Critique of Radiograph #24. 1  The diagnostic standard for the AP cervical spine view includes: 2  Demonstration of vertebrae C3 through T1, even if the patient is in a cervical collar. All soft tissues of the neck should be included on the AP view. 3  Radiograph density should include good penetration of the entire spine.
The enzyme named pepsin is released by some chief cells that can be found in the stomach. This enzyme has the capability and the role of degrading food proteins into peptides, thus producing digestion. Discovered in 1836, pepsin was the first revealed enzyme and also the first that was crystallized.
Pepsin cleaves Phe1Val, Gln4His, Glu13Ala, Ala14Leu, Leu15Tyr, Tyr16Leu, Gly23Phe, Phe24 in the insulin B chain. Pepsin exhibits maximal activity at pH 2.0 and is inactive at pH 6.5 and above, however pepsin is not fully denatured or irreversibly inactivated until pH 8.0. Therefore, pepsin in solution of up to pH 8.0 can be reactivated upon re-acidification. The stability of pepsin at high pH has significant implications on disease attributed to laryngopharyngeal reflux. Pepsin remains in the larynx following a gastric reflux event. At the mean pH of the laryngopharynx (pH = 6.8) pepsin would be inactive but could be reactivated upon subsequent acid reflux events resulting in damage to local tissues. In laryngopharyngeal reflux. Pepsin is one of the primary causes of mucosal damage during laryngopharyngeal reflux. Pepsin remains in the larynx (pH 6.8) following a gastric reflux event. While enzymatically inactive in this environment, pepsin would remain stable and could be reactivated upon subsequent acid reflux events.