Physiology of Respiration in Invertebrates

In physiology, respiration is the movement of oxygen from the outside environment to the cells within tissues, and the removal of carbon dioxide in the opposite direction. In these slides you will get to know about Physiology of Respiration in Invertibrates.

1. Physiology of respiration in invertebrates 20-pzo-002 VICTORIA MAUREEN.A

2. SYNOPSIS Introduction History Respiratory organs of invertebrates 1. Trachea and spiracles 2. Gill 3. Book lung 4. Book gills Respiration in 1. Protozoa 2. Porifera 3. Coelenterates 4. Aschelminthes and platyhelminthes 5. Annelids 6. Arthropoda 7. Mollusca 8 . Echinoderm Respiratory pigments Functions of respiration Videos Question bank Reference

3. INTRODUCTION The process of gas exchange in the body, called respiration. The act of inhaling and exhaling air in order to exchange oxygen for carbon dioxide The process of inhalation of oxygen and exhalation of carbon dioxide is known as respiration. There are two types of cellular respiration aerobic and anaerobic. One occurs in the presence of oxygen (aerobic), and one occurs in the absence of oxygen (anaerobic).

4. HISTORY Marcello Malpighi (1628-1694) was an Italian scientist who found the anatomical basis of respiration, He was one of the first biologists to make use of the newly invented microscope and is best known as the discoverer of the pulmonary capillaries and alveoli. Henri Dutrochet, a French physiologist who term 'respiration'. He also discovered and named the process of osmosis (passage of solvent through a semipermeable membrane) that occurs at cellular level in both plants and animals. 

5. Respiratory organs of invertebrates Trachea This respiratory organ is a hallmark of insects. It is made up of a system of branching tubes that deliver oxygen to, and remove carbon dioxide from, the tissues, The smallest tubes, tracheoles, penetrate cells and diffuse water, oxygen, and carbon dioxide. Tracheae are a system of tiny tubes that permit passage of gases into the interior of the body. Tracheal systems are highly efficient for these small, terrestrial animals. The pores to the outside, called spiracles, are typically paired structures, two in the thorax and eight in the abdomen. Periodic opening and closing of the spiracles prevents water loss by evaporation,

6. Gills Many invertebrates use gills as a major means of gas exchange Gills are branching organs located on the side of heads that have small blood vessels called capillaries. As the organism opens its mouth, water runs over the gills, and blood in the capillaries picks up oxygen that’s dissolved in the water.  Gills consist of plate-like structures called filaments that are covered by an array of lamellae enclosing a capillary blood network Oxygen-rich water passes through the narrow channels formed by the lamellar layers, where oxygen diffuses into the capillaries. The densely packed lamellar structure is advantageous because it provides a large surface area for oxygen transfer. 

7. Book lung It is a form of respiratory organ found in certain air-breathing arthropods (scorpions and some spiders). Each book lung consists of a series of thin plates that are highly vascular (i.e., richly supplied with blood) and are arranged in relation to each other like the pages of a book. These plates extend into an internal pouch formed by the external skeleton that opens to the exterior by a small slit. This provides an extensive surface for the exchange of oxygen and carbon dioxide with the surrounding air. There are four pairs in scorpions and up to two in spiders.

8. Book gills It is believed that book lungs evolved from book gills. Although they have a similar book-like structure, book gills are external, while book lungs are internal. Both are considered appendages because book lungs develop from limb buds before the buds flatten into segmented lamellae. Book gills are still present in the marine arthropod  Limulus  (horseshoe crabs) which have five pairs of them, the flap in front of them being the genital operculum which lacks gills.

9. PROTOZOA Single-celled organisms, such as bacteria and protozoa, are in constant contact with their external environment. Gas exchange occurs by diffusion across their membranes. The respiratory gases may diffuse in and diffuses out trough the general body surface, there are no special organ for respiration.

10. PORIFERA In sponges, the special respiratory organs are absent Gaseous exchange occurs by simple diffusion between the cells of sponges and the current of water Oxygen dissolved in water is taken in by diffusion through the general body surface and carbon di oxide is given out Amoebocytes distributes oxygen with in the mesenchyme and carry away carbon di oxide

11. COELENTERATES In coelenterates, the special respiratory organs are absent Their body cells are ore or less directly exposed to the environment, both cell layers absorb oxygen from and expel carbon dioxide into the surrounding water. the oxygen is absorbed into their first layer of skin, called the ectoderm. Then, it goes through to the second layer, called the endoderm. The oxygen molecules are used and excess oxygen is released as carbon dioxide.

12. ASCHELMINTHES AND PLATYHELMINTHES respiratory organs are absent  The body walls of aschelminthes are very thin and thus it acts as their respiratory system. In living flatworms and roundworms, the exchange of gases takes place through general body surface In parasitic form, there is no exchange of gases. Endo parasites lives n almost oxygen free environment and fulfills its relatively less energy requirements by anaerobic respiration Flatworms are small, literally flat worms, which 'breathe' through diffusion across the outer membrane. The flat shape of these organisms increases the surface area for diffusion, ensuring that each cell within the body is close to the outer membrane surface and has access to oxygen.

