Frog Anatomy Introducing the Frog: Belong to the group vertebrates Vertebrates include: sharks, fishes, amphibians, reptiles, birds,and mammals All vertebrates have a back bone and a body that is made of a head, trunk, and tail with paired limbs. Frog belongs to the class: Amphibia This includes salamanders, caecilians, frogs and toads. Frogs and toads make up 87% of all amphibians. This is a class known as the evolutionary transition from water to land. For this to occur certain adaptations in the adult body had to be made. The formation of lungs to breathe air Double circulatory system to accommodate lungs Formation of limbs to move on land A more rigid endoskeleton Lungs an efficient method for terrestrial animals to obtain oxygen. Double circulatory system Systemic circuit supplies blood to the body. Pulmonary circuit supplies blood to the lungs. Amphibians reproduce eggs and are laid in water. Amphibian larvae live there lives in aquatic environment. Tadpoles have gills and a tail for swimming. Frogs live what is called a Dual Life Bilateral symmetry animal can be divided into an equal mirror image called the sagittal plane. Frontal planes and transverse planes are two other types of planes. Anterior refers to the head region Posterior refers to the tail region Dorsal refers to the back region Ventral refers to the belly region External Structures Pattern and color on the frogs dorsal side is designed for camoflauge in green vegetation and the underside is light to camoflauge the frog when it swims across the top of the water. Structures and functions of the external structures 1. Tympanic membrane separates the outer environment from the middle ear. 2. Eye with the nictating membrane Membrane protects eyes under water. 3. Maxillary teeth Help frogs hold their prey and feed mostly on insects. 4. External nare Move air into the mouth through the internal nares. 5. Vomerine teeth Also hold prey, and are angled in. 6. Internal nare Area where air is drawn into from the external nare. 7. Opening to the Eustachian tube Tubes that connect to the middle ear and equalize air pressure in the head. 8. Glottis thin opening to the larynx and to the esophagus. 9. Tongue extend out from mouth. 10. Mandible lower jaw. 11. Opening to the vocal sac Only found in males, help vocalize. The Skeleton The skeleton is divided into two parts: The Axial and Appendicular skeleton Axial skeleton includes: Skull Vertebral column Sternum Appendicular skeleton includes: Pectoral girdle Pelvic girdle Appendages Frogs have a more rigid skeleton and an inflexible vertebral column. This helps transform the energy of the powerful hind legs into the movement of the body. 1. Atlas; 2. Exoccipital 3. Frontoparietal; 4. Sphenethmoid 5. Nasal; 6. Vomer 7. Premaxilla; 8. Maxilla; 9. Pterygoid 10. Squamosal; 11. Quadratojugal 12. Clavicle; 13. Coracoid 14. Humerus; 15. Radioulna 16. Vertebral column 17. Prepollux; 18. Phalanges 19. Metacarpals; 20. Carpals; 21. Scapula 22. Suprascapula; 23. Sacral Vertebra 24. Urostyle; 25. Ilium; 26. Pubis 27. Ischium; 28. Femur; 29. Tibiofibula 30. Astragalus; 31. Calcaneum 32. Prehallux; 33. Metatarsals; 34. Phallanges Muscular system Have some of the same muscles as humans since they are quadrupeds. There are two types of actions that describe all muscle: Flexion Bending a joint so that the angle of that joint decreases. Ex: Bending your elbow or knee. Extension extending a joint so that the angle of the joint increases. Ex: Straightening out your arm or leg. 1. Dorsalis scapulae; 2. Depressor mandibularis 3. Temporalis; 4. Deltoid; 5. Triceps brachii 6. Extensor carpi ulnaris; 7. Extensor digitorum communis 8. Anconeus; 9. external oblique 10. Latissimus dorsi; 11. Iliolumbaris 12. Triceps femoris; 13. Biceps femoris 14. Gastrocneumius; 15. Peroneus 16. Gracilis minor; 17. Semimembranosus 18. Piriformis; 19. Gluteus 1. Mylohyoid; 2. Sternoradialis; 3. Pectoralis major 4. Cutaneous pectoralis; 5. Rectus abdominus 6. Deltoid; 7. Extensor carpi radialis 8. Flexor carpi ulnaris; 9. Flexor carpi radialis 10. Pectoralis major; 11. Linea alba 12. External oblique; 13. Sartorius 14. Adductor magnus; 15. Gracilis minor 16. Gastrocnemius; 17. Tibialis posterior 18. Gracilis minor; 19. Triceps femoris 20. Adductor longus; 21. Extensor cruris 22. Tibialis anterior longus Digestive System Alimentary canal runs from mouth to anus. Pharynx where food enters mouth. Esophagus passageway from mouth to stomach. Stomach Breaks down food through muscle contractions and acids. Pyloric valve a valve that separates the stomach from the small intestine Small intestine Nutrient absorption and digestion. Duodenum first part of the small intestine. Ileum The portion of the intestine that is curved. Large intestine Digests bacteria, reabsorbs water, and forms feces. Cloaca Receives waste from kidneys, fluids from reproductive organs, and large intestine. It is a common opening for waste products inside the body. Liver, gallbladder, and pancreas all digestive glands that help the digestive process. The Internal Organs Lungs have a spongy texture and appearance. Transfers oxygen to the circulatory system. Pancreas Located between the stomach and small intestine. It is cream in color and lumpy in texture. It secretes pancreatic juices into small intestine. Also produces insulin, glucagon, and other hormones that are important in the regulation of sugar levels and metabolism of fats and carbohydrates. Spleen Very small and produces macrophages Macrophages engulf and digest foreign cells and dead cells. They eat