BIOH111 o Cell Biology Module o Tissue Module o Integumentary system o Skeletal system o Muscle system o Nervous system o Endocrine system Endeavour College of Natural Health endeavour.edu.au 1
Textbook and required/recommended readings o Principles of anatomy and physiology. Tortora et al; 14 th edition: Chapter 4 Endeavour College of Natural Health endeavour.edu.au 2
BIOH111 Tissue Module o Session 4 (Lectures 7 and 8): Tissue level organisation tissue types and general features of epithelial tissue o Session 5 (Lectures 9 and 10): Tissue level organisation general features of remaining tissue types and membranes Endeavour College of Natural Health endeavour.edu.au 3
BIOH111 Session 5: Lectures 9 and 10 Tissue Level Organisation Bioscience Department endeavour.edu.au
Objectives Lecture 9: o General features of the remaining tissue types and membranes. Connective tissue Lecture 10: o General features of the remaining tissue types and membranes. Muscular and nervous tissue Epithelial and synovial membrane Endeavour College of Natural Health endeavour.edu.au 5
CONNECTIVE TISSUE Structure: o Abundant and widely distributed o Two basic elements: cells (immature and mature) and extracellular matrix Immature cells have names that end in blast (e.g. fibroblast, chondroblast) Mature cells have names that end in -cyte (e.g. osteocyte) o Cells rarely touch and are loose in the extracellular matrix o Extracellular matrix is secreted by the cells o Consistency varies (can be liquid, gel or solid) o Good nerve & blood supply (except cartilage & tendons) Endeavour College of Natural Health endeavour.edu.au 6
CONNECTIVE TISSUE CELLS o Fibroblasts - secrete fibers and matrix o Adipocytes (fat cells) - store energy in the form of fat o White blood cells (leukocytes) immunity and defense - Macrophages develop from monocytes and engulf bacteria & debris by phagocytosis - Plasma cells develop from B lymphocytes and produce antibodies that fight against foreign substances - Mast cells produce histamine that dilate small blood vessels fibroblast adipocyte What do the names of the above cells tell you about their maturity stages? macrophage plasma cell mast cell Endeavour College of Natural Health endeavour.edu.au 7
CONNECTIVE TISSUE EXTRACELLULAR MATRIX Consists of 2 major components: 1. Ground Substance - can be fluid, semifluid, gelatinous or calcified depending on its composition and function - Structure: water and large organic molecules (combination of the complex adhesion proteins (fibronectin) and polysaccharides called glycosaminoglycans (GAG s) (these include: hyaluronic acid, chondroitin sulfate, dermatan sulfate, and keratin sulfate) - Function: support and interaction ground for connective tissue cells, stores water and provides medium for molecule diffusion from cells to bloodstream Endeavour College of Natural Health endeavour.edu.au 8
2. Fibers a) Collagen fibers - composed of the protein collagen; tough and resistant to stretching but allows some flexibility in tissue; e.g. bone, cartilage, tendons, and ligaments. b) Elastic fibers - composed of the protein elastin surrounded by the glycoprotein fibrillin; provide strength and stretching capacity; e.g. skin, blood vessels, and lungs. c) Reticular fibers - composed of collagen and glycoprotein; support in the walls of blood vessels, in spleen, in lymph nodes; supporting network around fat cells, nerve fibers, and skeletal and smooth muscle fibers. Endeavour College of Natural Health endeavour.edu.au 9
FUNCTIONAL CLASSIFICATION OF CONNECTIVE TISSUE Mature connective tissue is loosely classified based firstly on the structure (1-5) and then function (A-C) it performs: 1. Loose connective tissue loosely woven fibers throughout tissues; types: areolar (A), adipose (B) and reticular (C) 2. Dense connective tissue contains more numerous, thicker, and dense fibers but considerably fewer cells than loose connective tissue; types: Dense regular (A), dense irregular (B) and elastic (C) 3. Cartilage hyaline (A), fibrocartilage (B) and elastic (C) 4. Bone tissue 5. Liquid connective tissue blood (A) and lymph (B) Endeavour College of Natural Health endeavour.edu.au 10
1A: AREOLAR CONNECTIVE TISSUE o Cell types = fibroblasts, plasma cells, macrophages, mast cells and few white blood cells o All 3 types of fibers present o Gelatinous ground substance o It is found in the subcutaneous layer of the integument Endeavour College of Natural Health endeavour.edu.au 11
