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Invertebrates. Invertebrates. Review: Animals without backbones Last lab - Today. Invertebrates. Review: Animals are distinguished by their body cavity or lack of. Invertebrates. Review: Acoelomates -no body cavity No Cavity ( coelom ) between outer wall and digestive tract .
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Invertebrates Review: • Animals without backbones • Last lab - Today
Invertebrates • Review: • Animals are distinguished by their body cavity or lack of.
Invertebrates • Review: • Acoelomates -no body cavity • No Cavity (coelom) between outer wall and digestive tract
Invertebrates • Coelomates – have a body cavity(s) • Digestive system and body wall can move independently • Internal organs can be more complex • Coelomic fluid can assist with respiration, circulation, excretion Loss of pressure?
Invertebrate Coelomates • We will look at three Phylum today • PhlyumMollusca---Mollusks • Phylum Annelida ----Annelids • Phylum Arthropoda – Arthropods
Invertebrate Coelomates • PhlyumMollusca---Mollusks:
Invertebrate Coelomates • PhlyumMollusca---Mollusks: • Mollusks have a varied range of body structures • ALL have these 3 parts Foot Mantle Visceral Mass
Invertebrate Coelomates • PhlyumMollusca---Mollusks: • Circulatory systems - mainly open Open circulatory system circulating fluid is not enclosed in vessels at all times blood pumps into body cavities with the blood diffusing back to the circulatory system between cells Closed circulatory system blood confined at all times within vessels blood is pumped by a heart through vessels, and does not normally fill body cavities.
Invertebrate Coelomates • PhlyumMollusca---Mollusks: Circulatory system ( squids ) • Closed- blood is pumped by 3 hearts
Invertebrate Coelomates • PhlyumMollusca---Mollusks: • Respiratory system -most have one pair of gills • Digestive system -radula, "tongues“
Invertebrate Coelomates • PhlyumMollusca---Mollusks: • Food source * They bite • Luxury items * Agricultural pests • Historically important
Invertebrate Coelomates • Today's Dissection –Squid • Fantastic anatomy • 40 minutes for dissection
Invertebrate Coelomates • Phylum Annelida ----Annelids SegmentedMost have a pair of coeloms in each segment which allows independent movement *Moist environments
Invertebrate Coelomates • Phylum Annelida ----Annelids • Respiratory system • (usually) no specialized organs for gas exchange • Thin, permeable body wall – surface for gas exchange • Digestive system • complete digestive system, with mouth and anus • digestive tubes of earthworms have special structures, like a muscular wall and a gizzard
Invertebrate Coelomates • Phylum Annelida ----Annelids • Nervous system • two ventral nerve chords • one relatively big nervous cell concentration • Circulatory system • Closed • Move by peristalsis -waves of contractions and expansions • 2 main vessels • Dorsal moves blood anterior • Ventral moves blood posterior 10X magnification
Invertebrate Coelomates • Phylum Annelida ----Annelids • Reproductive system – Varies • Asexual-budding • Sexual • Earthworms • hermaphrodite
Invertebrates • Phylum Annelida ----Annelids • support terrestrial food chains both as prey • aerating and enriching soil • Minnesota? • Leeches ?
Invertebrate Coelomates • Dissecting the earthworm • FOLLOW DIRECTIONS in your lab book • Allow 20 minutes
Invertebrates • Phylum Arthropoda – Arthropods • Largest phylum • Paired jointed appendages • Hard exoskeleton • Have body cavities
Invertebrate Coelomates • Phylum Arthropoda – Arthropods • Circulatory systems - open
Invertebrate Coelomates Phylum Arthropoda – Arthropods • Respiratory system - do not breather using lung • Digestive system – Foregut, Midgut, hindgut Nervous system a brain and a ventral nerve cord
Remember the first day quiz….8.True or False Daddy Long legs are the most venomous spiders in the world. Scientific classification of spiders • Kingdom: Animalia • Phylum: Arthropoda • Class: Arachnida • Order: Araneae
Remember the first day quiz…. • Scientific classification • Kingdom: Animalia • Phylum: Arthropoda • Class: Arachnida • Order: Opiliones • cephalothorax separation • Silk glands • Venom glands
Invertebrates Coelomates • Class Insecta - Insect Characteristics • possess a hardened exoskeleton that is periodically shed during growth
Invertebrates Coelomates • Class Insecta - Insect Characteristics • Most adult insects have the following characteristics: • A body divided into three parts • (head, thorax and abdomen)
Invertebrates Coelomates • Class Insecta Insect Characteristics • Most adult insects have the following characteristics: • Three pairs of legs
Invertebrates Coelomates • Class Insecta Insect Characteristics • Most adult insects have the following characteristics: • Usually two pairs of wings (absent in many insects such as lice, fleas, ants; flies have one pair of wings)
Invertebrates Coelomates Reproductive system -varies Metamorphosis • There are two types of metamorphosis--incomplete and complete.
Invertebrates Coelomates • For today begin with: • Anatomy of a grasshopper • Complete this dissection in pairs
Dissection Participation Checklist Earthworm 1. Surgeon__________________________________ 2. Head nurse_______________________________ 3. Reader___________________________________ 4. Scribe____________________________________ Squid 1. Surgeon__________________________________ 2. Head nurse_______________________________ 3. Reader___________________________________ 4. Scribe____________________________________ Clean up 1. Dissection disposal__________________________________ 2. Tray cleaning______________________________________ 3. Instrument cleaning__________________________________ 4. Bench cleaning_____________________________________ I agree that I stayed until this lab station was clean and ready for the next lab to attend. 1.__________________________________________________________ 2.__________________________________________________________ 3.__________________________________________________________ 4.__________________________________________________________ ++++++++++++++++++++++++++++++++++++++++++++++++++++++ Professor Felker’s comments: