1. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

2. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All” Presented by- Kawsar Hawlader, Senior Lecturer Cambrian College, Dhaka

3. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

4. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

5. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All” Respiration is the sign of life and index of all biochemical activities takign place in the body. Respiration is a catabolic process in which the respired oxygen is used in the oxidation of food resulting in the release of energy. This energy is utilized for all the vital activities. Carbohydrates are mainly concerned with release of energy. Oxygen required for this process is obtained from the surrounding medium. Respiration is the sign of life and index of all biochemical activities takign place in the body. Respiration is a catabolic process in which the respired oxygen is used in the oxidation of food resulting in the release of energy. This energy is utilized for all the vital activities. Carbohydrates are mainly concerned with release of energy. Oxygen required for this process is obtained from the surrounding medium. Respiratory system

6. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

7. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

8. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All” Structure of gill: In Rohu four gills are present on either side of the phurynx in a gill chamber, thus there are four pairs of gills in total. The general structure of a mature gill is composed of several parts: * Gill rakers are bony parts on the pharyngeal margin of the gill and function in preventing food particles from entering the gill chambers. * Gill filaments are the feather-like projections of the gills across which diffusion of gases occurs. * Gill filaments also possess gill lamellae, which are small crevices through which water passes for diffusion. - lamellae are oriented parallel to the stream of water through the gills to maximize efficiency of diffusion. -the blood flow through the gills opposes the flow of water through the lamellae (countercurrent flow) and maximizes the efficiency of diffusion this is important because water has about 1/30th the oxygen concentration of air. Structure of gill: In Rohu four gills are present on either side of the phurynx in a gill chamber, thus there are four pairs of gills in total. The general structure of a mature gill is composed of several parts: * Gill rakers are bony parts on the pharyngeal margin of the gill and function in preventing food particles from entering the gill chambers. * Gill filaments are the feather-like projections of the gills across which diffusion of gases occurs. * Gill filaments also possess gill lamellae, which are small crevices through which water passes for diffusion. - lamellae are oriented parallel to the stream of water through the gills to maximize efficiency of diffusion. -the blood flow through the gills opposes the flow of water through the lamellae (countercurrent flow) and maximizes the efficiency of diffusion this is important because water has about 1/30th the oxygen concentration of air. Gill arch Gill raker Gill filaments

9. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

10. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All” Mechanism of Respiration: Inspiration: * Muscular contraction exerts in the floor of the pharynx and bucal cavity resulting in bucal cavity expanding. The bucal cavity pressure decreases. Mouth valve opens leading to opening of the mouth and water with dissolved oxygen enters from the outside because of reduced pressure. * At the same time the operculum bulges outwards leading to the opercular cavity expanding. The opercular cavity acquires a negative pressure i.e. pressure reduces therefore opercular valve closes. The expansion of the opercular cavity leads to pressure falling below that of the bucal cavity which has began to contract as a result water is sucked into the opercular cavity from buccal cavity and flows over the gills where gaseous exchange takes place. Inspiration: * Muscular contraction exerts in the floor of the pharynx and bucal cavity resulting in bucal cavity expanding. The bucal cavity pressure decreases. Mouth valve opens leading to opening of the mouth and water with dissolved oxygen enters from the outside because of reduced pressure. * At the same time the operculum bulges outwards leading to the opercular cavity expanding. The opercular cavity acquires a negative pressure i.e. pressure reduces therefore opercular valve closes. The expansion of the opercular cavity leads to pressure falling below that of the bucal cavity which has began to contract as a result water is sucked into the opercular cavity from buccal cavity and flows over the gills where gaseous exchange takes place.

11. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

12. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

13. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All” Air bladder/Swim bladder: The air bladder or swim bladder is a preamatic sac inside the abdomen that contain gas. It is present most bony fishes including Rohu fish. It lies in the body cavity and situated dorsal to the digestive tract and ventral to the vertebral column. Swim bladder of Rohu fish is an elongated white, thin walled sac divided into a small anterior chamber and a large posterior which are interconnected with each other. The anterior chamber is rounded and the posterior chamber is oval shuped. In both chambers of air bladder inner wall have a red colour gas gland celled the rete mirabile. Rete mirabile recives oxygen from the blood and posterior chamber absorbs the gas. The anterior chamber is connected to the oesophagus by a slender like duct which is called ductus preumaticus and such fish is called physostomous. Oxygen is the largest percentage of gas in the bladder; ritrogen and carbondioxide also fill is passively.

14. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”

15. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All” Group -A Write down structure of gills. Group-B Write down the process of respiration.

16. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All” Zoologist Nazrul Islam said to his friend, the process of energy producing by the help of O2 in a terrestrial special animal is difference from the aquatic animals under the phylum Chordata. The main organ of the special system is exceptional. a.What is operculum? b.What is meant by air–bladder? c.Describe the process which is occurred in the mentioned aquatic animal. d.Analyze the dissimilarity between mentioned organ of terrestrial animals and aquatic animals.

17. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All” Draw a figure of air- bladder.

18. MD. KAWSAR ALI HAWLADER,LECTURER OF BIOLOGY, CLASS-XI, CHAPTER-2 Cambrian Education Group “Total Education For All”