1. Opening Assignment 1.What are 2 functions of the nervous system? 2.Differentiate between the Central nervous system and the Peripheral Nervous system.

2. THE NERVOUS SYSTEM CHAPTER 9 By Mrs. Shaw

3. Student Learning Goals Chapter 9: Nervous System: Students will be able to 1.Describe the anatomy, histology, and physiology of the central and peripheral nervous systems and name the major divisions of the nervous system. (SC.912.L.14.21)SC.912.L.14.21 2.Describe the physiology of nerve conduction, including the generator potential, action potential, and the synapse. (SC.912.L.14.22 )SC.912.L.14.22 3.Identify the parts of a reflex arc. (SC.912.L.14.23 )SC.912.L.14.23 4.Identify the major parts of a cross section through the spinal cord. (SC.912.L.14.25 )SC.912.L.14.25 5.Identify the functions of the major parts of the brain, including the meninges, medulla, pons, midbrain, hypothalamus, thalamus, cerebellum and cerebrum (SC.912.L.14.27 )SC.912.L.14.27 6.Identify the major functions of the spinal cord. (SC.912.L.14.28 )SC.912.L.14.28

4. 9.1 Introduction ■The main function of the nervous system is communication and control of ALL body functions. ■It is the reason you can feel, think, remember, and move. ■It helps in coordination of all body functions both voluntary and involuntary.

5. Neurons ■The structural and functional units of the nervous system are called neurons ■They are specialized cells that function to react to internal and external changes in their surroundings. They then transmit information in the form of electrochemical changes called nerve impulses.

6. Neurons ■The 3 basic parts of a neuron are the cell body, the dendrites, and the axons. ■Nerves are bundles of axons.

7. Neuroglial Cells ■Nervous tissue also includes neuroglial cells ■Neuroglial cells provide physical support, insulation, and nutrients for neurons

8. 2 Parts of the Nervous System The nervous system is divided into two parts. The central nervous system (CNS) which includes the brain and spinal cord. The peripheral nervous system (PNS) consists of all the peripheral nerves that connect the CNS to the other body parts.

9. 9.2 General Functions of the Nervous System Add to Notes

10. Sensory Receptors and Integration ■Sensory receptors gather information by detecting changes inside and outside the body. ■Sensory receptors convert environmental information into nerve impulses which are then transmitted over peripheral nerves to the central nervous system. ■At the CNS, information is integrated which means that it is brought together, creating sensations, adding to memory, or helping produce thoughts that translate sensations into perceptions.

11. Motor Effectors ■Motor functions of the nervous system employ peripheral neurons to carry impulses from the CNS to the responsive structures called effectors. ■Effectors which are outside the nervous system, include muscles that contract and glands that secrete when stimulated by nerve impulses.

12. 2 types of motor functions ■Somatic nervous system ■Autonomic nervous system Motor Functions of the Peripheral Nervous System

13. Neuroglial Cells TypeLocationFunction Microglial cellsCNSSupport neurons and phagocytize bacterial cells and cellular debris OligodendrocytesCNS, along nerve fibers Provide the insulating layers of myelin, called myelin sheath, around axons within the brain and spinal cord AstrocytesCNS, found between neurons and blood vessels Provide structural support, join parts by their abundant cellular processes, and help regulate nutrient concentrations. EpendymalCNS,forms the epithelial like membrane around the specialized parts of the brain and lines the ventricles of the brain and the spinal canal. SchwannPNSWraps around the axons and create the insulating myelin sheath that enables the impulse to travel faster.

15. Structure of a Neuron Label the structure on the right using Fig. 9.4 on page 207. 1. dendrites 2. chromatophilic substance (like ER) 3. Cell body 4. Nucleus 5. Nucleolus 6. Neurofibrils (attach cell body to axon) 7. Axonal hillock (slight elevated area where the axon starts) 8. Nerve impulse Add Myelin, Schwann cell, Nodes of Ranvier, Neurilemma

16. White vs. Grey Matter ■Axons with myelin sheaths are called myelinated. Axons without the sheath are called unmyelinated. ■White matter consists of masses of myelinated axons. ■Grey matter consists of masses of unmyelinated axons.

