Question

1. Orthostatic hypotension is defined as the failure to maintain a fairly constant blood pressure during posture changes.  List all the functional locations within the cardiovascular system where a lack of function could lead to baroreceptor reflex dysfunction.  

2..  Describe in detail an example where the nervous system affects the circulatory system.

3. Describe in detail an example where the nervous system affects the circulatory system.

Answer 1

Blood Pressure: Baroreceptors

Imbalance between sympathetic and parasympathetic stimulation of cardiovascular system is one of etiologies of heart failure (HF). Baroreceptor reflex dysfunction (BRD) is a manifestation of this autonomic imbalance. Clinical determinants of BRD in early stages of cardiac dysfunction are not fully defined.

Orthostatic hypotension (OH) is a relatively common heterogeneous and multifactorial disorder often caused by autonomic dysfunction. This condition has a deleterious impact on quality of life and contributes to higher mortality rates. Supine hypertension is very common in patients with autonomic failure, limits the use of pressor agents, and can result in end‐organ damage. Current recommendations on the optimal management of these patients are based on expert opinion and poor‐quality small cross‐sectional studies including patients with primary autonomic failure and severe orthostatic hypotension. The authors present their treatment approach in 12 patients with disabling orthostatic hypotension and supine hypertension not related to primary autonomic failure, presenting to a referral center over a 4‐year period. The first step is to educate the patient about the pathophysiology and course of their disorder. Nonpharmacologic therapies and maneuvers are usually effective in relieving symptoms and preventing syncope. If needed, pharmacologic options such as fludrocortisones and midodrine are also available in patients with severe symptoms. Supine hypertension represents a challenge in the treatment of this condition. Therefore, elevation of the bed of the head and dosing of short‐acting antihypertensive agents at bedtime is often indicated.

2. CNS affects the circulatory system:

3. The posterior cerebral circulation is the blood supply to the posterior portion of the brain, including the occipital lobes, cerebellum and brainstem.

Your nervous system interacts with every other system in your body. In the same way that all of your cells need oxygen transported by the circulatory system, all of your tissues and organs require instruction and direction from the nervous system.

The regulation of the heart and peripheral circulation by the nervous system is accomplished by control centers in the medulla that receive descending input from higher neural areas in the brain and afferent input from mechanically and chemically sensitive receptors located throughout the body