2. Human Physiology: The Nervous System PPT #2 chapter 29 in text

3. Objectives and Questions: 1. I can describe the functions of the nervous system 2. I can describe the parts of a neuron cell and identify how they transmit electrochemical impulses. 3. I can compare and contrast the central and peripheral nervous systems 4. I can identify and explain different areas of the brain and their functions. 5. I can explain how the nervous system passes information between the external environment and the many parts of the body.

4. The Nervous system is: A physically connected network of cells, tissues and organs that allow us to communicate with and react to the environment and perform life activities.

5. Cool Nervous System Facts: As a fetus in the womb, neurons develop at the rate of 250,000 per minute. We have about 100 billion nerve cells in our brain by adulthood (over 600 miles worth) – yet we typically use around 4% at any given time Neurons are our largest cells Messages transmit at speeds up of to 180 MPH

6. FOUR PRIMARY FUNCTIONS OF NERVOUS SYSTEM 1. Sensing the world Vision, Hearing, Smell, Taste, Touch Vision, Hearing, Smell, Taste, Touch 2. Transmitting information 3. Processing information 4. Producing a response

7. The functional unit of the nervous system is the nerve cell, the NEURON The functional unit of the nervous system is the nerve cell, the NEURON They send electrochemical messages around the body They send electrochemical messages around the body provide support and protection for neurons Glial cells provide support and protection for neuronsneurons

8. Parts of a neuron Nerve Cell Nerve Cell Nerve Cell

9. Parts of nerve cell Dendrites : recieve chemical signals from neighboring cells. Dendrites : recieve chemical signals from neighboring cells. Cell Body: contains the nucleus & organelles Cell Body: contains the nucleus & organelles Axon: long extension that carries electrical messages away from the body to the terminal axons Axon: long extension that carries electrical messages away from the body to the terminal axons Terminal Axons: passes the signal to the next cell. Terminal Axons: passes the signal to the next cell. Myelin sheath: Protective covering for axon Myelin sheath: Protective covering for axon

10. 3 main types of neurons: 3 main types of neurons: Sensory neuron = detect stimuli Sensory neuron = detect stimuli Interneurons = relay sensory signals to brain then return message back to motor neurons. Interneurons = relay sensory signals to brain then return message back to motor neurons. Motor neuron = pass message from brain to rest of body for muscle response Motor neuron = pass message from brain to rest of body for muscle response This coordinated pathway is known as the REFLEX ARC This coordinated pathway is known as the REFLEX ARC Types of Neurons

12. Reflex Arc “ what happens when you step on a nail”? Reflexes are automatic The Stimulus (nail ) is received by the in the foot The Stimulus (nail ) is received by the sensory neurons in the foot This info travels to the spine, where the is triggered This info travels to the spine, where the interneuron is triggered The transmits signal to brain (through the spinal cord)and carries message back and stimulates the neuron, to move the foot The interneuron transmits signal to brain (through the spinal cord)and carries message back and stimulates the motor neuron, to move the foot

14. A progressive wave of electric and chemical activity along a nerve fiber that stimulates or inhibits the action of a muscle, gland, or other nerve cell *This is how the information moves from sensory neurons to interneuron to motor neurons

16. Central Nervous System (CNS)  Receives, interprets and sends signals to PNS  Has 2 main parts:  Brain – main control center  Spinal Cord – connects and relays nerve impulses to the brain 2 MAIN DIVISIONS:

17.  Connects CNS to all organ systems  Made up of:  Sensory Neurons: detect stimuli  Motor Neurons: carry signal to stimulate response  2 major subsystems:  Somatic – voluntary movement (balance, movement)  Autonomic – involuntary movement (digestion, fight or flight) PERIPHERAL NERVOUS SYSTEM (PNS)

18. Central Nervous System Central Nervous System Brain Brain Cerebrum Cerebrum Cerebellum Cerebellum Brain Stem and Pons Brain Stem and Pons Lobes (4) Lobes (4) Spinal Cord Spinal Cord “information superhighway” “information superhighway” Peripheral Peripheral Autonomic Autonomic Sympathetic Sympathetic Fight or Flight Fight or Flight Parasympathetic Parasympathetic Relaxation Relaxation Somatic Somatic Sensory and Motor Nerves Sensory and Motor Nerves Reflex Arc Reflex Arc Parts of the Nervous System

22. Smaller part of the brain,towards the backFUNCTIONS: Coordinates all movement Helps maintain posture, muscle control, and balance

23. Large front part of the brain Large front part of the brainFUNCTIONS: Voluntary activity Voluntary activity Memory Memory Language Language Receives and responds to sensory signals Receives and responds to sensory signals Controls motor functions Controls motor functions

24. Top layer of the brain Stores: experiences and/or learning Frontal- behavior & emotion Temporal- memory & emotion, speech and hearing Occipital- vision Parietal- Sensory info concerning touch

25. BRAIN STEM swallowing, coughing, sneezing, and vomiting swallowing, coughing, sneezing, and vomiting Includes the Includes the Medulla Oblongata Medulla Oblongata PONS Breathing Breathing Heart rate Heart rate Internal Organs Internal Organs Medulla Damage in this area will usually kill you.

26. “controls: emotions and memories” Damage to these areas can lead to amnesia or emotional disturbances