The muscular system is an organ system consisting of 3 types of muscles tissues: skeletal, smooth and cardiac muscles. It permits movement of the body which is one important function. Muscles also function is assistance of blood circulation throughout the body. When muscle is relaxed the valves that carry blood will be closed, and the valves open up for blood flow when muscle contract on it.
Muscles also help digestion as it help to move the food in the digestive system. The muscle move in wave like contraction in the guts and this is called peristalsis. Another is also important to control our postures. The muscular systems in vertebrates are controlled through the nervous system although some muscles can be completely autonomous.
The skeletal muscles is also known as striated muscle. The cell structure of it is long and cylinder and has nucleus at each end of the cell. It is the voluntary muscle that is used to effect the skeletal movement, posture and balance. It is completely under our conscious control , like moving our finger, neck , legs etc.
It also includes facial muscle like make us smiling and frowning. The properties of skeletal muscles includes excitability, irritability, contractility, extensibility, elasticity and adaptability. It creates 3 types of actions. Agonist which is the primary movers and antagonist as the secondary movers.
One making certain action happen and one support it, like the bicep and triceps when we flex our bicep. The 3rd is fixators which works as stabilizers.
The cardiac muscle make up the mass of the heart. It is also striated but branched and connected through intercalated disk which allow the muscle cell to resist to high blood pressure and the strain of pumping through lifetime.
It is responsible for the rhythmic contraction of the vital pumping organ of the heart to the whole body. Besides that, the cardiac muscle help to oxygenate the blood through left atrium and ventricle straight to the aorta before spreading to the whole body.
The smooth muscle is not striated and are tapered and each end is getting smaller and each has one nucleus in the center. The smooth or visceral muscle is also involuntary control or by subconscious.
It is found in the wall of organs and structures like stomach, esophagus, uterus etc. For the digestive system, it is super important as the food is moved with wave like contraction of the smooth muscle in a synchronized manner. The muscle will then break the food down for further process.
The smooth muscle also help to move the fluid through the whole body and the process of elimination from the gastro intestine system.