ANFS140 Week of 03/07/16
ANFS140 Week of 03/07/16 140
Popular in Functional Anatomy of Domestic Animals
verified elite notetaker
Popular in General Science
This 14 page Class Notes was uploaded by Rachel Schmuckler on Wednesday March 9, 2016. The Class Notes belongs to 140 at University of Delaware taught by Dr. Robert Dyer in Spring 2016. Since its upload, it has received 17 views. For similar materials see Functional Anatomy of Domestic Animals in General Science at University of Delaware.
Reviews for ANFS140 Week of 03/07/16
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 03/09/16
Bone Connective Tissue 4 types of cells Mesenchymal Cell Osteoprogenitor cell Osteoblast o Cell division o Synthesize and secrete bone o Deposit matrix to form lacunae Osteocyte o Buried in bone matrix o Intercannaliculi: arms projecting off of osteocyte that travels through the matrix to attach to another osteocyte in a different lacuna Osteoclast o Derived by fusion of monocytes (white blood cells) = multinucleated syncytium o Resorbs extracellular components of bone Hyaluronin, proteoglycans, water, collagen, calcium (hydroxyapatite), HCl Nutrients enter the bone in arteries that pass through the dense bone – nutrient foramens Can enter in the epiphysis, diaphysis, or metaphysis Artery splits into branches once inside the bone that run proximally and distally along the length of the bone Eventually penetrate back into the bone that later branch and run up and down the length of the dense bone (distribute nutrients, remove waste) Blood supply is centrifugal (blood flow in, but the rest of the flow is from the center outwards) Pass through periosteum through dense bone via nutrient foramen through endosteum to enter cancellous bone area up and down marrow cavity pass back into endosteum and dense via the Volksman’s Canal up and down the length of the dense bone via the Haversian’s Canal meet osteocytes in lacunae to deliver nutrients Underneath the endosteal membrane, there are circumferential lamellae (layers of bone) o Mesenchymal stem cells osteoprogenitor cells osteoblasts o Outer layer of irregular dense fibrous connective tissue that has fibroblasts and mesenchymal stem cells (that differentiate into osteoprogenitor cells and then to osteoblasts) o Inner layer of osteoblasts Sit on the outer layer of circumferential lamellae Synthesize and secrete bone matrix Inside the dense bone, there are multiple osteons/Haversian system o Circumferential rings of bone that sit around the Haversian Canal o Long axis of the column = long axis of bone Versus Volksman Canal which runs perpendicular o Lacunae with osteocytes inside osteon Nutrients out of Haversian canal, into osteon, into canaliculi, into lacunae Underneath the periosteal membrane, there are more circumferential lamellae o Outer layer of irregular dense fibrous connective tissue that has fibroblasts and mesenchymal stem cells (that differentiate into osteoprogenitor cells and then to osteoblasts) o Inner layer of osteoblasts Sit on the outer layer of circumferential lamellae Synthesize and secrete bone matrix Blood flow in dense bone Haversian Systems/Osteon Oriented parallel to the long axis of the bone Central haversian canal with concentric lamella of bone centered around it Osteocytes sit in lacunae within the rings of bone and are oriented around haversian canal o Attached to collagen fibers that are inside the lacunae o Long arms that travel down canaliculi to attach to/communicate with other cells Dense Bone Structure Appositional bone deposition by osteoblasts of periosteum creates circunfrential lamella (3-4 layers of bone) Thousands of osteons packed together o Oriented around a Haversian Canal and parallel to long axis of bone o Single osteon consists of concentric lamella of bone all oriented around a central haversian canal o Haversian systems are constantly turning over Osteoclasts synthesize and secrete HCl and enzymes to break down extracellular matrix and resorb bone Cells attached to collagen fibers are oriented parallel with the force of the bone (i.e. femur = up and down) Causes osteoclasts to digest bone in that orientation Appositional (Interstitial) Bone Growth Growth in width Arranged in layers around the entire circumference of the diaphysis Expands outer circumference of bone Eventually remodeled into osteon by cutting and closing cones of remodeling functions Deposit bone/circumferential lamellae under periosteum (osteoprogenitors, osteoblasts), resorb bone under endosteum (osteoclasts) Generating lots of circumferential lamellae around bone Osteoblasts and osteoclasts have coordinated activity Circumferential lamellae remodeled into osteons overtime Appositional bone deposition = interstitial bone growth Periosteum = fibrous connective tissue Constant turnover of bone Calcium used by all cells in the body to signal Eclampsia: calcium levels drop, no contraction in muscles, results in death Endochondral Ossification Growth in length Hyaline cartilage of epiphyseal plate = metaphysis Pushes epiphysis away from diaphysis o Chondrocyte replication and production of cartilage components (hyaluronin, proteoglycans, collagen fibers) Chondrocytes hypertrophy (enlarge and die) Cartilage becomes vascularized o Blood cells into tissue to deliver inflammatory cells that clean out dead tissue o Blood vessels deliver mesenchymal stem cells to cartilage matrix that turns into osteoprogenitor cells osteoblasts o Osteoblasts synthesize new bone components to replace cartilage components Articular cartilage not on picture (above epiphyseal plate) Zones of cartilage: o Reserve zone of chondrocytes o Chondrocytes proliferate (isogenous groups) Cartilage matrix formed, lacunae present Nutrients delivered through compression/release of cartilage (sponge