PTH AS 2201 1st Edition Exam 2 Study Guide Skeletal System Skeletal Tissues 1 What is the Skeletal System good for Support Protection Movement Blood Production Mineral and Electrolyte reservoir BONE Stronger stiffer mineral reservoir muscle attachment protection Types Compact cortical and Trabecular Spongy 2 Types of Cartilage Hyaline Chondrocytes in lacunae in collagen matrix Most abundant resilient to compression Where synovial joints 3 Types of Bone Compact Dense outside of bones Strong rigid CARTILAGE Flexible and shock absorbing Articular cartilage costal cartilage Tracheal rings Larynx Intervertebral disks External ear Nose Types Hyaline Elastic and Fibrocartilage Elastic Similar to Hyaline but has elastic fibers Tolerates bending Where epiglottis external ear Fibrocartilage Rows of thick collagen fibers Resists tension compression Where Annulus fibrosus of intervertebral disk knee meniscus labrum of shoulder Trabecular Inside bones and surrounded by marrow Better at shock absorption Adjacent to joints 4 Parts of Bone Diaphysis shaft of the bone long middle part Epiphysis rounded end of the bone Trabeculae inside the epiphysis gives the spongy look looks holey Medullary cavity inside the middle of the bone the central cavity Periosteum outermost membrane that covers the bone attached to compact bone by Sharpey s Fibers highly vascularized vessels and innervated nerves pain Endosteum tissue that lines the medullary cavity 5 What is diploe Specialized trabecular regions in the cranial vault 6 SEQUENCE OF GROWTH AND OSSIFICATION Condensation early embryonic organization of cells Ossification Cartilaginous elements undergo endochondral ossification Mesenchymal elements undergo intramembranous ossification Growth and Modeling immature juvenile element takes on its adult form Works in conjunction with ossification Remodeling adult bone is recycled and redistributed based on behavior 7 ENDOCHONDRAL OSSIFICATION Arteries induce ossification of cartilage precursor Chondrocytes proliferate die are replaced by osteoblasts that secrete osteoid and form bone 8 INTRA MEMBRANOUS OSSIFICATION Osteoblasts condense w in mesenchyme secrete osteoid and form bone Bones of face and cranial vault are derived via intramembranous ossification 9 Cartilage and Bone Growth Interstitial growth from w in Chondrocytes in matrix divide and secrete new matrix Matrix produced by chondrocytes w in the cartilage Appositional growth from outside Perichondrium dense connective tissue surrounding cartilage Secretes matrix actively Matrix produced by chondrocytes outside the cartilage in the perichondrium or produced by osteocytes in the periosteom or endosteum Cartilage growth ends w teen years No blood supply to chondrocytes cartilage gets nutrients from diffusion thru matrix Limits cartilage thickness growth Calcifies with aging MAKE SURE TO LOOK UP PICTURES OF THE 2 DIFFERENT TYPES OF GROWTH 10 What is Achondroplasia Premature closure of primary growth plates Sphenooccipital synchondrosis short cranial base moon shaped profile Autosomal dominant most common form of dwarfism 1 26 000 live births 11 What is the difference between modeling and remodeling Modeling Early growth adds length some shape Remodeling the bone still needs to modify its shape and internal physique to achieve adult form and respond to normal behaviors therefore remodeling 12 When is the ENTIRE skeleton replaced via remodeling During the 1st year then about 10 replaced each year Most of us are on our 3rd skeleton 13 LOOK UP A PICTURE IN NOTES OF REMODELING AND MATURING BONE Diagram LOOK UP A PICTURE OF A OSTEON AND ITS PARTS CENTRAL CANAL LAMELLAE OSTEOCYTE 14 What does Bone remodeling do Allows growth shaping repair and mineral turnover 15 Fun Fact Breaking long bones damage tissues throughout the element healing process somewhat replicates the modeling to remodeling transition 16 Vocabulary to know Osteoblasts secrete bone matrix Osteoclasts reabsorb bone Osteoporosis results from imbalance in normal building and degradation cycle Osteoarthritis articular cartilage is thin and doesn t have a good blood supply so it heals poorly Axial Skeleton Primary Function of the Axial Skeleton Protection Brain spinal cord internal organs The four elements 1 Skull 2 Hyoid 3 Vertebral column 4 Thoracic cage ribs sternum 1 Skull 24 bones Protects brain house sensory organs respiration mastication communication Mandible Cranium Neurocranium Facial Skeleton o Neurocranium Frontal Occipital Sphenoid Ethmoid Parietals 2 Temporals 2 Sphenoid has numerous foramina for passage of cranial nerves and vessels from the brain to orbit and face Ethmoid Cribriform plate olfactory bulb olfactory receptors odorants Temporal bones Squamous portion flat and Petrous portion dense part w inner ear and Mandibular fossa forms temporomandibular joint with mandible o Facial Skelton 14 Bones of the Face o Mandible jaw section o Vomer o Nasals 2 o Lacrimals 2 close by eyes o Maxillae 2 o Zygomatics 2 cheek bone o Inferior nasal conchae 2 o Palatine 2 3 Ear Ossicles o Malleus o Incus o Stapes 2 Hyoid Free floating bone in neck Functions o Site of muscle attachments o Mastication o Vocalization 3 Vertebral column 26 vertebrae 5 divisions protects spinal cord anchors pectoral and pelvic girdles o Cervical 7 o Thoracic 12 o Lumbar 5 o Sacral 5 o Coccyx 4 KNOW THE ANATOMY OF ONE VERTEBRAE o Spinous process Transverse process articular process vertebral foreman body Cervical Vertebrae C1 C7 o C1 Atlas Articulates with occipital Atlanto occipital joint permits yes movement o C2 Axis Atlanto axial joint permits no movement Thoracic Vertebrae T1 T12 o Possess ribs Lumbar Vertebrae L1 L5 o Large vertebral bodies Weight dissipation Sacrum o 5 fused vertebrae o Part of pelvis Coccyx o Tail bones CURVES OF THE SPINE o Lordosis curves anteriorly extra curvature in the lumbar region o Kyphosis curves posteriorly extended thoracic hump caused from aging osteoporosis o Osteoporosis Dowager s Hump o Scoliosis 4 Thoracic Cage Sternum 24 Ribs w costal cartilages Functions o Protect internal organs and aids in respiration Sternum o 3 bones Manubrium Body Xiphoid process o Articulates with Clavicles Ribs costal cartilages Ribs o 12 pairs of ribs Pair 1 7 true Pair 8 10 false Pair 11 12 floating o Functions are Protect internal organs such as heart and lungs Aids in respiration Appendicular Skeleton 1 What are the skeletal elements Upper Limb and Lower limb 2 Primary Function Movement 3 Upper Limb