Mblex Mometrix personal notes

Question 1

Concentric contractions / Eccentric contractions

Answer 1

Isotonic contractions include concentric contractions where muscles shorten and eccentric contractions where muscles lengthen, like lifting and lowering a book, respectively.

Question 2

Muscle spindles

Answer 2

Muscle spindle cells, located in the muscle belly, play a key role in proprioception by monitoring muscle length and movement, and they initiate reflexes to prevent muscle overstretching.

Question 3

Proprioception (sixth sense)

Answer 3

The body’s ability to recognize its position in space. It is our internal body awareness system. Ex: The reason you can touch your nose with your eyes closed or know the position of your limbs even without looking.

Question 4

Skeletal Muscle Tissue

Answer 4

Skeletal muscle tissue comprises bundles called fascicles, which are made of muscle fibers interconnected by connective tissue and supplied with blood, lymph, and nerve fibers; it has two types: Type I fibers, which are reddish and provide endurance via oxidative metabolism, and Type II fibers, which are white, suited for quick bursts of energy via anaerobic metabolism, with the muscle composition influenced by genetics and regular exercise.

Question 4

Muscle Shapes

Answer 4

Human muscles vary in shape and size based on their function, from the broad trapezius to the long bicep, with deeper ones for precise adjustments, and they’re classified as monoarticular or polyarticular based on the joints they span.

Question 4

Tendon Organs

Answer 4

Tendon organs, located at the musculotendinous junction, detect muscle tension and force on bones; when this force is too strong, they send signals to the CNS which triggers tendon reflexes to relax the muscle, preventing injury to the muscle, tendon, and bone.

Question 5

Insertion

Answer 5

The insertion of a muscle is the point where it attaches to the bone that moves when the muscle contracts. Think of it as the muscle’s “anchor” that moves.

Question 5

Origin

Answer 5

The origin of a muscle is the point where it attaches to the stationary bone. Think of it as the muscle’s “starting point” or “fixed anchor.”

Question 6

Motor End Plate

Answer 6

A “meeting point” between a nerve and muscle.
Receives signals (from neurotransmitters like acetylcholine) to tell the muscle to contract.