1B: ADIPOSE CONNECTIVE TISSUE o Consists of adipocytes which are specialized for storage of triglycerides. found wherever areolar connective tissue is located. reduces heat loss through the skin, serves as an energy reserve, supports, protects, and generates considerable heat to help maintain proper body temperature in newborns (brown fat). Endeavour College of Natural Health endeavour.edu.au 12
1C: RETICULAR CONNECTIVE TISSUE o Reticular connective tissue consists of fine interlacing reticular fibers and reticular cells forms the stroma of certain organs. helps to bind together the cells of smooth muscle. Endeavour College of Natural Health endeavour.edu.au 13
2A: DENSE REGULAR CONNECTIVE TISSUE o Collagen fibers in parallel bundles with fibroblasts between bundles of collagen fibers; white, tough and pliable when unstained forms tendons Endeavour College of Natural Health endeavour.edu.au 14
2B: DENSE IRREGULAR CONNECTIVE TISSUE o Contains collagen fibers that are irregularly arranged and is found in parts of the body where tensions are exerted in any direction occurs in sheets, such as the dermis of the skin. found in heart valves, the perichondrium, the tissue surrounding cartilage, the periosteum and white of the eyeball Endeavour College of Natural Health endeavour.edu.au 15
2C: ELASTIC CONNECTIVE TISSUE o Branching elastic fibers and fibroblasts; can stretch & still return to original shape Lung tissue, vocal cords, ligament between vertebrae, aorta Endeavour College of Natural Health endeavour.edu.au 16
3. CARTILAGE o Consists of a dense network of collagen fibers and elastic fibers embedded in chondroitin sulfate. strength is due to its collagen fibers resilience is due to the chondroitin sulfate Chondrocytes occur with spaces called lacunae in the matrix o It is surrounded by a dense irregular connective tissue membrane called the perichondrium. o Avascular (except in the perichondrium). Chondroitin sulfate and glucosamine are used as nutritional supplements to maintain joint cartilage. Why do you think the supplements benefit some individuals and not others? Endeavour College of Natural Health endeavour.edu.au 17
3A: HYALINE CARTILAGE o Most abundant (e.g. ends of bones), but weakest; found in joints, the respiratory tract, and the immature skeleton o Consists of fine collagen fibers embedded in a gel-type matrix o Affords flexibility and support and at joints, reduces friction and absorbs shock o Bluish-shiny white rubbery substance o No blood vessels or nerves so repair is very slow Endeavour College of Natural Health endeavour.edu.au 18
3B: FIBROCARTILAGE o Contains bundles of collagen fibers in ground substance o Lacks perichondrium o Strongest of the three types of cartilage, so functions in allowing rigidity & stiffness (e.g interverterbral discs; patella) Endeavour College of Natural Health endeavour.edu.au 19
3C: ELASTIC CARTILAGE o Contains a threadlike network of elastic fibers o Perichondrium is present o Provides strength and elasticity and maintains the shape of certain organs (even after deformations); e.g. ear, nose, vocal cartilages Endeavour College of Natural Health endeavour.edu.au 20
4: BONE (OSSEOUS) TISSUE o Consists of extracellular matrix containing mineral salts and collagenous fibers and cells called osteocytes. 2 types: 1. Spongy bone sponge-like with spaces and trabeculae trabeculae = struts of bone surrounded by red bone marrow 2. Compact bone solid, dense bone o Protects, provides for movement, stores minerals, site of blood cell formation This tissue will be covered in detail in Skeletal System Module Endeavour College of Natural Health endeavour.edu.au 21
cells tissue organ Bone cells o Osteogenic cells undifferentiated, stem cells can divide to replace themselves & can become osteoblasts found in inner layer of bones o Osteoblasts - form matrix & collagen fibers but can t divide o Osteocytes - mature cells that no longer secrete matrix and the principle cells of bone matrix o Osteoclasts - huge cells from fused monocytes (WBC) function in bone resorption Endeavour College of Natural Health endeavour.edu.au 22
Cells of Bone Osteoblasts Osteocytes Osteoclasts Endeavour College of Natural Health endeavour.edu.au 23
