03.01 Muscle Anatomy (anatomy and physiology)

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In this lesson, we're going to take a look at the structure and function of muscle anatomy.
There are three types of muscle in the body. They are skeletal, cardiac, and smooth muscle.

Skeletal muscle is involuntary muscle, and it's innervated by the somatic nervous system.

Cardiac muscle is an involuntary muscle, and it's innervated by the autonomic nervous system.

Smooth muscle, which is found in places like the intestines, are involuntary, and they are also innervated by the autonomic nervous system.

Now where all these muscles located?

Skeletal muscle is associated with bones. They're found surrounding cavities, and they also are found in the diaphragm and the extrinsic muscles of the eye. The extrinsic muscles of the eye are the outer muscles of the eye that are responsible for movement. So if you need to look to one side or the other it allows you to move your eyes in a certain direction.

Cardiac muscle is only found in the heart. It's pretty simple.

Smooth muscle is a little bit more complex, and that is found in the walls of hollow organs. So these are things like vessels, respiratory, Digestive, and excretory tracks. You can also find smooth muscle and a capsule of the spleen, and the intrinsic muscles of the eye. So these are things like the iris, or the muscles that are responsible for changing the shape of the lens to allow you to focus.

So what are the muscle functions? Well muscles are responsible for movement and propulsion.

Skeletal muscle is responsible for locomotion, so essentially all movements that are voluntary. These are things like grasping and head and breathing movements when you voluntarily take a breath. Cardiac muscle is responsible for propelling blood to the cardiovascular system, and it's an automatic process that you don't have to think about.

Smooth muscle is responsible for moving a bunch of other stuff for the body. The GI tract moves food, the urinary tract moves urine into the bladder, the bladder literally squeezes all of the urine out of the butter through the urethra. The uterus contracts during childbirth, and during defecation of the rectum contracts to propel stool out.

I know that muscles have a bunch of cool functions, but what else do they do?

Well they're also responsible for blood pressure regulation. Smooth muscle is responsible for contracting in the arterioles, so if you wanted to increase blood pressure the vasoconstrict, and if you want to lower blood pressure, the vasodilate.

Muscles are also responsible for posture. Skeletal muscle hold you up right, and you can have something called muscle tonus which is a slight muscle contraction throughout the entire body all the time so that you just don't fall into a heap of mess on the floor.

That muscles do is that they're responsible for body heat. Heat is a result of the muscles breaking down glucose, which is their normal process. Skeletal muscle contraction results in body heat, and says 40% of our body mass is made from skeletal muscles, it helps to keep us warm and helps to regulate their body temperature. If you noticed that when you've ever had a fever, you also get the chills. The reason is is that the body is trying to increase its core body temperature to break down whatever virus or bacteria that there, and by literally causing your muscles to shake, you increase body heat and it allows your body to increase your body core temperature

So let's recap.

There are three muscle types, skeletal cardiac and smooth muscle.

They’re are responsible for movement and propulsion. Skeletal muscle is voluntary and cardiac and smooth muscle involuntary.

the functions of the skeletal muscle are Locomotion, breathing, and eye movement.

Smooth and cardiac muscle are responsible for proposing food and fluids throughout the body.

The other cool functions they have or that they regulate body heat, posture and also blood pressure.

And that's it for a lesson on General muscle anatomy. Make sure you check out all the resources attached to this lesson. Now, go out and be your best selves today and as always, happy nursing
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