NEUR30003 Lecture Notes - Lecture 16: Alltrials, Nociceptor, Anterior Grey Column
Overall organization of neural structures that control movement. Large cholinergic neurons in the brainstem and motor cortex control skeletal muscles. Sensory structures: detects changes occurring in muscles. Brainstem and motor cortex: exert influence on. Lmn either directly or indirectly (more commonly send projections to spinal cord motor regions -> excite local circuit neurons -> control excitability of motor neurons) Only motor neurons send info out to muscle. Motor pools: the longitudinally oriented clusters of mns for a particular muscle. Looks at muscles from calf (gastrocnemius and soleus) where are the motoreneurons situated that activate those specific muscle. Traced location of motorneuron cell bodies- form clusters in lumba-sacral spinal cord: they occupy discrete territories with little overlap called motor neuron pools. If motor neurons are medial in ventral horn, then they innervate proximal muscles. If motor neurons are lateral in ventral horn, then they innervate distal muscles. Motor unit: each motor neuron innervates a collection of muscle fibers within a muscle.