A myograph is any device used to measure the

force In physics, a force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the Magnitu ...

produced by a

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

when under contraction. Such a device is commonly used in myography, the study of the velocity and intensity of muscular contraction. A myograph can take several forms: for tubular structures such as

blood vessel Blood vessels are the tubular structures of a circulatory system that transport blood throughout many Animal, animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the Tissue (biology), tissues of a Body (bi ...

s these include the pressure myograph (where a segment of a blood vessel is cannulated at either or both ends) and the wire myograph (where the blood vessel segment is threaded onto a pair of pins or wires); for skeletal muscle other devices such as the acceleromyograph can be used. In

pharmacology Pharmacology is the science of drugs and medications, including a substance's origin, composition, pharmacokinetics, pharmacodynamics, therapeutic use, and toxicology. More specifically, it is the study of the interactions that occur betwee ...

, myography is used to record muscle contraction in organ bath preparations. The related technique of

electromyography Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph to produce a record called an electromyogram. An electromyo ...

(EMG) is used to measure the electrical activity of the muscle instead of force. In addition, there is an optomyography (OMG) technique that uses active near-infra-red optical sensors.

Wire Myograph

A wire myograph is a type of laboratory apparatus that can measure the

contractility Contractility refers to the ability for self- contraction, especially of the muscles or similar active biological tissue *Contractile ring in cytokinesis *Contractile vacuole *Muscle contraction **Myocardial contractility *See contractile cell fo ...

of luminal tissue segments smaller than 2 mm in diameter. It is used by

pharmacologist Pharmacology is the science of drugs and medications, including a substance's origin, composition, pharmacokinetics, pharmacodynamics, therapeutic use, and toxicology. More specifically, it is the study of the interactions that occur between ...

s to measure the effect of test articles on

blood pressure Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...

or on airway contractility.

History of the wire myograph

Diagrams of the first ever wire myograph were revealed by Mulvany and Halpern in their 1976 paper "Contractile properties of small arterial resistance vessels in ..rats". The group based the design of this apparatus on a technique developed by Bevan and Osher to measure arterial contractility ''

ex vivo refers to biological studies involving tissues, organs, or cells maintained outside their native organism under controlled laboratory conditions. By carefully managing factors such as temperature, oxygenation, nutrient delivery, and perfusi ...

''. Development of the wire myograph was significant because it allowed researchers to estimate the effect of novel drugs on blood pressure for the first time.

Structure of the wire myograph

The structure of the wire myograph has not changed much since its invention in 1977. Tissues are mounted in the myograph bath via two wires threaded through their lumen. These wires are attached to two opposing stainless steel jaws which secure tissue in place throughout the culture period. Multi-myograph units can contain up to four separate tissue baths, allowing four different tissue segments to be cultured simultaneously.

References

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External links

Information on microvessel studies
(wire myograph)
Various types of blood vessel myographs

Blood vessel myographs
Exercise physiology