15.2 lecture
- 1. Central Nervous System • The CNS is the control center • Central Nervous System (CNS) = the division of the nervous system consisting of the brain and spinal cord. • Peripheral Nervous System (PNS) = the division of the nervous system consisting of all of the nerves located outside the CNS. • It includes the brain and spinal chord.
- 2. Central Nervous System • Brain = the part of the nervous system that controls most functions of the body. • Spinal Cord = the thick column of nerve tissues that links the brain to most of the nerves in the PNS. • Most impulses from the PNS travel through the spinal chord to get to the brain. • Your brain directs the response. • The impulse usually travels from the brain through the spinal column to the PNS.
- 3. The Brain and Spinal Cord • Brain contains 100 billion neurons. • All interneurons in the brain. • There are three main regions of the brain that receive and process information. • The are the cerebrum, the cerebellum, and the brain stem.
- 4. What are three main regions of the brain that receive and process information?
- 5. Cerebrum • Cerebrum = the part of the brain that interprets input from the senses, controls movement, and carries out complex mental processes. – learning and remembering • Right hemisphere – Controls skeletal muscles on the left side of the body – Associated with creativity and artistic ability • Left Hemisphere – Controls skeletal muscles on the right side of the body – Mathematical skills, language and logical thinking
- 7. Cerebellum and Brain Stem • Cerebellum = the part of the brain that coordinates muscle action and helps maintain balance. • Brain Stem = the part of the brain that lies between the cerebellum and the spinal cord, and controls the body’s involuntary actions.
- 8. WHAT ACTIONS DOES THE BRAIN STEM CONTROL?
- 9. The Spinal Cord • The spinal cord is the link between your brain and the peripheral nervous systems
- 10. Peripheral Nervous System • The peripheral nervous system consists of a network of nerves that branch out from the central nervous system and connect to the rest of the body. • The peripheral nervous system is involved in both involuntary and voluntary actions.
- 11. How Spinal Nerves Function • Signals travel in both directions. • Both sensory and motor neurons. • Sensory – PNS to CNS • Motor – CNS to PNS
- 12. Somatic and Autonomic Systems • Somatic Nervous System = the groups of nerves in the PNS that controls voluntary actions. • Autonomic Nervous System = the group of nerves in the PNS that controls involuntary actions.
- 13. WHAT KINDS OF ACTIONS ARE CONTROLLED BY THE AUTONOMIC NERVOUS SYSTEM?
- 14. Reflexes • Reflex = an automatic response that occurs rapidly and without conscious control. • Reflexes help to protect the body.
- 15. Signaling the Brain • It takes longer for the pain impulse to get to the brain than it does for the reflexes to occur. • Why is it important for the brain to be notified of events requiring a reflex action? • It helps a person: – recognize possible dangers – learn to avoid certain circumstances – understand why an injury occurred
- 16. Nervous System Injuries • Concussions and spinal cord injuries are two ways in which the central nervous system can be damaged.
- 17. Concussions • Concussion = a bruiselike injury of the brain that occurs when the soft tissue of the brain collides against the skull. • Tissue will heal itself. • Symptoms – headache – lose consciousness – confusion – drowsy
- 18. Spinal Cord Injuries • When the spinal cord is cut or crushed. • Damaged axons fail to carry impulses. • Paralysis – loss of movement in some part of the body.
Editor's Notes
- #9: involuntary actions
- #12: Sensory – PNS to CNS Motor – CNS to PNS
- #13: heartbeat? breathing? body temp?
- #15: i.e. blink, knee jerk, jumping when startled example – cotton ball and goggles
- #18: i.e. when you bump your head hard in a fall, car crash, sports injury helmet
- #19: Car crashes are the most common cause.