The study of the normal function of living organisms and the means by which it is achieved.

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Is the resting state of the forearm in the pronated or supinated position?

It seems to me that my forearm is naturally in a more pronated position than the anatomic (supinated) position and that it actually takes work to make it hold the supinated position. Anyone an expert ...
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75 views

Why do bats huddle during late fall?

In the late fall, bats hibernate in clusters with many bats pressed together and holding on to one another. Which of the following supposed advantages of huddling behavior is, in reality, not true? ...
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13 views

Does Sympaticus and lymphatic circulation cause feeling of thirsty after short shower?

I have been reading blogs, Guyton and Pocock about what triggers the feeling of thirsty. I am not convinced that is the fact of warm water time is short so not much water lost Assume that the ...
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17 views

What is the function of clot retraction?

I am thinking how clot retraction and fibrinolysis work together. I think that clot retraction is a process that gets clot towards fibrinolysis process. Fibrinolysis process then lyses the clot. ...
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29 views

What is the difference between intracardiac and extracardiac reflexes in cardiac regulation?

The primary parameters of heart pumping are strength of contractility (inotropic positive; Frank-Starling relationship) rate of relaxation (lusitropic positive) heart rate (chronotropic positive) ...
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19 views

How many systemic reactions in inflammation?

I have this sentence in my notes Inflammation consists of two local reactions and one systemic reactions. which is difficult for me to accept. Two local reactions are vascular and cellular. I ...
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2answers
134 views

Converting unit/mg or unit/ml into ng/ml, or vice-versa

I am working with the enzyme Cu/Zn Superoxide (SOD1) and i am quantifying them in ng/ml. However, most past studies has SOD1 quantified in unit/mg or unit/ml, and i need to compare the SOD1 level of ...
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22 views

Late control mechanisms of blood pressure (arterial) level?

I first covered the fast and moderate control mechanisms which I think are Fast control: Baroreceptive reflex (tonus), Chemoreceptive reflex (CO$_2$). Moderate control: Bicarbonate (ECF), ...
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32 views

Which processes are included in the process called cells eating themselves?

I am reading about atrophy and I am thinking to which processes the phrase cells eating themselves refer to. Cells need something to survive these difficult times. To decrease protein synthesis ...
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18 views

Order of events in hibernation

Arrange this in sequence : i. Heat loss exceeds heat production. ii.As body temperature falls, heat loss decreases. iii.Body temperature equals environmental temperature. ...
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86 views

Why can CO2 be transported dissolved in plasma?

Is it because CO2 is more soluble in water or has it got to do with the alkaline pH of plasma ?I here mean only aqueous CO2 transport from body cells to lungs.
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59 views

What stops the coagulation process?

Whenever there are minor/major injury to blood vessels, the platelets, fibrin, thrombin, etc. are recruited. They then seal the wound and block bleeding. What tells them that their job is done?
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86 views

All or none phenomenon

Let's say that the threshold potential of a neuron is +40 mV to make a muscle twitch. Now suppose we have two signals of +20 mV. So, this signal will cause the twitch in muscle because it has reached ...
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44 views

What is a good review article source for Physiology?

I am looking review articles for Physiology. For instance, Physiological explanation of steps of measurement of the metabolism by Douglas-Haldane. There is no section for Physiology or metabolism in ...
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85 views

Are humans more aggressive during a full moon? [closed]

Is it true that we are more agressive during the night when there is a full moon? If true, could this be a remnant from times where we needed to hunt for our food and so could see more at night when ...
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17 views

Are there naturally occurring Biological Pacemakers?

There are artificial biological pacemakers which express funny channels. I am thinking if it is possible to have also naturally occurring (only in recovery cases and in silent tissues) biological ...
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7 views

Mechanisms to start simultaneous depolarisation of two Pacemakers?

I am thinking the biochemical mechanisms of the simultaneous depolarisations of two pacemakers. My intuition Funny channels (but not alone) No autonomic nervous system (my conjencture) What are ...
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7 views

What are the mechanisms of disabling extrinsic control of heart?

I started this thread by thinking this question but I developed it further below What is the mechanism maintaining refractory period of pacemakers? My conjuncture is that the mechanism is the ...
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8 views

Which reflex arcs work in Heart with extrasystoles?

I am researching what is triggering the extrasystoles - initial idea from this thread about Which ionic channels of Pacemakers can work in very low frequencies in extrasystole? I am interested in the ...
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6 views

Which ionic channels of Pacemakers can work in very low frequencies in extrasystole?

At frequency 0-3 Hz. Like computer processors which can work at low frequencies and controlling under- and overvoltage. Normal most significant channels are Ca2+ and K+ that are changing. However, I ...
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10 views

Calling for Pressure pictures about Right and Left atrium

I am trying to understand the partially patent foramen ovale in patients with right-side heart failure. I am interested how the pressure in right and left atrium change in normal case in abnormal ...
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8 views

Laser surgery to stop damaged Sinus node from beating

I am trying to find any publication about laser surgery to stop the damaged sinus node which cannot anymore beat. I could only find publications which modifies SA node function. I am not sure if it ...
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16 views

Normal Frequencies in Heart

I am trying to visualise possible ranges of frequencies from different structures of heart: different valves and their possible frequencies heart sounds I - IV and their normal frequencties what can ...
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13 views

How do the symptoms of Sepsis affect heart function?

I have intuition that Sepsis with infection can cause spastic functioning of heart during systole heart working spontaneously in snatches during systole atrial fibrillation first contraction of ...
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50 views

Are females more flexible than males in all mammals?

It's common that human females have a more flexible body than males, (but I don't know why, so it'd be helpful if someone answers why so as well!) but does this apply to all mammals?
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How does vasomotor and bronchomotor reactions equilibrate local blood flow to correspond local ventilation?

