Psyc 301 Brain Dysfunction & Recovery Lecture Notes (PDF)

Psyc 301 Structural Brain Dysfunction & Recovery Neuroanatomy Jill Dosso, PhD Jan 2025 Speaking...

Psyc 301 Structural Brain Dysfunction & Recovery Neuroanatomy Jill Dosso, PhD Jan 2025 Speaking to you from the traditional, ancestral, and unceded territory of the xwməθkwəy̓əm (Musqueam) People.  2 Neuroanatomy: Three parts 1. Layout and directions 1. General layout of the nervous system 2. Directions in the nervous system 2. Divisions of the brain 3. Cells and neurotransmitters  3 Optional resources on Canvas 1. Neuroanatomy refresher mini-course (~45 min). There are even more links and resources at the end 2. Colouring!  4 Learning Objectives 1. Know the major divisions of the nervous system. 2. Know and apply neuroanatomical directional terms. 3. Draw and label a cross section of the spinal cord. 5  6 Peripheral NS Somatic NS The vertebrate nervous system is divided into two components Autonomic NS Nervous System Sympathetic NS 1. The peripheral nervous system (PNS) Brain 2. The central nervous system Parasympathetic NS Central NS (CNS) Spinal cord  7 Peripheral NS Somatic NS Autonomic NS Nervous System Sympathetic NS Brain The PNS is further dividedParasympathetic into: NS Central NS 1. The somatic nervous system (SNS) Spinal cord 2. The autonomic nervous system (ANS)  8 Peripheral NS Somatic NS Autonomic NS Afferent = arrive Nervous System Efferent = NS Sympathetic exit The SNS interacts with the external environment Brain Parasympathetic NS Central NS It has afferent nerves that carry sensory signals in from the skin, skeletal muscles, joints, eyes, ears, etc into the CNS Spinal It also has cordnerves that carry motor efferent signals from the CNS out to the skeletal muscles  9 Peripheral NS Somatic NS Autonomic NS Nervous System Sympathetic NS The ANS participates in the regulation of the Brain internal environment Parasympathetic NS Central NS It has afferent nerves that carry sensory signals from the internal organs to the CNS Spinal cord It has efferent nerves that carry motor signals from the CNS to internal organs  10 Peripheral NS Somatic NS Autonomic NS Nervous System The efferent nerves of the Sympathetic NS ANS are of two types: 1. Sympathetic nerves Brainenergy in which mobilize threatening situations Parasympathetic NS Central NS (e.g., via adrenal glands) 2. Parasympathetic nerves act to conserve energy or Spinal “rest and cord digest” (e.g., stimulate gut motility)  11 Peripheral NS Somatic NS Autonomic NS Nervous System Sympathetic The CNS is composed of two parts as well: NS Brain Parasympathetic NS Central NS Spinal cord The spinal cord 12 inner H-shaped core of gray matter: cell bodies and unmyelinated axons surrounding area of white matter: myelinated axons Some terminology 17 In the CNS: A cluster of cell bodies is called a nucleus (plural: nuclei) A bundle of axons is called a tract In the PNS: A cluster of cell bodies is called a ganglion (plural: ganglia) A bundle of axons is called a nerve, and axons are often called nerve fibres  18 Gray = cell bodies + capillary blood vessels White = myelinated axons https://operativeneurosurgery.com/doku.php?id=white_matter  19 19 To specify any location in the brain requires x, y, z https://library.med.utah.edu/WebPath/HISTHTML/NEURANAT/CNS272A.html  Directions in the nervous system 20 Towards the top Towards the nose Towards the tail Towards the bottom Towards the front Towards the back Anterior Posterior  22 Anterior Posterior  23 Note But textbook says… Anterior Posterior 24 Section planes 25  26 Think: horizon  27 corona: Latin “crown” http://www.nbcnews.com/news/nbcblk/beyonce-s-grammy-performance-proves-she-doesn-t-need-awards-n720056 28 Laterality 31 Unilateral: Ipsilateral: On 1 side On the same side Contralateral: Bilateral: On opposite sides On both sides  Part 2 Divisions of the brain  34 Topics 1. Divisions of the brain 2. Cortical lobes 3. Ventricles and CSF  35 Learning Objectives 1. List and discuss the 5 divisions of the human brain. 