Tissues

• Level of Biological Organization:

  1. Cells
  2. Tissue
  3. Organ
  4. Organ System
  5. Organism
• Tissue: a group of cells that has a similar structure and functions together as a unit
• Histology: Microscopic study of tissues
• Histopathology: the diagnosis and study of diseases of the tissue, which involves examining tissues and cells
• Histopathologist: the person who diagnose the tissue's disease
• Importance of tissue:

  1. Tissues brought about the division of labor in multicellular organism
  2. As a result of improved organization and higher efficiency, multicellular organisms have higher survival.
  3. Plants are autotrophic, so they produce their food through photosynthesis.
  4. Plants are stationary, meaning they use less energy
  5. Most plant tissues are dead and are just there to provide structural integrity.
  6. Animals are heterotrophic, meaning they don't produce their food
  7. Due to this animals need more energy to hunt for their food and move
• Animal tissue: includes Epithelial, Nervous, Connective, Muscle tissues
• Epithelial Tissue: tissue that covers and lines the body and its organs.
• Epithelial tissue: forms the covering and lining of all free body surfaces
• Epithelial Tissue: protects cells from mechanical injury and water loss.
• Intercellular spaces: how the special function of absorption and secretion are done
• Skin: First layer of defence
• Squamous: thin, irregular shaped tissue. Has large flattened nucleus. Found in mouth, alveoli, and surface of the skin
• Columnar Tissue: has elongated cells, and an oval shaped nucleus. Can be cilated or have a cilia. Secrets mucus and absorbs digested food. Found in intestine and gall bladder
• Cuboidal: square-shaped and spherical nucleus. Has the function of absorption and secretion. found in sweat glands, thyroid and kidney
• Nervous Tissue: specialized to transmit messages within the body.
• Neurons or Nerve cells: Cells of the nervous tissue
• Neurons or Nerve cells: has the ability to receive stimuli and to conduct impulses to the body
• Sensory Neurons: first to receive information and is related to the 5 senses
• Interneuron: second in line, chooses which neuron to send the signal to and what messages to transmit.
• Motor Neuron: is a neuron responsible for the movement of the body.
• Connective Tissue: A tissue specialized to connect and anchor various organs
• Connective Tissue: connects bones to each other, binds tissues, and gives support to various parts of the body by creating a packing around organs
• Connective Tissues: Main functions are binding, supporting, and packing
• Medium or matrix: is a homogeneous gel-like substance which forms the bulk of connective tissue
• Areolar: binds epithelial cells in matrix of the collagen and elastic fibres between organs.
• Fibrous: Contains a dense network of non-elastic collagen usually in elongated rows
• Fibrous: located in tendons and ligaments
• Cartilage: Chondrocytes found in the matrix
• Chondrocytes: cells responsible for the production of collagen and cartilage formation
• Cartilage: Absorbs shock
• Cartilage: located in joints, ear and nose
• Blood: transports waste, nutrients, and hormones around the body.
• Blood: found in the circulatory system
• Erythrocytes - RBC, Leucocytes - WBC, Thrombocytes - Platelets
• Adipose Tissue: Fat cells, store energy, provide insulation around organs and under the skin
• Bones: network of systems osteocyte in solid matrix or skeletal system
• Bones: provides framework for body and muscle attachments
• Osteocyte: responsible for the maintenance of bony matrix
• Muscular tissue: is a specialized tissue in animals which applies forces to different parts of the body by contraction