Structure and Function of the Nervous System PDF

Structure and Function of the Nervous System PSY 406 Trauma and Resilience Reference: Gazzaniga. M., Ivry. R. B. & Mangun. G. R. (2014). Cognitive Neuroscience: The Biology of the Mind, 4th edition. W. W. Norton & Company...

Structure and Function of the Nervous System PSY 406 Trauma and Resilience Reference: Gazzaniga. M., Ivry. R. B. & Mangun. G. R. (2014). Cognitive Neuroscience: The Biology of the Mind, 4th edition. W. W. Norton & Company Prepared by Asst. Mevla Yahya Structure and Function of the Nervous System It is important to understand the basic physiology of neurons and the anatomy of the nervous system. The anatomy of the neuron and an overview of how information is transferred both within a neuron, and from one neuron to the next. The anatomy and functions of the brain and the nervous system.  Structure and Function of the Nervous System The Structure of Neurons The nervous system is composed of two main classes of cells: Neurons: basic signaling units that transmit information throughout the nervous system. Glial cells: nonneural cells that serve various functions in the nervous system. Structure and Function of the Nervous System The Structure of Neurons Neurons, unlike other cells, possess dendrites and axon. Dendrites are branching extensions of the neuron that receive inputs from other neurons. Electrical signals travel along the length of the axon to its end, the axon terminals. Structure and Function of the Nervous System The Structure of Neurons Many dendrites have specialized processes called spines, little knobs attached by small necks to the surface of the dendrites, where the dendrites receive inputs from other neurons. Structure and Function of the Nervous System Neuronal Signaling Neurons receive, evaluate, and transmit information. This process is referred to as neuronal signaling. Information is transferred across synapses: from one neuron to the next from a neuron to a non-neuronal cell such as those in muscles or glands Structure and Function of the Nervous System Neuronal Signaling Neurons receive, evaluate, and transmit information. This process is referred to as neuronal signaling. Two types of transport: within neurons Involves changes in the electrical state of the neuron as electrical currents flow through the volume of the neuron. between neurons Occurs at synapses, typically mediated by chemical signaling molecules (neurotransmitters) but, in some cases, also by electrical signals. Regarding information flow, neurons are referred to as either presynaptic or postsynaptic. Most neurons are both presynaptic and postsynaptic : They are presynaptic when their axon makes a connection onto other neurons, and postsynaptic when other neurons make a connection onto their dendrites.  Structure and Function of the Nervous System The Role of Glial Cells An astrocyte makes contact with blood vessels and create a barrier, called the blood–brain barrier ( BBB ), between the tissues of the central nervous system and the blood. The BBB restricts the diff usionof microscopic objects (such as most bacteria) and large hydrophilic molecules in the blood from entering the neural tissue, but it allows the diffusion of small hydrophobic molecules such as oxygen, carbon dioxide, and hormones. Microglial cells come into play when tissue is damaged. They are phagocytes, literally devouring and removing damaged cells. In the central nervous system, oligodendrocytes form myelin; in the peripheral nervous system, Schwann cells carry out this task. Myelin is a good electrical insulator. Structure and Function of the Nervous System The Bigger Picture Structure and Function of the Nervous System The Bigger Picture Uses the Uses the neurotransmitter neurotransmitter norepinephrine as acetylcholine as its its transmitter. transmitter. Activates flight or Activates rest fight response. response.  Structure and Function of the Nervous System The Central Nervous System The CSF occupies the subarachnoid space between the arachnoid membrane and the pia mater, as well as the brain ventricles, cisterns and sulci, and the central canal of the spinal cord  Structure and Function of the Nervous System Consists of axons and glial cells, grouped together in tracts that The Central Nervous System run in association tracts from one region to another within a hemisphere, or may cross into the other hemisphere in tracts called commissures, e.g., corpus collosum. Is composed of neuronal cell bodies Structure and Function of the Nervous System The Spinal Cord Structure and Function of the Nervous System Navigating the Brain Structure and Function of the Nervous System Navigating the Brain Structure and Function of the Nervous System The Cerebral Cortex Structure and Function of the Nervous System Dividing the Cortex Cytoarchitectonically Structure and Function of the Nervous System Functional Division of the Cerebral Cortex Structure and Function of the Nervous System Functional Division of the Cerebral Cortex Structure and Function of the Nervous System Functional Division of the Cerebral Cortex Structure and Function of the Nervous System Functional Division of the Cerebral Cortex Structure and Function of the Nervous System Functional Division of the Cerebral Cortex Structure and Function of the Nervous System Functional Division of the Cerebral Cortex To summarize: Gyri are the protruding areas seen on the surface of the cortex; sulci, or fissures, are the enfolded regions of cortex. Brodmann divided the brain into distinct regions based on the underlying cytoarchitectonics. The lobes of the brain include the frontal, parietal, temporal, and occipital lobes. The frontal lobe is for planning, cognitive control, and execution of movements. The parietal lobe receives sensory input about touch, pain, temperature, and limb position, and it is involved in coding space and coordinating actions. The temporal lobe contains auditory, visual, and multimodal processing areas. The occipital lobe processes visual information. Association cortices are those regions of cortex outside the sensory specific and motor cortical regions. Association cortex receives and integrates input from multiple sensory modalities.  End.