Introduction to the nervous system and nerve tissue[1]
- 1. Introduction to the Nervous System and Nerve Tissue Three Basic Functions 1. Sensory Functions: Sensory receptors detect both internal and external stimuli. Functional unit: Sensory or Afferent Neurons 2. Integrative Functions: CNS integrates sensory input and makes decisions regarding appropriate responses Functional Unit: Interneurons or Association Neurons of the Brain and Spinal cord 3. Motor Functions: Response to integration decisions. Functional Unit: Motor or Efferent Neurons
- 2. Organization of the Nervous System to supply the three basic functions
- 3. Introduction to the Nervous System and Nerve Tissue
- 4. Introduction to the Nervous System and Nerve Tissue
- 5. Organization of the CNS Gray Matter: Contains neuron cell bodies W White Matter: Contains cell extensions organized into tracts
- 6. Organization of the CNS
- 7. Organization of a Nerve of the PNS
- 8. Introduction to the Nervous System and Nerve Tissue Structure of a Neuron Dendrites: Carry nerve impulses toward cell body. Receive stimuli from synapses or sensory receptors. Cell Body: Contains nucleus and nissl bodies, a form of rough endoplasmic reticulum. Axon: Carry nerve Impulses away from the cell bodies. Axons interact with muscle, glands, or other neurons.
- 10. Node of Ranvier
- 11. Introduction to the Nervous System and Nerve Tissue Types of Neurons
- 12. Introduction to the Nervous System and Nerve Tissue Types of Interneurons
- 13. Schwann cells--are the supporting cells of the PNS. Schwann cells wrap themselves around nerve axons, a single Schwann cell makes up a single segment of an axon's myelin sheath. Introduction to the Nervous System and Nerve Tissue
- 14. Nervous System Physiology: Distribution of Ions between ECF and ICF
- 15. Nervous System Physiology: Nerve Conduction Occurs because of Changes in Membrane Potential
- 16. Nervous System Physiology: Types of Channel Proteins
- 17. Nervous System Physiology: Mechanism that creates an Action Potential
- 18. Nervous System Physiology: Two Mechanisms of Action Potential Conduction along a neuron
- 19. Nervous System Physiology: Communication between neurons at a synaptic junction 1. Electrical Synapses: Communication via gap junctions between smooth muscle, cardiac muscle, and some neurons of the CNS. Provide fast, synchronized, and two-way transmission of information. 2. Chemical Synapses: Communication via chemical neurotransmitters that diffuse across a synaptic cleft. Provides slow one-way information flow
- 20. Nervous System Physiology: Communication between neurons at a synaptic junction Action potential arrives at a synaptic end bulb. Depolarization of membrane causes the opening of Ca2+ channels. Increase in (Ca2+) inside of presynaptic neuron triggers exocytosis of neurotransmitter Neurotransmitter diffuses across synaptic cleft and binds to receptor (ligand-gated channel) on postsynaptic neuron
- 21. Nervous System Physiology: Communication between neurons at a synaptic junction 5. Na+ channels open causing a depolarization (Na+ channels) EPSP (excitatory postsynaptic potential) or a hyperpolarization (Cl- channels) IPSP (inhibitory post- synaptic potential) of the postsynaptic neuron. 6. If depolarization reaches a threshold, an action potential is generated on the postsynaptic neuron.
- 22. Nervous System Physiology: Communication between neurons at a synaptic junction
- 23. Nervous System Physiology: Communication between neurons at a synaptic junction Neurotransmitters 1. Acetylcholine: Found in the PNS and CNS. EPSP and in parasympathetic neurons IPSP. 2. Amino Acids: Glutamate and Aspartate produce EPSP’s in the CNS. Gamma Aminobutyric Acid (GABA) produces IPSP’s in the CNS. Valium enhances the action of GABA.
- 24. Nervous System Physiology: Communication between neurons at a synaptic junction Neurotransmitters 3. Biogenic Amines: Norepinephrine and epinephrine produce EPSP’s in the sympathetic system. Serotonin controls mood and induction of sleep. 4. Gases: Nitric Oxide produce by the enzyme nitric oxide synthase. Causes vasodilation and erection.
- 25. Nervous System Physiology: Communication between neurons at a synaptic junction
- 26. Types of Neural Circuits