Hemolymph

Last updated
Collection of hemolymph from a worker honeybee. Bee hemolymph collection.png
Collection of hemolymph from a worker honeybee.
A grasshopper has an open circulatory system, where hemolymph moves through interconnected sinuses or hemocoels, spaces surrounding the organs. Differential Grasshopper 01.jpg
A grasshopper has an open circulatory system, where hemolymph moves through interconnected sinuses or hemocoels, spaces surrounding the organs.
Above is a diagram of an open circulatory system. An open circulatory system is made up of a heart, vessels, and hemolymph. This diagram shows how the hemolymph is circulated throughout the body of a grasshopper. The hemolymph is first pumped through the heart, into the aorta, dispersed into the head and throughout the hemocoel, then back through the ostia that are located in the heart, where the process is repeated. Open Circulatroy.gif
Above is a diagram of an open circulatory system. An open circulatory system is made up of a heart, vessels, and hemolymph. This diagram shows how the hemolymph is circulated throughout the body of a grasshopper. The hemolymph is first pumped through the heart, into the aorta, dispersed into the head and throughout the hemocoel, then back through the ostia that are located in the heart, where the process is repeated.

Hemolymph, or haemolymph, is a fluid, analogous to the blood in vertebrates, that circulates in the interior of the arthropod (invertebrate) body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which hemolymph cells called hemocytes are suspended. In addition to hemocytes, the plasma also contains many chemicals. It is the major tissue type of the open circulatory system characteristic of arthropods (for example, arachnids, crustaceans and insects). [1] [2] In addition, some non-arthropods such as mollusks possess a hemolymphatic circulatory system.

Contents

Oxygen-transport systems were long thought unnecessary in insects, but ancestral and functional hemocyanin has been found in the hemolymph. [3] Insect "blood" generally does not carry hemoglobin, although hemoglobin may be present in the tracheal system instead and play some role in respiration. [4]

Method of transport

In the grasshopper, the closed portion of the system consists of tubular hearts and an aorta running along the dorsal side of the insect. The hearts pump hemolymph into the sinuses of the hemocoel where exchanges of materials take place. The volume of hemolymph needed for such a system is kept to a minimum by a reduction in the size of the body cavity. The hemocoel is divided into chambers called sinuses.

Coordinated movements of the body muscles gradually bring the hemolymph back to the dorsal sinus surrounding the hearts. Between contractions, tiny valves in the wall of the hearts open and allow hemolymph to enter. Hemolymph fills all of the interior (the hemocoel) of the animal's body and surrounds all cells. It contains hemocyanin, a copper-based protein that turns blue when oxygenated, instead of the iron-based hemoglobin in red blood cells found in vertebrates, giving hemolymph a blue-green color rather than the red color of vertebrate blood. When not oxygenated, hemolymph quickly loses its color and appears grey.

The hemolymph of lower arthropods, including most insects, is not used for oxygen transport because these animals respirate through other means, such as tracheas, but it does contain nutrients such as proteins and sugars. Muscular movements by the animal during locomotion can facilitate hemolymph movement, but diverting flow from one area to another is limited. When the heart relaxes, hemolymph is drawn back toward the heart through open-ended pores called ostia. [5] Note that the term "ostia" is not specific to insect circulation; it literally means "doors" or "openings", and must be understood in context.

Constituents

Hemolymph can contain nucleating agents that confer extracellular freezing protection. Such nucleating agents have been found in the hemolymph of insects of several orders, i.e., Coleoptera (beetles), Diptera (flies), and Hymenoptera. [6]

Inorganic

Hemolymph is composed of water, inorganic salts (mostly sodium, chlorine, potassium, magnesium, and calcium), and organic compounds (mostly carbohydrates, proteins, and lipids). The primary oxygen transporter molecule is hemocyanin. [7] [3]

Amino acids

Arthropod hemolymph contains high levels of free amino acids. Most amino acids are present but their relative concentrations vary from species to species. Concentrations of amino acids also vary according to the arthropod stage of development. An example of this is the silkworm and its need for glycine in the production of silk. [8]

