional Anatomy nitrogen and oxygen. ○ Physiological Humans are carbon based organisms. Clinical Anatomy Humans are 60-70% made out of fluid. ○ Diseases and Disorders. NEUROANATOMY NEUROANATOMICAL ORGANIZATION Study of the relationship between structure and function in the nervous system. Molecular/Chemical Neurotransmitter The anatomy, physiology, and functions of the Level nervous system. Neuro = Nerves → as wired, no signal no output; Cellular Level Neuron Nerve cell Anatomy = Structure Brain is Directly linked to behavior and affects the Tissue Level Ganglion human. Nuclei Makes psychology a science. Cluster of Nuclei Solidifies planes and theories. Functional Neuroanatomy → associated with the Organ Hippocampus Hypothalamus functions and operations of the different Amygdala neuroanatomical parts. Cerebrum Clinical Neuroanatomy → Associated with the Cerebellum diseases and other pathological disorders of the Brain stem different neuroanatomical parts. System Level Somatic System STRUCTURAL ORGANIZATION OF HUMAN BODY Autonomic Cell (ex. squamous epithelial cells) System (Anatomic ○ Combination of atoms and molecules and functional ○ Smallest functional unit of system) microorganism. Subsystem Limbic System Tissue (ex. keratinized cornified epithelial cell) Basal ganglia ○ Combination of cells that function as one. Sympathetic and Organs (ex. Hair) Parasympathetic ○ Combination of tissues that produce a specific function. General System Central (CNS) Peripheral (PNS) ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Frontal, Parietal, Temporal, TERMINOLOGIES Occipital. Anatomy → Location, Relative Location, ○ Rotating the brain and slicing the Landmarks, Orientation. brian in an imaginary manner to see Function → Action, Sensory, Motor or Mixes, the inside part. Higher Level of Mental Function. Corpus Callosum, Cingulate Language of Anatomy → Latin/greek Gyrus, Pre-frontal. nomenclature, Scientific Names etc. Body Planes and Section (SOFT) Perspective of Anatomy → Lobar, Directional, ○ Sagittal → It runs vertically from the Regional, Dimensional, Planar, Cavities, Planes and top to bottom, and it divides the body Sections etc. into a left and right portion. PERSPECTIVE OF ANATOMY Median (Midsagittal) → Runs Directional Terms directly down the midline of ○ Superior (Cranial) →Toward the the body. Head/Upper or Above. Parasagittal Plane → Sagittal ○ Inferior (Caudal) → Towards the Planes that are uneven (not feet/Lower or Below. down the midline) ○ Anterior (Ventral) → Further to the front ○ Oblique → Any type of angle other /in front of than horizontal or vertical angle. ○ Posterior (Dorsal) → Further to the Obliques are odd angles. back/in back of ○ Frontal (Coronal) → Front and Back ○ Medial → Toward the midline (divides the Portion. body into left and right halves an Vertically from top to bottom. imaginary line) of the body ○ Transverse (across/Horizontal) → This ○ Lateral → Toward the side of the body is the only horizontal Plane, it divides ○ Intermediate (in between) the body into a top (superior) and ○ Proximal → Closer to the axial Body bottom (inferior) portion. (Towards the trunk) ○ Distal → Further from the axial body (further from the trunk) ○ Superficial (external) → Closer to the surface of the body ○ Deep (internal) → Further from the surface of the body Regional Terms ○ Anterior Body Surface landmarks examples are; Abdominal, Umbilical, and antecubital ○ Posterior Body Surface Landmark examples are; Scapular, Vertebral, and Paravertebral ○ However, the brain is imagined in a 3 dimensional manner ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA ○ Planes of Orientation in Relation to Body Body Cavities Position → The imaginary Plane cuts ○ Dorsal Cavities through the body giving access to the Cranial Cavity (houses the internal areas which then could be brain) manipulated/rotated so that it could be Spinal/Vertebral Cavity viewed further. (houses the spinal cord) ○ Ventral Cavities Thoracic Cavity (Chest Cavity) Mediastinum → contains the pericardial cavity (heart), trachea, esophagus, and thymus gland. Left Pleural Cavity → Houses of Left lung Right Pleural Cavity → Houses of right lung Abdominopelvic Cavity Anterior/Rostral → The Front of Abdominal Cavity → towards the front of the object. liver, stomach, Posterior/Caudal → The Back or pancreas spleen, Towards the back of the object. gallbladder, intestines, Lateral → The side or towards the and kidney) side of the object. Pelvic Cavity → Medial → The Middle or towards Bladder, Reproductive the middle object. organs large intestine Dorsal → On the Top when (sigmoid colon and referring to the brain and head rectum. only. Ventral → On the Bottom when referring to the brain and head only. Note: The ventral cavity is the Larger Cavity that contains visceral organs or guts. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA The Thoracic Cavity and Abdominopelvic Gyrus (plural: gyri) is a ridge or raised Cavity are separated by the diaphragm. fold on the brain's surface, found between two sulci. Gyri are the outwardly BASIC COMPARATIVE ANALYSIS OF THE NERVOUS folded parts of the brain that increase its SYSTEM TO OTHER ORGAN surface area. The features of the nervous system are not as Ex. Precentral, Postcentral, Superior delineated and specified as other organ systems; temporal a jumble of neurons to form thread-like features. The only organ system located in the dorsal cavity. Where the oldest living cell is located: neurons; their life-span is comparab;y larger than other cells, and can be found in the brain stem. Where the longest cell is located: nerve cell. DIVISION OF NERVOUS SYSTEM OVERVIEW Central Nervous System ○ Composed of the brain and the Spinal Cord. ○ Cerebrum → The