17. Check for Understanding 1.What are the three parts of a neuron? 2.The information that is relayed in the form of electrochemical changes within the nervous system is called a ____________________ ____________________. 3. _______________ __________________ transmit information via nerve impulses to the brain to be ________________________. The _____________________ __________________ then carry the response information to muscles and glands throughout the body so that an action can occur. 4.How are the Somatic and Autonomic system (motor effectors) different?

18. Classification of Neurons Neurons Classified by Structure TypeStructureLocation found MultipolarMany processes; one axonBrain and spinal cord BipolarOnly 2 processes; one is axon and one is dendrite Neurons in eyes, ears, nose UnipolarSingle process that divides into two branches that function as one axon Ganglia (masses of cell bodies) found outside brain and spinal cord

19. Classification of Neurons Neurons Classified by Function TypeFunctionStructure Sensory Neuron Afferent – carry impulses from peripheral nerves to the CNS Most are unipolar, some are bipolar InterneuronTransmit impulses from one area of brain or spinal cord to another Multipolar Motor NeuronEfferent – carry impulses from the CNS to effectors Multipolar

20. Neuron Function

21. Nervous System Part 1

22. Time for... Kahoot!

23. Neuron Structure Review 1.____________________ 2._____________________ 3._____________________ 4._____________________ 5._____________________ 6.______________________ 7._____________________ 8._____________________ Add Axon, Myelin, Schwann cell, Nodes of Ranvier, Neurilemma Word bank Axonal hillockNerve ImpulseNucleus NucleolusDendrites Chromatophilic substance Cell body Neurofibrils

24. Opening Assignment 1.The neuroglial cell that provide the insulating layers of myelin on axons in the CNS are called ______________________________. 2.The neuroglial cells that provide this myelin sheath on axons in the PNS are called ______________________________. 3.Neurons can be classified by ___________________ and _____________________. 4.Afferent nerves are ______________ neurons and efferent nerves are ________________ neurons. 5.What are the three structural shapes of neurons?

25. Opening Assignment 1.The neuroglial cell that provide the insulating layers of myelin on axons in the CNS are called oligodendrocytes. 2.The neuroglial cells that provide this myelin sheath on axons in the PNS are called Schwann cells. 3.Neurons can be classified by structure and function. 4.Afferent nerves are sensory neurons and efferent nerves are motor neurons. 5.What are the three structural shapes of neurons? Multipolar, bipolar, unipolar. Most neurons are multipolar.

26. 2003-2004 http://inside.salve.edu/walsh/cns_pns.jpg Add to notes: 12 Cranial nerves 31 Spinal nerves

27. 9.5 Cell Membrane Potential ■The surface of a cell membrane is usually electrically charged, or polarized, with respect to the inside. ■This polarization comes from unequal distribution of positive and negative ions between the sides of the membrane. ■A change in neuron membrane polarization and return to resting state is called an action potential.

28. Action Potential Na+ moves inK+ moves out

29. Impulse Conduction ■An unmyelinated axon conducts an impulse over it’s entire surface. ■A myelinated axons functions differently because the myelin insulates and protects almost all ion flow through the membrane it encloses. ■The nodes of Ranvier between the Schwann cells interrupt this sheath and allow nerve impulses to jump from node to node. This type of impulse conduction is termed saltatory and is many times faster than on an unmyelinated axon. ■The conduction of an impulse requires primarily active transport for the Na+ and K+ channels to open and close during the process.

30. 9.7 The Synapse ■Nerve Impulses travel along nerve pathways. The junction between any two communicating neurons is called a synapse. ■These neurons are not in direct contact so they must communicate via a synaptic cleft. ■Synaptic transmission of information is carried out by the release of neurotransmitters.

31. Synapse Transmission ■Presynaptic neuron has many distal ends of the axon called synaptic knobs that contain synaptic vesicles. ■When an action potential reaches the membrane of a synaptic knob, it increases the membranes permeability to calcium ions by opening the calcium channels. ■This influx of calcium causes some of the synaptic vesicles to attach to the membrane and release their neurotransmitters. ■These neurotransmitters travel across the synaptic cleft and react with specific receptors on the post synaptic neuron. The process of crossing the synaptic cleft is called synaptic transmission.