Proteins

Proteins present in the hemolymph vary in quantity during the course of development. These proteins are classified by their functions: chroma proteins, protease inhibitors, storage, lipid transport, enzymes, the vitellogenins, and those involved in the immune responses of arthropods. Some hemolymphic proteins incorporate carbohydrates and lipids into the structure. [9]

Other organic constituents

Nitrogen metabolism end products are present in the hemolymph in low concentrations. These include ammonia, allantoin, uric acid, and urea. Arthropod hormones are present, most notably the juvenile hormone. Trehalose can be present and sometimes in great amounts along with glucose. These sugar levels are maintained by the control of hormones. Other carbohydrates can be present. These include inositol, sugar alcohol, hexosamines, mannitol, glycerol and those components that are precursors to chitin. [1]

Free lipids are present and are used as fuel for flight. [10]

Hemocytes

There are free-floating cells, the hemocytes, within the hemolymph. They play a role in the arthropod immune system. The immune system resides in the hemolymph.

Comparisons to vertebrates

This open system might appear to be inefficient compared to the closed circulatory systems of the vertebrates, but the two systems have very different demands placed on them. In vertebrates, the circulatory system is responsible for transporting oxygen to all the tissues and removing carbon dioxide from them. It is this requirement that establishes the level of performance demanded of the system. The efficiency of the vertebrate system is far greater than is needed for transporting nutrients, hormones, and so on, whereas in insects, exchange of oxygen and carbon dioxide occurs in the tracheal system. Hemolymph plays no part in the process in most insects. Only in a few insects living in low-oxygen environments are there hemoglobin-like molecules that bind oxygen and transport it to the tissues. Therefore, the demands placed upon the system are much lower. Some arthropods and most molluscs possess the copper-containing hemocyanin, however, for oxygen transport. [11]

Specialist uses

In some species, hemolymph has other uses than just being a blood analogue. As the insect or arachnid grows, the hemolymph works something like a hydraulic system, enabling the insect or arachnid to expand segments before they are sclerotized. It can also be used hydraulically as a means of assisting movement, such as in arachnid locomotion. Some species of insect or arachnid are able to autohaemorrhage when they are attacked by predators. [12] Queens of the ant genus Leptanilla are fed with hemolymph produced by the larvae. [13] On the other hand, Pemphigus spyrothecae utilize hemolymph as an adhesive, allowing the species to stick to predators and subsequently attack the predator; it was found that with larger predators, more aphids were stuck after the predator was defeated.

See also

Related Research Articles

<span class="mw-page-title-main">Blood</span> Organic fluid which transports nutrients throughout the organism

Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells.

<span class="mw-page-title-main">Outline of biology</span>

Biology – The natural science that studies life. Areas of focus include structure, function, growth, origin, evolution, distribution, and taxonomy.

<span class="mw-page-title-main">Endocrine system</span> Hormone-producing glands of a body

The endocrine system is a messenger system in an organism comprising feedback loops of hormones that are released by internal glands directly into the circulatory system and that target and regulate distant organs. In vertebrates, the hypothalamus is the neural control center for all endocrine systems.

<span class="mw-page-title-main">Hemoglobin</span> Metalloprotein that binds with oxygen

Hemoglobin is a protein containing iron that facilitates the transport of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the exception of the fish family Channichthyidae. Hemoglobin in the blood carries oxygen from the respiratory organs to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers the animal's metabolism. A healthy human has 12 to 20 grams of hemoglobin in every 100 mL of blood. Hemoglobin is a metalloprotein, a chromoprotein, and globulin.

<span class="mw-page-title-main">Blood vessel</span> Tubular structure of circulatory system

Blood vessels are the structures of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away from the tissues. Blood vessels are needed to sustain life, because all of the body's tissues rely on their functionality.

<span class="mw-page-title-main">Circulatory system</span> Organ system for circulating blood in animals

The circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels. The circulatory system has two divisions, a systemic circulation or circuit, and a pulmonary circulation or circuit. Some sources use the terms cardiovascular system and vascular system interchangeably with circulatory system.

<span class="mw-page-title-main">Red blood cell</span> Oxygen-delivering blood cell and the most common type of blood cell

Red blood cells (RBCs), referred to as erythrocytes (from ancient Greek erythros 'red' and kytos 'hollow vessel', with -cyte translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system. Erythrocytes take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillaries.

