Diaphragm muscle tissue

Cobra venom helps the snake secure food by binding to acetylcholine receptors on the diaphragm of a bite victim, leading to the loss of function of the diaphragm muscle tissue and eventually death. In order to develop more potent antivenoms, scientists have studied what happens to the toxin once it has bound the acetylcholine receptors. They have found that the toxin is released from the receptor in a process that can be described by the rate law... 

In these studies, the diaphragm muscle tissue used was obtained from mice. The isolated tissue was equilibrated to Hank s solution, a defined nutrient media, for a minimum of 6 hours at 4 C. It was found that this tissue retained its viability for at least 24 hours stored in this fashion. 

Enzymatic N-demethylation of morphine also occurs in other opioid target tissues such as the GPI and hybrid cell lines but is absent in non-target tissue such as the diaphragm muscle. 

Figure 111.4 Isometric twitch contraction times. Time to peak twitch force (a) and half relaxation time of twitch force (b) are plotted for rat diaphragm muscle strips. Hypothyroidism was induced for 3 months in the rats prior to tissue extraction and in vitro evaluation. Hypothyroidism resulted in prolonged time to peak twitch force and half relaxation time. lndicates statistically significant difference from control muscle strips (p < 0.05). Error bars are SEM.

Muscle tissue function, including skeletal muscle and muscles of the diaphragm, which are required for breathing... 

Studies of the effect of muscle in vitro have included a variety of preparations, namely, heart-lung preparations, perfused limbs, perfused heart, and diaphragm. All these biological systems differ by the relative amount of muscle tissue in the preparation. 

The situation concerning a possible role for free radicals in fatigue of skeletal muscle therefore remains unclear. Antioxidants may have some inhibitory role in fatigue of a diaphragm preparation but our experiments using a similar intact skeletal muscle system have not supported these conclusions. It is therefore possible that antioxidants are only beneficial where tissue viability is compromised. Further work is required to clarify this area. 

Ligament of Treitz Suspensory muscle of the duodenum the tissue that connects the duodenum to the diaphragm. 

Recently Izumo et al. [100] have reported that the myosin multichain family is composed of six different myosin heavy chains that are all responsive to thyroid hormones. The same myosin heavy chain gene can be regulated differently by thyroid hormones, even in opposite directions, depending on the tissue in which it is expressed. Differential expression and regulation by thyroid hormones have been demonstrated not only in heart muscle cells (atrium and ventricle) but also in several skeletal muscles (soleus, diaphragm, masseter, etc.). 

GH also stimulates protein synthesis in heart muscle [87]. This effect seems to be associated with a fall in the concentration of cyclic AMP in the tissue [87], an effect which has also been shown by some workers for diaphragm [39] but not by others. 

Q3 Expiration in quiet breathing is passive. When inspiration ceases and the intercostal muscles and diaphragm relax, the volume of the thorax diminishes and the elastic tissues of the lung recoil. This recoil is sufficient to move the normal expiratory volume of air out of the lung. 

Inspiration is an active process involving the diaphragm and external intercostal muscles. Expiration is normally passive, because of relaxation of these muscles and recoil of lung tissue. 

Other Tissues. Sulphonylurea receptors have also been described for cardiac muscle, skeletal muscle and smooth muscle but do not appear to be of therapeutic benefit for lowering blood sugar (Panten et al., 1992). Specific binding to membranes isolated from other rat tissues (liver, lung, kidney, heart, spleen, diaphragm, duodenum, colon and stomach) was... 

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