largest part of the brain Peripheral Nervous System ○ Lobar Regions → Frontal, Parietal, ○ Composed of all the nerves outside of Temporal, Occipital, and Insula. the brain and the spinal cord such as ○ Cerebellum → Role in motor control, the somatic nerves and the cranial coordination, and balance. nerves 0.e., afferent and efferent It is located at the back of the nerves. brian, underneath the occipital lobes of the cerebral cortex, and above the brainstem. ○ Has left and right hemisphere and connected by the vermis in the middle. Fissure is a deep groove or cleft in the brain's surface. It is usually larger and more profound than a sulcus. divides the brain into major sections and lobes. They help to separate different functional areas and hemispheres. Ex. : Longitudinal, Transverse and Lateral Sulcus (plural: sulci) is a shallow groove or depression on the surface of the brain. Sulci are not as deep as fissures but serve to increase the surface area of the brain. Ex. Central, Parieto-occipital and calcarine ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Autonomic Nervous System Somatic Nervous System ○ More of a functional division rather than ○ Division of the Peripheral Nerves an anatomical Division compromising of the following: ○ Motor System ○ Can either be pure motor, pure sensory ○ Serves other than skeletal muscles; or mix Glands, Smooth Muscles, other neuron ○ Controls Voluntary action clusters, visceral. ○ Communicates with sense organs and ○ Synapse with second neuron (two-cell voluntary muscles. system) ○ CRANIAL NERVES → 12 Cranial Nerve ○ Has three functional division: Olfactor, and optic nerves have Sympathetic → Flight or Fight their own origins, while the Response, Increase heart rate, rest of the cranial nerves breathing ,etc inactive digestion originate from the brainstem Parasympathetic → Rest and Olfactory (Smell), Oculomotor Digest Response, Decrease heart (eye movement and pupil rate, active digestion ,etc, reflex), Trigeminal (face Vegetative Activities sensation and chewing), Facial Enteric → Regulating the process (face movement and taste), of digestion Glossopharyngeal (throat ○ Communicates with internal organs and sensation, taste, and glands swallowing), Accessory (Neck ○ More of a functional division rather than Movement), Optic (Vision), an anatomical division Trochlear and Abducens (Eye ○ Involuntary physiology (internal Movement), Vestibulocochlear environment) (hearing and balance), Vagus (movement, sensation, and abdominal organs), NERVOUS SYSTEM Hypoglossal (tongue Central (CNS) Brain and Peripheral (PNS) lies movement) Spinal Cord outside the brain and Spinal Cord Autonomic (ANS) Somatic (SNS) Communication with (communicates with sense internal organs and organs and voluntary glands muscles) Sympath Parasympat Sensory Motor etic hetic (afferent) - (efferent) - (Arousing (Calming) Sensory Motor ) input output ○ ○ SPINAL NERVES → 31 Pairs Note: Distributed and named based Both Brain and Spinal Cord are on the vertebral segments protected by Bone: the brain → Skull; where it originates from. Spinal Cord → Vertebrae. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Thalamic Group of Neurons: Acts as a relay SPINAL CORD AND ANATOMICAL DESCRIPTION center for sensory and motor signals and plays a role in consciousness, sleep regulation, and Ventral Horn → Anterior, Motor processing. cognitive processing. Dorsal Horn → Posterior, Sensory Processing. Commissural Fibers → connect the Interneuron → Connects Dorsal to ventral directly corresponding regions of the left and right or connect sensory to higher brain areas. hemispheres of the brain, allowing Gray Matter → Unmyelinated Fibers forming H or communication and coordination between the butterfly shape. two sides. White Matter → Myelinated Fibers Projection Fibers → connect the cerebral Efferent Nerves → Motor Connection cortex with other parts of the central nervous Afferent Nerves → Sensory Connection system (CNS), such as the brainstem, spinal cord, and subcortical structures like the basal ganglia and thalamus. They carry sensory information to the cortex and motor commands from the cortex to other areas. Association Fibers → connect different parts of the same hemisphere, facilitating communication between various cortical regions within one side of the brain. They are involved in linking sensory inputs with motor outputs and integrating different types of information. PARTS OF NEURON Note: There are two basic cells Glial (Glia), however Neuron is the Main Basic Cells Glial Cells → Support/ glial (Glue) - Holds cells in place Dendrites → Conduct information and Receive signals from the other neuron cells. Cell Body → Contains a Cell Nucleus Nucleus → Contains the genetic material ANATOMICAL DESCRIPTION (chromosomes) of the neuron cell. Axon → Conducts electrical impulses along Limbic system → role in regulating emotions, memory, and specific aspects of behavior. the neuron cell. Basal Ganglia → involved in regulating motor ○ Not all neurons are connected via control and cognitive and emotional functions. dendrite-axon Diencephalon → Includes the thalamus and ○ Conduct information away from the hypothalamus, regulating sensory and motor cell body signal relay, homeostasis, autonomic functions, and hormonal control. