Disorders of erythrocytes, or red blood cells (RBCs), include a range of conditions affecting their number, shape, or function.
Erythrocyte disorders can be broadly categorized into two main types: anemic and polycythemic conditions.
A low oxygen-carrying capacity of the blood due to the loss, lower production, or destruction of erythrocytes is termed anemia. Hemorrhagic anemia, for example, occurs when bleeding from an external wound or internal ulcer reduces erythrocyte counts.
On the other...

The cardiovascular system regulates the number of erythrocytes in the bloodstream to ensure optimal oxygen transport. It also prevents over-proliferation of these cells, which helps to maintain blood viscosity and flow rate.
Several factors influence the erythrocyte production rate, with tissue oxygen level being among the most critical. Intense exercise or high altitudes can cause tissue hypoxia, which triggers the kidneys to release more erythropoietin (EPO) into the bloodstream.
EPO then...

Disorders affecting blood volume, vascular tone, or vascular function can disrupt vascular homeostasis, including conditions like hypertension, hemorrhage, and shock.
Blood Pressure: Hypertension and Hypotension
Normal blood pressure is 120/80 mm Hg. Elevated blood pressure is 120-129/under 80 mm Hg. Hypertension, warranting treatment at 130/80 mm Hg, is often asymptomatic and can lead to severe cardiovascular events, aneurysms, peripheral arterial disease, chronic renal disease, or cardiac...

Endocrinal or hormonal intervention in the cardiovascular system is predominantly exerted by the catecholamines - epinephrine and norepinephrine, as well as a slew of hormones that interact with renal function to modulate blood volume.
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction while...

Blood is specialized connective tissue comprising about 8% of the body mass. It has a thick, liquid extracellular matrix that contains cells, dissolved proteins, and electrolytes, making it five times more viscous than water. Blood is warm, around 38°C, and has an alkaline pH ranging from 7.35 to 7.45.
The primary function of blood is to transport oxygen and carbon dioxide between tissues and the lungs. Oxygenated blood is bright red, while oxygen-depleted blood is darker. It also carries...

Blood plasma is a fluid that contains approximately 92% water and 8% solutes. The solutes include various types of proteins, which constitute about 7% of the total solutes in the plasma. The high-molecular-weight proteins—albumins, globulins, and fibrinogen—are essential to plasma function. Albumins, making up about 60% of the plasma proteins, maintain the osmotic balance within blood vessels by preventing excessive water leakage. Additionally, albumins serve as carrier proteins, binding to...