I am trying to find some figure(s) to explain this. There is probably better name for "bronchomotor" reaction. They seem to opposite terms and actually affecting same things (alveolar diameter/tone); ...
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7 views

To characterise diameter of capillaries in organs

I know that there exist Continuous capillaries (skeletal muscle, adipose tissue, connective tissue, pulmonary circulation), Fenestrated capillaries (small intestine, renal glomerulus, exocrine ...
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11 views

What is the quality rate of intrinsic autoregulation in the heart?

Autoregulation is the maintenance of constant blood flow to an organ in spite of fluctuations in Blood pressure. It involves the relaxation of myocardium and contraction. It is local. I know that ...
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17 views

Are there any forms of heart failure where cell size decreases?

I think hypertrophy happens in most of the cases. However, I am not sure if hypertrophy always happens. I started to think about wet lungs (pulmonary reason for the left-sided heart failure). Can the ...
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1answer
31 views

What are the physiological roles of Hydrogen sulfide?

I am thinking why hydrogen sulfide has its effects in the body. For instance, it is one Salmonella's virulence factor. I am not sure if such a balance equations holds ...
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35 views

Hypovolemia and orthostatic hypertension

What is the physiological mechanism behind the occurrence of orthostatic hypertension in the presence of hypovolemia?
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12 views

What are the movement mechanisms of thrombus?

I am thinking how thrombus (veins, arteries and heart) can move. Secondary mechanisms come to my mind only: some enzyme which lyses it, probably adhesion mechanism. Blood circulation (flow rate) is ...
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34 views

Effect of respiration on Arterial pressure

I am trying to explain the effect of respiration on arterial pressure. I am looking preferably some visual way to show it. How can you show the effect of respiration on arterial pressure? I am ...
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13 views

What is a good ECG book on Schema level?

I need to know ECG on scheme level, not on Guyton level. The problem is that I have read it on Guyton level and now I should find some review book about this review level. For instance, the ...
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220 views

Which processes are during the latent period of ventricular contraction?

The latent period is the time between the start of depolarisation and the start of contraction. I know that the contraction of ventricles starts after sufficient influx of Ca2+ and threshold ...
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21 views

To define the total Resistance of Systemic Blood Circulation

Some systems are in parallel so let's just call those like $R_{\text{lungs}}$. I got this formula $$R_{\text{total}}=R_A+R_a+R_c+R_V+R_v$$ where $R_c$ capillaries, $R_a$ arterioles, $R_A$ Small ...
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18 views

Why is the resting membrane potential of cardiomyocyte more stable than that of Pacemaker in Phase 4?

There must be some channels that keeps this very stable. It seems to be that the resting membrane potential of pacemaker cells is steadily increasing until the threshold voltage. I think the same must ...
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12 views

Why is Aorta sometimes called Compression chamber?

I find this statement that Aorta is called Compression Chamber in my study materials. Aorta can it keeps blood flowing it can accumulate potential energy for bumping and compression However, why ...
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14 views

Characteristics of radius of blood vessel

Which properties do determine the radius of blood vessel? I have these thoughts distension, elasticity, contractility and cross-sectional area of the walls. Is there any other properties?
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11 views

To understand synthesis of e-NOS and n-NOS with respect to Ca and calmodulin

I found this sentence in my notes interesting E-NOS and n-NOS are Ca, calmoduline dependant ferments. They are synthesized from in small conc as response to physiological signals which ...
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17 views

To understand Nitric oxide, iNOS and Tumour cells

I have this figure about nitric oxide and tumor which is for schematic for me to understand it The figure should probably say that tumour cell is induced by NO or alone to go apoptosis and it ...
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0answers
12 views

What are the main parameters for systemic circulation?

I have in my notes that main parameters for systemic circulation are ejected blood per minute central venous pressure (in the right atrium) work done by the heart something else What can this ...
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23 views

ADH Synthesis in Supraoptic and Paraventricular Nuclei of the Hypothalamus

I have this sentence in my notes: Neurons paraventricularis and supraorbitus check the situation and secrete ADH in the nuclei, which by axonal transport → neurohypophysis, where storage take ...
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1answer
34 views

Physiology of skin and leather: why do salt borders occur?

I discussed a leather store about the white border aka salt border on leather shoes. They said that it is due to inner features of leather and you could try to add some fat/cream to push it back ...
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28 views

What's the impact of graffian follicle on the ovum?

I've always wondered what's the function of graffian follicle other than synthesis of Oestrogens and Progestrone? What's the impact of the granulosa cells that composes the follicle on the ovum ...
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1answer
40 views

Can pheromones in perfume be formulated to cause agitation? [closed]

I generally don't care for female perfume. I have very sensitive olfactory receptors and in general, I just find perfume overwhelming. A couple weeks ago, my wife of almost 14 years and I were ...
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91 views

cellular respiration

What are the effects of addition of these chemicals to actively respiring cells ? Which of them would lead to INHIBITION of aerobic respiration ? Would cytochromes be actually taken up by cells ? ...
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0answers
11 views

Effect of axillary stretching on prevention of congestion from hyperemia

In exercising not-opposing muscles of arms (biceps, not triceps), hyperemia of tissues occurs i.e. active process in arteries. I feel personally sour muscles many days afterwards if I do not stretch ...
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1answer
29 views

Normal position of Electrical axis only in the III lead?

I found this sentence in my notes which is not exact enough: Electrical axes Excitatory processes have definite direction and magnitude and could therefore be represented as vectors. At ...
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1answer
27 views

Which chemical and hormonal effects on heart are by metabolites?

I am thinking which hormonal and chemical effects from: catecholamines thyroxin corticosteroids sex hormones prostaglandins Ca2+ Na+ K+ can be be regarded as metabolites i.e. intermediates or ...