analogy) o Chondrocytes hypertrophy The more the matrix, the harder it is for the nutrients to diffuse to cells Cell death o Calcification Blood vessels grow into dying cartilage in attempt to repair it Vascularized cartilage turns to bone Bone vessels contain mesenchymal stem cells Androgens = testosterone, slow the process down Trabeculae: dying cartilage that has bone being deposited around it Osteoprogenitor Cells Mitotic cell Generates progency cells From mesenchymal stem cell Found throughout bone periosteum, endosteum, Volksman and Haversian canals Osteoblasts Early progeny of osteoprogenitor cell Synthesizees and deposits extrcellular components of bone (hyaluronin, collagen, proteoglycans, hydroxyapatite crystals) o Hydroxyapatite crystals = calcium and phosphorous (CaPO4) Found in periosteum, endosteum, and closing cone of remodeling structures Osteocytes Mature osteoblast – develops from osteoblasts that encase themselves in extracellular bone components Exists in lacuna Connected to other osteoprogenitor cell series by long cytoplasmic arms that adhere to arms of other osteocytes/osteoblasts o Cytoplasmic arms exist in canaliculi channels extending from lacuna to lacuna Endogenous cell of bone – found throughout dense and cancellous bone Retains ability to synthesize as well as re-absorb extracellular bone components o Involved in calcium homeostasis and maintaining bone integrity Osteoclasts One cell type from myeloid (white blood cell) lineage Osteoclast is multinucleated cell formed by fusion of several cells together Osteoclast o Monocytic series of myeloid lineage (white blood cells) Location = endosteum and cutting cone of remodeling structures Function = re-absorption of extracellular bone components Enzymatic digestion of collagen fibers, hyaluronan, proteoglycans Synthesize and secrete proteases to digest components Acidic solubilization of hydroxyapitate crystals + Osteoclast synthesize and secrete H Osteocalcin, Osteoectin o Calcium-binding proteins o Synthesized by osteocyte or osteoblast o Unique to bone extracellular matrix o Forms nucleus of which hydroxyapatite crystals precipitate out onto Bone Remodeling Location = anywhere in dense and cancellous bone Process: o Osteoclasts absorb bone matrix Osteoclasts penetrate the bone (hot marble in butter) and align themselves along the force of the bone (most commonly a vertical force) Enzymatic digestion of organic components and acidic solubilization of hydroxyapitate crystals o New vascularization of hole from cutting cone Mesenchymal stem cells dragged in with new blood vessel that sits inside new Haversian canal Osteoprogenitor cells and osteoblasts formed o New bone formation Osteoblasts deposit bone matrix inside Haversian canal New concentric lamellae of bone formed around central canal of Haversian system In the closing cone End result = new Haversian system Muscle Tissues Muscle belly: grossly visible muscle, consists of billions of myofibers Muscle fascicle: grossly visible thread of muscle belly Myofiber: = individual muscle cell, = muscle fiber, bag that holds a clump of angel hair pasta, multinucleated, nuclei located immediately underneath the cell membrane, extends from the origin to the insertion Myofibril: contractile substance that fills the myofiber, looks like a clump of angel hair pasta, extends from the origin to the insertion Myofilament: protein structure that makes up the contractile element of a muscle cell, one strand of angel hair pasta 2 types – myosin and actin Myofilaments (myosin and actin) makes a myofibril. Myofibrils form a myofiber. Myofibers forms a muscle fascicle. Muscle fascicles form the muscle belly 3 Types of Muscle Cardiac (striated) Smooth Skeletal (striated) Fibrous Connective Tissue of Muscle Epimysium: outer layer, rind of a grapefruit, loose and irregular dense CT Perimysium: surrounds fascicles (divide muscle into pieces), spokes of CT that poke into fascicles, irregular dense CT Endomysium: subunit of perimysium, collagen fibers attach to myofiber plasma membrane All collagen fibers distributed thoughout these three layers are collected at the end of the muscle to form a tendon Motor Unit Neuron attaches to every myofiber If the attachment is destroyed, there is a loss of innervation to those myofibers and they die (loss of muscle mass) Motor units = one efferent somatic motor neuron and all the muscle fibers innervated by the neuron. o Can have 1 neuron per 2-3 myofibers – fine muscle control like that needed in the iris o Can have 1 neuron per 1000 myofibers – course muscle control like that needed in quadriceps to counteract gravity Sarcolemma: plasma membrane of a myofiber Sarcoplasm: cytoplasm of a myofiber Sarcomere: functional contractile unit of a muscle fiber SKELETAL MUSCLE!! Sarcomere = contractile unit, arranged side by side down a myofibril o During contraction, sarcomeres shorten by drawing the two ends towards the middle Myofibril Arrangement (1 sarcomere depicted) Myosin o Pink o Heavy chains o Appearance of a golf club at the molecular level with the heads at the ends and the handles tied together in the middle Actin o Green o Protein that has a globular structure o Interdigitating the myosin heavy chains o Alpha-actinin Holds actin together within their chains Anchors actin at the end of the sarcomere Also joins sarcomeres together by attaching the ends of actins together Ends are “welded” together down the length of the myofibril Rigid arrangement of myofilaments within the myofibril o Gives the myofibril the pattern of cross-striations Z-band: end of a sarcomere, where actin filaments from two sarcomeres are welded together end-to-end A-band: fill length of myosin heavy chains (golf club head to golf club head)
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'