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The difference between systolic (the upper number) and diastolic (the lower number) pressures is known as the pulse pressure: Systemic pulse pressure = Psystolic - Pdiastolic For a typical blood pressure reading of 120/80 mmHg the pulse pressure is therefore 40 mmHg. It is proportional to stroke volume, the amount of blood pumped from the heart in one ...


10

There is no direct link between the capillaries in the sinuses and the ear. The Eustachian tubes drain the middle ear (between the eardrum and the inner ear) into the nasopharynx, the part of the throat that is just behind the nose. The para-nasal sinuses drain into the nasal passages themselves at different points. The sinuses and middle ear constantly ...


10

Dizziness after eating, which can lead to falls and passing out, is called postprandial hypotension, and as the heart is indeed responsible for responding to hypotension by increasing it's rate - which can be seen in any number of clinical scenarios from blood loss to standing up too suddenly - failure to do so, for any reason including heart disease, can ...


9

Alternative Heart Morphologies Amphibians and some reptiles have a three-chambered heart, with 2 atria and a single ventricle. There are still separate circulatory pathways for the lungs and the rest of the body, but the oxygenated and oxygen-depleted blood mix in the ventricle, and are pushed at the same time to the lungs and body. The disadvantage of ...


8

Arterial Baroreceptors felling the pressure. Arterial blood pressure is normally regulated within a narrow range, with a mean arterial pressure typically ranging from 85 to 100 mmHg in adults. It is important to tightly control this pressure to ensure adequate blood flow to organs throughout the body. This is accomplished by negative feedback systems ...


7

This page (and many others) explain the idea rather well. This is more of a physics than a biology question, but the fundamental concepts are the same. In fact, contrary to what you wrote in the question, the measured blood pressure should be lower than expected if the arm is elevated above heart level. When you reduce the pressure on the bent pipe, the ...


7

The key is in fluid compartments and osmotic activity. For the purposes of this discussion, let us say that there are two fluid compartments the ExtraCellular Fluid (ECF) and IntraCellular Fluid (ICF). Only the ECF contributes to blood volume and blood pressure. Na is not only the major ECF ion, but it is also confined there. The ICF concentration of Na is ...


6

In the vascular system, pressure is what moves blood forwards, at least in an analogous manner to voltage...just like voltage, pressure itself doesn't move things, but a pressure gradient does. You are correct that the pressure applies in all directions, but the resistance of the blood vessels means that the pressure can only be relieved by flowing in one ...


5

Korotkoff sounds! The blood pressure measurement process is fairly cool, and goes like this. Inflate the cuff to well over plausible blood pressures (250mmHg or so). Slowly deflate the cuff while listening to the artery. When you start to hear sounds, that's when the systolic blood pressure is higher than the cuff pressure and the heart can squeeze a ...


5

Fluid movements across capillary wall is determined by 2 main factors. Hydrostatic Pressure (Blood Pressure) - tends to push fluid out of the blood vessel Osmotic Pressure - Tends to pull fluid back into the blood vessels mainly due to the presence of plasma proteins. (especially albumin) Important points you should know Hydrostatic pressure or blood ...


4

Blood pressure is sensed in blood vessels by baroreceptors. Baroreceptors are stretch-sensitive nerve fibers located primarily in the aortic arch and carotid sinuses. The baroreceptors send afferent fibers via the glossopharyngeal nerve to the nucleus tractus solitarii in the dorsal medulla in the brainstem. From there, efferent cardiovascular neurons send ...


3

First, a couple of considerations Heart rate (HR) is lower when seating, and even lower when lying. I assume that participants were seated when the first measure was taken. Cardiac output is not constant during the day. Depending on the moment, some factors such as digestion have an impact in Cardiac output, so take that into account when carrying out the ...


3

High blood pressure is caused by an excessive amount of fluid circulating in the blood vessels, or an excessively small mean blood vessel diameter. The later is more associated with stress situations and stressful lives, while the former is more related to the theme of your question: electrolyte balance. An electrolyte is any molecule that produces an ...


3

The human blood contains about 45% of erythrocytes and 54.3% of plasma by volume. The plasma contains about 92% water, while the erythrocytes, about 64% by weight. The blood is slightly less than 80% water. Dehydration occurs when water intake is insufficient to replace free water lost due to normal physiologic processes (like sweating, urination etc). ...


3

Sodium acts on the juxtaglomerular cells of the kidney, which are then activated to produce and secrete renin. Renin hydrolyses angiotensinogen into angiotensin I. Next angiotensin converting enzyme (ACE) converts angiotensin I to angiotensin II. Angiotensin II is the product that causes the increase in blood pressure, because it is a potent vasoconstrictor....


