Question

State the cause of elevated blood pressure in essential hypertension.

Explain how compensation by the renin-angiotensin pathway aggravates hypertension.

What is the cause of weak peripheral pulses when the iliac artery is blocked?

How does gangrene develop in arterial PVDs and why may healing following amputation to treat gangrene be reduced?

Explain how leg ulcers may develop in people with varicose veins.

Answer 1

Ans :-

* Factors in Essential Hypertension

A number of factors increase BP, including (1) obesity, (2) insulin resistance, (3) high alcohol intake, (4) high salt intake (in salt-sensitive patients), (5) aging and perhaps (6) sedentary lifestyle, (7) stress, (8) low potassium intake, and (9) low calcium intake.

Causes

There are two types of high blood pressure.

Primary (essential) hypertension

For most adults, there's no identifiable cause of high blood pressure. This type of high blood pressure, called primary (essential) hypertension, tends to develop gradually over many years.

Secondary hypertension

Some people have high blood pressure caused by an underlying condition. This type of high blood pressure, called secondary hypertension, tends to appear suddenly and cause higher blood pressure than does primary hypertension. Various conditions and medications can lead to secondary hypertension, including:

• Obstructive sleep apnea
• Kidney problems
• Adrenal gland tumors
• Thyroid problems
• Certain defects you're born with (congenital) in blood vessels
• Certain medications, such as birth control pills, cold remedies, decongestants, over-the-counter pain relievers and some prescription drugs
• Illegal drugs, such as cocaine and amphetamines.

* Renin angiotensin pathway aggravates hypertension by increasing vasoconstriction and blood volume which then can increase blood pressure. This is because the blood flow through the kidneys are decreased and they increase renin, angiotensin and aldosterone secretion.

Renin by itself does not really affect blood pressure. Instead, it floats around and converts inactive forms of angiotensin into angiotensin I. These inactive forms of angiotensin, which are produced by the liver, are not able to alter the blood pressure until renin changes them into angiotensin I.

The renin–angiotensin system (RAS), or renin–angiotensin–aldosterone system (RAAS), is a hormone system that regulates blood pressure and fluid and electrolyte balance, as well as systemic vascular resistance. ... Plasma renin then carries out the conversion of angiotensinogen, released by the liver, to angiotensin I.

The renin-angiotensin system or RAS regulates blood pressure and fluid balance in the body. When blood volume or sodium levels in the body are low, or blood potassium is high, cells in the kidney release the enzyme, renin. ... Angiotensin II causes blood vessels to constrict and blood pressure to increase.

Medium-/high-renin hypertension responds very well to agents such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and β-blockers, all of which block plasma renin activity, although addition of a sodium-volume depleting drug is sometimes required to control blood pressure.

The renin–angiotensin system (RAS), or renin–angiotensin–aldosterone system (RAAS), is a hormone system that regulates blood pressure and fluid and electrolyte balance, as well as systemic vascular resistance.

* peripheral pulse refers to the palpation of the high-pressure wave of blood moving away from the heart through vessels in the extremities following systolic ejection.Peripheral pulses can be used to identify many different types of pathology and are therefore, a valuable clinical tool.

A peripheral pulse refers to the palpation of the high-pressure wave of blood moving away from the heart through vessels in the extremities following systolic ejection.During systolic contraction of the heart, a high amplitude wave of blood gets ejected through the aortic valve out towards the periphery.

pulse is the rate at which your heart beats. ... When their pulse is absent, you can't feel it at all. A weak or absent pulse is considered a medical emergency. Usually, this symptom indicates a serious problem in the body. A person with a weak or absent pulse will often have difficulty moving or speaking.

* Treatment of gangrene :

1. Antibiotics. These medicines can be used to kill bacteria in the affected area.
2. Surgery to remove the dead tissue. This is called debridement.
3. Maggot debridement.
4. Hyperbaric oxygen therapy.
5. Vascular surgery.

Surgery to cut out the dead tissue, known as debridement, is often necessary to prevent the gangrene from spreading and to allow the surrounding healthy tissue to heal.

Generally, people who have dry gangrene have the best chance of a full recovery because dry gangrene doesn't involve a bacterial infection and spreads more slowly than do the other types of gangrene. However, when gangrene caused by an infection is recognized and treated quickly, the odds of recovery are good.

Gangrene can sometimes be treated without serious complications, especially if it is caught early. However, it can lead to amputation in some serious cases, particularly if it's not treated quickly. the gangrenous area covers a large part of your body. treatment is not provided quickly enough.

* The cause of venous ulcers is high pressure in the veins of the lower leg. The veins have one-way valves that keep blood flowing up toward your heart. When these valves become weak or the veins become scarred and blocked, blood can flow backward and pool in your legs. This is called venous insufficiency.

venous ulcer, sometimes called a varicose ulcer, is a leg wound that happens when the leg veins don't circulate blood back toward the heart. Blood can back up in the veins, building up pressure on the skin, which can cause an open sore to form.

The veins in your leg are tubes that carry the blood back from the foot towards your heart. The veins in your legs have one-way valves that make sure the blood flows up the leg and not back down. In some people, these valves are not very effective or can be damaged by thrombosis (clots) in the veins. If the valves are damaged, blood can flow the wrong way down the veins, which results in a very high pressure in the veins when standing up. This abnormally high pressure in the veins damages the skin and leads to the ulcers.