32. Let’s Practice 1.___________________________ 2.___________________________ 3.___________________________ 4.___________________________ 5.___________________________ A = __________________________ B = __________________________

33. Let’s Practice 1.mitochondria 2.Synaptic vesicle 3.Ca+ channels 4.Synaptic cleft 5.Receptors A = presynaptic neuron (synaptic knob) B = post synaptic neuron

34. Excitatory and Inhibitory Actions Excitatory neurotransmitters – increase membrane permeability, increases chance for threshold to be achieved Inhibitory Neurotransmitters– decrease membrane permeability, decrease chance for threshold to be achieved

35. Common Types of Neurotransmitters ■Acetylcholine – stimulates skeletal muscles ■Norepinephrine & Dopamine - sense of feeling good, when levels are low there is a possibility of depression) ■Serotonin = helps maintain mood balance – treats depression ■Endorphins = help block pain receptors and help us feel pleasure Synapses are highly susceptible to drugs and fatigue

36. How drugs affect the Nervous System ■Morphine, alcohol, ether and chloroform anesthetize nerve fibers. (inhibitory – CNS depressants) ■LSD produces it’s hallucinatory effect by interfering with nor-adrenaline & serotonin ■Cocaine, Speed, Ritalin, Adderall increase the level of norepinephrine and dopamine which increase alertness and also increase HR and BP. The increase in dopamine also leads to a euphoric feeling.

37. 9.8 Neuronal ■Neuronal pool – groups of neurons that make hundreds of synaptic connections and work together to perform a common function Add to notes

38. 9.9 Types of Nerves Sensory Nerves – conduct impulses into the brain or spinal cord Motor Nerves – carry impulses to muscles of glands Mixed Nerves - contain both sensory and motor nerves

39. 9.10 Steps in a Reflex Arc 1. Receptor - senses specific type of internal or external change 2. Sensory neuron - transmits nerve impulse from receptor into brain or spinal cord 3. Interneuron - conducts nerve impulse from sensory neuron to motor neuron. 4. Motor neuron - transmits nerve impulse from brain or spinal cord out to the effector. 5. Effector – muscle or gland that respond to the stimulation by the motor neuron and produces a reflex or behavioral reaction.

40. Reflex Behavior ■Reflexes –automatic subconscious responses to changes within or outside the body. –Help maintain homeostasis by controlling involuntary processes like heart rate, breathing rate, blood pressure, etc. –Types of reflexes ■Knee jerk reflex ■Withdrawal reflex -

41. Crash Course Nervous System Part 3

42. Check for Understanding 1.How many cranial nerves are there? _____________ Spinal nerves? ____________ 2.Nerve Impulses travel along ______________ __________________. The junction between any two communicating neurons is called a ______________________. 3._________________________ neurotransmitters – increase membrane permeability and increases chance for threshold to be achieved whereas ____________________________ neurotransmitters – decrease membrane permeability, decreasing the chance for threshold to be achieved 4. Put the following parts of a reflex arc in order from the first to last step _____ Interneuron _____ Motor Neuron _____Receptor ____ Effector _____Sensory Neuron

43. Add this drawing and labeling exercise to Worksheet #3 – due Friday 1.mitochondria 2.Synaptic vesicle 3.Ca+ channels 4.Synaptic cleft 5.Receptors A = presynaptic neuron (axon terminal) B = post synaptic neuron

44. Opening Assignment Fill in with correct terms 1.___________________________ 2.___________________________ 3.___________________________ 4.___________________________ 5.___________________________ A = __________________________ B = __________________________

45. New Drug to Help Fight Addiction ■http://abcnews.go.com/WNT/video/drug-helps-fight-drug-alcohol-addiction- neurotransmitters-shot-block-substance-abuse-get-high-11864642http://abcnews.go.com/WNT/video/drug-helps-fight-drug-alcohol-addiction- neurotransmitters-shot-block-substance-abuse-get-high-11864642

46. Frog Dissection PreLab ■External Anatomy: https://www.youtube.com/watch?v=u- LqS5AVRiohttps://www.youtube.com/watch?v=u- LqS5AVRio ■Internal Anatomy: https://www.youtube.com/watch?v=bOJyhk4QZvc https://www.youtube.com/watch?v=bOJyhk4QZvc