Deuterostome Animals #2

• Deuterostome animals are also eucoelomate, triploblastic, bilaterally symmetrical, and their embryonic development involves indeterminate cell lines and spiral cleavage.
• Intestine, Stomach, Spleen, Pancreas, Kidneys, Tympana (external), Cloaca, Fat bodies are structures and their functions must be known for practical 2.
• Protostome and Deuterostome animals differ in their embryonic development, with Deuterostomes having indeterminate cell lines, spiral cleavage, and the anus forming first from the blastopore.
• Deuterostomes are distinguished from protostomes via differences in embryological development, including radial instead of spiral cleavage, indeterminate instead of determinate cleavage, and the anus forming first from the blastopore.
• Deuterostomes are divided into two groups: Enchinoderms and Chordates, which includes humans.
• Echinoderms, as adults, are radially symmetrical and their larval forms are bilaterally symmetrical.
• Most Echinoderms have “spines” extending from their body, which are projections of their internal endoskeleton, not bone, it’s calcium carbonate.
• Echino means “spiny” and Derm means “skin”.
• Echinoderms have a water-vascular system, a series of internal water-filled canals that end in structures called tube feet, used for movement.
• The Phylum Echinodermata includes common species such as Sea stars, sea urchins, sand dollars, and sea cucumbers.
• Sea Star Anatomy can be traced through the water vascular system: madreporite → ring canal → radial canals → ampullae → tube feet.
• Chordates are defined by four key characteristics: Notochord, Dorsal hollow nerve cord, Pharyngeal gill slits, and the Anus forms first from the blastopore.
• Post-anal tail is a tail, posterior to the anus, which is only seen during embryonic development in apes and humans.
• The post-anal tail is divided into three subphyla: Urochordata (invertebrates), Cephalochordata (invertebrates), and Vertebrata (vertebrates).
• Chordata is a phylum that includes Tunicates, Lancelets, Jawless Fishes, Jawed Fishes, Amphibians, Reptiles, and Mammals.
• Tunicates are sessile (immobile) marine organisms, examples include Sea squirts and salps.
• Tunicates display all chordate characteristics only in their larval stage, and only have pharyngeal gill slits during adulthood.
• Urochordata is a subphylum of Chordata, known as Invertebrate Chordates, and are commonly referred to as Tunicates.
• Cephalochordata is a subphylum of Chordata, known as Invertebrate Chordates, and are commonly referred to as Lancelets.
• Lancelets have a dorsal hollow nerve cord that forms the spinal cord and brain.
• Pharyngeal pouches form aquatic in Cephalochordata, opening into gill slits which function as gills for gas exchange.
• In Cephalochordata, pharyngeal pouches do not form in terrestrial species, indicating a vestigial trait with no function.
• Notochord forms the vertebral column in Cephalochordata.
• Post-anal tail is lost in some species of Cephalochordata.
• Chondrichthyes are cartilaginous fishes, examples include sharks and rays, with a vertebral column made of cartilage.
• Actinopterygii are ray-finned fishes, examples include salmon and tuna, with a vertebral column made of blank.
• Amphibia transition to land, have aquatic larva, undergo metamorphosis, and become terrestrial adults.
• Reptilia are mostly terrestrial, have amniotic eggs, scales, and modified reptiles: BIRDS!
• Mammalia are mostly terrestrial, have placenta, fur, and mammary glands.
• Tetrapods include Amphibia, Reptilia, and Mammalia.
• Dissections include Bullfrog Dissection, which includes the heart, lungs, liver, gallbladder, small intestine, and large intestine.