ANS 330 Higher Brain Centers

What are higher brain centers?

most movements used in sports activities involve controlled and coordinated movement

What are the three higher brain centers?

primary motor cortex, basal ganglia, and cerebellum

primary motor cortex

control of fine and discrete muscle movement, right in front of center sulcus, located in the frontal lobe, part of the brain that decides what movement you want to make, ex. sitting in a chair and deciding to get up

basal ganglia

not part of the cerebral cortex, deep to the cortex, cluster of nerve cell bodies, putamen (shell), globes pallidus (pale globe), caudate nucleus (nucleus has a tail)

basal ganglia function

complex functions that aren't well known, know to be important in the initiation of movements of a sustained and repetitive nature (arm swinging while walking), control complex semi-voluntary movements such as walking and running, important in maintaining posture and muscle tone

cerebellum

crucial to the control of all rapid and complex muscular activities, helps coordinate timing of motor activities and the rapid progression from one moment to the next, monitoring, making corrective adjustments in the motor activities that are elicited by other parts of the brain

What function does the cerebellum assist?

assists the function of both primary cortex and basal ganglia

How does the cerebellum work?

it facilitates the movement patterns by smoothing out movement so that it is not jerky and uncontrolled

How does the cerebellum act as an integration center?

it compares your intended (programmed) activity with the actual changes occurring in your body, then it imitates corrective adjustments through the motor system, it decides how to best execute the desired movement given your body's current position and your muscle's current status

engrams

not well understood, memorized motor patterns, stored both in the sensory and motor areas of the brain, called upon as needed

What is muscular strength?

the maximal amount of force a muscle group can generate

muscular strength example

someone with max capacity to bench press 150 kg has 2x the strength of someone who can bench press 75 kg

What is muscular power?

the product of strength and the speed of movement

muscular power example

2 individuals may have the same strength but if one requires more time than the other to move an identical load the same distance, the first individual has more power

How is power increased?

almost exclusively through gains in strength, speed is a more innate quality that changes little with training

Power formula

power = (force x distance) / time

What is muscular endurance?

the ability of a muscle to sustain repeated muscle actions or a single sustained action, I.e. how many reps of bench pressing 75 kg, may be 75% of your strength (100kg)

How is muscular endurance increased?

through gains in muscular strength, through changes in local metabolic and circulatory function

How effective is resistance training?

it can produce strength gains of 25-100% in 3-6 months

What is muscular strength due to?

muscular size, but that's not the whole picture

super human strength

women increase muscle strength without the same amount of hypertrophy as men, similar results with children

Where does strength come from?

strength is not solely the property of muscle, it is the property of motor system

motor unit recruitment

very important in strength gains, usually recruited asynchronously meaning not all called on at the same instance

What does recruitment depend on?

it depends on summation of excitatory impulse and inhibitory impulses

What can strength gains result from?

recruitment of additional motor units to act synchronously so that more motor units are activated simultaneously, may be reduction or blocking inhibitory impulses

Does synchronization of motor units occur?

not sure, may be more motor units are recruited to perform a given task

autogenic inhibition

inhibitory mechanisms in neuromuscular systems might occur (GTOs)

What do the GTOs prevent?

prevents muscles from exerting more force than bones and connective tissue can tolerate

What happens during superhuman feats of strength?

major damage occurs to these structures

What happens when threshold of GTO is exceeded?

when tension on a muscle's tendons and internal connective tissue structures exceed the threshold of the GTO, motor neurons to that muscle are inhibited

What is this reflex called?

autogenic inhibition

How can autogenic inhibition be attenuated?

with resistance training