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA The vermis is also subdivided into a superior Myelin Sheath → Insulates the axon to help and an inferior portion, where the; protect the neuron cell and speed up transmission ○ The vermis coordinates the of electrical impulses. movements of the central body (e.g., Axon terminal → Transmits electrical and trunk, head, proximal limbs) and the paravermis area coordinates chemical signals to other neuron cells and effector movement from the distal limbs (e.g., cells. arms, legs, fingers, toes). Schwann Cell → Produces the myelin sheath ○ the superior portion is visible between Node of Ranvier → Allow diffusion of ions the two hemispheres. In comparison, Cell Membrane → Protects the Cell ○ its inferior portion is buried between Synapse → Where neurotransmitters are released the two hemispheres. from one axon terminal → binding to receptor Surface of the cerebellum has horizontal molecules of the other neuron. elevations, known as folia, and indentations Neurotransmitter → Chemical messengers that between the folia, known as sulci. our body can’t function without. ○ Some of these sulci are deeper than ○ carry chemical signals (“messages”) from others and they are said to subdivide one neuron (nerve cell) to the next target each hemisphere into three lobes, cell. Anterior lobe; Small Gap Junction → Small aqueous pores in the cell Spinocerebellum membranes of two adjacent cells Regulation of Muscle ○ Permit movement of small secondary Tone and adjusting messenger molecules from the cytoplasm movements of one cell (signaling cell) → cytoplasm of separated from the neighboring cell (target cell) posterior lobe by the primary fissure CEREBELLUM Posterior lobe; larger Assists with coordinating and adjusting voluntary Cerebrocerebellum movement. Responsible for ○ Posture, Balance, Maintenance of muscle assisting in planning tone and coordinated skilled voluntary & programming of motor activities. skilled or fine motor ○ Inorder to do things like riding a bicycle movements and many more it should be in contact Contains the with Cerebral Cortex. horizontal fissure Located below the occipital lobe of the cerebral separating superior hemispheres. In the posterior aspect. and inferior surface of Connected to the Midbrain, Pons and Medulla. the cerebellum. ○ It is connected to the brainstem via the The posterolateral superior, middle, and inferior cerebellar fissure separates the peduncles. flocculonodular lobe It is separated from the occipital and temporal from the posterior lobe. lobes, cerebrum via a horizontal dural reflection, Flocculonodular lobe; the tentorium cerebelli. Inferiorly positioned Vestibulocerebellum ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA The cerebellum can be seen as composed of the From lateral to medial this right and left cerebellar hemispheres and the consist 4 types nucleus narrow, intervening vermis. Dentate Maintenance of Posture Emboliform and Balance Globose It contains an essential Fastigial part of the vermis called ○ Cerebellar Cortex is a three layer nodule as well as two(2) structure lateral flocculi The innermost granular layer Cerebellum has an outer rim of gray matter, the is well-defined due to the cortex, an inner core of nerve fibers, the nucleic acids in the nuclei of medullary white matter, and the deep cerebellar its numerous small cells. nuclei, located within the white matter. The middle Purkinje layer, Lateral View → Cerebellar Peduncles: Contains composed of a single layer of Efferent and Afferent Axons between cerebellum large Purkinje cell perikaryons, and CNS is also easily recognizable. ○ Superior Cerebellar Peduncle The outermost Connects cerebellum with molecular layer is rich Midbrain in axons and dendrites Majority of Efferent Signals as well as capillaries ○ Middle Cerebellar Peduncle (CUT) that penetrate deep Connects cerebellum with Pons into this layer Majority of Afferent Signals ○ Cerebellar Cortex Three Functional ○ Inferior Cerebellar Peduncle Regions Connects Cerebellum with medulla Lateral Zone → Most lateral Majority of Afferent Signals and largest deep cerebellar Sagittal View Nuclei Cortex is Folded into FOLIA eating ridges with It sends signals to the small sulci in between, it is ridges, thinner, dentate nucleus. smaller, and organized in parallel layers which are Planning and called Folia programming ○ Folia enable the large area of cortex to fit Movements into small space Intermediate Zone → ○ The Folia contains an external gray matter Paramedian/Paravermal layer called cerebellar cortex. Send Signals to ○ A subcortical white matter region deep to Emboliform and external gray matter Globose Nuclei The shape of white matter within a (Interpose Nuclei) folia, creates a tree-like Modulating Motor arrangement known as arbor execution of Lateral vitae or tree of life descending motor ○ Cerebellar nuclei pathways Contains Multipolar Neurons that Median/Vermal Zone receive signals from cerebellar Sends signals to ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA cortex & other parts of Nervous ○ Controls motor movement and System reflexes. Involved in visual and Axons form cerebral peduncles auditory reflexes, eye movement Fastigial Nucleus which is control, and coordination of motor the most medial of the movements. deep cerebellar nuclei ○ Superior colliculi: Eye movements and located within the vermis visual processing and next to the 4th ○ Inferior Colliculi: Auditory processing ventricle ○ Major dopamine: Ventral tegmental Modulating motor (motivation and reward), Substantia execution of medial Nigra (Movements) descending motor pathway FUNCTION OF BRAINSTEM Thalamus are easily distinguished from each other in a midsagittal section of the cerebellum, Vital Autonomic Functions: Controls involuntary actions such as heartbeat, BRAINSTEM breathing, digestion, and blood pressure regulation. Connects the brain to spinal cord, located at the base of the brain Cranial Nerve Functions: Many cranial nerves Compose of the mesencephalon, metencephalon, originate from nuclei within the brainstem, and myelencephalon which control sensory and motor functions of Oldest part of central nervous