old red blood cells, platelets, and bacteria. The spleen removes the iron and other useful components before breaking down a blood cell. Fat bodies Located near the kidneys. They are energy reserves. Ovary Site where eggs are produced and also hormones. Kidney Excretes ions, water, and other nitrogenous wastes. Waste leaves body in the form of urea and ammonia and frogs can get rid of this waste through their skin. Urinary bladder Where urea and ammonia are stored until it is released through the cloaca. Mesentery double membrane that attaches the alimentary canal to the body wall. Contains many blood vessels, lymph vessels, and nerves. Gallbladder Round pea-green structure on the under surface of the right lobe of the liver. Stores and concentrates bile secreted by the liver and delivers it to the duodenum through the common bile duct. Bile digests and absorbs fats. Liver Larges organ inside body. Metabolizes carbohydrates and fats Produces bile. Disposes of old red and white blood cells. Contains hepatocytes that contain enzymes that detoxify poisons. Heart Three chambered heart that pumps blood throughout the body. It consists of the right & left atrium, and a central muscular ventricle. 1. Esophagus; 2. Left lung; 3. Stomach 4. Pancreas; 5. Spleen; 6. Fat bodies 7. Ovary; 8. Kidney; 9. Urinary Bladder 10. Cloaca; 11. Large intestine 12. Small intestine; 13. Mesentery 14. Gall bladder; 15. Lobes of the liver 16. Heart Respiratory system Positive pressure breathing gulping air into the lungs since they lack a diaphragm. Negative pressure breathing mammals do this by pulling air down into the lungs through the contraction of the diaphragm. Cutaneous respiration ability to breathe through the skin. Urogenital (reproductive & excretory) system Fertilization is external Eggs are released into the water as they are being fertilized. Aorta supplies highly oxygenated blood into the lower extremities of the body. Posterior vena cava Extends to upper and lower extremities of the body. Transports deoxygenated blood from the extremities to the heart. Ureter Transports urine to the urinary bladder. Seminal vesicle pair of glands close to the ureters. Secrete and produce semen. Adrenal gland located in the kidney. Produces hormones that regulate salt and act as a flight or fight response. Testis produce sperm and hormone testosterone. Ovary site of the creation of mature eggs and produces hormones related to reproduction. Oviduct transports the eggs from the ostia to the uterus. Ostium the ostia are the openings to the oviducts that receive the eggs from the body cavity. 1. Aorta; 2. Posterior vena cava 3. Fat bodies; 4. Kidney; 5. Ureter 6. Large intestine; 7. Cloaca 8. Urinary bladder; 9. Seminal vesicle 10. Adrenal gland; 11. Testis 12. Aorta; 13. Posterior Vena Cava 14. Ovary; 15. Large intestine; 16. Cloaca 17. Uterus; 18. Urinary bladder 19. Ureter; 20. Kidney; 21. Adrenal gland 22. Fat bodies; 23. Oviduct; 24. Ostium Circulatory System Arteries Carry blood away from the heart Veins Carry blood toward the heart. Double circulatory system Systemic circuit supplies blood to the body Pulmonary circuit supplies blood to the lungs. Mammals have a four chambered heart where the two circuits are completely separated. Right side serves the pulmonary circuit and left serves the systemic circuit Left and right atria and ventricles are completely separated Amphibians - Heart consists of three chambers Partial separation of the systemic and pulmonary circuits. 1. Right atrium; 2. Left atrium 3. Ventricle; 4. Internal carotid 5. Internal jugular 6. Conus arteriosus 7. External carotid; 8. External jugular 9. Subclavian artery 10. Subclavian vein 11. Pulmonary arteries & veins (leads to lungs) 12. Celiac artery 13. Hepatic portal vein 14. Celiacomesenteric artery (to stomach) 15. Ventral abdominal vein 16. Sciatic artery; 17. Sciatic vein 18. Common iliac artery 19. Femoral artery; 20 Femoral vein 21. Renal portal vein; 22. Aorta 23. Inferior vena cava 24. Systemic arch Nervous system Distributes sensory and motor impulses Nerve impulse electrical signal transmitted along neurons. Central Nervous System (CNS) consists of brain and spinal column Peripheral Nervous System (PNS) connects the central verves to the organs and other regions of the body. Autonomic Nervous System cranial nerves associated with involuntary body processes such as the heart rate, blood pressure, breathing, and digestion. The Frog Brain 1.Olfactory nerve 2.Optic nerve 3.Oculocomotor nerve 4.Trochlear nerve 5.Trigeminal nerve 6.Abducens nerve 7.Facial nerve 8.Acoustic nerve 9.Glossopharyngeal nerve 10.Vagus nerve 11.Branch of the sympathetic trunk (Not part of the cranial nerves) Eye ball and eye lid movement Motor nerve for superior oblique muscle Sensations in face and motor neuron for biting. Motor nerve for eye Motor and sensory nerve for pharynx and tongue Controls all involuntary movement. Branches for the nerves coming off of the spinal cord The Frog Brain 12. Spinal cord 13. Jugular ganglion 14. Medulla oblongata 15. Pituitary gland 16. Prootic ganglion 17. Infundibulum 18. Optic chiasma 19. Diencephalon 20. Cerebrum 21. Olfactory lobe Nervous system 1. Sympathetic nerves; 2. Cerebrum 3. Olfactory nerves; 4. Olfactory lobe 5. Optic nerve; 6. Optic lobe 7. Brachial plexus containing nerves (Containing nerves 1 3) 8. Radial nerve; 9. Ulnar nerve 10. Abdominal nerve 11. Nerves 4 6 (leading to abdomen 12. Sciatic plexus containing nerves 7 Sciatic nerve 14. Tibial nerve 15. Peroneal nerve 16. Filum terminale 17. Spinal cord