Entomology(Fisiologia De Insectos)

Physiology
• Digestive system • Excretory system • Ciculatory system • Respiratory system • Reproductive system • Hormonal system - molting process

DIGESTIVE SYSTEM
3 Sections:
Stomodaeum – anterior intestine ectodermal origen  Mesenteron – middle intestine endodermal origen  Proctodaeum – posterior intestine ectodermal origen

The Digestive System - long straight tube that runs fromthe mouth to the anus, - often divided into the 'fore gut', the 'mid gut' and the 'hind gut'. - behind the mouth are the Salivary Glands, - in most species these secreted saliva is generally a watery fluid that lubricates the food and contains a few enzymes to begin the processes of digestion. - However in some carnivorous insects the saliva is composed entirely of digestive enzymes (digestion ofthe food). - In other insects the salivary glands have become modified for purposes that have nothing to do with digestion. - In Lepidopteran caterpillars and Caddisfly larvae they have been converted to the production of silk, while in the - Queen Honey Bee they are called the mandibular glands and secrete hormones.

The Fore Gut (Stomodaeum) • The fore gut is generally considered toconsist of four sections, - Pharynx, - Oesophagus, - Crop - Proventriculus.

The Mid Gut (Mesenteron)
• Runs from the 'digestive or gastric caeca', to just before the Malpighian tubules. • The mid gut is lined by a semi permeable membrane composed of protein and chitin, like the cuticle, which allows the passage of liquids and dissolved substances to the midgut wall while preventing the passageof solid food particles.

MESENTERÓN

The Hind Gut (Proctodaeum)
• • From the mid gut food passes to the hind gut. The hind gut comprises of the: intestines Rectum the foremost part of the hind gut are the Malpighian tubules (act like our kidneys)

TUBULOS DE MALPIGHI

Function of the Malpighian tubules

•Waste removal; like nitrogenous wastes from the blood •Regulate water andsalt in blood

Nervous system
• The ventral nerve cord, resembles a railroad track running from the head posteriorly to the abdominal region. • The ventral nerve cord is made up of two nerve cords (connectives) that run longitudinally with a series of node-like ganglia. • The anterior most region of the ventral nerve cord is called the subesophageal ganglion. • Just dorsal to that structure isthe insect brain (or supraesophageal ganglion).

Nervous System

SENSILIAS

Respiration and circulation • Insect respiration is accomplished without lungs, using a system of internal tubes and sacs through which gases either diffuse or are actively pumped, delivering oxygen directly to the adjoining body tissues. • Since oxygen is delivered directly, the circulatory system is not usedto carry oxygen, and is therefore greatly reduced; it has no closed vessels, consists of perforated dorsal tube which pulses peristaltically, and in doing so helps circulate the hemolymph inside the body cavity. • Air is taken in through spiracles, openings on the sides of the abdomen.

The Heart and the Blood
• The haemolymph (blood) of insects flows freely around the inside of their bodies.(an insect's haemolymph is not responsible for the transmission of oxygen, this is the job of the Trachaea, and therefore does not contain haemoglobin, it is not red). • Normally it is a watery green color, though it is pigmented (colored) in some species. This haemolymph is a sort of soup rich in nutrients that flows around the inside of the insects body allowing the various organs to get atwhatever resources they need and into which they dump their waste products.

• These waste products are later removed from the haemolymph by the Malpighian tubules.
• Because insects do not have veins and arteries like us and the rest of the vertebrates, they do not have a complicated heart like ours either.

Hemolymph
• • • • Hemocytes Water Inorganic iones Organic molecules

Functions of...