Learning Objectives 7

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Learning Objectives 7
2010-11-03 18:12:39
Human anatomy Learning objectives Nervous tissue brain

Learning objectives 7 for chapters 14 and 15
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  1. Central Nervous System
    is composed of ONLY the brain and the spinal cord
  2. Peripheral Nervous system
    includes the cranial nerves (nerves that extend from the brain) spinal nerves (Nerves that extend from the spinal cord) and the ganglia (which are clusters of neuron cell bodies located outside the CNS)
  3. Unipolar neurons
    have a single short neuron process that emerges from the cell body and branches like a T. They start out as a bipolar but during development but their 2 processes fuse into a single process
  4. Bipolar neuron
    hav 2 neuron processes that extend from the cell body- one axon and one dendrite. These neurons are relatively uncommon in humans and primarily limited to some of the special senses.
  5. multipolar neurons
    are the most common type of neuron. Multiple neurons porcesses- many dendrites and a single axon- extending from the cell body.
  6. Sensory neurons
    transmit nerve impulses FROM sensory receptors TO the CNS. These neurons are specilaized to detect changes in their environment called stimuli. Most sensory neurons are unipolar
  7. Motor neurons
    transmit nerve impulses FROM the CNS TO muscle cells or glands. MOst of them extend to muscle cells and the nerve impulses they transmit cause these cells to contract. All motor neurons are mutipolar.
  8. interneurons
    lie entirely within the CNS and are multipolar structures, They recieve nerve impulses from many other neurons and carry out the integrative function of the nervous system, that is , they recieve, process and store information nd decide how the body responds to th stimuli. It is estimated that 99% of our neurons are interneurons.
  9. Glial Cells
    sometimes referred to as neuroglia occur within both the CNS and the PNS. They differ from neurons in that they are smaller and capable of mitosis. Glial cells don't transmit nerve impulses, but they do assist neurons with their functions. Collectively the glial cells physically protect and help nurish neurons and provide an organized, supporting framework for all the nervous tissue. Glial cells far outnumber neurons.
  10. Astrocyte
    A glial cell in the CNS thats large and is the most common glial cell. Helps bloodbrain barrior, regulate tissue fluid composition, provide structure and support, replaces damaged neurons and assists with the development.
  11. Ependymal cell
    A glial Cell of the CNS, made of simple cuboidal it just lines ventricles of the brain and central canal of spinal cord, and it assists in production and circulation of CSF.
  12. Microglial cell
    Small cell, least common of the glial cells found in the CNS. They defend againest pathogens removes debris phagocytizes wastes
  13. Oligodendrocyte
    A glial cell of the CNS its rounded and has extensions that wraps around CNS axons. It Myelinates and insulates CNS axons and allows faster nerve impulses conduction through the axon
  14. Satellite cell
    A glial cell of the PNS, a flat cell that protects nad regulates nutriants for the cell bodies in ganglia
  15. Neurolemmocyte
    A glial cell of the PNS thats a flattened cell wrapped around an axon of the PNS. It myelinate and insulates PNS axons and allow for faster nerve impulse conduction through the axon.
  16. Myelination
    is the process by which part of an axon is wrapped with a myelin sheath. Differs between the CNA and the PNA
  17. Myelian sheath
    • is a instulating cover around the axon consisting of cincentric layers of myelin. The overlapping plasma membrane form the meylin sheath.
    • CNS- its formed from oligodndrocytes, which can myelinate a 1 millimetter portion of MANY axons not just one.
    • PNS- made rom nurolemmocytes which wraps around 1 axon like tape around a pencil.
  18. Unmyelinated axons
    in the PNS and are associated with a neurolemmocyte but no melin sheath covers them, so it just rests in a portion of the neuroemmocyte rather than being wrapped by successive layers of the plasma membrane.
  19. Neurofibril nodes or nodes of ranvier
    is a small space interrupt the myelin sheath between adjacent oligodendrocytes or neurolemmocytes. At these nodes and only at these nodes can a changein voltage occur across the plasma membrane abd result in the movement of a nerve impulse. Thus in a myelinated axon the nerve impulse seems to jump from neurofibrial node to a neurofibrial node.
