Dissection 101 Reasons to Use the Dissection Video

Dissection 101: Reasons to Use the Dissection Video and Accompanying Power. Point Presentation Ø Reduce the number of specimens used by a class Ø Increase the quality of the dissection for the students Ø Review opportunity, increasing the learning experience for the students Ø Student unable to dissect due to pregnancy or hypersensitivity to the preservatives Ø Student chooses not to dissect due to ethical/moral reasons Click

Dissection 101: As an educator you are responsible for the implementation of the dissection activity described in the video and Power. Point. You must have safety procedures and rules established for your classroom and make sure all of the students follow the rules to ensure a safe environment. South Dakota Public Broadcasting and Dakota State University cannot in any way be responsible or liable for any injury as a result of performing the described dissection. Complete the dissection if you feel it is appropriate and safe for your individual class. Have fun and stay safe! Click

Dissection 101: Clam Click

Dissection 101: Umbo (location): Shell originates from here (oldest section of the shell) Dorsal (hinge side) Clam Shell produced by mantel in a series of rings, similar to the rings of a tree – does not indicate age Posterior (greater distance from umbo) Anterior (closer to umbo) Wood inserted during preserving process to keep the clam open for dissection Ventral (foot side - movement) Click

Exterior of the Clam Bivalve (2 shells) Umbo Dorsal (top view) Hinge Click

Clam Dissection 101: Cut both adductor muscles on either Slowly open the clam; continue to cut the side of the hinge; do not cut adductor muscles if there is resistance. Student Cuts: through the middle of the clam • You. Tube (dorsal side: posterior and anterior) • SDPB Always cut away from your hands and fingers Cut Click

Dissection 101: Many times one of the mantles will rip when the clam is pulled apart. Clam This is not part of the clam. It is an extra piece of wood accidentally left in the clam during preserving process. Click

Identify the following Structures Adductor muscles (2) relaxed – clam opens contracted – clam closes Click

Identify the following Structures Nacre/Mother of pearl Iridescent layer of the shell, pearls form here (torn) Pallial line Location on shell where mantle attaches Mantle Produces shell and provides protective and lubricated surface for the body structures Click

Identify the following Structures Remove the upper mantle and labial palps Labial palps (4) to expose gills and visceral mass Mantle Two on. Mantle each side of Produces the shell the mouth, used to sort food and move it toward Labial palps the mouth Cut Lay your scissors/scalpel flat; lift the upper mantel and labial palps with a forceps; slowly/carefully remove these structures Muscular Foot Gills (respiratory) Used for movement, Used to remove oxygen appears shrunken in from the water Mantle preserved clam Click Produces the shell

Identify the following Structures Top View Visceral mass Thick area above foot, digestive glands, intestines and gonads located here Foot Gills have featherlike appearance, usually two on each side Foot Visceral mass Mantle Click

Identify the following Structures Remove the gills and outer layer of the visceral mass Student Cuts: • You. Tube • SDPB Cut #2 Cut #1 Ø Cut #1: Lay your scissors/scalpel flat; lift the gills with a forceps; slowly/carefully remove the gills Ø Cut #2: Lay your scissors/scalpel flat and remove the outer layer of the visceral mass, circular shape cut Click

Identify the following Structures Gills, mantle and labial palps removed Tube-like intestines wind through the visceral mass Visceral mass with outer layer removed Digestive glands (usually green) produces enzymes to digest food Gonads (usually yellowish/white) reproductive function Click

Identify the following Structures Remove the membrane to expose the heart Heart Use a forceps & scalpel/scissors to remove the membrane Student Cuts: • You. Tube • SDPB Click

Identify the following Structures Heart (exposed by removing protective membrane) Gills, mantle, outer covering of visceral mass and labial palps removed Each specimen may appear a little different, damaged adductor muscle shown here (could indicate some type of disease or condition that attacked the muscle) Click

Dissection 101: Clam Produced by Dakota State University and South Dakota Public Broadcasting