3

The sound in question is called the Korotkoff sound: If the pressure is dropped to a level equal to that of the patient's systolic blood pressure, the first Korotkoff sound will be heard. As the pressure in the cuff is the same as the pressure produced by the heart, some blood will be able to pass through the upper arm when the pressure in the ...


3

The blood pressure is the fluid's movement "strength" in the arteries (or "artères", please edit my post with the correct english word) Blood pressure is a measurement of the strength of flow through the arteries. (I.e., the force per unit area exerted by the blood on arterial walls.) So replace vein with artery and your definition is correct. The "...


3

Weight gain increases blood pressure, the reason for this process is due to the effect of hormone called Leptin. Leptin is made by fat and circulates in the bloodstream to reach the brain, where it acts as a signal for energy reserves, adjusting both energy expenditure and the sensation of hunger – hence it is sometimes referred to as the ‘satiety hormone’...


2

Yes, treatment of thrombus can cause embolism. Hypertension favors hemorrhagic complications. Thrombolytics: Yes, they can cause paradoxical embolism, although it is a rare complication [1]. The most fearful complication of thrombolytic medication is major hemorrhage. And hypertension favors bleeding [2]. Catheter-directed thrombolysis: Hypertension (...


2

There are two levels to take your question at. The first is simpler but I'm not sure if it is what you are looking for: If you imagine the heart and all the blood vessels in your body as a closed plumbing system with no leaks (not entirely accurate) then when the heart contracts and squeezes the blood from the ventricles the total surface area the blood is ...


2

Ah, I'm afraid there are a near infinite number of variables that will make a general answer impossible. Factors such as: age, sex, weight, which vein, additional damage, heart condition, cholesterol level, body position, body temperature, and how the vein was cut and exposed will all lead to different answers. A general answer from someone with lots of ...


2

Yes it can! Its a very important cause of third spacing a.k.a. peripheral oedema, mainly due to decreased protein. Below is a list of causes of peripheral oedema due to fluid moving from the vascular bed to the peripheral spaces gathered from the following source: http://www.patient.co.uk/doctor/Peripheral-Oedema.htm Immobility: Increased fluid pressure ...


2

Many systems have this property. The plot you are looking at is the plot of the transfer function for blood vessel diameter vs time. A trick in mathematics or engineering is to understand a system is to sometimes look at at different system with the same properties that you do understand. For instance, a mass springer damper system is similar to a RLC ...


2

Alongside full guidance released by NICE they also produce treatment pathways which give further advice - here is the treatment pathway for hypertension. You've listed most of the investigations that would be considered in your original question. Investigations that may be considered as appropriate include: Urine dipping for proteinuria or haematuria ...


2

120/80 are not upper limits on blood pressure - many people have blood pressures far in excess of those numbers. Instead, these are numbers beyond which studies have shown connections to negative health outcomes - heart disease, for example. There is nothing magical about the numbers 120 or 80 besides their divisibility by 10; a blood pressure of 121/81 is ...


2

Preload is defined as the volume of blood that stretches the ventricle at the end of diastole. Therefore, when preload is increased, the end diastolic volume is increased. In simpler terms, there is more blood in the heart just prior to contraction. Even though there is more blood being ejected from the ventricle during systole (that is, there is an ...


2

While blood is flowing into the ventricle, it can never be at a higher pressure than where blood is flowing from: if it was, the flow would be going in the other direction. Flow is always from higher to lower pressure, if there is no pressure difference there is no flow. Before atrial contraction, the ventricle can have no more pressure than the ...


1

Answer: You are right that if you had one big pipe that was getting progressively narrower, the pressure in that pipe would increase. In the vascular system, you have one big pipe emptying into exponentially more small pipes. The total lumenal diameter of the small pipes is actually greater than the single big pipe. Even though each individual capillary has ...


1

Check out this consensus statement (PMID 17552466): J Vet Intern Med. 2007 May-Jun;21(3):542-58. Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats. Brown S1, Atkins C, Bagley R, Carr A, Cowgill L, Davidson M, Egner B, Elliott J, Henik R, Labato M, Littman M, Polzin D, Ross L, Snyder P, Stepien R; ...


1

I can't offer specific advice as to your personal readings, but it is normal to expect a difference in blood pressure between sitting & supine (lying down) positions. I have taken this quote from the Department of Health Care Sciences at Wayne State University website. Effects of body position on blood pressure Blood pressure is commonly ...


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