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Download Central Nervous System - York Catholic District School Board
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THE CENTRAL NERVOUS SYSTEM (CNS): Brain and Spinal Cord BRAIN Fun Facts The brain weighs approximately 3 pounds (1.4 kg) The brain can send out a message traveling at 289 km/s It has about 100 billion neurons Scientists believe there are more neurons in the human brain than there are stars in the Milky Way! 1. BRAINSTEM 1. MIDBRAIN: involved with visual reflexes 2. PONS: controls certain respiratory functions 3. MEDULLA OBLONGATA: regulates heart and lung functions, swallowing, vomiting, coughing, and sneezing 2. CEREBELLUM -coordinates muscle and skeleton movement to maintain posture, balance, and muscle tone 3. CEREBRUM the largest part of the brain 2 hemispheres: RIGHT and LEFT. has an outer portion called the “cerebral cortex” (area of conscious decision making) Lateralization The fact that certain activities are the almost exclusive domain of one of the 2 hemispheres. The left hemisphere is geared towards language, math, and logic The right hemisphere is geared towards musical, artistic and other creative endeavors. Most individuals with left cerebral dominance are right-handed. (Left-handed people have more right cerebral dominance) Right or left-brained? The Stroop test Right brain – identifies the colour itself Left brain – reads the colour word For most people, this is a challenging task, because there is a R-brain/Lbrain conflict! Which side to you tend to use for this test? 3. CEREBRUM Each hemisphere is divided into four lobes Frontal lobe: controls voluntary motor movements, emotional expression, and moral behavior Temporal lobe: controls memory, equilibrium, emotion, and hearing Parietal lobe: controls and interprets the senses and taste Occipital lobe: controls vision and various forms of expression Lobes of the cerebrum What is the name of this region? What is this called? The Story of Phinaeus Gage Scientists learned a lot about the functions of the frontal lobe due to the bizarre accident that left a young railroad worker by the name of Phinaeus Gage with a severely damaged frontal lobe. 4. DIENCEPHALON deep part of the brain contains the thalamus and the hypothalamus thalamus: receives, sorts and sends messages from the sense organs (eg. eyes, ears) to cerebral cortex hypothalamus: controls heart rate, blood pressure, temp. regulation, water and electrolyte balance, digestive functions, and glandular activities Cerebrospinal Fluid (CSF) watery fluid that contains various compounds flows throughout the brain and around the spinal cord cradles and cushions the brain also contained in VENTRICLES (cavities) in the brain Meninges Meninges: (from brain to cranium) – pia mater, arachnoid layer, dura mater (PAD) Meningitis - an inflammation of the meninges -caused by viruses or bacteria -symptoms: fever, headache, and stiff neck -can be fatal Meninges dura mater covers entire length of the spinal cord contains channels for blood to enter brain tissue space between dura mater and the bones of the spinal cord is called the “epidural space” arachnoid membrane weblike structure that runs across the space containing the cerebrospinal fluid pia mater thin membrane containing many blood vessels that nourish the spinal cord Brain injury Why do we wear helmets? A severe concussion can lead to coma Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. PET scan (Positron Emission Tomography) -The brain is injected with radioactive glucose -The more active the parts of the brain are, the more glucose is taken up, and the more “blue” the brain areas are -This technique is also used to analyze Alzheimer’s and stroke patients. brain activity Before cocaine use, brain is less active. After cocaine use, brain is more active. © Science VU/Visuals Unlimited Spinal Cord extends from the base of the brain to the first lumbar vertebra in the lower back contained within the vertebral column Vertebral canal – space that contains the spinal column protected by the vertebral column, the CSF, and by the spinal meninges Spina bifida defect in the spinal column in which the spinal cord protrudes outside the vertebrae Mild cases are visible only by X-ray Causes varying degrees of paralysis, lack of feeling and movement Spinal Cord Injuries if spinal cord is severed, paralysis will occur and affect the area below the injury Paralysis – loss of movement and sensation Three common types: Hemiplegia – paralysis on one side of the body, usually due to a stroke Paraplegia – paralysis from the waist down, often caused by a car/motorcycle accident, fall, gunshot or stab wound, or sports injury Quadriplegia – paralysis from the neck down (injury is below the C4 vertebra)
