PTA Review of Neuroanatomy (Sensory)

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PTA Review of Neuroanatomy (Sensory)
2014-01-14 21:15:47
PTA Sensory Neuroanatomy

PTA Chapter 5 Examination of Sensory Function
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  1. What is the function of a neuron?
    Neurons have a membrane that is designed to sends information to other cells. The axon and dendrites are specialized structures designed to transmit and receive information. The connections between cells are known as a synapses. Neurons release chemicals known as neurotransmitters into these synapses to communicate with other neurons.
  2. What is the role of interneurons?
    Interneurons are responsible for communicating information between different neurons in the body.
  3. What is the role of motor neurons?
    Motor neurons (EFFERENT) transmit information from the brain to the muscles of the body.
  4. What is the role of sensory neurons?
    Sensory neurons (AFFERENT) carry information from the sensory receptor cells throughout the body to the brain.
  5. What is Sensory Integration?
    It is the ability of the brain to organize, interpret, and use sensory information.

    In an intact system, this occurs automatically without conscious effort.
  6. Dendrite – one of the threadlike extensions of the cytoplasm of a neuron. Compose most of the receptor sites of the surface of neuron.
  7. Axon – singular fiber that carries info away from the cell body to synapse sites of other neurons, muscles or glands.
  8. How do neurons transmit and receive information?
    In order for neurons to communicate, they need to transmit information both within the neuron and from one neuron to the next. This process utilizes both electrical signals as well as chemical messengers.The dendrites of neurons receive information from sensory receptors or other neurons.  This information is then passed down to the cell body and on to the axon. Once the information as arrived at the axon, it travels down the length of the axon in the form of an electrical signal known as an action potential.
  9. Myelin – surrounds the axon of the neuron – lines the nerve fibers and aids in quick and accurate transmission of electrical current carrying data from one n. cell to the next.
  10. Once an electrical impulse has reached the end of an axon, the information must be transmitted across the synaptic gap to the dendrites of the adjoining neuron. In some cases, the electrical signal can almost instantaneously bridge the gap between the neurons and continue along its path.In other cases, neurotransmitters are needed to send the information from one neuron to the next. Neurotransmitters are chemical messengers that are released from the axon terminals to cross the synaptic gap and reach the receptor sites of other neurons. In a process known as reuptake, these neurotransmitters attach to the receptor site and are reabsorbed by the neuron to be reused.
  11. What is a Synapse?
    Synapse -  small gap separating neurons Approximately 20 nm wide

  12. What is White Matter?
    White matter – contains myelinated axon tracts, color changes  from the whiteness of myelin.  A 20 yr old male has approx. 170,000 km of myelinated  axons in the brain.
  13. What is Gray Matter?
    Gray matter – components of the CNS consisting of neuronal cell bodies color comes from capillary blood vessels and neuronal cell bodies
  14. What is a Tract?
    Tract – white matter carrying information  of a specific type. Example – pain and temperature.
  15. What are the components of the PNS?
    • PNS: Peripheral nervous system.
    • 1. SNS: Somatic nervous system.
    •         a. Sensory: Afferent nerves.
    •         b. Motor: Efferent nerves.

    • 2. ANS: Autonomic nervous system.
    •       Both have afferent and efferent neurons.
    •          a. Parasympathetic: Rest and digest.
    •          b. Sympathetic: Fight or flight.
  16. What are the components of the CNS?
    • CNS: Central nervous system.
    • 1. Brain: coordination and control center.
    • 2. Spinal cord: Various levels of input and some reflexes.
  17. Schwann cells
    Schwann cells: Myelinating cells of the PNS.