In pyloric stenosis,explain the cause of i non- bilious vomiting ii.aspiration pneumonia? ?

i. Non-bilious vomiting in pyloric stenosis is caused by the obstruction of the pyloric sphincter, which is the muscle at the bottom of the stomach that controls the flow of food into the small intestine. When this muscle becomes thickened and narrowed (stenosis), it can prevent food from passing through properly, leading to vomiting. The vomit is typically non-bilious because it has not yet reached the small intestine where bile is added to the digestive process.

ii. Aspiration pneumonia can occur in pyloric stenosis because the vomiting that occurs can lead to the inhalation of stomach contents into the lungs. This can cause irritation and inflammation in the lungs, leading to pneumonia. Aspiration pneumonia can be a serious complication of pyloric stenosis and requires prompt medical attention.

i. Non-bilious Vomiting

In pyloric stenosis, the pylorus, the outlet of the stomach, becomes narrowed due to hypertrophy and spasm. This narrowing obstructs the passage of food and gastric contents into the small intestine. As a result, the stomach becomes distended and can't empty effectively.

When the stomach is overloaded with contents, it triggers a reflex action called the "gastrocolic reflex." This reflex causes coordinated contractions of the stomach and small intestine, leading to forceful expulsion of stomach contents through vomiting.

Since the obstruction is at the pylorus, the vomitus primarily consists of undigested food and gastric secretions and does not contain bile. Bile is produced in the liver and gall bladder and is normally released into the duodenum to aid in fat digestion. However, due to the obstruction, bile cannot pass through the narrowed pylorus and hence is not present in the vomitus. Therefore, vomiting in pyloric stenosis is typically non-bilious.

ii. Aspiration Pneumonia

Aspiration pneumonia is a condition where foreign material, such as stomach contents, enters the lungs. In pyloric stenosis, frequent and forceful vomiting can lead to aspiration of gastric contents into the lungs.

When gastric contents enter the lungs, they can cause inflammation and damage to the lung tissue. This inflammation and damage can lead to an infection, resulting in aspiration pneumonia. Additionally, the acidic nature of gastric contents can further irritate and damage the delicate lung tissue, exacerbating the infection.

Therefore, in pyloric stenosis, recurrent non-bilious vomiting increases the risk of aspiration pneumonia due to the frequent passage of gastric contents into the mouth and the potential for these contents to be aspirated into the lungs.