system the head and neck. its dorsal aspect is mainly hidden from view in the Sensory and Motor Pathways: Acts as a whole brain, whereas its ventral and lateral pathway for ascending sensory information aspects are visible (from the body to the brain) and descending Medulla Oblongata → The bottom part motor commands (from the brain to the body). ○ regulates vital autonomic function Sleep and Arousal: Modulates sleep-wake breathing, heartbeat/rate, blood pressure cycles and levels of alertness. and swallowing, coughing and vomiting Integration of Reflexes: Coordinates reflexes Pons → The middle part involved in posture, balance, and coordination. ○ Acts as a relay station, transmitting CLINICAL RELEVANCE OF BRAINSTEM signals between cerebrum and cerebellum Conditions affecting the brainstem, such as ○ Regulating breathing, coordinates face strokes or tumors, can lead to impairments in and eye movements, facial sensations, hearing and balance. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Midbrain (Mesencephalon)→ Uppermost part of Medial Dorsal Nuclei the brainstem, connecting it to the diencephalon ○ Relate sensory, motor, and (thalamus and hypothalamus). olfactory with emotions breathing, heart rate, consciousness, and motor ○ It receive sits fibers from control. olfactory Cortex, and input It serves as a critical bridge between the spinal from amygdala and cord and higher brain centers, ensuring the Hypothalamus once received it smooth operation of essential physiological sends information to processes. prefrontal cortex which is an area responsible for attention, DIENCEPHALON personality, abstract Group of nerve nuclei, Portion of the Lateral Nuclei prosencephalon that surrounds the third ventricle ○ It is divided to a lateral dorsal It interposed between the cerebrum and the row, and a lateral ventral row, midbrain and we have the pulvinar Has four(4) regions: ○ Lateral Dorsal Row → is Thalamus divided into lateral dorsal ○ Most anterior part of each thalami form nuclei and lateral posterior tubercle shape known as Anterior nuclei tubercle ○ Lateral Ventral Row → consist ○ The posterior end is a more rounded part of ventral anterior and ventral called Pulvinar. lateral and part of a basal ○ In between the right and the left thalami, ganglia there’s a connection point called ○ Ventral anterior and lateral interthalamic Adhesion. responsible for initiation and planning of movement. ○ Ventro posterio Lateral Two thalami, structures composed of numerous nuclei, Nucleus (VPL) → Receives are connected to each other by a bridge of gray matter, the interthalamic adhesion (massa intermedia). sensory information for the trunk and limb, through a tract ○ Slice Thalamus and in superior originates from the Gracile perspective, Egg shaped structure divided fasciculus and the Cuneate into three different kinds of nuclear Fasciculus groups by the Y-Shaped structure called ○ Ventroposterior Medial the Internal Medullary Lamina that is a nucleus → Receives sensory white matter. information from the face as Anterior Nuclei within the anterior well as gustation, or sense of tubercle taste, receiving its senses Emotional Episodic from Trigeminal nerve through Memory; Ability to recall the trigeminal lemniscus. and mentally re experience Metathalamus specific episodes from ○ Medial Geniculate Body → Hearing, one’s personal past part of the auditory pathway that Ex. it keeps you awake at starts around the cochlea of the inner night, wondering about ear converts hearing into nerve signals ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA awkward situations you’ve Hypothalamus are the pituitary gland and its been in. infundibulum, the tuber cinereum, and Papez circuit Two mammillary bodies → Responsible for ○ through hair cells and sends through the Emotional Episodic memory, reflexes cochlear nerve to the cochlear nuclei in associated with olfaction Pons. The cochlear nuclei will then cross to ○ It will send axons to the anterior nuclei the other side and form the trapezoid body of the Thalamus, which will send its of Pons, and then ascend as the lateral fibers to the cingulate gyrus, and then lemniscus to the inferior colliculi. Then to the hippocampal area, then to the through the brachium of the inferior fornix, and back to the mammillary colliculus, the axons will reach the medial body. geniculate body, and then reach the primary auditory Cortex, which is located BASAL GANGLIA at the superior temporal Gyrus. ○ Lateral geniculate body two nuclei → It influences activity in areas of the brain like Vision, Visual Pathway. Within the retina of the motor cortex to affect the movement. your eyes, you have receptors for the 3nd Cognitive and Emotional. cranial nerve, the optic nerve. Much of the information the basal ganglia receives comes from the cerebral cortex and travels first to the caudate or putamen, the Pulvinar → It will receive fibers from the medial main input nuclei. geniculate body about hearing, Lateral geniculate body The globus pallidus and Substantia nigra are about vision, as well a superior colliculus fro reflexive, the main output nuclei, and they send as well as superior colliculus for movement reflexive projection out from the basal ganglia to the movement of the head through visual stimulus and cerebral cortex, mostly by way of the thalamus inferior colliculus for reflexive movement of the head as well as to nuclei in the brain stem. through auditory stimulus. All of those go to Pulvinar, Consist of some deep cerebral nuclei and and the Pulvinar sends the information primarily to the brainstem, nuclei, when damaged it produced tertiary areas of the brain. movement disorder. Nuclei, are large collections of cell bodies that Epithalamus are embedded deep in the white matter of the Very small area consists of: brain. ○ Pineal Body → produces one of the most Composed of the; important hormones in our body, ○ Caudate nucleus Melatonin make you sleep, it regulates the ○ Lenticular nucleus (putamen and sleep-wake cycle. globus pallidus), ○ Stria medullaris → habenular trigone → ○ subthalamic nucleus of the ventral Constitutes the dorsal surface of the thalamus diencephalon. ○ substantia nigra of the Subthalamus mesencephalon Under the thalamus, an essential part of the basal ganglia. Caudate Nucleus + Putamen = Striatum All the other structures of basal ganglia will work Nuclei have numerous connections with together with the Subthalamus to help start, stop, various regions of the CNS and coordinate voluntary movement. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Hypothalamus COMMISSURAL FIBERS (Transverse Fibers) Located around the anterior portion of the third ventricle. Connect an area in one hemisphere with an area in the opposite hemisphere which allows ○ Receive input → Input nuclei communication and coordination. ○ Project to other regions → Output nuclei Bundles of Axons that connects the right and ○ Receive input and project to other regions of the CNS, referred to as → Local left cerebral hemispheres interconnections and these are known as Four (4) Commissural Fibers intrinsic nuclei. ○ Corpus callosum → connects the neocortex of the right hemisphere with ASSOCIATION FIBERS (Arcuate Fibers) that of the left. It's a pathway of crucial Connects regions of a hemisphere to other regions importance to speech-language of the same hemisphere. functions Restricted to a single hemisphere ○ Anterior commissure → connects the Subsdivided into two major categories: They are right and left amygdala’s, the olfactory the axons of pyramidal cells and fusiform neurons. bulbs, and several cortical regions of ○ Short arcuate fibers, (U Fiber) the two temporal lobes. which connect adjacent gyri, ○ Posterior commissure → connects Do not usually reach the the right and left pretectal region and subcortical white matter of the related cell groups of the cerebral cortex; mesencephalon (midbrain) Most of them are confined to the ○ Hippocampal commissure → cortical gray matter. (commissure of the fornix) joins the ○ Long arcuate fibers, right and left hippocampus to one which connect non adjacent gyri, another. consist of the following fiber Corpus Callosum → Largest commissural, it tracts: connects the neocortex of the right Uncinate fasciculus hemisphere with that of the left compromises Cingulum four regions Superior longitudinal ○ Anterior-most rostrum fasciculus Inferior longitudinal ○ Curved Genu fasciculus ○ Relatively Flattened Body (its Fronto-occipital posterior-most region) fasciculus. ○ Splenium Forceps Major: ○ Connects occipital visual cortex from left to right side. ○ Fibers passes from splenium of corpus callosum Forceps Minar: ○ Connect frontal love from the right to left side ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA ○ Fibers passes from genu part of corpus Corticopetal Fibers and Corticofugal Fibers callosum ○ Corticopetal fibers → are afferent fibers that bring information from the thalamus to the cerebral cortex. ○ They consist of thalamocortical fibers. Nerves Fibers between the thalamus and the cerebral Cortex. ○ Corticofugal fibers → are efferent fibers that transmit information from the cerebral cortex to lower centers of the brain and spinal cord. They consist of the Corticobulbar Corticopontin, PROJECTION FIBERS Corticospinal Projection fibers are those that travel to and from Corticothalamic fibers. the cerebral cortex to convey elemental information involving afferent input and efferent output; It is restricted to a single hemisphere Connects the cerebral hemispheres with lower levels namely: ○ Corpus Striatum ○ Diencephalon ○ Brainstem ○ Spinal Cord Majority of these fibers are axons of pyramidal cells and fusiform neurons. LIMBIC LOBE It is a component parts of the internal capsule, Hemispheral Regions in the medial aspects of that is subdivided into the: the cerebral cortex that surrounds corpus ○ Anterior Limb callosum and the diencephalon. ○ Genu It includes the following: ○ Posterior Limb ○ Cingulate Gyrus ○ Retrolenti form ○ Parahippocampal Gyrus ○ Sublenti ○ Hippocampal Formation form Regions ○ Subcallosal Gyrus Corpus Callosum is NOT a part of the limbic lobe. ○ Par-olfactory Gyrus Genu → the anterior extent of the corpus callosum ○ Paraterminal Gyrus ○ It bends inferiorly and turned posteriorly. ○ Forming a slender connection → the rostrum with the anterior commissure. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Hippocampal Sulcus → Above the Parahippocampal Gyrus ○ Which separates the parahippocampal Gyrus from the hippocampal formation composes of the: Hippocampus, Subiculum and Dentate Gyrus Splenium → The posterior extent of the corpus callosum is bulbous in shape. Cingulate Gyrus → Located above the corpus callosum. ○ It is the crescent-shaped, or arched, convolution on the medial surface between the cingulate sulcus and the Subcallosal Gyrus → beneath the rostrum of corpus callosum. the corpus callosum ○ Separated from it by the callosal sulcus. Lamina Terminalis → Connection between the anterior commissure and the optic chiasma ○ It follows the curvature of the corpus ParOlfactory Gyrus & Partermina Gyrus → callosum and dips beneath the splenium The cortical tissue anterior to the lamina to continue anteriorly as the isthmus of terminalis. the cingulate gyrus. Subcallosal Area Parahippocampal Gyrus → The interior-most ○ Subcallosal extent. ○ Par olfactory Uncus → Anterior-most extent ○ Preterminal Gyri INSULA It is believed to be associated