Animal Body Structure Cell Tissue Organ system Organism

Four Major Tissues Types • • Epithelial Muscle Connective Nerve

Epithelial Tissue • Cover body cavities and surfaces – Protection • Example – skin – Secretion • Example – salivary glands – Absorption • Example – small intestine • Constantly being replaced

Muscle Tissue • Contain contractile fibers – Proteins - actin and myosin

Muscle Tissue Smooth Muscle • Arteries and veins • Digestive tract • Involuntary Skeletal Muscle • Move bones • Voluntary Cardiac Muscle • Heart • Controlled by pacemaker

Connective Tissue • Loose connective tissue – Supports and nourishes epithelium • Fibrous connective tissue – Bone, tendons, ligaments, cartilage and bone – Support, protection and movement • Specialized – Adipose (fat) – fuel storage – Blood and lymph – transport and immunity

Connective Tissue Cartilage Fibrous Loose Adipose Blood Bone. Cells - Fat

Nerve Tissue • Neurons – – Transport signals Senses Information processing Control movement Transmit Receive Pass Chemical chemical electrical signal to other from alongcell • Glial Cells Axon

Groups of Tissues Form an Organ

Many Different Cell Types from One Genome • Pattern of genes determines cell type • Cells work together in a tissue – Cell communication – Limit growth – Repair damage tissue

Abnormal Gene Expression • Cancer – Abnormal tissue – Abnormal cell communication – Abnormal growth

Homeostasis • Maintaining a constant internal environment – Dynamic Equilibrium

Feedback Systems • Negative feedback – Maintains constant conditions – Dynamic equilibrium • Positive feedback – Enhances response

Negative Feedback • Three Parts – Sensor – Control Center – Effector

Negative Feedback

Positive Feedback