Nervous System + Locomotion

Question 1

describe monosynaptic reflexes

Answer 1

motor neurons that are involved in spinal cord connect with muscle. stress receptor in muscle goes to spinal cord, synapses in spinal cord to effector. just one synapse.

Question 2

describe polysynaptic reflex

Answer 2

involves multiple neurons. sensory stim, goes down afferent path to spinal column. interneurons get info, then synapse onto efferent path, which synapses onto muscle to cause contraction/effector.
ex. to move arm away, need to coordinate the bicep to contract and tricep to relax to move arm away.

Question 3

describe antagonistic muscles

Answer 3

somatic system coordinates timing and strength of muscle contractions
muscles arranged in antagonistic pairs (extensors and flexors)
motor pool is a collection of motor neurons that innervates a muscle
muscle contraction depends on coordination between motor pools of antagonistic muscles

Question 4

describe levels of motor control

Answer 4

lowest level of motor control is motor neuron (including collection of motor neurons that make up the motor pool that innervates muscle)
repetitive motor output depends on central pattern generators (CPGs)

Question 5

describe CPGs

Answer 5

central pattern generators are networks of neurons in the spinal cord. they produce rhythmic motor patterned outputs in absence of input from higher centres. motor patterns can be modified.

the rhythmic motor behaviour is a direct readout of the pattern of neuronal activity, its a straightforward connection between neural function and behaviour. They coordinate antagonistic muscles while walking

not well understood in humans, but could have therapeutic applications

Question 6

describe muscle memory

Answer 6

muscle memory is the coordination of a person’s muscles, joints and neurological system involved in an action.
once a movement is performed frequently, it can be replicated without conscious effort or thought = muscle memory.

ability to duplicate the activity allows for precision and fluency, and works despite long term inactivity.

Question 7

describe muscle memory in the brain

Answer 7

Main motor cortex (M1): important for control and execution of motor behaviour and enables voluntary movement. when a person is learning new motor skills, there is an increase in M1 activity

basal ganglia: engaged in action selection, movement initiation and motor learning. role in procedural memory.

cerebellum: motor coordination, maintaining balance, learning new motor abilities. fine tunes motor output. plays role in acquisition, retention and timing of motor abilities, which suggests a role in muscle memory.

Question 8

describe muscle memory in the muscles

Answer 8

when muscles are stressed to point of hypertrophy, they grow new cells to get stronger. More myomuclei are added as the muscle grows (some are borrowed form satellite cell fusion) and these persist even during atrophy. early exercise allows individuals to “bank” myonuclei to draw upon later in life.