with taste, and perhaps other visceral functions Forms the floor of the lateral sulcus The circular sulcus (circuminsular fissure) surrounds the insula and separates it from the adjacent frontal, parietal, and temporal lobes. Lateral surface of the insula is subdivided into several short and long gyri ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA The Extensions of the lateral fissure LOBES OF CEREBRAL HEMISPHERE demarcate the inferior frontal gyrus into three subregions: FRONTAL LOBE. ○ Pars triangularis Lateral Aspect ○ Pars opercularis Frontal Lobe region located anterior to the ○ Pars orbitalis. precentral sulcus, subdivided into: ○ Superior frontal Gyrus ○ Middle Frontal Gyrus ○ Inferior frontal gyri ○ This subdivision is due to the presence, though inconsistent, of two longitudinally disposed sulci, the superior and inferior frontal sulci. Broca’s Area → Function in speech production ○ In the dominant hemisphere, a region of the inferior frontal gyrus. The frontal lobe extended from the frontal pole to the central sulcus, constituting the anterior one-third of the cerebral cortex. Precentral Gyrus → Posterior Gyrus of frontal Lobe ○ Consist of Primary motor area ○ Bordered anteriorly by the precentral sulcus and posteriorly by the central sulcus. Olfactory Sulcus → longitudinally disposed on its inferior aspects ○ Medial to this sulcus is the gyrus and olfactory tract. rectus (straight gyrus) ○ Lateral to it are orbital gyri ○ Partly occupied by the olfactory bulb ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA The remainder of the parietal lobe, separated from the postcentral gyrus by the postcentral sulcus, is subdivided by the inconsistent intraparietal sulcus into the superior and inferior parietal lobules. Superior Parietal Lobule → An association area involved in somatosensory function. At its posterior extent, the olfactory tract bifurcates to form the lateral and medial olfactory striae. Olfactory trigone → The intervening area between the two striae is triangular in shape ○ it abuts the anterior perforated substance. Medial Aspect The frontal lobe is bordered by the arched cingulate sulcus. ○ Forms the boundary of the superior aspect Latter is separated into: Division of Inferior of the cingulate gyrus. parietal Lobe Anterior paracentral lobule → The ○ Supramarginal gyrus → which quadrangular-shaped cortical tissue anterior to integrates auditory, visual, and the central sulcus is a continuation of the somatosensory information, precentral gyrus ○ Angular gyrus → which receives visual input. PARIETAL LOBE. Extends from central sulcus to the parieto-occipital sulcus Interposed between the frontal and occipital lobes and above the temporal lobe. Lateral Aspect Postcentral Gyrus → Its anterior-most gyrus, ○ is the primary somesthetic area to which primary somatosensory information is channeled from the contralateral half of the body. Medial Aspect Parieto-occipital sulcus and calcarine fissure → Separates parietal lobe from occipital lobe. ○ Calcarine Fissure → Inferior continuation ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Lateral Aspect Three parallel gyri, separated by the inconsistently present superior and middle temporal sulci. ○ Superior temporal gyri ○ Middle temporal gyri ○ Inferior temporal gyrus Major Structure ○ Anteriorly positioned paracentral lobule Wernicke’s area ○ Located in superior temporal gyrus → continuation of the post central gyrus ○ Responsible for the individual’s ability ○ Posteriorly positioned precuneus to speak and understand the spoken and written word. TEMPORAL LOBE. The temporal lobe, the “thumb of the boxing glove,” Situated inferiorly to the lateral fissure and anterior to the parieto-occipital sulcus. Temporal Pole → The anterior-most aspect of the temporal lobe Superior aspect of the temporal lobe ○ Hidden within the lateral fissure. Primary Auditory Complex It is Separated: ○ Whose surface is marked by the ○ from the frontal and parietal lobes by the obliquely running transverse temporal lateral fissure gyri (of Heschl) ○ from the occipital lobe by an imaginary ○ Heschl's gyrus, is a large lump or plane that passes through the bumps on the lower bank of the parieto-occipital sulcus Sylvian (or lateral) fissure, the most posterior-medial half of which is primary auditory cortex ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Inferior Aspect OCCIPITAL LOBE. Inferior temporal sulcus that is interposed The occipital lobe extends from the between the inferior temporal gyrus and the lateral parieto-occipital sulcus to the occipital pole. occipitotemporal gyrus (fusiform gyrus). The occipital lobe extends from the occipital pole to the parieto-occipital sulcus. Lateral Aspect Superior and inferior occipital gyri ○ Separated from each other by the horizontally ○ Running lateral occipital sulcus Medial Aspect Subdivided into the: separated from each other by the calcarine fissure. The collateral sulcus ○ Superiorly located cuneate gyrus (cuneus) ○ Inferiorly positioned lingual gyrus Striate Cortex (Calcarine Cortex) ○ The cortical tissue on each bank of ○ separates the fusiform gyrus from the this fissure parahippocampal gyrus of the limbic lobe. ○ Forms the primary visual cortex. