Anatomy and Physiology 1 - Study Questions: Muscle Tissues

What’s inside a whole muscle?

is made up of bundles of long, thin cells called muscle fibers. Inside these fibers are proteins that help the muscle contract and relax.

What is a sacromere?

is the basic unit of a muscle. It's the part that contracts and relaxes to make the muscle move.

How does actin and myosin cause muscle contraction?

They are proteins in muscle fibers. During muscle contraction, myosin grabs onto actin and pulls, causing the muscle to shorten and generate force.

What are the steps of cross-bridge cycling?

1. The myosin (a protein in muscle) attaches to actin (another protein) forming a 'bridge'.

2. Myosin pulls actin, causing the muscle to contract.

3. Myosin detaches from actin.

4. The cycle starts again when myosin reattaches to a new spot on the actin, ready to pull again.

How does the release of calcium cause muscles to contract?

When a muscle needs to contract, signals from the nerves cause calcium to be released. This calcium binds to proteins in the muscle, triggering the muscle to contract.

When a nerve signal reaches a muscle fiber, what happens?"

it triggers the muscle to contract or relax.

How does a muscle’s length affect its strength?

it can affect how strong it is. When a muscle is at its optimal length, it can contract and generate the most force. If it's too short or too stretched, it can't contract as powerfully.

How does the frequency of stimulation affect the force of a muscle?

The frequency of stimulation refers to how often a muscle is signaled to contract. If the muscle is stimulated frequently, it can generate more force than if it's stimulated less often. This is because the repeated signals can add up and produce a stronger muscle contraction.

What is tetanus?

is a serious bacterial infection that causes stiffening and tightening of muscles, often leading to a locked jaw.

What is the latent period and why does it exist?

is a short delay from when a muscle receives a signal to contract, to when it actually starts contracting. It's the time needed for the muscle to prepare for the action.

What are motor units, and how do we control how strongly one of our muscles contracts?

are groups of muscle fibers that are controlled by a single nerve. By deciding how many motor units to use, we can control how strongly a muscle contracts.

What are the differences between red and white muscle fibers?

Red muscle fibers are meant for endurance and use oxygen to function, while white muscle fibers are for quick, short bursts of strength but tire quickly.