mamm. phys - Lab 1 (histology)

  1. whats the extracellular matrix (ECM)?
    complex structural tissue component surrounding and supporting cells of the mammalian tissues
  2. what does the ECM control?
    Gesticulation and tissue differentiation
  3. what is the purpose of gesticulation?
    • Is to position the 3 embryonic germ layers:
    • 1. Ectoderm
    • 2. Endoderm
    • 3. Mesoderm
  4. what is the ectoderm?
    brain, skin, nails, epithelium of the nose and teeth
  5. what is the endoderm?
    inner linings of the digestive and respiratory tract
  6. what is the mesoderm?
    muscles, circulatory and excretory systems of the body
  7. what are he components of the ECM?
    • Water
    • Proteins (collagen, elastin, fibronectin and laminins)
    • Proteoglycans
  8. what is the role of collagen?
    Strong, flexible protein fiber
  9. what is the role of elastin?
    Elastic protein fibers
  10. what is the role of fibronectin and laminins?
    Help connect the ECM components to the cells by binding with integrins in plasma membranes
  11. what are proteoglycans?
    • mostly carbohydrates (sugars)
    • EX. heparin
  12. what is the role of proteoglycans?
    • Absorb water
    • Provides lubrication and resiliency
    • Acts as a shock absorber for joints
  13. what is the role of epithelial cells?
    @ lumen aspect of organs
  14. what do fibroblast do?
    • Cells responsible  for the synthesis of ECM components
    • Found in large number of connective tissue
    • Involved in wound healing
  15. what is the role of capillaries?
    Feed the cells
  16. what is the role of glycosaminoglycans (GAGs)?
    Major components of joint cartilage, joint fluid and other soft connective tissue
  17. what is the role of the macrophage?
    Removal of cell debris
  18. What are the principal types of tissue?
    • 1. Epithelial tissue
    • 2. Connective tissue
    • 3. Muscle tissue
    • 4. Nervous tissue
  19. what is the role of epithelial tissue?
    outer layer of skin, lining of respiratory, digestive tract
  20. what is the role of connective tissue?
    bones, joints, cartilage, tendons
  21. what is the role of muscle tissue?
    heart, skeletal, smooth (walls of hallow organs)
  22. what is the role of the nervous tissue?
    brain, spinal cord, sensory organs
  23. What are the  2 types of epithelial tissue?
    • 1. Covering and lining: organized sheets of cells forming a barrier (ex. epidermis)
    • 2. Glandular epithelium: makes up most of the glands in the body
  24. what are the locations of epithelium tissue?
    1. Lining epithelium: covers the body and some of its parts line the serous cavities (thoracic and abdominal), blood and lymphatic vessels, respiratory, digestive and genitouitary tracts

    2. Glandular epithelium: secretory units of endocrine and exocrine glands
  25. what are the functions covering/lining epithelium?
    • Protects against underlaying tissues against physical damage, drying out, chemical injury and infection
    • Allows and regulates the passage of materials (diffusion, absorption, filtration, section, excretion) into or out of tissues of the body which they cover or line
    • Oxygen, food and waste pass through one or more epithelial layer
    • Specialized epithelia form sensory parts of organs such as the eye, ear, mouth (taste buds) and nose (olfactory)
  26. what are the functions of the glandular epithelium?
    • Specialized for producing secretions that are watery-fluid containing salts, enzymes, hormones, mucus, fats
    • oTHERS: milk, insulin, sweat, saliva, calcitonin, tears and bile
  27. what are the general  functions of epithelial cells?
    • Protection
    • Sensory function
    • Secretion - glandular epithelium
    • Absorption
    • Excretion
  28. what are the characteristics of epithelial tissue?
    • Extremely limited amounts of intracellular matrix material
    • Appear as continuous sheet cells packed tightly together
    • Epithelial layer attaches to an underlying layer of connective tissue by the basement membrane and is AVASCULAR (no blood supply/there are no blood vessels)
  29. what is the apical surface?
    All epithelia have 1 free surface which is exposed at the body surface or at the lumen (space) of the body cavity, duct, tube or vessel
  30. what are the characteristics of covering/lining epithelia based on?
    • # of cell layers
    • Cell shape
    • Specialization of their cell surface
  31. what are the 2 different cell layers?
  32. 1 layer: simple epithelium
    Several layers: stratified epithelium.
  33. what happens when 2 or more layers are present?
    Most cells do not reach the basement membrane, the epithelium is classified as stratified
  34. what are the different shapes of cells?
    • Flat: squamous epithelium (in lungs),
    • Square: cuboidal epithelium (tubules),
    • Rectangular: columnar epithelium (mucus membranes),
    • Transitional epithelium: if the shape changes depending of the degree of stretching of the tissue (respiratory system/cilia)
  35. how do you figure out  what type of cells you are dealing with?
    By looking at the shape and the position of the nuclei

