2. Neural Control

3. Nervous System Functions (Neurons) Sensory input Detect & receive Internal or external Integration Process & interpret Motor output Muscles & glands

4. Nerve Pathway Stimulus Sensory Neurons Interneurons Motor Neurons EffectorsResponse

5. Nervous System Types Nerve Net Cnidarians Sensory neurons in epidermis Motor neurons in all tissues

6. Nervous System Types Ladder-Like Plathyhelminthes Long nerves Ganglia (“brain”) Integration

7. Nervous System Types Advanced Invertebrates More advanced Cephalized Brain Ventral nerve cord Branching nerves

8. Nervous System Types Vertebrate More advanced Many more neurons 1 million in insects Vertebrates 1,000-1 billion more! Two divisions Central nervous system Peripheral nervous system

9. Nerve Cells Neuron Primary cell type Conducts impulses Neuroglial Support/nourish neuron Non-excitatory 9:1 ratio

10. Neuroglial Cells—CNS

11. Neuroglial Cells—PNS

12. Neurons Characteristics Excitable Longevity High Metabolic Rate Sometimes Large Amitotic May Regenerate

13. Neurons Sensory (afferent) Detects stimuli Carry signal to CNS Interneuron (association) Transmit between neurons in CNS Motor (efferent) Carry signal to muscle or gland

14. Neurons Axon Soma Dendrite Myelin sheath Axon terminal Synapse

15. Neurons Myelin Sheath Insulating Myelinated transmit faster

16. Neurons Synapse Chemical Electrical

17. Neurotransmitters Acetylcholine Most common Neuromuscular junction Norepinephrine Involuntary functions Dopamine Many functions Behavior & mental ability Serotonin Mood Sleep

18. Nerve Impulse Resting potential Na + higher outside of cell K + higher inside of cell

19. Nerve Impulse

21. Sodium gates open Sodium moves into cell Action potential starts Potassium gates open Potassium moves out of cell Electrical charges across membrane switch “Wave” of charge moves along axon

22. Nerve Impulse Myelinated axons transmit signal faster

23. Nerve Impulse All-or-nothing Refractory period Cannot respond to signal

24. Central Nervous System Brain & spinal cord White matter—myelinated Grey matter—unmyelinated Meninges Cerebrospinal fluid

25. Central Nervous System Brain Alligator—0.003% body weight Sperm whale—0.06% Rat—0.5% Human—2%

26. Brain Cerebrum Integrates & analyzes Frontal lobe—motor control Parietal lobe—sensory from body Occipital lobe—vision Temporal lobe—hearing, emotions

27. Brain Thalamus Relay station Memories, emotions Hypothalamus Homeostasis Sleep, sex, thirst, etc. Medulla Oblongata Heart rate, breathing, blood pressure Involuntary muscle contractions

28. Brain Pons Fine-tune breathing Hearing/sight reflexes Cerebellum Coordinate movement Gordon Weebles

29. Brain Limbic System Learning Memory Fear & pleasure Facial expressions

30. Peripheral Nervous System Cranial & spinal nerves

31. Peripheral Nervous System 12 pairs Cranial Nerves 31 pairs Spinal Nerves

32. Peripheral Nervous System Somatic Sensory signals to skeletal muscle Synapses in brain or spinal cord Reflexes

33. Peripheral Nervous System Reflex arc

34. Peripheral Nervous System Autonomic Involuntary Cardiac muscle Smooth muscle Glands

35. Autonomic Nervous System Sympathetic “Fight or flight” Excitement Exercise Emergency Embarassment Parasympathetic “Rest & digest” Digestion Defecation Diuresis

36. Autonomic Nervous System OrganParasympatheticSympathetic Eye (pupil)ConstrictDilate GlandsStimulates secretionInhibits secretion Heart muscleSlows & steadies rateIncreases rate & force LungsConstricts bronchiolesDilates bronchioles Digestive tractIncreases digestionDecreases digestion BladderPromotes voidingInhibits voiding Mental activityNo effectIncreases alertness

37. Autonomic Nervous System