2. Know all major brain structures within each of 5 divisions. 3. Describe the location and function of the corpus callosum. 4. Know the major fissures. 5. Know the major components of the limbic system and basal ganglia. 6. Know the lobes of the cerebral cortex. 7. Understand the important roles of CSF. Divisions of the brain 36 midbrain hindbrain forebrain 18-21 day old human embryo: 3 divisions  37 Before birth, these 3 swellings become 5 structures Greek cephalo = head forebrain … midbrain Mesencephalon “the brainstem” hindbrain Myelencephalon, aka medulla 38 Composed largely of tracts carrying signals between the rest of the brain and the body Metencephalon 39 Pons: houses many fibre tracts and part of reticular formation Cerebellum: 50% of all neurons in the brain! Massively connected to cortex -- multiple cerebro- cerebellar systems Involved in movement and timing  40 Before birth, these 3 swellings become 5 structures Greek cephalo = head forebrain … midbrain Mesencephalon “the brainstem” hindbrain Mesencephalon 41 Composed of: the tectum (“roof”), which contains nuclei that receive and relay: visual information (superior colliculi) auditory information (inferior colliculi) the tegmentum (“floor”), which contains nuclei related to: motor function (substantia nigra and red nucleus) pain (periaqueductal grey) Reticular formation 42 Reticulum means “little net” In the myel-, met- and mesencephalon (midbrain + hindbrain) Many nuclei that play roles in arousal, attention, cardiac and respiratory reflexes, and other jobs  Disorders of mid- and hindbrain 43 Dejerine syndrome (bilateral medial medullary stroke) Respiratory failure Paralysis of all four limbs Tongue dysfunction https://www.youtube.com/watch?v=R3LyZRfy6_A  Disorders of mid- and hind-brain 44 Chiari malformation Compression and distortion of cerebellum due to skull shape Symptoms Headache Neck pain Coordination issues Swallowing issues https://www.youtube.com/shorts/I7ojgJ1928I https://www.americanbrainfoundation.org/diseases/chiari-malformation/  Disorders of mid- and hindbrain 45 Pontine Tegmental Cap Dysplasia A rare genetic disorder of pons and cerebellum formation due to a developmental error in axon growth and guidance Systems affected: Hearing, gaze, swallowing, facial movements, abnormal gaze, swallowing, facial movements Barth et al., 2007 https://www.youtube.com/watch?v=-KOSvw_iJfM&lc=z133gldw4wrct3r0323xwtjg5vnqftnff Diencephalon 46 Composed of: the thalamus the hypothalamus  Thalamus 47 2-lobed structure Many different types of nuclei – some process and relay info between receptors and cortex Nuclei may be specific to one sense or non-specific and involved in multimodal integration  Thalamo-cortical loops and consciousness 48 General anesthetics tend to act upon the nonspecific nuclei of the thalamus (as well as other structures) Abnormal synchronization in the thalamo-cortical network can cause absence (“ab-sonce”) seizures  Hypothalamus 49 Plays an important role in behaviours such as feeding, sex, sleeping, temperature, emotion, and movement Acts upon the body’s endocrine (hormone) system via the pituitary gland Telencephalon 50 The largest division of the brain Basal ganglia Limbic system Cerebral cortex  Basal ganglia 51 “Lower knots” Collection of nuclei highly connected to cortex, thalamus, and midbrain Involved in movement and learning  Limbic system 52 Includes (among other structures): Hippocampus (“seahorse”) – plays a role in spatial memory Amygdala (“almond”) – plays a role in emotion Cortex (“bark”) 55  56 Sulci deep enough to indent the ventricles are also called fissures  57 90% of human cerebral cortex is isocortex (sometimes called neocortex) = 6-layered 10% is allocortex =