  20. Saltatory conduction
    a nerve impulse jumps from neurofibril node to neurofibril node (associated with a myelinated axon)
  21. Continuous conduction
    in a unmyelinated axon, the nerve impulse must travel the entire length of the axon membrane.
  22. electrical synapse
    the plasma membrane of the presynaptic and postsynaptic cells are bound tightly together. electical synapses are fast and secure and they permit 2-way signaling.
  23. Gap junctions
    Is at the synapse and is formed by connexons between both plasma membranes facilicate the flow of ions, such as sodium ions between the cells.
  24. Chemical synapses
    the most numerous type of synapse is the chemical synapse, at these junctions the presynaptic membrane releases neurotransmitters . The neurotransmitter molecule are released only from the presynaptic cell. They bind to receptor protiens found only in the plasma membrane of the postsynaptic cell and this causes a brief voltage change across the membrane of the postsynaptic cell. Thus a unidirectional flow of information and communication takes places
  25. Gray matter
    houses motor neuron and interneuron cell bodies, dendrites, telodendria and unmyelinated axons. during brain development an outer superficial region of gray matter forms from migrating peripheral neurons. As a result the external layer of gray matter called the cerebral cortex and covers the surfacee of most of the adult brain.
  26. White matter
    derives it color form the myelin in the myelinated axons. The white matter lie deep to the gray matter.
  27. Cortex
    the external layer of gray matter.
  28. Cerebral nuclei
    internal clusters of gray matter which are oval spherical or sometimes irregular shaped clusters of neuron bodies.
  29. Cranial Meninges
    are 3 connective tissue layers that seperate the soft tissue of the brain from the bones of the cranium. (From deepest to superficial) the cranial meninges are the pia mater, the arachnoid and the dura mater.
  30. Vetricles (of the brain)
    are cavities or expansions within the brain tht derived from the lumen of the embryonic neural tube. The ventricles are continuouse with one another as well as with the central canal of the spinal cord.
  31. lateral ventricles
    (2) are in the cerebrum seperated by a thin medial partition called the septum pellucidum
  32. 3rd ventricle
    is within the diencephalon is a smaller ventricle. each lateral ventrical communicates with the 3rd ventricle through an opening called the interventriculat foramen
  33. 4th ventricle
    is between the pons and the cerebellum it merges into the central canal of the spinal cord.
  34. Cerebrospinal fluid (CSF)
    is a clear colorless liqued that circulates in the ventricles and the subarachnoid space. CSF bathes the exposed surfaces of the CNS and completely surrounds the bain and spinal cord. It provides buoyancy protection and enviromental stability.
  35. Choroid plexus
    where the cerebrospinal fluid is formed in each ventricle. It is composed of a layer of ependymal clels and the capillaries that lie within the pia mater. CSF is produced by secretion of a fluid from the ependymal cells that originates from the blood plasma.
  36. Arachnoid Villi
    Fingerlike extensions of the arachnoid project through the dua mater into the dural venous sinuses to form this.
  37. Cerebral nuclei
    are paired irregular masses of gray matter buried deep within the central white matter in the basal region of the cerebral hemispheres inferior ti the floor of the lateral ventricle. (ganglion is best restricted to clusters fo neuron cell bodiesoutside the CNS whereas a nucleus is a collection of cell bodies within the CNS)
  38. Caudate nucleus
    ha a enlarged heaad and arching tail. When a person begins to walk the neurons in thus nucleus stimulate the appropriate muscles to produce the patterhnn and rhythem of am and leg extensions.
  39. Amygdaloid body
    is an expended region at the tail of the caudate nucleus. It participates the expression of emotions control the behavioral activities and development of moods
  40. Diencephalon
    included in the epithalamus the thalamus and the hypothalamus.
  41. Brainstem
    connects the prosencephalon and cerebellum to the spinal cord. 3 regions form the brainstem, the mesencephalon the pons and the medulla ablongata. It also contains many autonomic centers and reflex centeers required for our survival and it houses nuclei of many cranial nerves.
  42. Cranial nerves
    Oh once one takes the anatomy fine very good vacations are heavenly!! Olfactory optic oculomotor trohclear trigeminal abducens facial vestibulocochlear glossophayngeal vagus accessory hypoglossal