Frog Dissection What is the name of this famous Muppet frog?? KERMIT

AMPHIBIAN CHARACTERISTICS Moist, thin skin without scales Aquatic larva changes to terrestrial adult Feet without claws Respiration with gills, lungs, skin, mouth Closed 2 loop circulation Ectothermic (cold blooded) Eggs without shells or multicellular membranes

FROG ANIMALIA CHORDATA VERTEBRATA “backbone” AMPHIBIA “double life” LATIN meaning KINGDOM _____________ PHYLUM ____________________________ SUBPHYLUM ___________________________ CLASS _______________________________ ORDER _____________________________ ANIMALIA CHORDATA VERTEBRATA “backbone” AMPHIBIA “double life” ANURA “without a tail”

MOST vertebrates have nuclei in their RBC’s MAMMALS DON’T

ECTOTHERMIC “cold blooded” Body temperature is dependent on surrounding environment

HIBERNATION/ ESTIVATION FAT stored in FAT BODIES provides energy

Nictitating membrane

Functions Nictitating Membrane Tympanic Membrane – membrane that covers the eye Tympanic Membrane – membrane that functions as an eardrum

NO CLAWS

What sex is it?

Incision 1: The brain Insert the scissors into the frogs mouth. Cutting down the middle of his upper jaw…cut between the eyes. Once you have reached the back of the frogs head…cut behind the eye to the lower jaw Remove half of the frogs head

Incision 2: Skin First Place your frog on its back and pin it to the dissecting tray. Make a small cut through the lifted skin with the scissors. BE CAREFUL and only cut the skin layer. Use the scissors to continue the incision up to the midline all the way through the frog’s skin.

Incision 3: Skin Horizontal Use the scissors to make sideways incisions in the skin. The first incisions are made between the front legs. The next incisions are made just above the rear legs Be careful to only cut through the skin, not the muscle.

Incision 4: Separate Skin After you've opened the flaps of skin, pin them to the dissection tray.

Incision 5: First Muscle Incision Repeat the incisions, this time through the abdominal muscle. Be careful that you don't cut too deeply. The muscle is thin. It is easy to DAMAGE the organs underneath.

Incision 6: Chest Bone Cut through the chest bones. Use your hands to break apart the rib cage.

Incision 7: Muscle Horizontal Make the horizontal incisions. Just as you did with the skin, make a sideways incision in the muscle with the scalpel. Make the first incision between the front legs. The next incision is just above the rear legs. Again, be careful that you don't cut too deeply.

Incision 8: Muscle Separate Separate the muscle flaps from the organs below. Pin the muscle flaps back far enough to allow easy access to the internal organs.

Incision 9: Triangular Flaps Cut the triangular of its throat region. Make an incision from the throat to the tip of the jaw. Pin back the flaps

Functions Vomerine - Glottis Eustachian Tube Tongue Pharynx Esophagus – teeth on the roof of the mouth Glottis – Opening in the mouth ; airway Eustachian Tube – Tubes that equalize pressure to the eardrum Tongue – Used to capture food ; attached to front Pharynx – muscle that helps pull in food Esophagus –food enters (food tube); leads from the mouth to the stomach

BRAIN – controls the body functions

Fat Bodies Function – stores fat for energy the body cavity might be full of yellow-orange fat bodies. Spaghetti shaped

Organ: Heart Function – pumps blood You should also be able to see the heart in 1st layer It is a small triangular shaped organ…just above the liver. Ventricle chamber = Lower (single) chamber of the frogs heart

Organ: Stomach Function – major sight of digestion esophagus empties into this organ leads to the small intestines Pyloric sphincter – regulates food exiting the stomach.

Organ: Liver Function – Largest organ ; 3 lobes ; secretes bile for digestion the first organ we can see when you open the skin and muscles layer. The liver is a large, brownish colored organ covering most of the body cavity.

Peritoneum – spider-web like membrane that covers the organs

Organ: Small Intestine Function – absorption of digestive nutrients The small intestine is a long, folded, tube like organ that comes from the stomach. Leads to the large intestines Duodenum = first stretch of the small intestines

LARGE INTESTINE Function – removes water from digestive waste; concentrates feces Wider than the small intestines

Mesentery holds intestines together

Organ: Spleen Function - Produces and stores new RBC’s and processes old worn out ones Round reddish organ

Organs 9: Lungs Function – exchange O2 and CO2 The lungs are difficult to locate in a preserved frog. They're at the back end of the body cavity.

Organ: Kidneys Function - Filters liquid waste Remove waste from blood and dilute it with water to make urine Bean shaped

URINARY BLADDER STORES URINE MADE BY KIDNEYS Lowest part of the frog cavity

Organ: Gall Bladder Function –stores bile Under the liver small, greenish sac. You might have the students remove the gall bladder as they might cut through it when they remove the liver. Again, the students are supposed to be exploring here, but it’s your choice if you want them to remove the gall bladder at this time. I have mixed emotions. I think I would want them to explore, then remove the organs and place them on the worksheet so I could determine what they retained during the exploration. Or you could have them remove it at slide 21. Your choice.

CLOACA Last stop before waste/sperm/ or urine exits DIGESTIVE EXCRETORY REPRODUCTIVE

Organ: Pancreas Function – produces enzymes to help with digestion lift the stomach and intestines with the forceps. The pancreas is a thin, yellowish ribbon.

TESTES – makes sperm

TESTES KIDNEY

Female Frogs If you have a female frog, you will need to remove the ovaries before you can see layer four. Ovaries – Makes eggs Oviduct – Long tube that runs around the kidneys; carries eggs

Females may have black & white eggs

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