Describe the structures and regulatory mechanisms essential for both Essay

Describe the structures and regulatory mechanisms essential for both quiet and heavy breathing - Essay Example As diaphragm contracts and moves down, the chest cavity is enlarged reducing lung pressure. Air moves in to equalize the pressure. When the diaphragm relaxes, it moves back to its original position pushing air out due to the increased pressure in the chest cavity. In heavy breathing, many other muscles are involved. During the inspiration process, the lower ribs are raised up and out by the external intercostal muscles. The process increases lateral as well as anterposterior proportions of the thorax. Sternomastoids and the scalene muscles also aid the process by helping raise and push the sternum and the upper ribs2. This creates a pressure gradient which draws air into the alveoli. Unlike quiet expiration which is predominantly passive, heavy expiration requires the functioning of several muscles. The most important muscles here are the ones making up the abdominal wall. They include the internal and external obliques and the rectus abdominus. The transverse abdominus also plays a role in the process. These abdominal wall muscles raise the intra- abdominal pressure by contracting3. It results in the pushing up of the diagram. The upward movement raises the pleural and alveolar pressure thus driving air out. The ribs are also pushed down and in during heavy expiration by the internal intercostals. The breathing rate is controlled by the respiratory center in the brainstem. It is responsible for sending signals to the various respiratory muscles thus dictating when to breathe. The spinal cord is directed to maintain breathing by the medulla4. A part of the brain called the pons, located near the medulla, is key in smoothening the breathing and respiration pattern. Synchronization occurs between the involved neural centers and the muscle movement in order to ensure smooth breathing. The control occurs automatically and continuously. One

Regulation of cancer cell proliferation using siRNA tchnology Research Paper - 2

Regulation of cancer cell proliferation using siRNA tchnology - Research Paper Example The cancer stem cells are connected to maintain the unlimited and self-renewal growth capabilities of cancer while only consist of a small potion of the tumor. Consequently, cancer stem cells could be responsible for tumor progression, metastasis, and drug/treatment resistance development. Other studies have proved that small interfering RNAs (siRNAs) play a big on what genes are expressed or not expressed through gene silencing capabilities. Excitingly, siRNAs might provide some new perception into the complexities of cancer. These siRNA molecules could hold a huge potential therapeutically in the fight against cancer. This paper, discuses the functions of siRNAs and cancer stem cells and explain the link between these 2 topics. The paper also present methods to employ in current and forthcoming research to study the topics and expound upon different molecular therapy options that may have implications in altering cancer stem cells dysregulation and fighting