Skeletal System - Copy.pdf

KIRSI IRISH SULIT, RRT OBJECTIVE Explain the functions of the skeletal system Composition of the bones – Extracellular matter – Cellular component Factors that affects the growth and maintenance Identify the four principal types of bones and name the major bones in the human body, i...

KIRSI IRISH SULIT, RRT OBJECTIVE Explain the functions of the skeletal system Composition of the bones – Extracellular matter – Cellular component Factors that affects the growth and maintenance Identify the four principal types of bones and name the major bones in the human body, including their names and locations.  COMPOSED OF: Bones- made of connective tissue reinforced with calcium and specialised cells. Cartilage-a strong, flexible connective tissue that protects your joints and bones Joints-the part of the body where two or more bones meet to allow movement Ligaments-bands of tough elastic tissue around your joints.  SUPPORT: Hard framework that supports and anchors the soft organs of the body. PROTECTION: Surrounds organs such as the brain and spinal cord. MOVEMENT: Allows for muscle attachment therefore the bones are used as levers. STORAGE: Minerals and lipids are stored within bone material. BLOOD CELL FORMATION: The bone marrow is responsible for blood cell production. Bone Markings Bone Surface is not smooth, but shows: Bone markings which reveal where: -muscles, tendons, and ligaments attatched -nerves and blood vessels pass *bone marking may be: 1-projections or processes or 2-depressions or cavities  Compact bone – Outer layer of bone, very hard and dense. – Organized in structural units called Haversian systems. – Matrix is composed of Ca salts (Ca carbonate and Ca phosphate) – Osteocytes – living bone cells that live in matrix. Porous (Spongy) bone – Located in the ends of long bones. – Many spaces that are filled with red bone marrow which produces bone cells.  Spongy bone – Trabeculae – needle-like threads of spongy bone that surround the spaces. Add strength to this portion of the bone. Cartilage – Matrix is a firm gel with chondrocytes suspended in the matrix.  Classification of Bones Long bones Typically longer than wide Have a shaft with heads at both ends Contain mostly compact bone Examples: Femur, humerus Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Classification of Bones Short bones Generally cube-shape Contain mostly spongy bone Examples: Carpals, tarsals Classification of Bones on the Basis of Shape Figure 5.1 Classification of Bones Flat bones Thin and flattened Usually curved Thin layers of compact bone around a layer of spongy bone Examples: Skull, ribs, sternum Classification of Bones Irregular bones Irregular shape Do not fit into other bone classification categories Example: Vertebrae and hip Gross Anatomy of a Long Bone Diaphysis Shaft Composed of compact bone Epiphysis Ends of the bone Composed mostly of spongy bone Figure 5.2a Structures of a Long Bone Periosteum Outside covering of the diaphysis Fibrous connective tissue membrane Sharpey’s fibers Secure periosteum and underlying bone Arteries Supply bone cells Figure 5.2c with nutrients Structures of a Long Bone Articular cartilage Covers the external surface of the epiphyses Made of hyaline cartilage Decreases friction at joint surfaces Figure 5.2a Structures of a Long Bone Medullary cavity Cavity of the shaft Contains yellow marrow (mostly fat) in adults Contains red marrow (for blood cell formation) Figure 5.2a Microscopic Anatomy of Bone Osteon (Haversian System) A unit of bone Central (Haversian) canal Opening in the center of an osteon Carries blood vessels and nerves Perforating (Volkman’s) canal Canal perpendicular to the central canal Carries blood vessels and nerves Microscopic Anatomy of Bone Figure 5.3 Microscopic Anatomy of Bone Lacunae Cavities containing bone cells (osteocytes) Arranged in concentric rings Lamellae Rings around the central canal Sites of lacunae Figure 5.3 Microscopic Anatomy of Bone Canaliculi Tiny canals Radiate from the central canal to lacunae Form a transport system Figure 5.3 Changes in the Human Skeleton In embryos, the skeleton is primarily hyaline cartilage During development, much of this cartilage is replaced by bone Cartilage remains in isolated areas Bridge of the nose Parts of ribs Joints  Bone Growth Epiphyseal plates allow for growth of long bone during childhood New cartilage is continuously formed Older cartilage becomes ossified Cartilage is broken down Bone replaces cartilage Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Bone Growth Bones are remodeled and lengthened until growth stops Bones change shape by gravity &muscle pull Bones grow in width through periostium Long Bone Formation and Growth Figure 5.4a Types of Bone Cells Osteocytes Mature bone cells Osteoblasts Bone-forming cells Osteoclasts Bone-destroying cells Break down bone matrix for remodeling and release of calcium (Resorption) Bone remodeling is a process by both osteoblasts and osteoclasts FACTORS THAT AFFECT BONE GROWTH AND MAINTENANCE HEREDITY- genes plays a big factor in the skeletal system. Some of these genes affects the growth. Also some genetic abnormality can be passed down. Ex: Osteogenensis Imperfecta, Fibrous Dysplasia etc. NUTRITION- these are the raw materials of which our bone made off, any defficiency from any of these minerals may affects the growth and maintenance of the bone. FACTORS THAT AFFECT BONE GROWTH AND MAINTENANCE Hormones-make important contribution in bone growth and maintenance. These hormones help regulate cell division, protein synthesis, calcium metabolism and energy production (refere to table 6-1 for their specific function) Exercise or stress- for bones, exercise means bearing certain