Organ (anatomy)

In biology, an organ or viscus is a collection of tissues joined in a structural unit to serve a common function. In anatomy, a viscus /ˈvɪskəs/ is an internal organ, and viscera is the plural form.

Organs are composed of main tissue, parenchyma, and "sporadic" tissues, stroma. The main tissue is that which is unique for the specific organ, such as the myocardium, the main tissue of the heart, while sporadic tissues include the nerves, blood vessels, and connective tissues. Functionally related organs often cooperate to form whole organ systems. Organs exist in all higher biological organisms, in particular they are not restricted to animals, but can also be identified in plants. In single-cell organisms like bacteria, the functional analogue of an organ is called organelle.

A hollow organ is a visceral organ that forms a hollow tube or pouch, such as the stomach or intestine, or that includes a cavity, like the heart or urinary bladder.

Organ systems

Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system. The functions of organ systems often share significant overlap. For instance, the nervous and endocrine system both operate via a shared organ, the hypothalamus. For this reason, the two systems are combined and studied as the neuroendocrine system. The same is true for the musculoskeletal system because of the relationship between the muscular and skeletal systems.

Biology

Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy. Modern biology is a vast and eclectic field, composed of many branches and subdisciplines. However, despite the broad scope of biology, there are certain general and unifying concepts within it that govern all study and research, consolidating it into single, coherent fields. In general, biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the synthesis and creation of new species. It is also understood today that all organisms survive by consuming and transforming energy and by regulating their internal environment to maintain a stable and vital condition.

Subdisciplines of biology are defined by the scale at which organisms are studied, the kinds of organisms studied, and the methods used to study them: biochemistry examines the rudimentary chemistry of life; molecular biology studies the complex interactions among biological molecules; botany studies the biology of plants; cellular biology examines the basic building-block of all life, the cell; physiology examines the physical and chemical functions of tissues, organs, and organ systems of an organism; evolutionary biology examines the processes that produced the diversity of life; and ecology examines how organisms interact in their environment.

Biology (journal)

Biology is a quarterly, peer-reviewed, open access, scientific journal covering research on all aspects of biology. It was established in 2012 and is published by MDPI. The editor-in-chief is Chris O'Callaghan (University of Oxford). The journal publishes reviews, research papers, and communications.

Subject Areas

This journal covers all topics related to biology. More detail about the journal and its scope is available in the first editorial. Research fields of interest include, but are not limited to:

Biology: The Unity and Diversity of Life

Biology: The Unity and Diversity of Life is a college-level introductory biology textbook that covers basic biochemistry, anatomy, taxonomy, evolution, biotechnology and ecology. The book is designed to create in students a broad foundation of knowledge in biology and is frequently used in AP Biology classes in American high schools. Each book includes an interactive CD-ROM with links to additional instructional material. Like many textbooks new versions are printed every few years and reflect new gains in scientific knowledge. The book is published by Brooks/Cole and is currently in its twelfth edition. It was primarily compiled by Cecie Starr and Ralph Taggart with pictures and illustrations by Lisa Starr.

The book was translated into few languages, among others into Hebrew, published by the Open University of Israel.

External links

Organ

Organ may refer to the following:

Biology and medicine

Music

Organ, Hautes-Pyrénées

Organ (French pronunciation: ​[ɔʁɡɑ̃]) is a commune in the Hautes-Pyrénées department in south-western France.

See also

References

Organ (music)

In music, the organ (from Greek ὄργανον organon, "organ, instrument, tool") is a keyboard instrument of one or more divisions, each played with its own keyboard, played either with the hands or with the feet. The organ is a relatively old musical instrument, dating from the time of Ctesibius of Alexandria, who is credited with inventing the water organ. It was played throughout the Greek and Roman world, particularly during races and games. During the early medieval period it spread from the Byzantine Empire, where it continued to be used in secular and imperial court music, to Western Europe, where it gradually assumed a prominent place in the liturgy of the Catholic Church. Subsequently it re-emerged as a secular and recital instrument.

Overview

Pipe organs use wind moving through pipes to produce sounds. Since the 16th century, pipe organs have used various materials for pipes, which can vary widely in timbre and volume. The pipes are divided into ranks and controlled by the use of hand stops and combination pistons. Although the keyboard is not expressive as on a piano and does not affect dynamics (pressing a key only turns the sound on or off), some divisions may be enclosed in a swell box, allowing the dynamics to be controlled by shutters. Some organs are totally enclosed, meaning that all the divisions can be controlled by one set of shutters. Some special registers with free reed pipes are expressive. These instruments vary greatly in size, ranging from a cubic yard to a height reaching five floors, and are built in churches, synagogues, concert halls, and homes. Small organs are called "positive" (easily placed in different locations) or "portative" (small enough to carry while playing). Increasingly hybrid organs are appearing in which pipes are augmented with electronic additions. Great economies of space and cost are possible especially when the lowest (and largest) of the pipes can be replaced.