C9 Combined PDF

26/04/2022 How does it all work? Part 1: The spinal cord and spinal nerves Dr Flavia Di Pietro Acknowledgement: Dr Ajanthy Shan [email protected] WARNING This material has been reproduced and communicated to you by or on behalf of Curtin University in accordance with section 113P of the Copyrig...

26/04/2022 How does it all work? Part 1: The spinal cord and spinal nerves Dr Flavia Di Pietro Acknowledgement: Dr Ajanthy Shan [email protected] WARNING This material has been reproduced and communicated to you by or on behalf of Curtin University in accordance with section 113P of the Copyright Act 1968 (the Act) The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice. Please note that these unit materials contain images/videos of cadaveric material obtained under the Anatomy Licence held by the Anatomy Facility at Curtin University and are bound by the regulations of the Anatomy Act of Western Australia (1930). These images/videos are for study purposes only and must not be shared or distributed outside of this Blackboard site as this constitutes a breach of the Anatomy Act. A breach of the Anatomy Act is considered to be student misconduct and is dealt with in accordance with Statute No.10 Student Discipline. 1 26/04/2022 Specific Learning Objectives 1. Describe the peripheral nervous system (PNS) with reference to the somatic nervous system and motor division of the autonomic nervous system. 2. Describe the anatomy of the PNS including peripheral ganglia, spinal and cranial nerves and associated central nervous system (CNS) structures. 3. Identify the main regions of the brain. 4. Describe the functions of the brain. 5. State main organs and functions of the endocrine system. 6. Define a hormone. 7. Understand the difference between neural and hormonal control of homeostasis 2 26/04/2022 Textbook readings The spinal cord  Extends from the foramen magnum to the first or second lumbar vertebrae  Divided into regions:   Cervical  Thoracic  Lumbar  Sacral  Coccygeal 31 pairs of spinal nerves 3 26/04/2022 The spinal cord Conus medullaris Meninges  Connective tissue surrounding the brain and spinal cord  Functions:  Protection  Contains cerebrospinal fluid  Forms partitions inside the skull 4 26/04/2022 Meninges  Dura mater:   Arachnoid mater:   Subdural space Subarachnoid space – CSF and blood vessels Pia mater:  Many small blood vessels Spinal cord 5 26/04/2022 PNS Brain Spinal cord Cortex of brain and nuclei Ganglion Outer cortex (and deep nuclei) Inner Nerve tracts Nerves Deeper Outer CNS Grey matter (cell body, dendrites, unmyelinated axons, axon terminals and neuroglia) White matter (myelinated axons) Organisation in the spinal cord  Sensory – travels through the dorsal roots  Motor – travels through the ventral roots  Spinal nerves are mixed  Both sensory neurons & motor neurons 6 26/04/2022 Organisation in the spinal cord  Motor neuron cell bodies are in the horns of the grey matter  Somatic – ventral horn  Autonomic – lateral horn Nerve coverings  Connective tissue – 3 layers  Endoneurium – surrounds each axon (Schwann cells here too)  Perineurium – surrounds a fascicle (a group of axons)  Epineurium – surrounds several fascicles, i.e. nerve  i.e. a nerve is a bundle of axons, and the sheaths, in the PNS 7 26/04/2022 Organisation of spinal nerves Spinal nerves Vertebral bones Cervical 8 pairs 7 bones Thoracic 12 pairs 12 bones Lumbar 5 pairs 5 bones Sacral 5 pairs 5 bones Coccygeal 1 pair 5 fused = 1 bone Vertebra Spinal nerve Compendium questions 1. What are the major parts of the brain? 2. What are the main lobes, sulci and gyri of the cerebrum? 3. What connects the two cerebral hemispheres? 4. What advantage do convolutions give the cerebrum? 5. How do white matter and grey matter differ? 6. What are the roles of the thalamus and hypothalamus? 7. What are the roles of the brainstem? 8. What and where are the functional areas of the cerebrum? 9. What information does the cerebellum receive and how does it use this information? 10. Where does the spinal cord begin and end in adults? 8 26/04/2022 Compendium questions 11. Where do sensory and motor nerve roots enter and leave the spinal cord? 12. What are the divisions of the ANS and where do they emerge from the CNS? 13. Distinguish between somatic motor and autonomic motor neuron pathways 14. What are ganglia? 15. What effect does each part of the ANS have on the body? 16. What are the main endocrine organs? 17. What is negative feedback? 18. How does a neural stimulus differ from a hormonal one? 19. How does the nervous system influence the endocrine and vice versa? 9 29/04/2022 How does it all work? Part 2: The brain and cranial nerves Dr Flavia Di Pietro Acknowledgement: Dr Ajanthy Shan [email protected] WARNING This material has been reproduced and communicated to you by or on behalf of Curtin University in accordance with section 113P of the Copyright Act 1968 (the Act) The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice. Please note that these unit materials contain images/videos of cadaveric material obtained under the Anatomy Licence held by the Anatomy Facility at Curtin University and are bound by the regulations of the Anatomy Act of Western Australia (1930). These images/videos are for study purposes only and must not be shared or distributed outside of this Blackboard site as this constitutes a breach of the Anatomy Act. A breach of the Anatomy Act is considered to be student misconduct and is dealt with in accordance with Statute No.10 Student Discipline. 