Chapter 49 the nervous system ppt

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Chapter 49 the nervous system ppt

  1. 1. Chapter 49: Nervous Systems By: Jordan Masterson
  2. 2. Difference Between Invertebrates and Vertebrates <ul><li>Invertebrates </li></ul><ul><li>Vertebrates </li></ul><ul><li>Cnidarians are the simplest animals with nervous systems and radial symmetry. </li></ul><ul><ul><li>Examples: Hydras and Jellyfish </li></ul></ul><ul><li>Series of interconnected nerve cells form a diffuse nerve net , a web like system of neurons. </li></ul><ul><li>The Central Nervous System (CNS) consists of the brain and spinal cord. </li></ul><ul><ul><li>Local dorsally (On The Back) </li></ul></ul><ul><li>The Peripheral Nervous System (PNS) transmits sensory and motor signals between the CNS and the rest of the body. </li></ul>
  3. 3. Comparison Figure 49.UN02 Nerve net Hydra (cnidarian) Salamander (vertebrate) Sensory ganglia Spinal cord (dorsal nerve cord) Brain
  4. 4. Figure 49.4 Central nervous system (CNS) Brain Spinal cord Peripheral nervous system (PNS) Cranial nerves Ganglia outside CNS Spinal nerves
  5. 5. Vertebrate Nervous System <ul><li>The simplest circuits are found in the reflex responses in which sensory input is linked to motor output without the involvement of the brain. </li></ul><ul><ul><li>Example: a doctor using a mallet to trigger a knee-jerk reflex </li></ul></ul>
  6. 6. Peripheral Nervous System <ul><li>Afferent Neurons send information to the CNS. </li></ul><ul><ul><li>Example: Sensory Functions </li></ul></ul><ul><li>Efferent Neurons transmit information away from the CNS. </li></ul><ul><ul><li>Example: Motor Functions and Automatic Nervous System </li></ul></ul><ul><li>Automatic Nervous System </li></ul><ul><ul><li>Sympathetic Division: Activation corresponds to arousal and energy generation (“Fight or Flight “). </li></ul></ul><ul><ul><li>Parasympathetic Division: Activation promotes calming and a return to self-maintenance (“Rest and Digest”). </li></ul></ul><ul><ul><li>Enteric Division: Controls activity of the digestive tract, pancreas, and gallbladder. </li></ul></ul>
  7. 7. Parasympathetic division Action on target organs: Constricts pupil of eye Stimulates salivary gland secretion Constricts bronchi in lungs Slows heart Stimulates activity of stomach and intestines Stimulates activity of pancreas Stimulates gallbladder Promotes emptying of bladder Promotes erection of genitalia Cervical Thoracic Lumbar Synapse Sacral Sympathetic ganglia Sympathetic division Action on target organs: Dilates pupil of eye Accelerates heart Inhibits salivary gland secretion Relaxes bronchi in lungs Inhibits activity of stomach and intestines Inhibits activity of pancreas Stimulates glucose release from liver; inhibits gallbladder Stimulates adrenal medulla Inhibits emptying of bladder Promotes ejaculation and vaginal contractions Figure 49.8
  8. 8. Regions of the Brain Figure 49.UN04 Spinal cord Cerebral cortex Cerebellum Medulla oblongata Pons Hindbrain Midbrain Forebrain Cerebrum Thalamus Hypothalamus Pituitary gland
  9. 9. The Vertebrate Brain is Regionally Specialized <ul><li>The Brainstem: The Pons and Medulla serve as a relay station for information traveling between the PNS and higher brain. </li></ul><ul><li>The Cerebellum: helps coordinate motor, perceptual, and cognitive functions. </li></ul><ul><li>The Diencephalon: The Thalamus is the main center through which sensory and motor information passes to the cerebrum. The Hypothalamus regulates homeostasis and basic survival behaviors. </li></ul><ul><li>The Cerebrum: has two hemispheres that are important in planning and learning movements. The Corpus Callosum provides communication between the right and left cerebral cortices. </li></ul>
  10. 10. The Cerebral Cortex <ul><li>Four Lobes: frontal, temporal, occipital, and parietal </li></ul><ul><li>Information Processing in the Cerebral Cortex: Adjacent association areas process particular in the sensory input and integrate information from different sensory areas. </li></ul><ul><li>Language and Speech: Portions of the frontal and temporal lobes are essential for generating and understanding language. </li></ul><ul><li>Lateralization and Cortical Function: The left cerebral hemisphere plays a dominant role in mathematics and logical operations. The right cerebral hemisphere mainly deals with pattern recognition and nonverbal thinking. </li></ul><ul><li>Emotions: The experience of emotions involves many regions of the brain, with the amygdala playing a major role in generating emotions. </li></ul>
  11. 11. Changes in Synaptic Connections Figure 49.19 N 2 N 1 N 2 N 1 (a) Synapses are strengthened or weakened in response to activity. (b) If two synapses are often active at the same time, the strength of the postsynaptic response may increase at both synapses.
  12. 12. Nervous System Disorders <ul><li>Schizophrenia: Characterized by hallucinations and delusions, which affect neuronal pathways that use dopamine as a neurotransmitter. </li></ul><ul><li>Depression: Patients that exhibit a persistent low mood are often treated with drugs that increase the activity of biogenic amines in the brain. </li></ul><ul><li>Alzheimer’s: Age-related dementia where neurofibrillary tangles and amyloid plaques form on the brain. </li></ul><ul><li>Parkinson’s: Motor disorder caused by the death of dopamine-secreting neurons with the presence of protein aggregates. </li></ul>
  13. 13. Drug Addiction and Brain Reward System Figure 49.23 Nicotine stimulates dopamine- releasing VTA neuron. Inhibitory neuron Dopamine- releasing VTA neuron Cerebral neuron of reward pathway Opium and heroin decrease activity of inhibitory neuron. Cocaine and amphetamines block removal of dopamine from synaptic cleft. Reward system response

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