Hemolymph

	Email		Print
	Bookmark		Link

Hemolymph

Hemolymph or haemolymph is the blood

Blood

Blood is a specialized bodily fluid that delivers necessary substances to the body's Cell s ? such as nutrients and oxygen ? and transports waste products away from those same cells....
analogue used by all arthropod

Arthropod

Arthropods are animals belonging to the Scientific classification Arthropoda , and include the insects, arachnids, crustaceans, and others....
s and most mollusks that have an open circulatory system. In these animals there is no distinction between blood and interstitial fluid

Interstitial fluid

Interstitial fluid is a solution which bathes and surrounds the cells of multicellular animals. It is the main component of the extracellular fluid, which also includes Blood plasma and transcellular fluid....
. The liquid fills all of the interior (the hemocoel

Hemocoel

Animal locomotion

In biomechanics, animal locomotion is the study of how animals motion . Most animals move in order to find food, a mate, escape predators, find suitable microhabitats, etc....
can facilitate hemolymph movement, but diverting flow from one area to another is limited.

Discussion

Ask a question about 'Hemolymph'

Start a new discussion about 'Hemolymph'

Answer questions from other users

Full Discussion Forum

Encyclopedia

Hemolymph or haemolymph is the blood

Blood

Arthropod

Interstitial fluid

Hemocoel

Animal locomotion

Heart

The heart is a muscle organ in all vertebrates responsible for pumping blood through the blood vessels by repeated, rhythmic contractions, or a similar structure in annelids, mollusks, and arthropods....
relaxes, blood is drawn back toward the heart through open-ended pores (ostia

Ostium

From Latin ostium, mouth, entrance, or river mouth. An ostium is a small opening or orifice, as in a body organ or passage.It can mean the following...
).

Hemolymph is composed of water

Water

Water is a common chemical substance that is essential for the survival of all known forms of life. In typical usage, water refers only to its liquid form or States of matter, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam....
, inorganic

Inorganic chemistry

Inorganic chemistry is the branch of chemistry concerned with the properties and behavior of inorganic compounds. This field covers all chemical compounds except the myriad organic compounds , which are the subjects of organic chemistry....
salt

Salt

A salt, in chemistry, is defined as the product formed from the neutralisation reaction of acids and base . Salts are ionic compounds composed of cations and anions so that the product is electrically electric charge ....
s (mostly Na⁺

Sodium

Sodium is an element which has the symbol Na , atomic number 11, atomic mass 23 amu , and a common oxidation number +1. Sodium is a soft, silvery white, highly reactive element and is a member of the alkali metals within "group 1" ....
, Cl^-

Chlorine

Chlorine...
, K⁺

Potassium

Potassium is a chemical element. It has the symbol K , atomic number 19, and atomic mass 39.0983. Potassium was first isolated from potash, hence the name....
, Mg²⁺

Magnesium

Magnesium is a chemical element with the symbol Mg, atomic number 12, atomic weight 24.3050 and common oxidation number +2.Magnesium, an alkaline earth metal, is the ninth most abundance of the chemical elements in the universe by mass....
, and Ca²⁺

Calcium

Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the earth's Crust ....
), and organic compounds

Organic chemistry

Organic chemistry is a discipline within chemistry which involves the science study of the structure, properties, composition, chemical reaction, and preparation of chemical compounds that contain carbon....
(mostly carbohydrate

Carbohydrate

Carbohydrates or saccharides are the most abundant of the four major classes of biomolecules. They fill numerous roles in living things, such as the storage and transport of energy and structural components ....
s, protein

Protein

Proteins are organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid Residue ....
s, and lipid

Lipid

Lipids are broadly defined as any fat-soluble , naturally-occurring molecule, such as fats, oils, waxes, cholesterol, sterols, fat-soluble vitamins , monoglycerides, diglycerides, phospholipids, and others....
s). The primary oxygen transporter molecule is hemocyanin

Hemocyanin

Hemocyanins are respiratory proteins in the form of metalloproteins containing two copper atoms that reversibly bind a single oxygen molecule ....
.

There are free-floating cells, the hemocyte

Hemocyte

A hemocyte is a cell that plays a role in the immune system of invertebrates. It is found within the hemolymph.Hemocytyes are phagocytes of invertebrates....
s, within the hemolymph. They play a role in the arthropod immune system

Immune system

An immune system is a collection of biological processes within an organism that protects against disease by identifying and killing pathogens and tumour cells....
.

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.

In the grasshopper

Grasshopper

Grasshoppers are insects of the suborder Caelifera in the order Orthoptera. To distinguish them from Tettigoniidae, they are sometimes referred to as short-horned grasshoppers....
, 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

Hemocoel

A hemocoel is a cavity or series of spaces between the organs of organisms with open circulatory systems, like most arthropods and mollusks. A combination of blood, lymph, and interstitial fluid called hemolymph circulates through the hemocoel....
where exchanges of materials take place.

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.

This "open" system might appear to be inefficient compared to closed circulatory systems like those possessed by mammals, but the two have very different demands being 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

Invertebrate trachea

Many terrestrial animal arthropods have evolved a closed respiratory system composed of spiracles, tracheae, and tracheoles to transport metabolism gasses to and from tissue....
. Hemolymph plays no part in the process in most insects. In a few insects living in low-oxygen environments, there are 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

Copper

Copper is a chemical element with the symbol Cu and atomic number 29.It is a ductile metal with very high thermal and electrical conductivity....
-containing hemocyanin

Hemocyanin

Hemocyanins are respiratory proteins in the form of metalloproteins containing two copper atoms that reversibly bind a single oxygen molecule ....
, however, for oxygen transport.

Therefore the copper carbonate is not able to be removed via the xylem from whence it supplies the main arteries with oxygen.

External links

Boston Globe article on hemolymph: