Tissues

Spare Parts In The News

Organization of Multicellular Organisms Cells – smallest living unit Tissue – like cells working together Organ – 2 or more tissues that function together Organ system – 2 or more organs working together

Tissue Types Epithelial Connective Muscle Nervous

Humans as a Model for Vertebrate Architecture Coelom with 2 parts Thoracic cavity Abdominal cavity Internal skeleton Nerve cord & brain Surrounded by bone

Epithelial Tissues Coverings & linings of the body Functions Protection Absorption Sensation Secretion Excretion Surface transport

Epithelial Tissues Sheets of cells packed together Types Cell shape Number of layers Characteristics Usually thin layers Very few blood vessels Regenerate readily Basement membrane

Classifying Epithelial Tissues Shape of cells Squamous Cuboidal Columnar Layers Simple Stratified Pseudostratified Transitional

Simple Epithelial Tissues

Simple Epithelial Tissues

Simple Epithelial Tissues

Stratified Epithelial Tissue Stratified Squamous Stratified Cuboidal Rare type Stratified Columnar

Pseudostratified Epithelium

Transitional Epithelium

Connective Tissues Cells in a non-living matrix Functions of connective tissue Structural Provide body support Defensive Protect body from attack Isolating Storehouses

Cell Types of Connective Tissue Fibroblasts Secrete fibers into matrix Cartilage Cells (chondrocytes) Secrete matrix of gel & fibers Bone cells Make matrix of fibers that become mineralized

Fiber Types Collagen Reticular Elastic Protein collagen Protein reticulin Elastic Protein elastin

Connective Tissue Types Dense Fibrous Connective Tissue

Connective Tissue Types Reticular Connective Tissue

Connective Tissue Types Elastic Connective Tissue

Connective Tissue Types Loose Connective Tissue

Connective Tissue Types Hyaline Cartilage

Connective Tissue Types Elastic Cartilage

Connective Tissue Types Fibrocartilage

Connective Tissue Types Bone

Bone Structure Internal structure Spaces with marrow Compact bone Spongy bone Spaces with marrow

Connective Tissue Cells that Defend Leukocytes – white blood cells Granulocytes Agranulocytes Lymphocytes Macrophages Mast cells

Granulocytes Lobed nuclei Circulate with blood

Agranuloctytes Lymphocytes Location Circulate in blood Organs of lymphatic system Cells of immunity

Agranulocytes Macrophages Engulf & digest particles

Agranulocytes Mast Cells Involved in inflammatory response In blood & other tissues Play a role in allergic reactions

Connective Tissue & Cells that Isolate Adipose Cells mostly lipids Function Store energy Insulation Padding

Connective Tissue & Cells that Isolate Blood Cells Plasma Mobile transport Gasses Oxygen Carbon dioxide Nutrients Waste products

Muscle Tissue Muscle cells = muscle fibers Cells contain filaments Myofibrils Organized arrangement

Muscle Tissue Types Myofibrils shorten Smooth Muscle Skeletal Muscle Cardiac Muscle Myofibrils shorten Causes movement

Smooth Muscle

Skeletal Muscle

Cardiac Muscle

Nervous Tissue Cells Neurons Support cells Conduct messages

Neurons Dendrites Axon Reception of stimulus Impulse toward cell body Impulse away from cell body Toward another neuron or tissue

Neurons

Nerves Clusters of axons & dendrites

Organ Systems

Homeostasis Maintaining a stable internal equilibrium Requires cells, tissues, organs, & organ systems to work together

Maintaining Homeostasis Feedback loops Information fed to body’s control system Two methods Negative feedback Positive feedback

Negative Feedback Most common feedback used by the body Works like a thermostat Changes are registered Adjustments are made Homeostasis is maintained

Positive Feedback Mechanism moves in the same direction as what triggers the change Not common in human bodies Disrupts the steady state Example: contractions in childbirth

End chapter 26