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Flashcards in Neuroanatomy 2 Deck (19):

Describe the direct activation (pyramidal) sysytem. What does it control? Where do impulses originate?

  • Controls Voluntary motor movements
  • Impulses originate at the cortex
  • Eg. Smile


Describe the indirect activation (extrapyramidal) system. What does it control? What is it a system of? Where do impulses originate?

  • Controls involuntary movements
    • Posture, tone
  • Intricate system of subcortical connections between the cortex and the cranial/spinal nerves
  • Impulses originate in the brain stem
  • Eg. smile


Describe the primary cortexes. What do they provide? How many in each lobe? What are the three sensory cortexes? Motor?

  • Provide simple analysis of sensory or motor information
  • One in each lobe of the brain
  • Sensory:
    • Primary auditory cortex
    • Primary visual cortex
    • Primary sensory cortex
  • Motor
    • Primary motor cortex

A image thumb

Describe association areas. What do they do (sensory, motor)? Are they separate? How many are there?

  • The portion of the brain that process information that come from the primary sensory cortexes
  • Organizes and plans movement that will go to the motor cortex
  • Distinct, but highly interconnected with each other.
  • One for each lobe
    • Temporal association area
    • Frontal association area
    • Parietal association area
    • Occipital association area


Describe the temporal association area. What does it contain?

´Temporal association area
´Contains Wernicke’s area
´Not really important for this section


Describe the frontal association area. What is it important for?

Critical in initiating and planning motor movements


Describe the parietal association area. Where is it located? What does it integrate? What is it important for?

  • Located between the visual centers and the motor centers of the brain
  • Integrates visual information with sensory input
  • Critical for integrating visually guided movements (hand-eye coordination)


Describe the occipital association area. What does it interpret?

Interprets visual information and feeds it to the parietal lobe


Describe the thalamus. What is it the center of in the brain? Where is it located? What may be its function?

  • Relay center of the brain
  • Located on either side of the ventricles
  • Sits just above the midbrain
  • Function isn’t fully understood (may refine movements further)


Describe the basal ganglia. What is it connected with? Where are they located? What are they important for? What can damage cause?

  • Complex structure
  • Highly connected with other parts of the brain
  • Located lateral to either side of the thalamus
  • Critical for smoothing slow and continuous movements
  • Damage can cause:
    • Rigidity, tremor and difficulty initiating movements  (Parkinson’s disease) OR
    • Smooth, sudden uncontrollable movements (Huntington’s disease)


Describe the cerebellum. Where is it located? What does it receive input from? What is it responsible for? What skills does it impact (2)? What does it regulate (2)?  What does it contribute to? What does it control and smooth?

  • Attached to the back of the brain stem
  • Receives input from
    • the association cortexes
    • sensory receptors throughout the body (eg. inner ear).
  • Coordinates Voluntary Movements
    • Impacts both gross and fine motor skills
    • Regulates force of movements
    • Regulates tone
    • Contributes to maintaining balance
    • Coordinates and smooths skilled movements


Describe cortical tracts. What are the two kinds? Where do each go? What do each control?

  • Corticospinal tract:
    • Axons that descend from the cortex to the spinal cord.
    • Synapses in spinal cord relay signals to spinal nerves that control arms, legs, etc.
  • Corticobulbar tract:
    • Axons descend from cortex to the brain stem
    • Synapses in the brain stem relay signals to the cranial nerves which control speech, among other things. 


Describe synapses. What are neurotransmitters? Where do they communicate to? What are the two kinds of neurotransmitters? What can imbalance cause?

  • Neurotransmitters: chemicals the communicate across the synaptic cleft
    • To other neurons
    • To the neuromuscular junction
  • Excitatory Neurotransmitters
  • Inhibitory Neurotransmitters
  • Imbalance can have significant motor repercussions (eg. Spasticity)


Describe the neuromuscular junction. Where do lower motor neurons terminate? What does the junction closely resemble? How many muscle fibers will the axon innervate for gross movements? Precise/fine movements?

  • Lower motor neurons terminate at a muscle fiber.
  • Junction closely resembles a synapse
  • One axon my innervate hundreds of muscle fibers for gross movements (eg. Thigh)
  • For more precise/fine movement an axon will only activate a few muscle fibers. (eg. face muscles) 


Describe the motor system

A image thumb

Descibe the brainstem. What does it consist of? What is it a passageway between/for? What does it control? What emerges from the brainstem? What is located within the brainstem?

  • Midbrain, Pons, Medulla
  • Passageway between cortex and spinal cord for neural tracts
  • Controls integrative and reflexive actions (respiration, consciousness, some cardiovascular functions)
  • The place where cranial nerves emerge from the Central Nervous System. Cranial nerve cell nuclei are located within the brain stem


Describe upper motor neurons. Where do they run from? What do they meet? What do they make up? What are they neurons of?

Motor Neurons that run from the cortex to meet the cranial/spinal nerves.
Make up the corticobulbar and corticospinal tracts
Neurons of the central nervous system
Orange tracts in the picture


Describe lower motor neurons. What neurons are they? What do they connect to? Where do they originate and extend to? What are they nerves of?

Peripheral Motor Neurons
Neurons that connect to cortical tracts
Originate in the brain stem or spinal cord and extend to the periphery
The cranial nerves or the spinal nerves


Describe cranial nerves. How may are there? Where do they emerge from? What can they be? What do they control?

  • 12 Pairs of nerves (one on either side)
  • Emerge from the brain stem
  • May be Sensory, Motor, or Both
  • Control muscles for speaking and eating

Look at spinal nerves in book!