2 INTERESTING NERVOUS SYSTEM FACTS Nerve impulses to and from the brain travel as fast as 170 miles per hour.Ever wonder how you can react so fast to things around you or why that stubbed toe hurts right away? It’s due to the super-speedy movement of nerve impulses from your brain to the rest of your body and vice versa, bringing reactions at the speed of a high powered luxury sports car.The brain operates on the same amount of power as 10-watt light bulbYour brain generates as much energy as a small light bulb even when you’re sleeping.
3 NOTES – THE CENTRAL NERVOUS SYSTEM (CNS) 2 parts1. brain2. spinal cord
4 Parts of the BrainBRAINSTEM (4 parts)1. Medulla OblongataFunction: regulation of heart rate, breathing, swallowing, vomit response, coughing, sneezingall involuntary actions
5 2. Ponsfunctions as a bridge between the cerebrum and cerebellum
6 3. Midbrainfunctions in hearing and visual reflexes4. Reticular Activating System (RAS)located scattered in the brainstemfunctions in arousing & maintaining consciousnessdamage here results in a coma
7 Cerebellumprocesses inputs of cerebral cortex and sensory receptorsresults in smooth, coordinated movements of skeletal musclesinjury results in loss of muscle tone and coordination
8 Diencephalon (interbrain) Thalamusfunctions to sort out all the sensory impulses from the bodyHypothalamusEXTREMELY IMPORTANT in maintaining homeostasis
9 What the hypothalamus controls Autonomic Control Centerblood pressure, heart rate, digestive tract, eye pupil (involuntary responses)Emotional Responsespain perception, pleasure, fear, etc. (limbic system)body temperature, hunger, thirst, sleependocrine system hormonesHypothalamus Disturbancesbody wasting, or obesity, sleep problems, dehydration, emotional imbalances, and more
10 The Cerebrumgray matter on the surface of the cerebrumCerebral Cortexenables us to perceive, communicate, remember, understand, appreciate and move voluntarily (consciousness)
11 3 functional areas of the Cerebral Cortex 1. Motor Areascontrols movements of skeletal muscles, speech and eyes2. Sensory Areasconscious awareness of sensations (hot, cold, pressure, pain)3. Association Areasconnect different parts of the cortexinvolved in recognizing smells, tastes, etc.
12 Examples of Association Areas sensory association areasvisual association areasauditory association areasgeneral interpretation area: integrates all incoming signals into a single thoughtprefrontal cortex: most complicated part of brain – intellect and complex learning (abstract ideas, judgment, reasoning)
13 Cerebral White Matterfunctions to provide communication between cerebral areasalso provides communication between cerebrum and the rest of the brain
14 Brain Disorders (some examples) Parkinson’s Diseasedeficiency of the neurotransmitter dopamineEpilepsysudden burst of irregular electrical activity in brain – can lead to seizures, convulsionsStrokeblood clot in brain – paralysis appears on side of body opposite to side of brain affectedAlzheimer’s Diseasepart of cortex shrinks, neurons lostresults in dementia, memory loss, disorientation, loss of body function