    Squamous epithelium:  if the nuclei are flat and parallel to the free surface

    Columnar epithelium: if the nuclei are oval and parallel to the axis of the cell and situated at its base

    Cuboidal epithelium: if the nuclei are round and situated in the middle of the cell

  36. what are the 2 types of epithelia?
    • 1. The simple epithelia:
    • Being composed of 1 layer of cells only,
    • they are very thin.
    • They are found in areas of minimum wear and tear.
    • Main function:to allow passage of substances between the lumen and the surrounding tissues.

    • 2. The stratified epithelia:
    • Being composed of several layers of cells, they are very thick.
    • Main function: is to protect the tissues that they cover.
    • The shape of the cells closest to the basement membrane is quite different from that of the cells at the top, near the lumen.
    • Thus, the problem is: how can you further classify the stratified epithelia? By convention, stratified epithelia are further classified according to the shape of the cells at the free surface.
  37. 8 Classes of epithelia
                                                      Image Upload 1

                                                  Image Upload 2
  38. what are the simple squamous epithelium?
    • Thinnest
    • 1 layer of flat cells (having 1 flat nucleus).
    • Found in: alveoli in lungs, kidney in glomeruli, lining of the heart, blood vessels in the lymphatic system
    • Well adapted for diffusion, filtration and secretion
  39. what are simple cuboidal epithelium?
    • 1 layer of cuboidal cells with 1 round nucleus
    • Found in : small glands, kidney tubules and ovary surface
    • Adapted for secretion and absorption of surfaces
  40. what are simple columnar epithelium?
    Composed of 1 layer of the columnar cells with 1 oval nucleus

    • 1) Non ciliated:
    • Contain microvili on apical surface
    • Found: in the digestive lining and is involved in absorption and secretion of mucus

    • 2) Ciliated:
    • Has cilia on apical surface
    • Found : in the small bronchi, uterine tubes and part of the uterus

  41. what are simple pseudo stratified epithelium?
    • 1 layer of cells
    • All cells rest on basement membrane
    • Cells are different heights
    • Nuclei are at different levels
    • Can be ciliated or non-ciliated on apical surface

    • 1) Non ciliated
    • Found: in lining of male urethra and ducts of large glands

    • 2) Ciliated
    • Found: in trachea, primary bronchi and in the most upper respiratory tract
    • Involved in secretion and propulsion of mucus
  42. what are stratified squamous cells?
    • thickest of all epithelia
    • has several layers 
    • may or may not contain keratin

