Animal Tissues

• Animal


  Any of a group of multicellular eukaryotic organisms that have evolved independently from unicellular eukaryotes, largely because they have developed muscles and hence mobility, which has stimulated the further development of tissues and organ systems
• General cell types of animal cells

  • Skin cells
  • Muscle cells
  • Blood cells
  • Fat cells
  • Nerve cells
  • Bone cells
  • Stem cells
• Skin cells


  Consist of keratinocytes and melanocytes. Keratinocytes make up 90% of all skin cells and produce a protein called keratin. Melanocytes produce melanin which gives color to skin.
• Muscle cells


  Myocytes or muscle cells are long tubular cells that help organisms move their limbs and organs
• Blood cells


  Can be either red blood cells which deliver oxygen to different parts of the body, or white blood cells which find and destroy pathogens and other harmful substances in the body
• Fat cells


  Adipocytes or lipocytes are storage cells for fats and lipids which are reserves of energy
• Nerve cells


  Neurons or nerve cells are the main cells of the nervous system. They carry messages and deliver signals to different body parts using their dendrites and axons
• Bone cells


  Osteocytes are the majority of cells embedded within the substance of a fully formed lobe
• Stem cells


  Can develop into specialized cells for organs/tissues
• Tissue


  A group of specialized cells and the intercellular substance around them that are adapted to work together to perform particular functions
• Four basic types of animal tissue

  • Epithelial tissues
  • Connective tissues
  • Muscle tissues
  • Nervous tissues
• Epithelial tissue


  A type of tissue made up of tightly packed cells commonly seen outside the body as coverings or as linings of organs and cavities
• Simple squamous epithelial tissue


  Made up of plate-like cells, for the exchange of material through diffusion. Lines blood vessels and lung alveoli.
• Stratified squamous epithelial tissue


  Multilayered and regenerates quickly, for protection. Found in skin, mouth, vagina.
• Simple cuboidal epithelial tissue


  Made of cube-shaped cells, for secretion. Found in glands and renal tubules.
• Stratified cuboidal epithelial tissue


  A rare type, for the protection of areas such as ducts of sweat glands, mammary glands, and salivary glands.
• Simple columnar epithelial tissue


  Made up of brick-shaped cells, for protection, secretion and active absorption. Lines the stomach and intestines.
• Pseudo-stratified columnar epithelial tissue


  Made up of single-layer cells, for the lining of the respiratory tract and usually lined with cilia.
• Connective tissue


  Made up of fibrous cells, assists in support and protection of organs and limbs and depending on the location in the body it may join or separate organs or parts of the body.
• Types of connective tissue

  • Loose/areolar
  • Dense fibrous
  • Adipose
  • Blood
  • Cartilage
  • Bone
• Loose/areolar connective tissue


  The most abundant form of collagenous connective tissue, holds organs in place and attaches epithelial tissue to other underlying tissues.
• Dense fibrous connective tissue


  Tissue with fibers as its main matrix element. Ligaments connect two bones, and tendons connect bones to the muscles.
• Adipose connective tissue


  Stores fats which function to insulate the body and store energy. Found below the skin and around internal organs.
• Blood connective tissue


  The only fluid connective tissue, flows through blood vessels carrying oxygen, nutrients, hormones, and antibodies to different parts of the body.
• Cartilage connective tissue


  Characterized by collagenous fibers embedded in chondroitin sulfate, functions as a cushion between bones.
• Bone connective tissue


  A hard-connective tissue that forms the framework of the body.
• Muscle tissues


  Tissues composed of long cells called muscle fibers that allow the body to move voluntarily or involuntarily.
• Types of muscle tissue

  • Skeletal muscle
  • Cardiac muscle
  • Smooth muscle
• Skeletal muscle


  Muscles that connect to bones and allow a wide range of movements and functions, voluntary.
• Cardiac muscle


  Makes up the thick middle layer of the heart, its contraction and relaxation produce heartbeats which force blood to circulate, involuntary.
• Smooth muscle


  Muscles with cells arranged closely to form sheets, propels substances or objects along internal passageways, found mostly in the walls of hollow organs, involuntary.
• Nervous tissues


  Composed of nerve cells called neurons and glial cells that function as support cells.
• Neurons


  Sense stimuli and transmit electrical signals throughout the animal body.
• Functions of animal tissues

  • Epithelial tissue: Provides a barrier, specialized for secretion and absorption, protects from microorganisms/injury/fluid loss, excretes waste
  • Connective tissue: Hold other tissues together, maintain mineral homeostasis, connect and support different tissues/organs/body parts
  • Muscle tissue: Responsible for all body movements, both inside and out, help organs carry out their functions
  • Nervous tissue: Responsible for carrying electrical and chemical signals, transmit nerve impulses around the body