Animal Tissues

• Epithelial tissue covers the surfaces of organs, lines body cavities, and forms glands.
• Four types of tissue: Epithelial, Muscular, Connective, and Nervous
• Tissue is a group of similar cells as to structure and function.
• Histology or study of tissues.
• There are 4 major types of animal tissues: epithelial, connective, muscular and nervous tissues.
• Epithelial tissues cover organisms and their organs such as the linings of the mouth, gut, lungs, heart & blood vessels; form glands that secrete products like in salivary & sebaceous glands.
• Tight junction allows adjacent cells to adhere side by side and this works to seal off a tissue and prevent entrance of pathogens.
• Basement membrane is a thin membrane found at the basal layer of the epithelial tissue that serves as its boundary to the connective tissue.
• Lamina propia attaches to basal surface of basement membrane with blood vessels that supply the epithelial tissue.
• Apical specializations include microvilli, stereocilia and cilia.
• Cells in epithelial tissue are compactly arranged with very little or no intercellular matrix between them.
• Epithelial tissue can have surface specialization such as the cilia, keratin, goblet cells or brush border.
• Connective tissues connect, bind, attach parts together.
• Types of connective tissue include Dense Collagenous (Fascia, Tendon, Ligament), Dense Elastic, Reticular, Adipose, Cartilage (Elastic, Hyaline & Fibrocartilage), Blood, Bone.
• Extracellular Matrix or ECM is composed mostly of collagen and ground substance that acts as a lubricant & barrier.
• Fibroblast specialized cells synthesize collagen and ECM while fibrocytes are old, inactive fibroblasts.
• Muscular tissues are responsible for contraction and body movement.
• There are 3 types of muscle tissues: skeletal, smooth, cardiac muscles.
• Voluntary muscles are those that can be controlled at will like skeletal muscle.
• Involuntary muscles are those that cannot be controlled by the will like smooth and cardiac muscles.
• Skeletal muscles are made up of elongated cells that are striated, multinucleated and are responsible for quick and forceful contractions.
• Smooth muscles are made up of fusiform or spindle-shaped cells, non-striated that contracts slowly and are found in internal organs like the digestive organs.
• Cardiac muscles are made up of elongated, branched, striated cells and are responsible for the involuntary, rhythmic contractions of the heart.
• Nervous tissues are specialized for reception and conduction of impulses and are located in the brain and spinal cord.
• Neurons are the cells of this tissue.
• Types of neurons include sensory that carry information from receptors to CNS and motor that carry impulses from CNS to effectors.
• There are 2 Major Types of Plant Tissues: Meristematic or Embryonic and Non-meristematic or Permanent.
• Meristematic tissues include Apical (tips of shoots & roots), Intercalary (at nodes), Lateral Meristems (along the sides of stems & roots).
• Permanent or Non-meristematic tissues include Fundamental (Parenchyma, Collenchyma, Sclerenchyma) and Vascular (Phloem, Xylem).
• Parenchyma is the most abundant of all cell types & found in all major plant parts.
• Collenchyma is composed of unevenly thick-walled cells.
• Sclerenchyma has evenly thick and tough cell wall, with lignin (carbohydrate) and for support.