ZOO

• Categories of Tissues


  • Epithelium
  • Connective
  • Muscle
  • Nervous
• Epithelium


  • Lines, covers, and protects other tissues and organs
  • Characterized by cells tightly packed together and the presence of a cell secretion called the basement membrane
  • Named by cell layers, cell shape, and presence or absence of cilia
• Squamous epithelium


  Cells very thin, much wider than they are thick
• Simple squamous epithelium


  • Air sacs of respiratory
  • Lining of blood vessels, heart and lymphatic tubes
  • Diffusion-movement of molecules an area of high to low concentration
  • Filtration- movement of molecules across a membrane because of hydrostatic pressure
• Stratified squamous epithelium


  • Skin, Vagina, Esophagus, Mouth
  • Protects underlying tissues in areas subject to abrasion
• Cuboidal epithelium


  Cells cube shaped - secretion and absorption
• Simple cuboidal epithelium


  • Kidney, Tubules, Endocrine and Exocrine glands (thyroid gland, pancreas, ovaries) sweat and salivary glands
  • Enzyme secretion and absorption
• Stratified cuboidal epithelium


  • Sweat gland ducts, salivary gland, ovarian follicle
  • Secretion, absorption, protection against infection
• Columnar epithelium


  • Elongated cells, much longer than they are wide
  • Presence of goblet cell for mucus secretion
• Simple columnar epithelium


  • Line the digestive tract, gallbladder and excretory ducts of some glands
  • Has microvilli at surface for absorption
• Pseudostratified ciliated columnar epithelium


  • Consist of angle layer of columnar cells but appear to be more than 1
  • Presence of goblet cell that produces mucus
  • Lines the bronchi, trachea, uterine tubes and some of the uterus
  • Propels mucus or reproductive cells by ciliary action
• Transitional epithelium


  • Appears cuboidal when unstretched and squamous (flattened) when stretched
  • Elasticity is the key characteristic
• Transitional epithelium


  • Lining of urinary bladder, ureter, superior urethra
  • Accommodate fluctuation in the volume of fluid in organs
• Connective tissue


  • Characterized by the cells widely separated from each other in a matrix that is produced by the cells
  • Tissue protects and supports
  • Cell Matrix composed of ground (liquid, gel, gum or solid) and fibers (non-elastic and elastic)
• Types of connective tissue


  • Connective tissue proper (loose/areolar, dense)
  • Specialized connective tissues (adipose, cartilage, bone, blood)
• Loose (areolar) connective tissue


  • Gel like ground with both elastic and non-elastic fibers running though the ground in many directions
  • Wraps and cushions organs
  • Under the skin, around and within muscles, hypodermis
• Dense connective tissue

  • Nuclei and fibers arranged in parallel rows
  • Fibers mostly non-elastic
  • Tendons and ligaments (Regular)
  • Dermis of the skin (Irregular)
  • Provide tensile strength
• Adipose (fat) tissue


  • Adipose cells contain a large vacuole which in the live cell contains lipids
  • Cell nucleus and cytoplasm are pushed out to edge of cell membrane
• Adipose (fat) tissue


  • Around kidneys, under the skins, breast
  • Storage cells for adipose (lipids) reserve fuel, insulator, support and protects organs
• Cartilage


  • Ground of matrix is gum like
  • Cells are found in Lacunae within the matrix
  • Chondrocytes – mature cartilage cells
  • Chondroblasts – immature cartilage cells
• Types of cartilage


  • Hyaline Cartilage
  • Elastic Cartilage
  • Fibrocartilage
• Bone/Osseous tissue


  • Ground of matrix is solid (calcium carbonate)
  • Has blood supply and nerves running through the Haversian canal systems
  • Most rigid connective tissue, hard strong yet lightweight
  • Osteocyte – mature bone cell
  • Osteoblast – immature bone cell
  • Osteoclast – bone-breaking cell
• Types of bone marrow


  • Red Marrow
  • Yellow Marrow
• Compact bone


  • Outer, solid dense
• Spongy bone


  • Inner, porous
• Blood


  • Liquid matrix = plasma (90% water, 10% plasma proteins, electrolytes, hormones, oxygen, glucose, etc.)
  • Formed elements (erythrocytes, leukocytes, platelets/thrombocytes)
  • Transport oxygen, carbon dioxide, hormones minerals, nutrients and wastes
• Muscle tissue


  • Skeletal, Smooth, Cardiac
• Nervous tissue


  • Neurons - functional unit of the nervous system
  • Excitability - ability to respond to stimuli
  • Conductivity - ability to conduct signal
• Neuron structure


  • Cell body
  • Dendrites - short, threadlike branches that conduct signals toward the cell body
  • Axon - relatively long, cylindrical process that conducts signals away from the cell body
  • Axon protected by a laminated lipid sheath called myelin
• Neuroglial cells


  • Oligodendrocytes
  • Schwann Cells
  • Astrocytes
  • Ependymal
  • Microglial
• Structural classification of neurons


  • Multipolar neurons
  • Bipolar neurons
  • Unipolar neurons
• Functional types of neurons


  • Sensory (receptor or afferent)
  • Interneurons
  • Motor (effector or efferent)