Functional Neuroanatomy Lecture Notes PDF

Functional Neuroanatomy (BMS 345) Lecture 1: Neuroanatomy Overview Stone-Roy Outline 1. Overview of course 2. Nervous System definitions 3. Parts of a neuron 4. Nuclei/tracts/pathways 5. Parts of the Central Nervous System 1. Spinal cord 2. Brainstem 3. Cerebellum...

Functional Neuroanatomy (BMS 345) Lecture 1: Neuroanatomy Overview Stone-Roy Outline 1. Overview of course 2. Nervous System definitions 3. Parts of a neuron 4. Nuclei/tracts/pathways 5. Parts of the Central Nervous System 1. Spinal cord 2. Brainstem 3. Cerebellum 4. Diencephalon 5. Cerebral hemispheres 6. Directional Terms 7. General functions of cranial nerves Reading: Nolte Chapters 1 & 3: pages 1-10, 25, 28, 31-33, 56-71 This material should be a review (from BS300). Notes *** Notes in this course are put together by your lecturers to help provide a more complete overview of what was covered in class, but they do not cover everything, and should not be used as an alternative to taking your own notes during lecture *** Definitions: Central Nervous System (CNS) = brain + spinal cord (Fig 1-1 from Nolte) Peripheral Nervous System (PNS) = nerves + ganglia Neuron = nerve cell Groups of cell bodies => cortex, nuclei, spinal cord columns & ganglia CNS PNS Parts of neuron (Fig 1-3 from Nolte) Soma & dendrites-------------------axon--------------------------------nerve terminal input output circle line fork or Y Grey Matter White Matter Grey Matter Nucleus/Cx Tract Nucleus/Cx (Ganglion-PNS) (Nerve-PNS) Extremely important point!! Within the CNS we will be talking about nuclei and tracts. You must understand what is found in each of these regions. Nuclei contain cell bodies, dendrites, and nerve terminals - - The communication center = where neurons within the CNS talk to each other. Tracts contain axons. That's it (except for glial cells). No neuronal cell bodies, no dendrites, no nerve terminals, No communication (in reality, it’s more complicated, but we’ll assume no communication for this class) Analogy: You can think of the Nuclei as Cities - lots of communication between inhabitants and the Tracts as Freeways - just a pathway from A to B. No communication. Note: a group of cell bodies in the PNS = a ganglion (rather than a nucleus), different name (you'll run across that a lot in neuroanatomy) but all the same principles apply. within a given tract - all the axons serve a similar function e.g., the optic tract contains axons of neurons found in the retina and this tract carries visual information to more central regions. Similarly, within one nucleus, all the neurons found there serve a similar function. e.g., lateral geniculate nucleus of the thalamus - group of neuronal cell bodies involved with vision Pathway = group of nuclei and tracts carrying similar information = functional system e.g., neurons in the eye send axons thru optic nerve & optic tract, synapse in the lateral geniculate nucleus, these LGN neurons send their axons thru particular tracts to a specific region of the cerebral cortex. All of these nuclei & tracts collectively make up a pathway or functional system involved in vision. Directional terms: Superior = toward the top of the skull Inferior = toward the bottom of the spinal cord Medial = near the midline Lateral = away from the midline Parts of the CNS (Fig 1-2 from Nolte) Starting at the inferior (caudal) end -> spinal cord, medulla, pons, midbrain, diencephalon, cerebral hemispheres Brainstem Forebrain and cerebellum - located posterior to the pons and medulla, but not part of the brainstem. Spinal Cord: spinal nerves - bring info into and out of the CNS contains ascending tracts -- groups of axons bringing info to brain " descending " -- " " " info from brain " nuclei -- groups of cell bodies processing information Medulla: continuous with the spinal cord part of the brain stem cranial nerves IX, X, XI & XII enter &/or exit at the level of the medulla & it contains associated nuclei - respiration & cardiac centers contains ascending tracts -- groups of axons bringing info to brain " descending " -- " " " info from brain " specific nuclei -- groups of cell bodies processing information Pons: continuous with medulla also part of the brainstem CN VI, VII, VIII enter &/or exit at the medulla/pons junction. CN V is huge and located right in the middle of the pons major relay to cerebellum contains ascending tracts -- groups of axons bringing info to brain " descending " -- " " " info from brain " specific nuclei -- groups of cell bodies processing information Midbrain: continuous with the pons it is also part of the brainstem (Brainstem = medulla, pons & midbrain) CN III & IV exit at the level of the midbrain - visual reflexes contains ascending tracts -- groups of axons bringing info to brain " descending " -- " " " info from brain " specific nuclei -- groups of cell bodies processing information Cerebellum: located basically in the roof of the pons it is not part of the brainstem involved with motor functions Diencephalon: = subthalamus, hypothalamus, thalamus, epithalamus Most common terminology Hypothalamus = important for homeostasis. Keeping body and brain within specific parameters necessary for health and life. Examples: temperature, feeding drive, etc. Thalamus = antechamber to the cerebral cortex. All sensory info (except olfaction) goes thru the thalamus first Cerebral Hemispheres: Cerebral cortex, subcortical white matter, basal nuclei Cerebral cortex = layers of neuronal cell bodies about 5 mm thick huge sheet - too big to fit in skull as a smooth layer, so convoluted into bumps and creases. bumps = gyri creases = sulci. Each of these bumps and creases are named -You'll be learning the names of some of gyri and sulci involved in particular functional systems in lab. - Perception, voluntary movement, "higher functions" Subcortical white matter = masses of tracts bringing information to and from each region of cerebral cortex Basal nuclei (also referred to as basal ganglia). these are groups of cell bodies involved in motor functions that are located deep to the cerebral cortex within the cerebral hemispheres More directional terms: (Fig 3-1 from Nolte & figure from lab) Review the directional terms covered in lab. Also, Fig. 3-1 in your text is very good. Posterior/Anterior/Superior/Inferior - these do not change depending on location in CNS and are the preferred terms. Other terms are still used though & are defined below. dorsal vs ventral For your body: dorsal = your back ventral = your front For spinal cord & brainstem = same as body dorsal = posterior ventral = anterior rostral = toward the brain caudal = toward the feet For forebrain (diencephalon & cerebral hemispheres) - different dorsal = superior = top of your head ventral = inferior = underneath surface rostral = anterior = toward the front caudal = posterior = toward the back reason: rostrocaudal axis is bent at the brainstem/diencephalon junction General functions of cranial nerves I. Olfactory - smell II. Optic - vision III. Oculomotor - Eye movement & pupil response IV. Trochlear - Eye movement V. Trigeminal – Somatosensation of head, chewing  VI. Abducens – Eye movement VII. Facial – sensory and motor incl. taste, innervation of muscles of facial expression, salivary glands VIII. Vestibulocochlear – sensory. Head position and movement, hearing, IX. Glossopharyngeal - Visceral sensory, taste, X. Vagus – visceral innervation, parasympathetic, taste XI. Accessory – neck and shoulder muscles XII. Hypoglossal – tongue muscles