Animal Cell Types and Tissues Part 2

• Major Types of Connective Tissue

  • Loose connective tissue
  • Fibrous connective tissue
  • Bone
  • Cartilage
  • Adipose Tissue
  • Blood
• Different Functions of Connective Tissue

  • Mechanical support - bone, cartilage, fibrous
  • Bind structures to preserve integrity of organization - fibrous/loose connective tissue
  • Exchange of metabolites between blood and tissues - red blood cells
  • Storage of energy reserve in adipose tissues - adipose connective tissue
  • Protection against infection - white blood
  • Injury and repair - blood platelets
• General Properties of Connective Tissue

  • Paucity (sparseness) of cells
  • More intercellular substance (fibers and ground substance)
  • The intercellular substance or extracellular matrix generally consists of a web of fibers embedded in a uniform foundation that may be liquid, jellylike, or solid
• Types of Connective tissue cells

  • Fixed
  • Wandering cells (blood tissue)
• Fixed cells


  • Fibroblast/Fibrocyte - Fibrous and Loose connective tissue
  • Adipocytes Adipose tissues
  • Mesenchymal Stem cell in bone
  • Osteocytes/osteoblasts - bone
  • Chondrocytes cartilage
  • Fixed macrophage - loose connective tissue
• Wandering cells (blood tissue)

  • White blood cells - (e.g. monocytes, lymphocytes, eosinophils, etc)
  • Red blood cells
• Fibers or Ground Substances surrounding cells of connective tissue

  • Collagenous fibers
  • Reticular fibers
  • Elastic fibers
  • Amorphous ground substance (fillers)
• Collagenous fibers


  • Made up of thick collagen
  • Flexible, non elastic and do not tear easily when pulled lengthwise, unbranched
  • Strong but flexible
  • For strength and flexibility
• Reticular fibers


  • Very thin and branched
  • Composed of thin collagen
  • They form tightly woven fabric/network that joins connective tissue to adjacent tissue
• Elastic fibers


  • Long threads of elastin
  • Elastin fibers provide rubber quality
  • Branched and stetchable
• Amorphous ground substance (fillers)


  • Glycosaminoglycans (carbohydrate-protein complex) such as chondroitin sulfate (a lot in the cartilage)
  • Permit diffusion of nutrients, substances, water, gases, and wastes
  • Important in areas where small blood vessels are absent
• Fibrous connective tissue


  • Dense due to its large number of collagenous fibers
  • Fibers are organized into parallel bundles surrounding fibroblasts
• Tendon


  Attaches muscle tissues to bones; serves to move the bone or structure attached
• Ligament


  Fibrous connective tissue that attaches bone to bones, and usually serves to hold structures together and keep them stable
• Loose connective tissue


  • Binds epithelia to underlying tissue
  • Functions as packing material
  • Holds organs in place
  • Has all three fiber types
  • Two cell types predominate - fibroblasts and fixed macrophages
• Adipose tissue


  • Specialized form of loose connective tissue that stores fat in adipose cells (adipocytes)
  • Pads and insulates the body and stores fuel as fat molecules
  • Each adipose cell contains a large fat droplet (lipid) that swells when fat is stored and shrinks when the body uses fat as fuel
  • Has few fibers (reticular fibers)
• Cartilage


  • Has an abundance of collagenous fibers embedded in a rubbery matrix made of a ground substance called chondroitin sulfate (a protein-carbohydrate complex)
  • Chondrocyte cells secrete collagen and chondrotin sulfate (needed for the formation of collagen)
  • Can withstand compression and tension
  • Enervate and avascular
• Subtypes of cartilage


  • Hyaline cartilage
  • Fibrocartilage
  • Elastic cartilage
• Hyaline cartilage


  • Bluish white, translucent, homogenous
  • Has significant proportion of collagen fibers
  • Covers joint surfaces and rib ends, part of bone formation
  • Present in the nose, larynx, and trachea (respiratory tract)
  • Skeletal cartilage in the embryos of all vertebrates
  • Skeletal cartilage of adult sharks and rays
  • Provides support and reinforcement
• Fibrocartilage


  • Contains many large collagenous fibers
  • Found in intervertebral disks, pubic symphysis, disks of knee joint, and pads between femur and tibia
  • Absorbs compression shock
• Elastic cartilage


  • Contains fine collagenous fibers and many elastic fibers
  • Found in external ears, eustachian tube (connects throat to middle ear), epiglottis
  • Maintains a structure's shape while allowing great flexibility
• Bone


  • Functions as a skeletal supporting for most vertebrates
  • Mineralized connective tissue
  • Mixture of collagens plus minerals
  • Osteoblasts deposit a matrix of collagen fibers
  • Calcium, magnesium, and phosphate ions combine and harden within the collagen matrix to form the mineral hydroxyapatite
  • Combination of hard mineral and flexible collagen makes bone harder than cartilage without being brittle
  • Vascular
• Components of blood


  • Plasma (55%)
  • Formed elements (45%)
• Plasma


  Intercellular matrix consisting of water, salts, and a variety of dissolved proteins
• Dissolved solids in plasma

  • Proteins (fibrinogen, albumin, globulin)
  • Nutrients/supplies for cells (glucose, fats and fat-like substances, amino acids, salts)
  • Cell products (enzymes, hormones, antibodies)
  • Cellular waste products (urea, uric acid)
• Formed elements of blood

  • Red blood cells (erythrocytes)
  • White blood cells (leukocytes)
  • Platelets (thrombocytes)
• Red blood cells (erythrocytes)


  Responsible for O2 and CO2 exchange
• White blood cells (leukocytes)


  Fight against infections
• Platelets (thrombocytes)


  Fight against infection
• Muscle Tissues

  • composed of long cells called muscle fiber cells that
  • can contract when stimulated by nerve impulses (i.e., sliding filament model)
  • muscle contraction accounts for most of the energy-consuming cellular work in active animals
  • Muscle cells contains actin and myosin which together enable muscles to contract
• Types of Muscle Tissue

  • Skeletal - found in muscle connected to skeletal system, Striated, responsible for voluntary movement
  • Cardiac - found in the heart
  • Smooth - found in intestines, Lack striations, is found in the walls of the digestive tract, urinary bladder, arteries, and other internal organs.
• 1. cylindrical

  A) 1.

  B) 2

  C) 4

  D) 5

  E) 3

  F) 6

  G) 7

  H) 8

  I) 9

  J) 10

  K) 11

  L) 12
• Nervous Tissues


  Irritability and conductivity; senses stimuli and transmits signals from one part of the animal to another
• Nervous Tissues


  • Functions in the receipt, processing, and transmission of information
• Neuron


  Functional unit of nervous tissue
• Glial cells


  Support cells
• Types of glial cells

  • Astrocytes
  • Microglia
  • Oligodendrocytes
  • Ependymal cells
• Neurons


  • Comprised of cell body, axons and dendrites
• Dendrite


  Transmits nerve impulses from their tips toward the rest of the neuron
• Axon


  Transmits impulses toward another neuron or toward an effector, such as a muscle cell