    • 1) keratinized 
    • forms the epidermis of the skin

    • 2) non keratinized 
    • lines wet surfaces subject to abrasion like lining of the mouth, tongue, esophagus, part of the epiglottis
  43. what are stratified cuboidal cells?
    • has several layers
    • surface is composed of cuboidal cells
    • Role = proetction
    • Found in = largest ducts of sweat glands, mammary glands, and
  44. what are stratified columnar cells?
    • Composed of columnar cells
    • Vary rare
    • Lines part of the urethra, large ducts of some glands, portion of the eye
    • Role = protection and secretion
  45. what are transitional epithelium?
    • Found in = lining of surfaces of organs subjected to stretch such as the bladder, the ureters and part of the urethra
    • If stretched, looks like a stratified squamous epithelium 
    • If unstretched, looks like a stratified cuboidal epithelium
  46. what is the glandular epithelium?
    Specialized cells that secrete exocrine or endocrine substances
  47. what are exocrine glands?
    • Release their products into the free surface of the skin or of the open cavities of the body
    • Discharge secretions into ducts
    • ex. salivary of sweat gland
  48. what are endocrine glands?
    • "ductless" glands
    • discharge secretions directly into the blood or interstitial fluid
  49. what are the different types of glandular epithelium?
    • Apocrine
    • Holocrine
    • Merocrine
  50. what are apocrine epitehlium?
    • Product pinches off and is released form Apex
    • Ex. mammory glands, hair follicle, goblet cells in the duodenum
  51. what are holocrine epithelium?
    Product collect in the cell, then when product is released the plasma membrane ruptures
  52. what are merocrine (eccrine) cells?
    • Most common type
    • Secrete through the plasma membrane
    • Ex. salivary glands, gastric glands, sweat glands in body acting in cooling system (different from apocrine sweat gland)
  53. what are sebaceous gland?
    Produce sebum and lubricate skin and hair
  54. what is connective tissue?
    Most abundant tissues
  55. where do you find connective tissue?
    Everywhere in the body
  56. what is the function of connective tissue?
    connects, supports, transports, insulates, repairs (scar tissues) and protects
  57. how does connective tissue work in insulation?
    Fat cells or adipose tissue is a connective tissue that cushions organs and insulates them and provides reserve energy fuel
  58. how does connective tissue work in transportation?
    Blood is a connective tissue and it carries and delivers oxygen and nutrients to tissues
  59. what are histological characteristics of connective tissues?
  60. what are the 4 main types of connective tissue?
    • 1. Fibrous
    • 2. Cartilage
    • 3. Bone
    • 4. Blood
  61. what are different types of  fibrous connective tissue?
    • 1.Loose
    • a. LOOSE (Aerolar ex. fascia, fat (protection and insulation)
    • b. Dense regular ex. tendons and ligaments (flexible but strong)
    • c. Dense irregular ex. symphysis pubis joint (very strong, little flexibility)
  62. what are different types of cartilage tissue?
    • Gives firm but flexible support
    • Elastic: ear, epiglottis, nose
    • Hyaline: trachea rings, joint surface of bone, larynx
    • Fibrocartillage: symphysis pubis bone (connection of bones together)
  63. what are different types of bone tissue?
    • 1. Compact bone
    • 2. Spongy bone - mineralized ECM
  64. classification of connective tissue
    Image Upload 3
  65. 2. what is cartilage?
    • composed of specialized cells called chondroblasts
    • produce a large ECM composed of collagen fibres, abundant ground substance rich in proteoglycan and elastin fibres
  66. how does cartilage differ from other tissue?
    The only cell type present is chondrocyte

