Anatomy and physiology of Honey Bees.pptx
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The document provides an overview of the anatomy and physiology of honey bees. It discusses the main body systems of bees including the digestive, respiratory, nervous, circulatory, excretory, and reproductive systems. For each system, it describes the key anatomical structures and their functions. It also covers several important glandular systems such as the hypopharyngeal glands, mandibular glands, venom gland, Dufour's gland, and wax glands. The document provides detailed information on the internal workings of honey bees.
Anatomy and physiology of Honey Bees.pptx
- 1. A N AT O M Y & P H Y S I O L O G Y O F H O N E Y B E E S D R . M A N D E E P R A T H E E T R A I N I N G A S S I S T A N T K V K , K A I T H A L C C S H A U , H I S A R - 1 2 5 0 0 4
- 2. ANATOMY & PHYSIOLOGY OF HONEY BEE • The internal morphology (Anatomy) of honey bees essentially corresponds to that of other insects. The same can be said about physiology (vital functions). Logically, anatomical peculiarities and vital functions are interrelated. • DIGESTIVE SYSTEM • RESPIRATORY SYSTEM • NERVOUS SYSTEM • CIRCULATORY SYSTEM • EXCRETORY SYSTEM • REPRODUCTIVE SYSTEM • GLANDULAR SYSTEM
- 4. DIGESTIVE SYSTEM • The digestive system is composed of three main sections, the foregut, midgut, & hindgut • The foregut (first third of the digestive tract) and hindgut (last third of the digestive tract) form as invaginations from either end of the developing bee. • The foregut and hindgut are lined with cuticle, this means that these are not sites for nutrient absorption in the bee since nutrients cannot traverse the cuticular lining. • In contrast, the midgut is not lined with cuticle, thus making nutrient absorption its primary function. • The lining of both are shed as a bee molts (sheds its exoskeleton) during larval development
- 5. • The foregut is composed of the mouth, esophagus, and crop of the honey bee. • The esophagus is simply a tube that runs from the mouth in the head, through the thorax, and into the crop in the abdomen. • The crop, or honey stomach as it is called sometimes by beekeepers, is a spherically shaped organ in the abdomen serves as a site for nectar storage. • The crop can expand significantly when it is full of honey or nectar, so-much-so that the abdomen swells. • The foregut and midgut are separated by a valve called the proventriculus which is located at the end of the crop. This valve can grind and pulverize food particles (such as pollen) and filter pollen out of the crop contents. • Food passes through the proventricular valve and into the bee’s midgut or ventriculus FOREGUT
- 6. • The midgut is the primary site of enzymatic digestion of food and absorption of nutrients • It is lined by the peritrophic membrane • This membrane protects the digestive cells (the cells that line the internal surface of the midgut) while allowing absorption of the nutrients straight into the hemolymph. • Next along the digestive tract are the Malpighian tubules • These occur at the end of the midgut and are, essentially, spaghetti/maggi-like extensions of the tract that float freely in the bee’s body cavity. • The Malpighian tubules extract waste products from the hemolymph. They produce uric acid granules help with osmoregulation (water management) MIDGUT
- 7. • The hindgut, or final section of the digestive system, is composed of the ileum and rectum. • The ileum, sometimes called the small intestines, is a short tube that connects the midgut to the rectum. • The rectum is important for the absorption of water, salt, and other beneficial substances prior to waste excretion. • There are small areas on the rectum called rectal pads. These sections reabsorb >90% of the water that was used by the Malpighian tubules to collect waste. The latter is an important function. • Uric acid solids and other unused foodstuffs, such as the of pollen grains, are excreted as relatively solid feces. HINDGUT
- 8. RESPIRATORY SYSTEM • No specific organ for gas exchange • Tracheal system which consists of spiracles, tracheas, air sacs and tracheoles (here gas exchange really occurs) • The spiracles are external holes that used for ventilation. Both in larvae and adults there are 10 pairs and all of them except the second —which is very small— have closing valves. • Spiracles are opened in response to low concentrations of oxygen or high concentrations of carbon dioxide in tissues, allowing the air to enter and exit. • Tracheas are conduits that communicate spiracles with the air sacs. The longest are those of the first pair. • The valve of the first spiracle does not close completely. This first spiracle is also the entry point of the mite Acarapis woodi. and it feeds on hemolymph and obtains it by perforating the trachea.