cells tissue organ Bone (Osseous) TISSUE o Type of connective tissue as seen by widely spaced bone cells separated by matrix. Matrix - 25% water, 25% collagen fibers & 50% crystallized mineral salts (hydroxyapatite and some calcium carbonate) o Calcification or mineralization process of mineral salts deposition in a framework of collagen fibers Mineral salts confer hardness on bone while collagen fibers give bone its great tensile strength o Bone is not completely solid - small spaces for vessels and red bone marrow o 2 types: compact and spongy bone Endeavour College of Natural Health endeavour.edu.au 24
Compact Bone Structure: solid, hard layer of bone; makes up the shaft of long bones and the external layer of all bones Function: resists stresses produced by weight and movement Endeavour College of Natural Health endeavour.edu.au 25
Compact Bone HISTOLOGY o Arranged in units called osteons or Haversian systems. Osteons contain blood vessels, lymphatic vessels, nerves, osteocytes and calcified matrix o Osteons are aligned in the same direction along lines of stress. Endeavour College of Natural Health endeavour.edu.au 26
Spongy Bone Structure: light of bone; found only on the interior of the bones; most of the structure of short, flat, and irregular bones (e.g. ribs), and the ends of the long bones Function: supports and protects the red bone marrow Endeavour College of Natural Health endeavour.edu.au 27
SPONGY BONE HISTOLOGY o Arranged in trabeculae (latticework of thin plates of bone) that surround many red marrow filled spaces o Trabeculae are irregularly arranged. Endeavour College of Natural Health endeavour.edu.au 28
5: LIQUID CONNECTIVE TISSUE 5A: Blood o liquid matrix called plasma o formed elements red blood cells, leukocytes and platelets o Supply of oxygen and immunity 5B: Lymph o Extracellular fluid flowing in lymph vessels. o Similar composition as plasma but contains less protein than plasma o Immunity and movement of molecules (e.g. nutrients absorbed from small intestine) This tissue will be covered in detail in BIOH122 (next semester) Endeavour College of Natural Health endeavour.edu.au 29
Revision Talk in groups of 3-4: why do you think all these different connective tissues are important? What is the difference between the cells and extracellular matrix that constitute the specific connective tissue type? Can you connect this to the cell module think about cellular processes you learned there to understand the tissue module.. Endeavour College of Natural Health endeavour.edu.au 30
Objectives Lecture 9: o General features of the remaining tissue types and membranes. Connective tissue Lecture 10: o General features of the remaining tissue types and membranes. Muscular and nervous tissue Epithelial and synovial membrane Endeavour College of Natural Health endeavour.edu.au 31
MUSCLE TISSUE Consists of elongated cells called musle fibres or myocytes that are modified for contraction using ATP as energy. Muscle tissue provides motion, maintenance of posture and heat. o Classified into 3 types based on function and location: 1. Skeletal muscle tissue striated, voluntary control 2. Cardiac muscle tissue - striated, involuntary control 3. Smooth (visceral) muscle tissue non-striated, involuntary control This tissue will be covered in detail in Muscle System Module Endeavour College of Natural Health endeavour.edu.au 32
Skeletal Cardiac Smooth Multi-nucleated cells Motion, posture, heat protection and production Attached to bones by tendons Branched, mononucleated cells Contraction Heart Mononucleated cells Motion Walls of hollow internal structures (e.g. blood vessels, airways) Endeavour College of Natural Health endeavour.edu.au 33
NERVOUS TISSUE Composed of only two principal cell types: 1. Neurons (nerve cells) - consist of a cell body and two types of processes called dendrites and axons; neurons are sensitive to stimuli, convert stimuli into nerve impulses, and conduct nerve impulses to other neurons, muscle fibers or glands. 2. Neuroglia - protective and supporting cells Red - glia; green - neurons Comment on the neuron and glia shape and its link to its function. Endeavour College of Natural Health endeavour.edu.au 34
Revision Talk in groups of 3-4: think in an integrative way about the cells and tissues how does cell s shape influence its function? Why is it important to know the connections between the cells? What happens to the tissue if those connections are lost? Membranes next Endeavour College of Natural Health endeavour.edu.au 35
