Effect of covid-19 to the immune and vascular system.
	1.	COVID-19 cases can progress through a series of three stages.The first two are when the body attacks the virus. The third and more troubling stage is when the immune system goes haywire, attacking the virus with such ferocity that it does far more damage than the virus itself. Understanding the stages has major implications for how to treat patients. As the virus then replicates itself, the human body's immune system tries to stop it, responding with virus-specific antibodies and T cells That comes with much more severe symptoms as your immune system really ramps up its response. And that's when you start to see the more breathlessness which progresses to hypoxia or low oxygen levels and even progressive things much more severe like pneumonia or acute respiratory distress syndrome. when the virus replicates so fast the immune system can't get it under control before it spreads to the lungs. They can become inflamed, causing breathing problems. This can happen if a large amount of virus infects the body. the third stage is something scientists call the hyperinflammatory phase. Basically, the body's immune system begins to attack itself. The virus is not as active. It's still there, but it's the inflammation and the body's response to the virus that starts to limit the organ system,That phase, the heart starts to become dysfunctional and the kidneys start to become dysfunctional. And one sets in a stage of multisystem organ failure. And that's what kills people with this virus. We know that during severe SARS-CoV-2 infection,  heart function may decrease. Sometimes this decrease is a consequence of the systemic inflammatory response to infection, and occasionally, in some people, because of direct viral infection in the heart. Viruses can cause significant inflammation which can injure the heart and can worsen a person’s existing heart condition even if the virus does not enter the heart directly. Although COVID-19 is a new virus, cardiologists are already familiar with the effects of other viral infections on the heart. These often cause inflammation of the lining of the heart (pericarditis), the heart muscle (myocarditis) or trigger worsening of existing heart conditions such as heart attack or heart failure. All these complications are associated with other viral infections, and we are experienced in dealing with these, especially if we do not have to care for too many people at once. This is why the distancing measures and self-isolation in place are so essential to slow the numbers of people developing COVID-19.

Importance of the subsartorial canal to the lower limb:

	2.	The subsartorial canal is an aponeurotic tunnel in the middle third of the thigh, extending from the apex of the femoral triangle to the opening in the adductor magnus, the adductor hiatus. It’s also known as Adductor canal.

The adductor canal serves as a passageway for structures moving between the anterior thigh and posterior leg. It transmits the femoral artery, femoral vein (posterior to the artery), nerve to the vastus medialis and the saphenous nerve – the largest cutaneous branch of the femoral nerve.

Intraocular and extraocular muscles and it’s nerves:

	3.	The intraocular muscles: include the ciliary muscle, the sphincter pupillae, and the dilator pupillae. The ciliary muscle is a smooth muscle ring that controls accommodation by altering the shape of the lens, as well as controlling the flow of aqueous humor into Schlemm's canal. The intrinsic eye muscles are innervated by the autonomic systems and include the iris sphincter and the ciliary muscle (innervated by the parasympathetic component of cranial nerve III), and the radial pupillodilator muscles (innervated by the ascending cervical sympathetic system).
Extraocular muscles: The extraocular muscles are the six muscles that control movement of the eye and one muscle that controls eyelid elevation (levator palpebrae). The actions of the six muscles responsible for eye movement depend on the position of the eye at the time of muscle contraction. extraocular muscles are innervated by lower moyor neurons that form three cranial nerves: the abducens, the trochlear, and the oculomotor. The abducens nerve(cranial nerve VI) exits the brainstem from the pons-medullary junction and innervates the lateral rectus muscle. The trochlear nerve (IV) exits from the caudal portion of the midbrain and supplies the superior oblique muscle. In distinction to all other cranial nerves, the trochlear nerve exits from the dorsal surface of the brainstem and crosses the midline to innervate the superior oblique muscle on the contralateral side. The oculomotor nerve (III), which exits from the rostral midbrain near the cerebral peduncle, supplies all the rest of the extraocular muscles. Although the oculomotor nerve governs several different muscles, each receives its innervation from a separate group of lower motor neurons within the third nerve nucleus.