1 29/04/2022 Specific Learning Objectives 1. Describe the peripheral nervous system (PNS) with reference to the somatic nervous system and motor division of the autonomic nervous system. 2. Describe the anatomy of the PNS including peripheral ganglia, spinal and cranial nerves and associated central nervous system (CNS) structures. 3. Identify the main regions of the brain. 4. Describe the functions of the brain. Textbook readings 2 29/04/2022 The brain Three brain regions in the early embryo.  Forebrain  Midbrain  Hindbrain The brain  Cerebrum Diencephalon Forebrain  Cerebrum  Diencephalon  Midbrain  Hindbrain  Pons  Medulla oblongata  Cerebellum Brainstem Midbrain Brainstem Pons Medulla oblongata Cerebellum 6 3 29/04/2022  The brain Forebrain  Cerebrum  Diencephalon  Midbrain  Hindbrain  Pons  Medulla oblongata  Cerebellum Brain stem 7 The brainstem Brainstem 4 29/04/2022 Medulla Oblongata Medulla oblongata  The centre for autonomic reflexes – maintaining body homeostasis  Cardiovascular centre – regulates HR, force of heart contraction, diameter of vessels  Respiratory centre – regulate rate/depth of breathing  Other reflexes like hiccups, swallowing, vomiting, coughing and sneezing Forebrain Cerebrum Diencephalon Midbrain Hindbrain Pons Medulla oblongata Cerebellum Pons  Definition – bridge  Tracts here  Longitudinal tracts connecting spinal cord to brain  Transverse tracts cerebrum to cerebellum  Sleep centre  Respiratory centre Pons Forebrain Cerebrum Diencephalon Midbrain Hindbrain Pons Medulla oblongata Cerebellum 5 29/04/2022 Midbrain Midbrain  Receives and integrates visual, auditory and tactile sensory input  Then (initiates) orients movements of the head, eyes in response  Controls movements of the eye Forebrain Cerebrum Diencephalon Midbrain Hindbrain Pons Medulla oblongata Cerebellum Cerebellum  Helps control locomotion  Fine motor control  Posture and balance control Cerebellum Forebrain Cerebrum Diencephalon Midbrain Hindbrain Pons Medulla oblongata Cerebellum 6 29/04/2022 Diencephalon  Thalamus  Subthalamus  Epithalamus  Hypothalamus Diencephalon Forebrain Cerebrum Diencephalon Midbrain Hindbrain Pons Medulla oblongata Cerebellum Diencephalon – a focus on the thalamus  Paired structure  Cluster of nuclei  Sensory relay centre  Also influences moods and actions associated with strong emotions – fear and rage. 7 29/04/2022 Diencephalon – a focus on the hypothalamus  Most inferior part of diencephalon  Cluster of nuclei  Central controller of the endocrine system   Infundibulum (stalk) connects to pituitary gland Autonomic, endocrine, muscle control, body temp regulation, food and water intake, emotions, sleep-wake cycle, sexual development & behaviour Cerebrum-Temporal Lobe Cerebrum Cerebrum Cerebrum - Insula Lobe Gyri – elevated tissue or folds Sulci – grooves Fissures – deep grooves 8 29/04/2022 Cerebrum  The pre-central gyrus – primary somatic motor cortex  The post-central gyrus – primary somatic sensory cortex (‘somatosensory’)  Frontal lobe: motor function, motivation, planning, regulation of mood, sense of smell  Parietal lobe: receives and evaluates sensory info, not special senses Cerebrum-Temporal Lobe Cerebrum  Occipital lobe: receives and integrates visual input  Temporal lobe: receives and evaluates input for smell and hearing. Role in memory  Insula (insular lobe/insular cortex): receives and evaluates taste information Cerebrum - Insula Lobe 9 29/04/2022 Cerebrum Grey matter (cell body, dendrites, unmyelinated axons, axon terminals and neuroglia) White matter (myelinated axons) CNS PNS Brain Spinal cord Cortex of brain and nuclei Ganglion Outer cortex (and deep nuclei) Inner Nerve tracts Nerves Deeper Outer Limbic system  The ‘emotional brain’  Memory  Motivation, emotion, learning  (and influences autonomic and endocrine systems) 10 29/04/2022 Meninges FYI – meningitis Ventricles  4 continuous ventricles  Lined with ependymal cells  Lateral (x 2)  Third  Fourth  CSF produced in ventricles. Circulates 11 29/04/2022 Cerebrospinal fluid  Fluid found around the brain and spinal cord  Most CSF is produced by the choroid plexus  Protects brain and spinal cord; cushion; bathes  Allows brain to float within cranial cavity  Similar to blood serum, without most of proteins Cranial nerves 12 29/04/2022 Compendium questions 1. What are the major parts of the brain? 2. What are the main lobes, sulci and gyri of the cerebrum? 3. What connects the two cerebral hemispheres? 4. What advantage do convolutions give the cerebrum? 5. How do white matter and grey matter differ? 6. What are the roles of the thalamus and hypothalamus? 7. What are the roles of the brainstem? 8. What and where are the functional areas of the cerebrum? 9. What information does the cerebellum receive and how does it use this information? 