- 9. RESPIRATORY SYSTEM • The main tracheas extend to the sides of the body and form large widenings • Gas exchange occurs in the so-called tracheoles • Oxygen is directly carried to all parts of the body by a series of tubes called tracheas • Honeybees’ breathing is almost opposite to that of all vertebrates. Air is transported towards the blood. • Air sacs (or tracheal sacs) play an essential role in tracheal ventilation. They intervene in the flight mechanism. All of the sacs are interconnected. • Honeybees’ blood is a clear and yellowish liquid (called hemolymph).
- 10. NERVOUS SYSTEM • Larvae have a brain with a suboesophageal ganglion, as well as eleven ganglia, longitudinal corners formed by pairs of twin nerves. • Adult bees have a larger brain with a suboesophageal ganglion, as well as seven ganglia which form a ventral cord that runs below the gastrointestinal tract. • In the thorax are two thoracic ganglia. The nerves that come from the first of them are directed to the first pair of legs. • The nerves of the second ganglion are directed towards the flight muscles and the second and third pairs of legs. • In the abdomen there are five other ganglia that regulate intestines and breathing organs functions. The last two, somewhat larger than the others, regulate the reproduction organs and the stinger. • Each of the three parts of honeybees body (head, thorax and abdomen) function more or less independently. • Worker bees’ brain is much larger than that of the drones in spite of being the head of the last ones greater. Our greatest interest lies in the fact that it is the target of neurotropic viruses.
- 11. CIRCULATORY SYSTEM • The circulatory system of honeybees is composed of a long tube that runs throughout their body. • It is closed at the abdominal end and open in the head. It stretches along the digestive track. • Its main function is the transport of nutrients and removal of waste. • Its components are; hemolymph, ventral and dorsal diaphragms, heart, aorta and antennae vesicles. • The hemolymph is a complex fluid that contains cells called lymphocytes. These cells have phagocytic capacity. • Bees’ heart located dorsally in abdomen is formed by ventricles joined together by valves called ostia. Ostiolar chambers are joined by valves that open only forward, this allows the advancement of hemolymph, but not its recoil. • The dorsal and ventral diaphragms are responsible for circulation in the abdomen and help blood to return from the thorax. Antennae vesicles pump blood to the antennae.
- 12. EXCRETORY SYSTEM MALPIGHIAN TUBULES • It is formed by the Malpighian tubules, which remove substances from blood and pour them into the anterior intestine to eliminate them with faeces. These substances are mainly nitrogen derivatives. It is the target of Malpighamoeba mellificae causing amoebiasis FAT CELLS • They form thin membranes that are scattered along the abdomen walls. • In winter these cells are poor in fat and rich in albumin, while in summer is the other way around. • Among fat cells are the oenocytes, which are cells related wax metabolism. These cells, along with fat, contain and glycogen. Pseudomonas apiseptica grows here before invading the blood and causing septicaemia
- 13. REPRODUCTIVE SYSTEM: QUEEN • Two pear-shaped ovaries constituted by long tubes called ovarioles which end in little tips. Ovarioles are full of ovules (oocytes) in different stages of maturation. • A queen (2n=32) can lay up to 2,000 eggs/day and 200,000 eggs/year. • Ovaries end in separate oviducts, which then join in a common conduit, or middle oviduct. At its base it communicates with the spermatheca, which is where the spermatozoa of copulas are accumulated • This system continues with the vagina, which ends at the vaginal opening, which is protected by a fold. Ovary with mature yellow eggs Shiny spermatheca
- 14. • Drones’ reproductive system is made up of two testes, two vasa differentia, two seminal vesicles, two mucus glands, ejaculatory duct and copulatory organ. • Testes are formed the testicular tubes inside them is where spermatozoa are produced. • The vasa differentia communicate testicles with the seminal vesicles. • The seminal vesicles produce secretions that accompany spermatozoa and inside them they finish maturing. • Mucus glands produce a substance that solidifies in contact with air and water, but not with seminal secretions. • The ejaculatory duct communicates the mucus glands with the copulatory organ. • The copulatory organ is introduced in queen’s bursa copulatrix and it is detached from the drone once semen is introduced, REPRODUCTIVE SYSTEM: DRONE
- 15. GLANDULAR SYSTEM HYPOPHRYNGEAL GLANDS • Hypopharyngeal glands consist of a pair of long duct coiled in the sides of the head of worker bees • In queens they are rudimentary and in drones they do not exist. • Their protein rich secretion’s product serves as food for larvae in their first three days of life and for queens throughout their lives. It’s the well-known royal jelly. When bees mature, these glands lose their functionality. SALIVARY GLANDS • These glands are found in head and thorax (post-cerebral or thoracic). The two common ducts pour saliva (slightly alkaline aqueous liquid) on both sides of the tongue. • Saliva helps dilute honey and dissolve sugar crystals. In addition, it moistens the substances involved (pollen at the time of collection). • It also contains enzymes which are responsible for the transformation of nectar and honeydew in honey.
