circulation, in anatomy and physiology, the continuous movement of blood throughout the body, driven by the pumping action of the heart..
Description.
The circulatory system is which transports blood, nutrients, oxygen, and hormones throughout the body.
This is one of the most important organ systems that define an organism's physiology.
In humans, a measure of the circulatory system's function can be obtained by taking the blood pressure..
The circulatory system is made up of blood vessels that carry blood away from and towards the heart.
Arteries carry blood away from the heart and veins carry blood back to the heart.
The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide..
Blood Flow
Like all fluids, blood flows from a high pressure area to a region with lower pressure.
Blood flows in the same direction as the decreasing pressure gradient: arteries to capillaries to veins.
The rate, or velocity, of blood flow varies inversely with the total cross-sectional area of the blood vessels..
Blood flow through a blood vessel is determined by two factors: (1) pressure difference of the blood between the two ends of the vessel, also sometimes called "pressure gradient" along the vessel. (.
2) The impediment to blood flow through the vessel, which is called vascular resistance..
The circulation of the blood was discovered in 1628 by William Harvey.
Blood pressure was first measured in animals by Hales (1733).
Reliable blood pressure measurements in humans were rendered possible at the beginning of the 20th century through the efforts of Mahomed, von Basch, Potain, Riva-Rocci and Korotkoff..
Blood flows through pipe-like channels called blood vessels.
The heart is a portion of the vascular system, consisting of a compact but hollow mass of muscle that acts rhythmically as a pump and owing to the presence of valves suitably placed, drives the blood in one constant direction through the body..
In physics, circulation is the line integral of a vector field around a closed curve.
In fluid dynamics, the field is the fluid velocity field.
In electrodynamics, it can be the electric or the magnetic field..
Blood flow must obey the principles of conservation of mass, momentum, and energy.
Applied to any given region of space, the principle of conser- vation of mass means that whatever flows in must flow out..
Summary.
The circulatory system delivers oxygen and nutrients to cells and takes away wastes.
The heart pumps oxygenated and deoxygenated blood on different sides.
The types of blood vessels include arteries, capillaries and veins..
The correct option is C.
Haemodynamics.
Haemodynamics refers to the fluid dynamics of blood flow.
It involves the study of all the factors governing blood flow..
3.
The average circulation time in normal resting adults for the blood to travel from the arm vein, through the heart and lungs, and up to the mouth, is 13 seconds, as determined by sodium dehydrocholate.
The normal range is 10 to 16 seconds..
Your heart is the only circulatory system organ.
Blood goes from the heart to the lungs to get oxygen.
The lungs are part of the respiratory system.
Your heart then pumps oxygenated blood through arteries to the rest of the body..
William Harvey and the discovery of the circulation of the blood..
The circulation of the blood links the sites of oxygen utilization and uptake in the body; thus, it is critical to ensuring that oxygen-rich blood reaches tissues and that oxygen-poor blood is transported away from tissues and back to the lungs..
Blood vessels, blood and blood clots sense and respond to numerous biochemical and biomechanical stimuli, which are often altered in disease.
Technologies to better recapitulate the in vivo mechanics of blood and blood tissues have enabled new functional studies, for example, the investigation of platelet adhesion, spreading39,40and force29.
From an engineering viewpoint, the circulatory system consists of a remarkably complex branching network of tubes that convey the blood ( the vasculature; Fig. 4.1), and two pulsatile pumps in series to force the blood through the tubes (the heart).
The vasculature consists of arteries, arterioles, capillaries, venules, and veins.
When considering physiologic blood flow, it is simplest to think of the blood flowing through pipes or cylinders, and from that basic understanding add in the complexities.
Normal blood flow can be thought of as simple laminar flow in most instances (for exceptions, see pathology).
A visualization of laminar flow can be seen in the figure below.
Blood cells further experience a range of external forces by the haemodynamic environment, and they also exert forces to remodel their local environment.
Therefore, the biophysics and material properties of blood cells and blood play an important role in determining blood behaviour in health and disease.
