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Organismic Biology. Lecture 4 NatSci II Josephine B. Guerrero, MD Asst. Professor, Department of Biology. Levels of Organization. Cells Tissues Organs Organ Systems Organism. tissues. Plant Tissues:.
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Organismic Biology Lecture 4 NatSci II Josephine B. Guerrero, MD Asst. Professor, Department of Biology
Levels of Organization Cells Tissues Organs Organ Systems Organism
Plant Tissues: • Meristematic – immature, undifferentiated, rapidly dividing; apical meristem and lateral meristem • Fundamental • Parenchyma – thin-walled; cortex and pith • Collenchyma – irregularly thickened; periphery of stems and leaves • Sclerenchyma – thick walls; fibers, sclereids (seeds and seed coats) • Vascular- responsible for the movement of materials inside the plant; xylem vs. phloem
Sclerenchyma Parenchyma Collenchyma
Animal Tissues: • Epithelial – covers external and internal surfaces; attached to a basement membrane • Connective – “connects” or supports other structures , “fills” body layers or spaces • Muscle – capable of contraction for movement • Nervous – for propagation of electrical impulses • Reproductive – gametes for reproduction
Epithelial Tissues • According to Shape of Cells • Squamous – flat, polygonal • Cuboidal – equal height, width, thickness • Columnar – greater height than width and thickness • Transitional – varies in shape from cuboidal to squamous depending on the degree of distention of the organ where it is found
Epithelial Tissues • According to Number of Layer of Cells • Simple – only one layer of cells directly attached to basement membrane • Stratified – more than one layer; the innermost layer is attached to the basement membrane • Pseudostratified – appears to have several layers; in reality, only one layer
Simple Squamous Simple Cuboidal Simple Columnar
Components of Connective Tissue • Matrix – mucopolysaccharides, ground substance or “background” where other components are embedded • Fibers • Collagen – most resilient • Elastic – has the ability to be stretched and return to its original configuration • Reticular – fine, branched fibers; most delicate
Components of Connective Tissue • Cells • Fibroblast – produces fibers and matrix • Osteoblast, osteocyte, osteoclast –in bone • Chondroblast, chondrocyte – in cartilage • Adipocyte – in adipose tissue • Macrophage – phagocytic cell • Mast cell – produces chemical mediators as histamine for inflammation
Hyaline Cartilage Fibrocartilage Elastic Cartilage
Skeletal Muscle – striated, voluntary; multinucleated; peripheral nuclei; cylindrical cells Cardiac Muscle – striated, involuntary; uninucleated; central nuclei; cylindrical branched cells Smooth Muscle – nonstriated, involuntary; uninucleated; central nuclei; fusiform or spindle-shaped cells
Reproductive Tissue Male Gamete = sperm Female Gamete = ovum
Organ Systems in Plants: Root System (usually underground) Shoot System (usually above ground)
Integumentary System: • Functions mainly for protection • Other functions include thermoregulation, secretion, absorption, excretion • Derived structures from integument include scales, feathers, horns, claws, nails and hair
Types of Integument Amoeba – cell membrane Paramecium – pellicle Soft-bodied aquatic invertebrates or those which thrive in most environments – single-layer epidermis Worms, arthropods – cuticle; cuticle of arthropods have chitin In snails and other animals, the epidermis secretes an exoskeleton.
Types: Hydroskeleton Exoskeleton Endoskeleton Function: Support Form Attachment of muscles Protection Skeletal System
Movement in Organisms Amoeboid movement- Amoeba; exhibited by some cells in complex organisms Contractile fibrils in cilia and flagella – ciliates and flagellates Smooth and striated muscles (in layers or separate muscles) – cnidarians, arthropods, worms, molluscs, vertebrates
Modes of Digestion • Single cell prokayotes/eukaryote – intracellular, by enzymatic action • Fungi (molds & mushrooms) – absorptive • Plants – rare via external acid • Animals – internal; complex combination of mechanical and chemical processes
Chemical Digestion Needed to convert macromolecules to simplest forms that can be absorbed • CHO to monosaccharides • CHON to amino acids • Fats to glycerol and fatty acids • Carried out by: • Salivary glands – amylase • Stomach – pepsin • Small intestine – pancreatic amylase, trypsin, chemotrypsin, carboxypeptidase, pancreatic lipase, dissacharidases, dipeptidases,
Modes of Circulation: • Plants – xylem (transpiration cohesion) phloem (active transport osmosis) • Lower animal forms (open type) – blood or circulatory fluid directly bathes cells • Higher animal forms (closed type) – blood or circulating fluid stays inside blood vessels (arteries, veins, capillaries) • Requires a pumping organ, circulating fluid and the channels for the fluid
Immunity • Non-specific Immune Mechanisms or Innate Immunity • Intact skin and mucous membranes as protective barrier • Chemical mediators: lysozymes, histamine, interferons • Phagocytic cells • Inflammation
Immunity • Specific or Adaptive Immunity – exhibits specificity and memory • Cell-mediated Immunity or Cytotoxic Immunity – T cells/T lymphocytes (Killer T cells) • Antibody-mediated or Humoral Immunity – B cells/B lymphocytes produce antibodies (Immuneglobulins)