<span class="mw-page-title-main">Hemocyanin</span> Proteins that transport oxygen throughout the bodies of some invertebrate animals

Hemocyanins (also spelled haemocyanins and abbreviated Hc) are proteins that transport oxygen throughout the bodies of some invertebrate animals. These metalloproteins contain two copper atoms that reversibly bind a single oxygen molecule (O2). They are second only to hemoglobin in frequency of use as an oxygen transport molecule. Unlike the hemoglobin in red blood cells found in vertebrates, hemocyanins are not confined in blood cells, but are instead suspended directly in the hemolymph. Oxygenation causes a color change between the colorless Cu(I) deoxygenated form and the blue Cu(II) oxygenated form.

<span class="mw-page-title-main">Microcirculation</span> Circulation of the blood in the smallest blood vessels

The microcirculation is the circulation of the blood in the smallest blood vessels, the microvessels of the microvasculature present within organ tissues. The microvessels include terminal arterioles, metarterioles, capillaries, and venules. Arterioles carry oxygenated blood to the capillaries, and blood flows out of the capillaries through venules into veins.

A respiratory pigment is a metalloprotein that serves a variety of important functions, its main being O2 transport. Other functions performed include O2 storage, CO2 transport, and transportation of substances other than respiratory gases. There are four major classifications of respiratory pigment: hemoglobin, hemocyanin, erythrocruorin–chlorocruorin, and hemerythrin. The heme-containing globin is the most commonly-occurring respiratory pigment, occurring in at least 9 different phyla of animals.

Vitellogenin is a precursor of egg yolk that transports protein and some lipid from the liver through the blood to the growing oocytes where it becomes part of the yolk. Normally, it is only found in the blood or hemolymph of females, and can therefore be used as a biomarker in vertebrates of exposure to environmental estrogens which stimulate elevated levels in males as well as females. "Vitellogenin" is a synonymous term for the gene and the expressed protein. The protein product is classified as a glycolipoprotein, having properties of a sugar, fat and protein. It belongs to a family of several lipid transport proteins.

<i>Blaberus giganteus</i> Species of cockroach

Blaberus giganteus, the Central American giant cave cockroach or Brazilian cockroach, is a cockroach belonging to the family Blaberidae. One of the world's largest cockroaches, it is native to the warm parts of the Neotropical realm.

<span class="mw-page-title-main">Spider anatomy</span> Physiology of Spiders (order Araneae)

The anatomy of spiders includes many characteristics shared with other arachnids. These characteristics include bodies divided into two tagmata, eight jointed legs, no wings or antennae, the presence of chelicerae and pedipalps, simple eyes, and an exoskeleton, which is periodically shed.

<span class="mw-page-title-main">Red king crab</span> Species of crustacean

The red king crab, also called Kamchatka crab or Alaskan king crab, is a species of king crab native to cold waters in the North Pacific Ocean and adjacent seas, but also introduced to the Barents Sea. It grows to a leg span of 1.8 m (5.9 ft), and is heavily targeted by fisheries.

<span class="mw-page-title-main">Common octopus</span> Species of cephalopod

The common octopus is a mollusk belonging to the class Cephalopoda. Octopus vulgaris is one of the most studied of all octopus species, and also one of the most intelligent. It ranges from the eastern Atlantic, extends from the Mediterranean Sea and the southern coast of England, to the southern coast of South Africa. It also occurs off the Azores, Canary Islands, and Cape Verde Islands. The species is also common in the Western Atlantic.

Insect physiology includes the physiology and biochemistry of insect organ systems.

<span class="mw-page-title-main">Opiliones anatomy</span>

Opiliones are an order of arachnids and share many common characteristics with other arachnids. However, several differences separate harvestmen from other arachnid orders such as spiders. The bodies of opiliones are divided into two tagmata : the abdomen (opisthosoma) and the cephalothorax (prosoma). Unlike spiders, the juncture between the abdomen and cephalothorax is often poorly defined. Harvestmen have chelicerae, pedipalps and four pairs of legs. Harvestmen were traditionally thought to have two eyes, except in the case of eyeless species. Developmental genetic work has shown that living species retain up to six eyes, including one pair of rudimentary median eyes and one pair of rudimentary lateral eyes.