10. Where does the spinal cord begin and end in adults? Compendium questions 11. Where do sensory and motor nerve roots enter and leave the spinal cord? 12. What are the divisions of the ANS and where do they emerge from the CNS? 13. Distinguish between somatic motor and autonomic motor neuron pathways 14. What are ganglia? 15. What effect does each part of the ANS have on the body? 13 29/04/2022 How does it all work? Part 3: The autonomic nervous system Dr Flavia Di Pietro Acknowledgement: Dr Ajanthy Shan [email protected] WARNING This material has been reproduced and communicated to you by or on behalf of Curtin University in accordance with section 113P of the Copyright Act 1968 (the Act) The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice. Please note that these unit materials contain images/videos of cadaveric material obtained under the Anatomy Licence held by the Anatomy Facility at Curtin University and are bound by the regulations of the Anatomy Act of Western Australia (1930). These images/videos are for study purposes only and must not be shared or distributed outside of this Blackboard site as this constitutes a breach of the Anatomy Act. A breach of the Anatomy Act is considered to be student misconduct and is dealt with in accordance with Statute No.10 Student Discipline. 1 29/04/2022 Specific Learning Objectives 1. Describe the peripheral nervous system (PNS) with reference to the somatic nervous system and motor division of the autonomic nervous system. 2. Describe the anatomy of the PNS including peripheral ganglia, spinal and cranial nerves and associated central nervous system (CNS) structures. 3. Identify the main regions of the brain. 4. Describe the functions of the brain. Textbook readings 2 29/04/2022 Functional divisions of the nervous system Nervous system Peripheral nervous system Autonomic nervous system Motor (efferent) Sensory (afferent) Sympathetic (“fight or flight”) Parasympathetic (“rest and digest”) Central nervous system Somatic nervous system Motor (efferent) Sensory (afferent) Enteric nervous system Motor (efferent) Sensory (afferent) 5 Comparison of autonomic vs somatic nervous systems 6 3 29/04/2022 A comparison of neuron arrangement Somatic nervous system Autonomic nervous system 7 Functional divisions of the nervous system Nervous system Peripheral nervous system Autonomic nervous system Motor (efferent) Sensory (afferent) Sympathetic (“fight or flight”) Parasympathetic (“rest and digest”) Central nervous system Somatic nervous system Motor (efferent) Sensory (afferent) Enteric nervous system Motor (efferent) Sensory (afferent) 8 4 29/04/2022 Anatomy of the functional divisions of the ANS Sympathetic and parasympathetic nervous systems   Sympathetic division  ‘thoracolumbar division’  T1 – L2 Parasympathetic division  ‘craniosacral division’  4 cranial nerve nuclei & S2 –S4 5 29/04/2022 Sympathetic versus parasympathetic divisions  Dual ANS innervation of structures/organs (i.e. both sympathetic and parasympathetic neurons innervating them)  Two divisions maintain homeostasis by adjusting body functions  i.e. ANS can adjust activity in both directions due to dual innervation  Not all organs have dual innervation.  Some organs – one division may be predominant  Sympathetic greater influence in conditions of physical activity or stress; parasympathetic greater influence in resting conditions Sympathetic versus parasympathetic divisions   Sympathetic division  Fight or flight  Fright or flight  ‘E’ = exercise, emergency, excitement, embarrassment Parasympathetic division  Rest and digest  ‘D’ = digestion, defecation, diuresis 6 29/04/2022 Heart rate and force of contraction Sympathetic division Parasympathetic division Increased Decreased Airways Dilation Constriction Blood vessels Mainly constriction BUT vasodilation to skeletal muscles No effect Digestive tract Decreased motility & secretion, sphincters constrict Increased motility & secretion, sphincters relax Liver Increased glucose release to blood No effect Gallbladder Relaxation Contraction Glands (salivary, gastric, lacrimal, pancreatic) Decreased secretion Increased secretion Sweat glands Increased secretion No effect Pupil of the eye Dilation Constriction Cellular metabolism Increased metabolic rate No effect Regulation of the autonomic nervous system 7 29/04/2022 Compendium 9 questions 1. What are the major parts of the brain? 2. What are the main lobes, sulci and gyri of the cerebrum? 3. What connects the two cerebral hemispheres? 4. What advantage do convolutions give the cerebrum? 5. How do white matter and grey matter differ? 6. What are the roles of the thalamus and hypothalamus? 7. What are the roles of the brainstem? 8. What and where are the functional areas of the cerebrum? 9. What information does the cerebellum receive and how does it use this information? 10. Where does the spinal cord begin and end in adults? Compendium 9 questions 11. Where do sensory and motor nerve roots enter and leave the spinal cord? 12. What are the divisions of the ANS and where do they emerge from the CNS? 13. Distinguish between somatic motor and autonomic motor neuron pathways. 14. What are ganglia? 15. What effect does each part of the ANS have on the body? 8