INSECT STRUCTURE AND

FUNCTION

INSECT STRUCTURE AND

FUNCTION

IN MULTICELLULAR ORGANISMS THE

UNIFORM DISTRIBUTION OF

METABOLIC MATERIALS BECOMES

A PROBLEM.

IN MULTICELLULAR ORGANISMS THE

UNIFORM DISTRIBUTION OF

METABOLIC MATERIALS BECOMES

A PROBLEM.

HEMOCOEL

INSECT CIRCULATORY SYSTEMINSECT CIRCULATORY SYSTEM

SIZE MATTERS

IN INSECTS, CIRCULATION IN THE FLUID-FILLED BODY CAVITY (HEMOCOEL) IS SUPPLEMENTED BY A LONGITUDINAL

DORSAL VESSEL (MESODERMAL ORIGIN).

IN INSECTS, CIRCULATION IN THE FLUID-FILLED BODY CAVITY (HEMOCOEL) IS SUPPLEMENTED BY A LONGITUDINAL

DORSAL VESSEL (MESODERMAL ORIGIN).

THE DORSAL VESSEL IS

DIVIDED INTO:

THE DORSAL VESSEL IS

DIVIDED INTO:

A TUBULAR, MULTI-CHAMBERED,

CONTRACTILE HEART (ABDOMINAL)

A DORSAL AORTA (THORACIC)

OPEN CIRCULATORY SYSTEM

OPEN CIRCULATORY SYSTEM

CLOSED CIRCULATORY SYSTEM

CLOSED CIRCULATORY SYSTEM

BLOOD ENTERS THE HEART VIA

PAIRED OPENINGS

CALLED OSTIA

BLOOD ENTERS THE HEART VIA

PAIRED OPENINGS

CALLED OSTIA

THE INSECT HEART IS SUSPENDED MID-DORSALLY IN THE

ABDOMINAL CAVITY BY A SERIES OF PAIRED ALARY

MUSCLES AND A MEMBRANOUS

DORSAL DIAPHRAM.

THE INSECT HEART IS SUSPENDED MID-DORSALLY IN THE

ABDOMINAL CAVITY BY A SERIES OF PAIRED ALARY

MUSCLES AND A MEMBRANOUS

DORSAL DIAPHRAM.

HEMOLYMPH IS PUMPED FORWARD

THROUGH THE AORTA AND ENTERS THE

HEMOCOEL AT THE BASE OF THE INSECT

BRAIN.

HEMOLYMPH IS PUMPED FORWARD

THROUGH THE AORTA AND ENTERS THE

HEMOCOEL AT THE BASE OF THE INSECT

BRAIN.

HEMOLYMPH THEN FLOWS POSTERIORLY AROUND THE GUT (PERIVISCERAL SINUS) AND VENTRAL NERVE CHORD (PERINEURAL SINUS)

VIA A MEMBRANOUS VENTRAL DIAPHRAM.

HEMOLYMPH THEN FLOWS POSTERIORLY AROUND THE GUT (PERIVISCERAL SINUS) AND VENTRAL NERVE CHORD (PERINEURAL SINUS)

VIA A MEMBRANOUS VENTRAL DIAPHRAM.

HEMOLYMPH FLOW IS

ASSISTED BY LOCOMOTORY

MOVEMENTS AND ABDOMINAL

CONTRACTIONS.

HEMOLYMPH FLOW IS

ASSISTED BY LOCOMOTORY

MOVEMENTS AND ABDOMINAL

CONTRACTIONS.

HEMOLYMPH CIRCULATION MAY ALSO BE ASSISTED BY ACCESSORY PULSATING MEMBRANES

(WINGS AND APPENDAGES).

HEMOLYMPH CIRCULATION MAY ALSO BE ASSISTED BY ACCESSORY PULSATING MEMBRANES

(WINGS AND APPENDAGES).

HEMOLYMPH FLOWS DORSALLY THROUGH

THE DORSAL DIAPHRAM AND INTO

THE PERICARDIAL SINUS.

IT REENTERS THE HEART THROUGH

PAIRED OPENINGS CALLED OSTIA.

HEMOLYMPH FLOWS DORSALLY THROUGH

THE DORSAL DIAPHRAM AND INTO

THE PERICARDIAL SINUS.

IT REENTERS THE HEART THROUGH

PAIRED OPENINGS CALLED OSTIA.

INSECT INSECT HEMOLYMPH HEMOLYMPH

DOES NOTDOES NOT CARRY CARRY

OXYGEN TO OXYGEN TO ORGANS AND ORGANS AND

TISSUES TISSUES

INSECT INSECT HEMOLYMPH HEMOLYMPH

DOES NOTDOES NOT CARRY CARRY

OXYGEN TO OXYGEN TO ORGANS AND ORGANS AND

TISSUES TISSUES

OPEN CIRCULATORY SYSTEM VS TRACHAEL SYSTEMOPEN CIRCULATORY SYSTEM VS TRACHAEL SYSTEM

Insect Blood Cells

• Hemocytes– Prohemocytes

(pluripotent & clotting function)

– Plasmatocytes(phagocytic)

– Granulocytes(phagocytic

• Phagocytosis

• Encapsulation

Insect Infection ResponseThere are no hemocytes equivalent to mammalian

lymphocytes.

Thus there are no serum proteins equivalent to immunoglobulins (antibodies).

However, there are substances present and/or inducible that may have anti-infective qualities:

Lectins – sugar specificity, agglutinate microbesCecropins – protein disrupt microbe cell membranesVarious hemolymph enzymes

CIRCULATING HEMOLYMPH FACILITATES:CIRCULATING HEMOLYMPH FACILITATES:

HYDROSTATIC LOCOMOTION

INFLATION OF WINGS AND EXOSKELETON

RETENTION AND DISSIPATION OF HEAT

PHAGOCYTOSISENCAPSULATION

NUTRIENT DISTRIBUTION WASTE REMOVAL

ECDYSIS