Bio Notes February 3

Bio Notes February 3 - Bio Notes Key Green Subphylum Blue...

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Bio Notes February 3, 2009 Key: Green- Subphylum Blue- Phylum Highlight- class Red- Group Class Aves- Birds 1 o Evolved from Theropods Long tailed animals moving on two feet, with three clawed fingers, and a furcula (wishbone) o Adaptations for powered flight Feathers Wings Light, hollow bones containing air spaces o Four-chambered heart o Very efficient lungs With air sacs occupying spaces between internal organs and within certain bones o Excrete solid metabolic waste (uric acid) o Stores food temporarily in crop (extended sac-like portion of digestive tract) o ENDOTHERMS Maintain constant body temperature o Well-developed nervous system o Excellent vision and hearing Key concept: limbs, necessary appendages, a body covering that retards water loss, amniotic egg, were all key adaptations which contributed to the success of terrestrial animals Mammals o Hair o Mammary glands o Differentiated teeth o Three middle-ear bones o Have highly developed nervous system and muscular diaphragm o Endotherms o Monotremes Duck billed platypus, spiny anteaters Lay eggs, suckle young via mammary glands o Marsupials Kangaroo with young in pouch (marsupium) and nourished by mothers milk via mammary glands Kangaroo soon after birth, born in embryo state and then continues development in pouch
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o Placental mammals (eutheria) Characterized by placenta For exchange between embryo and mother o Mammal evolution Many groupings that come from amniote ancestor ANATOMY AND PHYSIOLOGY Neural Signaling (Chapter 40) Ability to react to various stimuli (external and internal): reception, transmission, integration, and action by effectors Response to stimulus o Stimulus originates outside or inside the body o Information is received by afferent (sensory) neurons (either external or internal) o Transmittal to the CNS (central nervous system) o Leads to integration and interpretation of the signal by interneurons (99% nerves) o Transmittal to effectors (efferent motor neurons): muscles and glands o Those muscles and glands then carry out the action or response o (Afferent when into the nervous system and efferent when out of the nervous system) o Now known that neurogenesis occurs regularly in at least several regions of the adult mammalian brain Neurons o Specialized to receive stimuli o Dendrites Many branched dendrites Extend from cell body of neuron Specialized to receive stimuli and send signals to the cell body Short, highly branched processes o Axons A single long axon Extends from neuron cell body Forms branches (axon collaterals) Surrounded by schwann cells in PNS (peripheral nervous system) o These glial cells form a myelin sheath Myelin sheath Surrounds and insulates many axons Fatty white substance In the CNS sheath is formed by other glial cells
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Bio Notes February 3 - Bio Notes Key Green Subphylum Blue...

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