The prime mover of inspiration is the a. diaphragm, b. internal intercostals, c. external intercostals, d. abdominal wall muscles.

Video transcript

Hi, everyone. Let's take a look at this practice problem together, which of the following muscles is dome shaped and is responsible for inhalation. The answer options are a pectoralis minor, B, sternocleidomastoid, C diaphragm and D Rectus Abdominus. So, inhalation is part of breathing. So it's when we are taking in air. So let's go ahead and talk through each of these answer options. When people talk about working out their chest, they usually say that they're working out their pet pecks and they are referencing the pectoralis muscles. Now, the pectoralis minor is the smaller of the pectoralis muscles. So it's located in the chest and it helps to stabilize the scapula and shoulder joint. It is not responsible for inhalation. So we can eliminate it the sterno cyto mastoid muscle. This muscle tells us where it is. So the origin is at the sternum and the clavicle. Thus, we have sterno and clio and it inserts onto the mastoid. Now, this is a neck muscle and it helps to rotate and flex the neck. So, option B is incorrect as well. Option D, the Rectus Abdominus, this is one of our ab muscles. The term six pack abs refers to the rectus abdominus and this muscle flexes the spine so we can eliminate it as well. That means the correct answer is diaphragm. This is the dome shaped muscle. It's located under the lungs. And when you breathe in air, the diaphragm is going to contract and flatten, which creates a vacuum and allows air to be drawn into the lungs. So it's actually dome shaped when the muscle is relaxed and when it relaxes it pushes air out of the lungs. So again, the correct answer is option. C diaphragm. All right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.