summary on insect circulatory system

The Insect Circulatory System

0 Insects have an open circulatory system.

0 The hemocoel is filled with hemolymph that bathes the organs

0 Insects have local pulsatile organs at the bases of appendages that pump hemolymph

0 It does not carry oxygen along its circulation.

Insect Circulatory Organs

DORSAL VESSEL

0 principal organ responsible for blood circulation

0 lies along the dorsal midline of the insect body

HEMOCOEL

0 the compartmentalized structure of this cavity is due to the presence of one or two fibromuscular septa

Insect Circulatory Organs

HEART

0 usually closed at its posterior end and bears a number of valvular openings (ostia)

ALARY MUSCLES

0 fibromuscular innervated structures attached laterally to the body wall and vary in number from 1-13 pairs

Insect Circulatory Organs

HEMOLYMPH

0 Colorless liquid that bathes the insect tissues

0 Only about 10% are hemocytes and the rest of the hemolymph content is watery plasma

0 Known functions:

- phagocytosis

- coagulation

- encapsulation of foreign objects

- wound healing

Insect Circulatory Organs

HEMOLYMPH COMPOSITION:

0 90% Water

0 Inorganic ions

0 Nitrogenous wastes

0 Carbohydrates

0 Lipids

0 Proteins and enzymes

0 Pigments

0 Hormones

Insect Circulatory Organs

HEMOLYMPH FUNCTIONS:

0 Lubricant for tissues and internal organs

0 Hydraulic medium (caterpillars, wing expansion, etc.)

0 Transport medium for nutrients, wastes and hormones

0 Storage (amino acids, water, and glycerol)

0 Heat exchange

0 Immune response

Circulation

0 When the heart contracts, the valves of the ostia are closed by the pressure and the hemolymph is moved forward and dumped into the head area.

0 Alary muscles aid the contractions of the heart.

Circulation

0 The blood circulation is also aided by the presence of the dorsal and ventral diaphragms, which consists of sets of muscles that divide the hemocoel into various sinuses.

The Insect Circulatory System

Overview

VERTEBRATES

INSECTS

0 Closed circulatory system

0 Blood

0 Heart

0 Oxygen Transportation

0 Open circulatory system

0 Hemolymph

0 Dorsal Vessel

0 Transport of other substances

References

http://home.sandiego.edu/~gmorse/2010BIOL348/Biol348_Website/Lectures/2010_02_15_lecture_4.pdf

http://www.faculty.ucr.edu/~insects/pages/teachingresources/stoffolano/2.pdf

http://insects.about.com/od/morphology/ss/internalanatomy_4.htm