13. ANNELIDA Respiration in annelids occurs primarily through their moist skin, although certain species have evolved specialized gills or use paired projections called parapodia in gas exchange. In earthworms the respiration mainly occurred or performed through skin the called as cutaneous respiration The blood of earthworm contains a respiratory pigment – Haemoglobin in a dissolved state in its plasma The epidermis of the body wall acts as a permeable membranes through which the atmospheric oxygen diffuses in its capillaries and combine with haemoglobin to form oxyhaemoglobin

14. The oxyhaemoglobin is circulated by blood into the tissues where oxygen tension is very low and carbon di oxide tension is high The oxyhaemoglobin breaks up to release oxygen to the tissues and haemoglobin in a reduced state Now carbon di oxide from tissue diffuses into the blood due to its high tension. The carbon di oxide is carried by the blood generally in a dissolved condition and when it reacts to the epidermal capillaries it diffuses from the blood to the atmosphere due to low tension

15. ARTHROPODA Aquatic arthropods possess gills for respiration and are covered by the exoskeleton, which is thin in this area and not a barrier to the exchange of gases. Terrestrial arthropods possess tracheae and book lungs as respiratory organs. The small, external openings (spiracles) reduce water loss, the chitinous lining prevents collapse Book lungs are chitin-lined internal pockets containing many blood-filled plates over which air circulates. Most spiders possess tracheae and book lungs, but large spiders (such as tarantulas) and scorpions possess book lungs alone.

16. The respiratory system of cockroach is very well developed to compensate the absence of respiratory pigment in the blood Ten pairs of spiracles or stigmata are present on the lateral side of the body. The largest first pair is present on the mesothorax. The second pair is on the metathorax and the rest eight pairs are on the first eight abdominal segments. the haemocoel con­tains a network of elastic, closed air tubes or tracheae. Three longitudinal tracheal trunks are present on each side of the abdominal cavity.

17. MOLLUSCA Basically all molluscs breathe by gills that are called ctenidia (comb-gills) because of their comb-like shape. A ctenidium is shaped like a comb or a feather, with a central part from which many filaments or plate-like structures protrude, lined up in a row In land snails and slugs, mantle cavity has evolved into primitive lung the mantle cavity forms a pulmonary chamber, the inner surface of which is highly vascularised. Many molluscs have a siphon which expels water and wastes

18. ECHINODERMS In echinoderms (starfish, sea urchins, brittle stars), most of the respiratory exchange occurs across tube feet (a series of suction-cup extensions used for locomotion). Echinoderms typically breathe and respire by the simple diffusion of gases like oxygen and carbon dioxide in and out of their body cell membranes. However, this exchange is supplemented by extensions of the coelomic, or body-fluid, cavity into thin-walled “gills” or dermal branchiae that bring the coelomic fluid into close contact with seawater. Respiratory tree is the branches of cloaca just inside the anus with the help of the drawing water through the anus and then expelled

19. Respiratory Pigments in Invertebrates In order to facilitate the transport of oxy­gen to different parts of the body, most ani­mals have developed respiratory pigments. In general, respiratory pigments are coloured proteins that contain a metallic element in their constitution and have the property of forming loose combination with oxygen and sometimes with carbon dioxide. Four different (biochemically) respiratory pigments are recognized – haemoglobin, chlorocruorin, haemocyanin , and haemerythrin . Even in the same phylum there may be several distinct pigments

20. Haemoglobin: It is the most efficient respiratory pigment. It is widely distributed in the animal kingdom, starting from some protozoa like Paramoecium to almost all verte­brates except eel larvae and some Antarctic fishes. Some invertebrate phyla viz., Porifera, Cnidaria and Ctenophora, totally lack it

21. Haemocyanin: Among various copper- proteins occurring in nature, only haemo ­ cyanin can reversibly combine with oxygen and thus, serves as a transport pigment. It is found in Chitons, some gastropods and cephalopods amongst the molluscs and in crustaceans and Limulus amongst the arthro­pods. It always remain dissolved in the plasma.

22. Chlorocruorin: This green coloured metalloprotein is found in the plasma of certain polychaet families. It is a metalloprotein with the metal being iron (Fe ++ ); the metalloporphyrin is similar to heme of haemoglobin except that one vinyl (CH = CH 2 ) group is replaced by formyl (0=CH) group in Chlorocruorin. The porphyrin is called chlorocruoheme.

23. Haemerythrin: This violet coloured pigment is found inside the corpuscles of animals ex.polychaete worm Magelona. It is also an iron containing metalloprotein but has no porphyrin. Pinna globin: This brown coloured, manganese containing pigment is present in the plasma of Pinna.

24. Functions of respiration Delivers oxygen to the cells in your body. Removes waste gases, including carbon dioxide, from the body when you exhale. Breathing – movement of air Sound Production Olfaction, or Smelling, Is a Chemical Sensation

25. Question bank PART-A Define respiration? What are the types of respiration? Name the Respiratory organs of invertebrates? What is Trachea? What are tracheoles? What are Spiracles? Define Gills? What are gill filaments? What is book lung? What are book gills? Define diffusion? What is the role of Amoebocytes in poriferan respiration? Define cutaneous respiration? What is oxyhaemoglobin ? What is ctenidia ? What is dermal branchiae? What is Respiratory tree ? What is respiratory pigments? What are the types of respiratory pigment?

26. PART-B Explain the mechanism of respiration in insects? Explain the mechanism of respiration in annelids? State the functions of respiration? Give an account of respiratory organ “ book lung ” ? PART-C Explain the types of respiratory organs in invertebrates ? Give a detailed account of types of respiratory pigments?

27. References https://byjus.com/biology/respiration-cockroach-earthworm https://www.notesonzoology.com/cockroaches/process-of-respiration-in-cockroaches-invertebrates/1989 https://www.britannica.com/science/respiratory-system/Basic-types-of-respiratory- https://www.webmd.com/lung/picture-of-the-trachea https://www.toppr.com/guides/science/respiration-in-organism/respiration-in-other-animals/ https://phylumrespiratioryexamin.weebly.com/porifera.html https://www.vedantu.com/question-answer/respiration-occurs-in-annelids-by-a-skin-b-gills-class-11-biology-cbse-6010e70fdfcfb40cf08fd05c Book: Manual of zoology part 1 Invertebrata Volume 1 and 2 BY- M. Ekambaranatha Ayyar T.N Ananthakrishnan