Ex. 9 & 10 Overview of the Skeleton & The Axial Skeleton.
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Ex. 9 & 10 Overview of the Skeleton & The Axial Skeleton Slide 2 Important figures & quiz knowledge All figures (except 10.9) and tables are important to know & understand Review sheet ex. problems are important to next weeks quiz Probably will use a diagram from the review sheet ex. problems (either Ex. 9 or 10) on the quiz Need to know sheets Slide 3 Slide 4 Bone markings Know primary bone marking names & descriptions Be able to use bone markings to ID disarticulated bones Be able to use bone markings to understand articulation morphology Table 9.1, pg. 113 Slide 5 Classification of bones Two basic kinds of osseous tissue (differ in their texture): Compact bone smooth and homogeneous. Spongy bone/cancellous bone composed of small trabeculae (bars) of bone and lots of open space. Further classification (based on gross anatomy): Long bones Bones are much longer then they are wide. In general consists of a shaft with heads at either end. Composed predominantly of compact bone. Ex.: Femur and bones of the fingers phalanges. Short bones cube shaped. Contain more spongy bone than compact bone. Ex.: Tarsals and carpals. Flat bones thin, with two layers of compact bone with a layer of spongy bone in between them. Many are curved. Ex.: bones of the skull. Irregular bones bones that do not fall into one of the preceding categories. Ex.: vertebrae. Sesamoid bones special types of short bones formed in tendons. Ex.: Patellas kneecaps. Wormian/ Sutural bones tiny bones between cranial bones. Except for patellas, the Sesamiod bones and Wormian bones are not included in the 206 bone count because they vary in number and location in different individuals. Slide 6 Slide 7 Bone markings Bone Markings Reveal where bones form joints with another bones, where muscles, tendons, and ligaments were attached, and where blood vessels and nerves passed Two categories: Projections/ processes that grow out from the bone and serve as sites of muscle attachment or help form joints Depressions /cavities are indentations or openings in bones that serve as conduits for nerves and blood vessels Table 9.1; page 113 Projections that are sites of muscle and ligament attachment: Tuberosity Large rounded projection that may be roughened Crest Narrow, usually prominent, ridge of bone Trochanter Very large, blunt, irregularly shaped process Line Narrow ridge of bone that is less prominent than a crest Tubercle Small rounded process Epicondyle Raised area on or above a condyle Spine Sharp, slender, often pointed projection Process Prominence or projection Processes that help to form joints: Head Bony expansion carried on a narrow neck Facet Smooth, nearly flat articular surface Condyle Rounded articular projection Ramus Armlike bar of a bone Cavities: Antrum Chamber within a bone Sinus Space/cavity within a bone, filled with air and lined with mucous membrane Depressions and openings that allow blood vessels and nerves to pass: Meatus Canal-like passageway Fossa Shallow, basinlike depression in a bone, often serving as an articular surface Groove Furrow Fissure Narrow, slitlike opening Foramen Round or oval opening through a bone Slide 8 Gross anatomy of long bone Major features, figure 9.3, page 115 Diaphysis shaft Periosteum fibrous membrane covering. Blood vessels and nerves travel through to invade the bone Perforating (Sharpeys) fibers fibers of the periosteum the penetrate into the bone Perforating (Volkmann's) canals run into compact bone and marrow cavity from the periosteum, at the right angles of the shaft. Complete the communication pathway between the bone interior and its external surface. Cells: Osteoblasts bone forming cells Osteoclasts bone destroying cells Shaft: Medullary cavity central cavity of the shaft Yellow marrow - adipose tissue Red marrow forms blood cells Found in Marrow cavities in infant In adult occupies spaces b/n trabeculae of spongy bone, to the interior of the epiphyses Endosteum lines inside of the shaft, trabeculae of spongy bone, and canals of compact bone Contains osteoblasts and osteoclasts Epiphysis the end of long bone. Thin layer of compact bone with a layer of spongy bone in between. Articular cartilage covers epiphyseal surface in place of the periosteum Glassy hyaline cartilage provides a smooth surface to prevent friction at joint surfaces Epiphyseal plate thin area of hyaline cartilage that provides for longitudinal growth of the bone during youth Epiphyseal lines remnants of epipyseal plate, ones the bone has stopped growing Slide 9 Slide 10 Slide 11 Slide 12 Histology Osteon /Haversian system central canal and all the concentric lamellae surrounding it Central (Haversian) canal runs parallel to the long axis of the bone and carries blood vessels nerves, and lymph vessels through the body matrix Osteocytes mature bone cells