  67. what are lacunae house cells?
    Lacuna hole or pit is a small space containing a chondrocyte in cartilage or an osteocyte in bone
  68. why would cartilage heal slowly?****
    • Its has no direct blood supply
    • Chondrocytes are supplied by diffusion
  69. what are chondroblasts?
    They secrete the ECM (composed of fibres) of cartillage
  70. where are chrondroblast found?
    • In the outer layer of cartilage
    • As chondroblasts secrete matrix and fiber, the become trapped inside it and mature into cells called chondrocytes
  71. Chondroblast, chondrocyte, lacuna
    Image Upload 4
  72. what is fibrocartilage?
    the strong dense fibres that fill the matrix convey shock absorbing qualities
  73. 3. what is bone tissue?
    • Highly specialized connective tissue
    • Cells (osteocytes) = embedded in a calcified matrix
    • Image Upload 5
  74. what are the functions of bone tissue?
    • Support
    • Protection
    • Point of attachment for muscles
    • Reservoir for minerals
    • Supports blood forming tissue
  75. what is compact bone?
    Found forming most of the hard shell of a bone
  76. what is the Haversian Canal?
    Blood vessels, connective tissue, nerves
  77. what is the Canaliculi?
    Small canal allowing for nutrients to travel between lacunae
  78. what is the Lamellae?
    Concentric rings - form the bone matrix
  79. what is the Lacunae?
    Spaces in the bone (holes) where the osteocytes are located
  80. what is the osteon?
    Basic structural unit of compact bone
  81. Compact bone
    Image Upload 6
  82. what is spongy (cancellous) bone?
    Forms a network of hard beams of bone tissue inside many bones
  83. what is blood tissue?
    • Most unsual connective tissue
    • Exits in liquid state
  84. what is the composition of whole blood?
    • Plasma = 55%
    • Formed elements (RBC, WBC, Platelets) = 45%
  85. what are the functions of blood?
    • Transportation
    • Regulation of body temperature
    • Regulation of body pH
    • WBC destroy bacteria
    • Circulating blood tissue is formed in the red bone marrow by a process called hematopoiesis
  86. Summary of connective tissue type
    Image Upload 7
  87. what is muscle tissue?
    • cells specialized in contraction
    • Are elongated and can change their shape by becoming shorter and thicker
  88. what are some histological characteristics common to ALL MUSCLE TISSUES?
    • They're made of many cells together
    • They are well vascularized (lots of blood vessels)
    • They're elongated
    • They contain microfilaments
  89. what are the 3 kinds of muscle tissue?
    • 1. Skeletal muscle
    • 2. Smooth muscle
    • 3. Cardiac muscle
  90. what is skeletal muscle?
    • Striated voluntary
    • Thread like cells with many cross striations
    • Very long rod shaped cells
    • Multinucleated (normal)
    • Image Upload 8
  91. what is smooth muscle?
    • No striations
    • Elongated
    • Fusiform shaped cells
    • 1 nucleus per cell
    • Image Upload 9
  92. what is cardiac muscle?
    • Striated
    • Branching cells with intercalated disks (formed by meeting of plasma membranes of 2 cells)
    •  1 or 2 nuclei present (in the centre)
    • Are only found in the heart

    • Image Upload 10
  93. what type of muscle lines arteries and veins?
    • Smooth muscles
    • You can see the difference in wall thickness
    •                                                Image Upload 11
  94. what is the purpose of having artery and veins lining the smooth muscle?***
    Arteries : It relaxes to allow more blood to flow to an area, and contracts to restrict the local blood flow

     smooth muscle that gently pumps blood back to the heart.

  95. what is the function of nervous tissue?
    • Rapid regulation and integration of body activities
    • Its Ectodermal
  96. what are some specialized characteristics of nervous tissue?
    • Excitability
    • Conductivity
  97. what are some organs containing nervous tissue?
    • Brain
    • Spinal cord
    • Nerves
  98. what is a neuron?
    Conducting unit of a system
  99. what is  the structure of a nervous tissue?
  100. Basic function of the nervous tissue is to rapidly regulate and integrate actions from the body
    Has well developed excitability and conductivity characteristics
  101. what is the cell body?
    • Aka the soma
    • Spherical part of the neuron that contains the nucleus and most of the organelles
  102. what is an axon?
    Transmits nerve impulse away from cell body and axon
  103. what are dendrites?
    Transmits nerve impulse towards cell body and axon
  104. what is myelin?
    • Substance rich in lipids and proteins that forms layers around the nerve fibres 
    • Acts as insulation
  105. how does a neutron look like?
    Image Upload 12
  106. what are glial cells?
    Support, protect and bind neurons
  107. what are the histological characteristics of the nervous tissue?
    • 1. Made of many cells close together
    • 2. Most of the cells are strongly branching
Card Set
mamm. phys - Lab 1 (histology)
mamm. phys