Animal Cell Types and Tissues Part II

• Connective tissues - mechanical support, exchange of metabolites between blood and tissues, storage of energy reserve in adipose tissues, bind structures to preserve integrity of organization, protection against infection, injury and repair
• Extracellular matrix - generally consists of a web of fibers embedded in

  a uniform foundation that may be liquid, jellylike, or solid
• Label the following.

  A) Fibrocytes

  B) Adipocytes

  C) Mesenchymal

  D) Osteocytes

  E) Chondrocytes

  F) Fixed Macrophage

  G) White blood cells

  H) Red blood cells

  I) Fibroblasts

  J) Stem cells

  K) Adipose cells

  
• Collagenous fibers - made up of thick collagen flexible, non-elastic and do not tear easily when pulled lengthwise, unbranched
• Reticular fibers - very thin and branched and composed of thin collagen wherein they form a tightly woven fabric/network that joins connective tissue to adjacent tissues
• Elastic fibers - long threads of elastin and these fibers provides a rubbery quality
• Amorphous ground substance - Fills spaces in between cells and fibers, permit diffusion of nutrients, substances, water, gases, and waste and are important in areas where small blood vessels are absent
• Fibrous connective tissue - dense due to its large number of collagenous fibers wherein fibers are organized into parallel bundles surrounding fibroblasts and forms tendons and ligaments
• Tendon - attaches muscle tissue to bones and serves to move the bone or structure attached.
• Ligament - attaches bone to bone, and usually serves to hold structures together and keep them stable.
• Loose connective tissue - binds epithelia to underlying tissues, functions as packing materials, holding organs in place, has all three fiber types
• Two cell types predominate in its fibrous mesh of loose connective tissue. What are they?

  Fibroblasts, Fixed macrophages
• Adipose tissue - specialized form of loose connective tissues that store 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 and 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
• chondrocyte cells - secrete collagen and chondroitin sulfate (needed for the formation of cartilage)
• Hyaline cartilage - bluish white, translucent, and homogenous, has significant proportion of collagen fibers and 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

  – support and reinforcement
• Fibrocartilage - contains many large collagenous fibers, intervertebral disks, pubic symphysis, disks of knee joint, and pads between

  femur and tibia and absorbs compression shock
• Elastic cartilage - contains fine collagenous fibers and many elastic fibers, external ears, eustachian tube (connects throat to middle ear), epiglottis, maintains a structure’s shape while allowing great flexibility
• Bone - Functions as a skeleton supporting most vertebrates (mixture of collagen + minerals)
• Osteoblasts - are cells that deposit a matrix of collagen fibers
• Calcium, magnesium, and phosphate ions combine and harden

  within the collagen matrix of the developing bone wherein the ions form the mineral hydroxyapatite
• In the plasma of blood, what are the proteins that can be found?

  Albumin, globulin, fibrinogen
• Label the following

  A) Red blood cells

  B) White blood cells

  C) Platelets

  
• Label the following

  A) Skeletal

  B) Cardiac

  C) Smooth

  
• Muscle tissue - 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
• Nervous tissue - irritability and conductivity; senses stimuli and transmits signals from one part of the animal to another
• What is the functional unit of nervous tissue?

  Neuron
• 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
• What are the three main types of neurons?

  Sensory(afferent), motor (efferent), interneurons
• Afferent neurons - arriving toward the brain/CNS (central nervous sys)
• Efferent neurons - signals exiting from the brain/CNS to muscles
• interneuron - local connections between neighboring neurons.