Desiccation tolerance refers to the ability of an organism to withstand or endure extreme dryness, or drought-like conditions. Plants and animals living in arid or periodically arid environments such as temporary streams or ponds may face the challenge of desiccation, therefore physiological or behavioral adaptations to withstand these periods are necessary to ensure survival. In particular, insects occupy a wide range of ecologically diverse niches and, so, exhibit a variety of strategies to avoid desiccation.

<span class="mw-page-title-main">Circulatory system of gastropods</span>

As in other molluscs, the circulatory system of gastropods is open, with the fluid, or haemolymph, flowing through sinuses and bathing the tissues directly. The haemolymph typically contains haemocyanin, and is blue in colour.

The common raven, also known as the northern raven, is a large, all-black passerine bird. Found across the Northern Hemisphere, it is the most widely distributed of all corvids. Their Northern range encompasses Arctic and temperate regions of Eurasia and North America, and they reach as far South as Northern Africa and Central America. The common raven is an incredibly versatile passerine to account for this distribution, and their physiology varies with this versatility. This article discusses its physiology, including its homeostasis, respiration, circulatory system, and osmoregulation.

References

  1. 1 2 Chapman 1998, p. [ page needed ].
  2. ↑ Wyatt, G. R. (1961). "The Biochemistry of Insect Hemolymph". Annual Review of Entomology. 6: 75–102. doi:10.1146/annurev.en.06.010161.000451. S2CID   218693.
  3. 1 2 Hagner-Holler, Silke; Schoen, Axel; Erker, Wolfgang; Marden, James H.; Rupprecht, Rainer; Decker, Heinz; Burmester, Thorsten (2004-01-20). "A respiratory hemocyanin from an insect". Proceedings of the National Academy of Sciences. 101 (3): 871–874. Bibcode:2004PNAS..101..871H. doi: 10.1073/pnas.0305872101 . ISSN   0027-8424. PMC   321773 . PMID   14715904.
  4. ↑ Hankeln, Thomas; Jaenicke, Viviane; Kiger, Laurent; Dewilde, Sylvia; Ungerechts, Guy; Schmidt, Marc; Urban, Joachim; Marden, Michael C.; Moens, Luc; Burmester, Thorsten (2002-06-04). "Characterization ofDrosophilaHemoglobin". Journal of Biological Chemistry. 277 (32): 29012–29017. doi: 10.1074/jbc.m204009200 . ISSN   0021-9258. PMID   12048208.
  5. ↑ Richards, O. W.; Davies, R.G. (1977). Imms' General Textbook of Entomology: Volume 1: Structure, Physiology and Development Volume 2: Classification and Biology. Berlin: Springer. ISBN   0-412-61390-5.
  6. ↑ Zachariassen, Karl Erik; Baust, John G.; Lee, Richard E. (1982). "A method for quantitative determination of ice nucleating agents in insect hemolymph". Cryobiology. 19 (2): 180–4. doi:10.1016/0011-2240(82)90139-0. PMID   7083885.
  7. ↑ Sowers, A.D; Young, S.P; Grosell, M.; Browdy, C.L.; Tomasso, J.R. (2006). "Hemolymph osmolality and cation concentrations in Litopenaeus vannamei during exposure to artificial sea salt or a mixed-ion solution: Relationship to potassium flux". Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 145 (2): 176–80. doi:10.1016/j.cbpa.2006.06.008. PMID   16861020.
  8. ↑ Chapman 1998, p. 108.
  9. ↑ Chapman 1998, p. 111.
  10. ↑ Chapman 1998, p. 114.
  11. ↑ Decker, H.; Hellmann, N.; Jaenicke, E.; Lieb, B.; Meissner, U.; Markl, J. (1 October 2007). "Minireview: Recent progress in hemocyanin research". Integrative and Comparative Biology. 47 (4): 631–644. doi:10.1093/icb/icm063. PMID   21672868.
  12. ↑ Bateman, P. W.; Fleming, P. A. (2009). "There will be blood: Autohaemorrhage behaviour as part of the defence repertoire of an insect". Journal of Zoology. 278 (4): 342–8. doi:10.1111/j.1469-7998.2009.00582.x.
  13. ↑ Genus Leptanilla Australian Ants Online

Sources

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.