1.What do you understand by the term “endothelium-dependent” vasodilation?  Explain?

the term “endothelium-dependent” vasodilation means the endothelium controls vascular tone in a paracrine fashion through releasing diffusible soluble mediators that can act on physically contiguous cells.

2. When we talk about the NOS enzyme, what is meant by “constitutive” and “inducible” enzymes and what are the pathological and physiological implications thereof?

when exposed to inflammatory mediators iNOS are expressed through transcriptional induction which means NO synthesis is not regulated by calcium. eNOS and nNOS’s NO synthesis is dependent on calcium regulation as they are expressed continuously produced regardless of cells' needs (constitutive). complexes between calmodulin and Cytosolic calcium form which then binds and activates eNOS and nNOS.

3.Explain how NO contributes to fatal pathology of septic shock

Components which are present in bacteria such as endotoxins and cytokines cause the formation of iNOS in smooth muscle cells and macrophages. It is a systemic inflammatory response to an infection. The accumulation formation of nitric oxide in a large area results in shock and severe hypertension which can be fatal.

4.Which autacoids mechanism of action depends on effects on the guanylyl cyclase-cGMP system

Nitric oxide

5.NO may be toxic to the cell.  Which mechanisms are available to the body to counter this detrimental effect of NO?

Homeostasis counters the detrimental effect.

6.Name a way in which NO can act pro-inflammatory. Give examples where it will have advantages or disadvantages.

when there is an overproduction in abnormal conditions it induces inflammation and thus a acts as a pro-inflammatory this is advantageous as inflammation increases blood flow to the affected area thus speeding up the rate of healing of injured tissue then again it can result in pain of a swollen joint when it is used which can be discomforting.

7. In what possible neurological and mental illnesses is NO involved?

Alzheimer's, Huntington's disease, Parkinsonism,