I think it is 3 but im not 100% sure
Pharyngeal constrictor muscles (superior, middle and inferior)
The pharyngeal constrictor muscles are a group of muscles that form the lumen of the pharynx. After you swallow, an act that you have control, it starts a involuntary contraction by these muscles to propel the bolus downwards.
The calcium get into your body through Vitamin D.
<u>Explanation:</u>
In order to make the bones healthy, calcium and phosphorus is very essential. Calcium cannot be made by human body. The body only gets the calcium it needs, by means the food you eat, or from supplements. Vitamin D plays a major role in the absorption of calcium in human body. Calcium is a major mineral in a human body that helps in the proper working of body cells and nerves.
The quantity of the minerals like calcium, phosphorous,etc that are present in a segment of bone determines the density of bone. A percentage of 15 to 20 of calcium is absorbed from the diet that human intake. When the levels of vitamin D is low, there will be lower intake to calcium by gut. This causes the bones to become weaker.