MEMBRANES Membranes are flat sheets of pliable tissue that cover or line a part of the body. Two types: 1. Epithelial membranes - consist of an epithelial layer and an underlying connective tissue layer (lamina propria); include mucous membranes (A), serous membranes (B), and the cutaneous membrane or skin (C). 2. Synovial membranes line joints and contain only connective tissue. Endeavour College of Natural Health endeavour.edu.au 36
1A: MUCOUS MEMBRANES Mucous membranes (mucosae) line cavities that open to the exterior (e.g. mouth, stomach, vagina, urethra). o Epithelial layer: epithelial and goblet cells secrete mucous and enzymes to form barrier for the microbes, keep the membrane moist and to digest the surrounding nutrients; tight junctions between cells prevent simple diffusion of most substances. o Connective tissue: is areolar connective tissue type and is called the lamina propria. Endeavour College of Natural Health endeavour.edu.au 37
1B: SEROUS MEMBRANES Lines a body cavity that does not open to the outside (e.g. chest or abdominal cavity); pleura, peritoneum and pericardium o Epithelial layer: Simple squamous cells that secrete serous fluid that acts as a lubricant to the underlying organs o Connective tissue: is areolar connective tissue type. o Two layers: parietal layer (attached to the walls of cavity) and visceral layer (covers organs in cavity) Endeavour College of Natural Health endeavour.edu.au 38
1C: CUTANEOUS MEMBRANES Cutaneous membranes cover body surfaces o Epithelial layer: Keratinised stratified squamous epithelium called epidermis o Connective tissue: is dense irregular and areolar connective tissue type. This tissue will be covered in detail in Integumentary System Module Endeavour College of Natural Health endeavour.edu.au 39
2: SYNOVIAL MEMBRANES o Composed of specialized cells called synovicytes which secrete slippery synovial fluid; this ensures friction-free movement, nourishment to the underlying cartilage and removal of any microbes o Line joint cavities of all freely movable joints, bursae and tendon sheaths This tissue will be covered in detail in Skeletal System Module Endeavour College of Natural Health endeavour.edu.au 40
For next class: Thinking within your own interests (e.g. nutrition) think about and then write how you would apply the knowledge you acquired in cell and tissue modules within a clinic/patient environment or as a problem you wanted to investigate (e.g. why vitamins only help certain people and not others). Clearly outline a problem you selected and why and how would you approach the problem if you were a practitioner. If you are stuck for ideas read section 4.10 in your textbook as a starting point.. NOTE: this is NOT ASSESSED and NOT compulsory and not a right/wrong answer exercise. It is here to make you think about biology in the scope of your own interests. Please hand in the paragraph to the lecturer at the start of the next session. You will receive feedback on your knowledge of biology, your approach and your writing but NO MARKS. Endeavour College of Natural Health endeavour.edu.au 41
TISSUE REPAIR: RESTORE HOMEOSTASIS o Tissue repair is the process that replaces worn out, damaged, or dead cells. o Each of the four classes of tissues has a different capacity to replenish its parenchymal cells. Epithelial cells are replaced by the division of stem cells or by division of undifferentiated cells. Some connective tissues such as bone has a continuous capacity for renewal whereas cartilage replenishes cells less readily. Muscle cells have a poor capacity for renewal. Nervous tissue has the poorest capacity for renewal Endeavour College of Natural Health endeavour.edu.au 42
TISSUE REPAIR: RESTORING HOMEOSTASIS o Worn-out, damaged tissue must be replaced o Fibrosis is the process of scar formation. If the injury is extensive granulation tissue (actively growing connective tissue) is formed. o Adhesions, which sometimes result from scar tissue formation, cause abnormal joining of adjacent tissues, particularly in the abdomen and sites of previous surgery. These can cause problems such as intestinal obstruction. Endeavour College of Natural Health endeavour.edu.au 43
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