Lecture 5 PHCL2610 Central Nervous System (CNS) PDF

Lecture 5 PHCL2610 Central Nervous System (CNS) Ana Maria Oyarce Ph.D. Department of Pharmacology – HEB280C Office hours: TBD or by appointment Phone: (419)383-1919 Email: [email protected] 1  T...

Lecture 5 PHCL2610 Central Nervous System (CNS) Ana Maria Oyarce Ph.D. Department of Pharmacology – HEB280C Office hours: TBD or by appointment Phone: (419)383-1919 Email: [email protected] 1  Topics Brain Spinal cord Protection of brain and spinal cord Brain portions and functions Spinal cord structure and function Material Vander’s Human Physiology 16 th Edition. Copyright 2023 Chapter 6. Section D: Structure of the Nervous System 2  The Nervous System The nervous system has two major divisions: The central nervous system (CNS), composed of the brain and spinal cord The peripheral nervous system (PNS), consisting of the nerves that connect the brain or spinal cord with the body’s muscles, glands, sense organs, and other tissues 3  Central Nervous System Composed of the brain and spinal cord CNS Functions Control of voluntary movements  Contraction of muscles Control of involuntary movements  Breathe  Digestion of food Processing of incoming sensory information from organs/tissues senses pain Source of thoughts, emotions and memories 4  Brain & Spinal Cord Protection Bone skull and vertebrae or vertebral column provide a hard, outer protection Meninges three membrane layers surrounding the brain and spinal cord Dura mater (outermost layer), Arachnoid mater (middle layer) and Pia mater (inner) Ventricles connected cavities filled with cerebrospinal fluid, which cushions and bathes the brain and spinal cord  Cerebrospinal fluid (CSF) continually made & reabsorbed back into the blood stream  CSF in subarachnoid space (between arachnoid and pia matter)  CSF protects, cushions, provides nutrients and maintains electrolyte balance for neurons as well as clears waste products and regulates intracranial pressures 5  Major Brain Subdivisions The brain is divided into portions External portions 1. Cerebrum or cortex (4 lobes) 2. Brainstem a. Midbrain b. Pons c. Medulla oblongata 3. Cerebellum Internal portions 4. Diencephalon a. Thalamus b. Hypothalamus 6 7  The Diencephalon  It is composed of the:  Thalamus (major)  Hypothalamus (major)  Pineal gland  Pituitary gland  It is part of the limbic system involved in motivation, emotion, learning, and memory  Know Thalamus and Pineal gland for Exam 1  Hypothalamus and Pituitary will be covered in Exam 2 material 8  The Diencephalon: The Thalamus A central relay station relay motor (movement) and sensory signals (except smell) to parts of the brain (cerebral cortex) for interpretation It also regulates sleep, alertness, and wakefulness Involved in focusing attention Damage can affect many functions and can lead to permanent COMA http://themoloch.tumblr.com/post/573270261/the-diencephalon 9  Diencephalon: The Hypothalamus Located below the thalamus Helps maintain body homeostasis, including…  Heart rate & blood pressure  Body temperature  Thirst, hunger  Digestive movements & secretions  Reproduction  Influences the endocrine system function connection to the pituitary gland  Influences the autonomic nervous system http://themoloch.tumblr.com/post/573270261/the-diencephalon 10 Diencephalon: The Pituitary and Pineal Glands Pituitary Gland  A protrusion off the bottom of the hypothalamus at the base of the brain  Called the “master gland” of the endocrine system controls release of hormones that maintain body homeostasis Pineal Gland  A cone-shaped bump sticking out of the roof of the diencephalon  Produces melatonin a molecule that modulates wake/sleep patterns regulates internal clock 11  The Brain Stem Connects the brain to the spinal cord Composed of 3 major parts 1. Midbrain Acts in visual & auditory reflex actions 2. Pons It contains part of the respiratory center (quantity of inhaled air with each breath) 3. Medulla Oblongata contains the cardiac center (heart rate), vasomotor center (blood pressure) and respiratory center http://www.training.seer.cancer.gov  Site of many cranial nerves (PNS) → nerves are bundles of axons (or nerve fibers) 12 Somatic-Sensory Division: Cranial Nerves Nerves exiting the cranium Do not memorize the nerves 13 CNS: Spinal Cord  Is a long, thin, tubular bundle of nervous tissue that runs from the brain to the lower back via the spinal canal Functions  It conducts sensory information from the periphery (effectors) to the brain  It conducts motor information from the brain to the periphery or effectors (skeletal, cardiac & smooth muscles, & glands)  Coordinates many reflex actions independently of the brain 14  Spinal Cord  Spinal cord is divided into five different parts  31 spinal nerves branch off from the left and right sides of the spinal cord  Nerves from the different parts innervate (synapse) different tissues and/or organs 15  Peripheral Nervous System Cranial nerves and spinal nerves deliver commands from your brain and spinal cord to and from parts of your body The innervation of different organs and tissues by cranial and spinal nerves is known as the peripheral nervous system (PNS) 16 17