CNS and PNS PDF

*Review *Review  The Cerebellum Controls all voluntary movements and some involuntary The cerebellum helps with balance, rate of muscle contraction, and the muscles position in relation to gravity Also plays a role in sensory perception to maintain balance (inner e...

*Review *Review  The Cerebellum Controls all voluntary movements and some involuntary The cerebellum helps with balance, rate of muscle contraction, and the muscles position in relation to gravity Also plays a role in sensory perception to maintain balance (inner ear)  Brain Stem Connect the spinal cord to all other parts of the brain Made up of the Medulla Oblongata and Pons Pons transfers nerve signals between cerebellum and medulla Medulla controls involuntary activities – Breathing – Heartbeat – Blood flow – Coughing Meninges: Layers of connective tissue that surround and protect the brain and spinal cord Cerebrospinal fluid: Fluid between the meninges that acts as cushion, protects from toxic substances, and provides nutrition to the brain *Discuss Try the Brain Hemisphere quiz here! *Basically any nerve not in the brain/spinal cord  THE SOMATIC NERVOUS SYSTEM Regulates activities that ARE UNDER CONSCIOUS CONTROL, i.e. movement of skeletal muscles. –Every time you lift your finger or wiggle your toes, you are using the motor neurons of the Somatic Nervous System.  THE AUTONOMIC NERVOUS SYSTEM Regulates activities that are automatic, OR INVOLUNTARY. The nerves of the Autonomic Nervous System control functions of the body that are NOT UNDER CONSCIOUS CONTROL. MAINTAINING HOMEOSTASIS IN THE FUNCTIONING OF MANY ORGANS OF THE BODY. –Examples: heart rate, breathing rate, digestion salivation ect.... Divided into 2 parts: Sympathetic and Parasympathetic “Fight or flight” “Sit and digest”  Sympathetic “Fight or Flight” Nervous System The sympathetic nervous system prepares the body for sudden stress –For example if you see a robbery taking place. When something frightening happens, the sympathetic nervous system takes over –makes the heart beat faster –diverts blood to your muscles and chest –makes the pupils dilate –causes the adrenal glands at the top of the kidneys to release adrenaline, to give extra power to the muscles for a quick getaway. This process is known as the body's "fight or flight" response.  Parasympathetic “Sit and Digest” Nervous system It prepares the body for rest. Slows heart rate It also helps the digestive tract move along so our bodies can efficiently take in nutrients from the food we eat. Opposite of the sympathetic *Discuss: Is this somatic or autonomic?