- 16. MANDIBULAR GLANDS • They are placed on the head of worker bees and queens (drones lack them). The excretory duct pours secretions into the inside of the jaws. • In worker bees it produces a fraction of the royal jelly and in queens releases a pheromone that plays an important role in the social cohesion of the colony (binding effect to worker bees, inhibition of queen cells construction, attraction of drones in nuptial flights). • Queen mandibular glands release queen substance. NASSANOV GLAND • The Nasonov’s gland is an odoriferous gland, located in the dorsal part of the of workers, in the anterior face of the 7th abdominal tergite. When bees are at rest it not appreciated. • This gland is only seen when bees dilate their abdomen and adapt the characteristic “call” position with the abdomen upwards and beating their wings. Then it gives off a characteristic smell that identifies and attracts to all the bees of the same colony that can be disoriented. GLANDULAR SYSTEM
- 17. VENOM GLAND • The defense apparatus is composed mainly of the sting and the poison bag. • The sting has a pair of lancets attached to each other so that they form a channel, through which poison passes. Then, comes out by the curved teeth or beards that gird the tip of the lancets. • Each lancet has about nine teeth, with their tips turned back like a hook, and when they dig into the wound, they cannot get it out. When bees try to remove the sting, they are unable to do and in this struggle lose this organ and part of the intestine, which leads them to die. • Another component is a whitish vesicle called “venom sac”. It contains a liquid that is produced by two glands that drop their secretions in this bag, one of which pours an acidic substance and the other an alkaline substance. None of these substances toxic itself, but when combined produce a strong irritation with subsequent inflammation. GLANDULAR SYSTEM
- 18. VENOM GLAND • The defense apparatus possess powerful muscles which bees to nail the lancets into the wound. They also do contractile movements that last a few minutes after being detached from the bee. • Due to those movements, poison is still being introduced into the wound. The sting of the queen is smooth, curved and somewhat longer than that of workers. It is only used when queens fight each other. • Once a worker bee stings, the bee tries to get away. The sting has barbs preventing the sting to be pulled out. • The sting apparatus breaks off and is left behind. • The sting, venom gland, and muscles controlling the gland, will work autonomously to pump venom into the victim. • Alarm pheromone is also released to “mark” the victim. This sends a signal to other bees to sting you again. GLANDULAR SYSTEM
- 19. DUFOUR'S GLAND • Occurs only in females (queens and workers) and it is absent in drones. It is an unpaired and unbranched epithelial sac • The Dufour gland in the honeybee exits between the sting lancets • 12 fold activity in queens • The Dufour's gland secretion is attractive to workers and can be responsible for retinue formation around queens and laying workers, help distinguish queen worker eggs • During development it is formed as GLANDULAR SYSTEM
- 20. KOSCHEVNIKOV’S GLAND • Occurs only in females (queens and workers) and it is absent in drones • The Koschevnikov gland is located near the sting shaft • Released by queen for cluster of workers around it • In honey bee workers the gland produces an alarm pheromone that is released when a stings GLANDULAR SYSTEM
- 21. QUEEN AND WORKER GLANDS
- 22. QUEEN GLANDS
- 23. WAX GLANDS • Four pairs, one for each sternite (4th-7th). In each sternite there are light-coloured areas called “wax mirrors” that carry pores where the greasy secretion of the wax glands, located in the inner part of each sternite, comes out. • The wax scales are carried by bees to their mouth with the second of legs • Irregular pentagon shape and are very small, each weighing 0.0008 g • Approximately 1,250,000 flakes = 1 kg of wax • Only bees have wax glands. They begin to work approximately at the day 12 of the bee’s life and end at the day 20, when bees become foragers • To make wax bees have to consume a lot of pollen and honey. When hives are loose bees consume about 15 kg of honey and pollen to produce 1 kg of wax. • On the contrary, when hives are strong, they consume only about 10 kg of honey and pollen. GLANDULAR SYSTEM
Editor's Notes
- #15: As the drones mature, testes lose size until they get reduced to 1/3 of their original size (pre-birth).