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Gray matter CEREBRUM ○ Collection of nerve cells bodies along with neuroglia cells. ○ Forms outer, surface layer of cerebral Observed from above, hides the remainder of the hemispheres. brain from view. Cerebrum is the Largest part of ○ Extensive collections of gray matter the Brain are also present in the diencephalons, Cerebrum is a hollow structure, and the cavities namely, within the cerebral hemispheres are called the Epithalamus right and left lateral ventricles. Thalamus ○ Communicate with the third ventricle via Hypothalamus the interventricular foramen (foramen of Subthalamus Monro). White matter ○ Septum Pellucidum → The two lateral ○ Made up of myelinated axons & forms ventricles are separated by two closely bulk of deeper structure of the adjoined non-nervous membranes, each cerebrum Ependymal cells line each lateral ○ Role → To connect various areas of ventricle, and protruding into each cerebrum together i.e. structurally & ventricle is a (choroid plexus) functionally. choroid plexus → manufactures cerebrospinal fluid. Only outer gray matter layer can be called cerebral The midline longitudinal cerebral fissure, cortex occupied in life by the falx cerebri, incompletely separates the cerebral hemispheres. Cerebral Hemisphere Meninges → Enveloped by protective membranes ○ Made of two(2) large oval cerebral Cerebral Cortex hemisphere (Right & Left), ○ Composed of a highly folded collection of superficially resemble the surface of a gray matter. shelled walnut → separated by a deep ○ Deep to the cortex is a central core of white longitudinal fissure (contains corpus matter that forms the bulk of the callosum) cerebrum and represents fiber tracts, ○ Each cerebral hemisphere resembles supported by neuroglia, ferrying the shape of a boxing glove, information destined for the cortex and ○ The cerebral hemispheres are narrower cortical responses to other regions of the posteriorly, at the occipital pole than central nervous system (CNS) anteriorly, at the frontal pole. ○ Within the mass of white matter are ○ Lobes of the cerebral hemispheres. collections of neuron cell bodies Each cerebral hemisphere is Lumped together under the rubric subdivided into five/six lobes: of basal ganglia, even though, Frontal lobes technically, they are nuclei. Parietal lobes ○ This folding increases the surface area Temporal lobes (thumb) and presents elevations, gyri, depressions, Occipital lobes and sulci. Insula (Central Lobes) Corpus Callosum Limbic Lobe ○ A large myelinated fiber tract that forms ○ Among the 2 cerebral hemispheres one an anatomical and functional connection is dominant by its function such as between the right and left hemispheres. language-speech, comprehension. ○ The floor of the cerebral fissure is formed Fissure of Sylvius → It is a lateral fissure that by the corpus callosum separates the Temporal lobe from the parietal lobe. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA AUTONOMIC NERVOUS SYSTEM Island of Reil → The floor of the lateral fissure is formed by the insula The autonomic nervous system is a motor ○ that is hidden by the frontal, parietal, and system temporal opercula (Latin for “lids”), It does not serve skeletal muscle cells. Instead regions of the same named lobes. It innervates: Cortical constituents of the limbic system are also ○ cardiac muscle cells considered to be a region of the cerebral ○ smooth muscle cells hemisphere. ○ secretory cells of glands Although the geographic distributions of many of Preganglionic or presynaptic neuron → The the sulci and gyri are relatively inconsistent, some neuron whose cell body is located in the CNS regularly occupy specific locations, are synapses with a second neuron recognizable in most brains, and are named. (postganglionic or postsynaptic neuron) Sulci → generally smaller and shallower than the ○ Preganglionic neuron's axon is fissures, and one of these. myelinated and known as the Central sulcus (central sulcus of Rolando), → preganglionic fiber. separates the frontal lobe from the parietal lobe. Cell bodies of preganglionic Parieto-occipital Sulcus and Calcarine Fissure sympathetic neurons are → Separates occipital located in the lateral horn of the thoracic and upper lumbar Lateral Aspect spinal cord (T1 to L2,3). The division between the parietal and occipital In contrast, preganglionic lobes is not readily evident when viewed from the parasympathetic neurons are lateral aspect. located in the brain (and their ○ It is defined as the imaginary line between axons travel with CN III, VII, IX, the preoccipital notch and the and X) and the lateral horn of parieto-occipital notch. the sacral spinal cord (S2–S4). ○ Peripheral processes → accompany Medial Aspect the preganglionic autonomic fibers It is delimited on the medial aspect of the cerebral into their respective ganglia but do not hemisphere. synapse. ○ Where the boundary between these two Postganglionic or postsynaptic neuron → structures is the parieto-occipital sulcus situated on a ganglion in the PNS. and its continuation, the calcarine fissure. ○ The axon of the postganglionic neuron synapses with a gland's cardiac muscle cell, smooth muscle cell, or secretory cell. Thus, the autonomic nervous system is said to be a two-cell system, and synapses always occur within an autonomic ganglion. Postganglionic cell bodies of sympathetic neurons are usually located near the spinal cord, within the sympathetic chain ganglia, or a little farther away, in the collateral ganglia. The cell bodies of postganglionic parasympathetic neurons, however, are located in ganglia ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA in the vicinity of the innervated ○ dorsal root ganglia enter the spinal viscera. cord via dorsal rootlets, bringing The cell bodies of the sensory sensory information to the CNS. neurons that supply the viscera Interneurons connect two neurons are located in the dorsal root (e.g., unipolar sensory neurons of the ganglia of spinal nerves or in the dorsal root ganglia to the ventral horn sensory ganglia of cranial nerves, motor neurons). along with the somatic sensory Thus, interneurons can facilitate or inhibit a neurons. motor response to a sensory stimulus. ○ Peripheral fibers → continue to accompany the postganglionic autonomic The white matter of the spinal cord → composed of fibers to the same destinations. ascending and descending tracts of nerve fibers that These sensory neurons are not connect regions of the CNS. considered part of the autonomic Ventral and dorsal rootlets at each spinal cord nervous system despite their level join each other to form the spinal nerves route. that leave the spinal cord at regular intervals, Sensory information relayed by these autonomic indicative of its segmentation. sensory nerves is not registered as part of the Attached to each dorsal root is a dorsal root conscious experience, and even pain sensations ganglion, housing the soma of the unipolar are experienced as “referred pain” in somatic (pseudo-unipolar) neurons regions of the body (e.g., angina pectoris, where pain sensations arising in the heart muscle are GRAY MATTER experienced as pressure in the chest, back, and Unmyelinated fibers forming H or butterfly arm (regions served by the same segmental spinal shape. nerve). Arranged in sheathes (cerebral cortex)/smaller collection of nerve cell bodies (nucleus) ENTERIC NERVOUS SYSTEM ○ Occasionally ganglion (e.g., basal Situated entirely within the wall of the digestive ganglia) tract and controls the entire digestive process. Neurons that leave the CNS The enteric nervous system can function quite well ○ Principal cells → Motoneurons on its own if the sympathetic and (Somatic and Autonomic) parasympathetic components are severed. ○ Interneurons → Relay information from one group) of neurons to another within the CNS SPINAL CORD e.g.. Interneuron of a reflex arc, Cylindrical aggregate of nervous tissue, where Two major categories of neurons; white matter surrounds a central cylinder of gray Are those whose axons leave the CNS matter. and The spinal cord's neurons are arranged so those Interneurons, Whose axons remain concerned with somatic motor function are within the CNS. located in the ventral horn, and their axons leave via the ventral rootlets. WHITE MATTER These are accompanied by axons of the ○ preganglionic sympathetic neurons Myelinated Fibers, many of whose axons are located in the lateral horn of the spinal wrapped in a myelin sheath. cord in the thoracic and upper lumbar Composed of processes of neurons regions and axons of preganglionic Has a white color parasympathetic neurons located in the Funiculi → Large Bundles of axon lateral horn of the sacral spinal cord. Fasciculi → Small nerve bundles of axon ○ The spinal cord's dorsal horn is where Commissures → Axons that cross the midline central processes of unipolar neurons of to connect identical structures on opposing sides, Connect Left and Right Hemisphere. ALAON F. NOTES NEURO-ANATOMY  PSY432 LESSON #: LESSON TITLE FIRST SEMESTER | ACADEMIC YEAR 2024-2025 | PROF. EDILBERTO GONZAGA Axons that travel up or down the CNS and cross SOMATIC NERVOUS SYSTEM the midline from one side to the other hemisphere are said to decussate (intersect) at the point of Sensory neuron (unipolar cell bodies) are crossing over. attached in the dorsal root ganglia NO SYNAPSE Happens in the DORSAL ROOT AFFERENT AND EFFERENT NERVES GANGLIA Unipolar neurons separates into short central and peripheral processes Afferent Nerves ○ Human do not have unipolar neuron, Definition: Afferent nerves, also known as sensory they have pseudo-unipolar) nerves, carry sensory information from the body's Short Central Process: Neuron bifurcates → peripheral regions to the central nervous system joins other processes to form dorsal rootlets (CNS). that enter the spinal cord Function: They transmit signals from sensory Peripheral Process: Goes to a sensory receptors (e.g., in the skin, muscles, and organs) to receptor → when stimulated, depolarizes the the brain and spinal cord. These signals can peripheral process include sensations such as touch, pain, Wave of depolarization spreads to the central temperature, and proprioception (the sense of process → central process transmits the body position). stimulus either to an interneuron (3 neuron Pathway: The information travels from sensory reflex arcs) or motoneuron (in a two neuron receptors through the peripheral nerves to the reflex arcs) spinal cord and then to the brain, where it is ○ Incoming information is transmitted processed and interpreted. to higher levels of the brain Example: Nerves that carry information from the Processed cognitively or eyes (optic nerve) to the brain, or from the skin to subconsciously or both the spinal cord. Motor Neurons are Multipolar Neurons ○ Cell bodies of motor neurons are Efferent Nerves located in the ventral horn of the spinal cord Definition: Different nerves, also known as motor ○ Serve Skeletal muscles Cells only nerves, carry motor commands from the central ○ Motor Neuron axons leave via ventral nervous system to the body's muscles and glands. rootlets that join the dorsal rootlets to Function: They transmit signals that result in form the spinal nerve muscle contraction, gland secretion, and other Each spinal nerve bifurcates (separate) actions that produce movement and responses in forming a Smaller Dorsal Primary Ramus and the body. Larger Ventral Primary Ramus Pathway: The information travels from the brain ○ Dorsal Primary Rami → supply and spinal cord through motor neurons to the sensory and motor innervation target muscles or glands, causing them to (stimulate) respond accordingly. ○ Ventral Primary Rami → supply lateral Example: Nerves that transmit signals from the and anterior portion of the trunk brain to the muscles of the limbs, such as the Thorax and abdomen nerves sciatic nerve, which controls the muscles in the supplied by the Ventral leg.