in lacunae (chambers), arranged in concentric circles (circumferential lamellae) around the central canal Lamellae one of the tubular layers of bone surrounding the central canal in an osteon Interstitial lamellae remnants of circumferential lamellae that have been broken down due to bone remodeling Canaliculi tiny canals radiating outward from a central canal to the lacunae of the 1st Lamella and then form lamella to lamella Form dense transportation network through the hard bone matrix, connecting all living cells of the osteon to the nutrient supply Allow each cell to make what it needs for nourishment and to pass along the excess to the next osteocyte Slide 13 Slide 14 Cartilages of skeleton Perichondrium dense connective tissue, surrounding cartilage Chondrocytes and chondroblasts are responsible for the cartilage growth and repair Acts like a girdle to resists distortion, when cartilage is subjected to pressure Location and Basic Structure Articular cartilages cover the bone ends at movable joints Costal cartilges connect ribs to the sternum (breast bone) Laryngeal cartilages constructs larynx (voice box) Tracheal and bronchial cartilages reinforce other passageways of the respiratory system Nasal cartilages support external nose Intervertebral discs separate and cushion bones of the spine (vertebrae) External ear cartilage cartilage that support external ear Classification of cartilage (Chapter 6, page 78-9) Matrix non-living material secreted by chondrocytes, containing jelly like ground substance and fibers Hyaline cartilage most of the skeletal cartilages Only collagen fibers are present in the matrix Provides sturdy support with some resilience Elastic cartilage More elastic fibers More flexible Cartilages of external ear and epiglottis Fibrocartilage two rows of chondrocytes alternating with rows of thick collagen fibers Found where hyaline cartilage joins tendon or ligament Has a great tensile strength and can withstand heavy compression Constructs inervertebral discs and the cartilage within the knee joint Slide 15 Slide 16 Slide 17 Divisions of the skeleton & skull Subdivisions of skeleton Axial skeleton bones that lie around the body's center of gravity Appendicular skeleton bones of the limbs/ appendages 28 skull bones (8 cranial, 14 facial, and 6 ear bones) Cranium encloses and protects brain tissue Facial bones present eye in an anterior portion and form the base for the facial muscles All facial bones except for mandible (lower jawbone) join the maxilla (upper jaw bone) Sutures interlocking joint, joins most skull bones (except TMJ) Notes from Chapter 12: At birth the human body has about 375 bones By adulthood, some of the bones have fused together to give us a total of 206 bones in our body Fontanels fibrous membranes Indentations between the bones of the fetal skull These will ossify as fetus ages (20-22 month). Allow the fetal skull to be compressed slightly during birth, and allow brain growth during late fetal life. Slide 18 Skull: cranium The Cranium: Eight large, flat (mostly) bones. All single except for Parietals and Temporals, which come in pairs. Frontal Bone anterior portion of the cranium. Forms forehead, superior part of the orbit, and a floor of anterior cranial fossa Supraorbital foramen (notch) opening above each orbit allowing blood vessels and nerves to pass Parietal Bone (2) Posterior to the frontal bone, forming sides of the cranium Sagittal suture midline articulation point of the two parietal bones Coronal suture point of interaction of parietals with frontal bones Temporal Bone (2) Inferior to parietal bone on lateral skull Four major parts: Squamous region adjacent to the parietals Zygomatic process bridgelike projection joining the zygomatic bone (cheekbone) anteriorly, forming zygomatic arch Mandibular fossa rounded depression on the inferior surface of the zygomatic process, point where mandibular condyle of the mandible (lower jaw) joins the cranium Tympanic region surrounds the external ear opening. External auditory meatus canal leading to eardrum and middle ear Styloid process needlelike projection inferior to external auditory meatus; attachment point for muscles and ligaments of the neck Mastoid region area posterior to the ear Mastoid process rough projection inferior and posterior to external auditory meatus; attachment site for muscles Petrous region forms the lateral portion of the skull base Occipital Bone most posterior bone of the cranium, forms floor and back wall Foramen magnum large opening in base of occipital, which allows the spinal cord to join with the brain Occipital condyles rounded projections lateral to the foramen magnum that articulate with the facets of the 1st cervical vertebrae atlas Sphenoid Bone bat-shaped bone forming the anterior plateau of the middle cranial fossa across the width of the skull Ethmoid Bone irregularly-shaped bone anterior to the sphenoid; forms