weight which bones are specialized to do, without these bones will eventualy lose calcium faster the it is replaced (refer to table 6-2: Osteoporosis)  Closed fracture (simple): skin is intact Open fracture (compound): skin is open Greenstick : bone splits longitudinall(children’s are prone to this) Comminuted: two or more intersecting breaks create several fragments Impacted: broken bones are forced into one another: many fragments created Pathologic: bones breaks w/o apparent trauma; bone disorders Fractures Fracture reduction : 1-closed reduction ,no surgery is needed 2-open reduction ,surgery is needed (ORIF-Open Reduction Internal Fixation )  Healing time for simple fracture is 6-8 weeks (longer in elderly people) It occurs in FOUR major events 1-hematoma formation 2-fibrocartilage callus formation 3-bony callus formation 4-bone remodelling  Axial division – Skull and associated bones Auditory ossicles Hyoid bones – Vertebral column – Thoracic cage(Ribs+ sternum) Appendicular division -Pectoral girdle -Pelvic girdle  Axial division – Skull and associated bones:  Auditory ossicles  Hyoid bones – Vertebral column – Thoracic cage Ribs + sternum  Sutures – Immovable joints that join skull bones together Form boundaries between skull bones Four sutures: – Coronal – between parietal and frontal – Sagittal– between parietal bones – Lambdoid – between the parietal and occipital – Squamous – between the parietal and temporal ✓Fontanels – usually ossify by 2 years of age  Sagittal Frontal (Coronal) Squamous Lambdoid Sutures  The Adult Skull skull = 22 bones cranium = 8 bones: frontal, occipital, 2 temporals, 2 parietals, sphenoid and ethmoid facial bones = 14 bones: nasals, maxillae, zygomatics, mandible, lacrimals, palatines, inferior nasal conchae, vomer. skull forms a larger cranial cavity -also forms the nasal cavity, the orbits, paranasal sinuses mandible and auditory ossicles are the only movable skull bones cranial bones also: attach to membranes called meninges -stabilize positions of the brain, blood vessels -outer surface provides large areas for muscle attachment that move the head or provide facial expressions Bones of the Cranium  Frontal Parietal Temporal Nasal Vomer Zygoma Maxilla Mandible Frontal View  Frontal Parietal Sphenoid Nasal Temporal Zygoma Occipital Maxilla Mastoid Process Mandible External Auditory Meatus Lateral View Nasal (2) Maxillae (2) Zygomatic (2) Mandible (1) Lacrimal (2) Palatine (2) Inferior nasal conchae (2) Vomer (1)   part of the nasal complex  Paired cavities in ethmoid, sphenoid, frontal and maxillary  Lined with mucous membranes and open into nasal cavity though openings called ostia  Resonating chambers for voice, lighten the skull ◼ frontal sinuses  Sinusitis is inflammation of the membrane (allergy) ◼ sphenoid sinuses ◼ ethmoid sinuses  infection can easily spread from one sinus to the other ◼ maxillary through the nasal cavity  can also spread to other tissues http://www.wisc-online.com/objects/index.asp?objID=AP12104  26 vertebrae – 24 individual vertebrae – Sacrum – Coccyx Seven cervical vertebrae Twelve thoracic vertebrae Five lumbar vertebrae Sacrum and coccyx are Fused together.  Body – weight bearing  Vertebral arch – pedicles – laminae  Vertebral foramen  Seven processes – 2 transverse – 1 spinous – 4 articular  Smaller bodies  Larger spinal canal  1st and 2nd cervical vertebrae are unique – atlas & axis  All articulate with ribs  Have heart-shaped bodies  Each side of the body bears demifacets for articulation with ribs –Allows rotation and prevents flexion and extension  Bodies are thick and strong  Allows flexion and extension – rotation prevented  Forms the posterior wall of pelvis Formed from 5 fused vertebrae Superior surface articulates with L5 Inferiorly articulates with coccyx Figure 7.18a, b  Is the “tailbone” Formed from 3 – 5 fused vertebrae Offers only slight support to pelvic organs  Forms the framework of the chest Components of the bony thorax – Thoracic vertebrae – posteriorly – Ribs – laterally – Sternum and costal cartilage – anteriorly Protects thoracic organs Supports shoulder girdle and upper limbs Provides attachment sites for muscles Figure 7.19a  Formed from three parts : – Manubrium – superior part Articulates with medial end of clavicles – Body – bulk of sternum Sides are articulate for costal cartilage of ribs 2–7 – Xiphoid process – inferior end of sternum Ossifies around age 40  All ribs attach to vertebral column posteriorly – True ribs - superior seven pairs of ribs Attach to sternum by costal cartilage – False ribs – inferior five pairs of ribs ,attach indirectly to the sternum –floating ribs ribs 11–12 are short and free anteriorly.  Abnormal spinal curvatures – Scoliosis – an abnormal lateral curvature – Kyphosis – an exaggerated thoracic curvature – Lordosis – an inward lumbar curvature – “swayback” Stenosis of the lumbar spine – A narrowing of the vertebral canal  Allows us to move and manipulate objects Includes all bones other than axial skeleton, it includes: – the limbs (upper & lower limbs) – the supportive girdles (pectoral &pelvic girdles) Figure 8–1  Also called the shoulder girdle Connects the arms to the body Positions the shoulders Provides a base for arm movement Figure 8–2a  Consists of: – 2 clavicles – 2 scapulae Connects with the axial skeleton only at the manubrium(claviculosternal joint) Figure 8–2b, c  Also called collarbones Long, S-shaped bones Originate at the manubrium (sternal end) Articulate with the scapulae (acromial end)  Also called shoulder blades Broad, flat and triangular Articulate with arms and collarbone Figure 8–3a  Arms, forearms, wrists, and hands Note: arm (brachium) = 1 bone, the humerus Figure 8–4  Also called the arm The long, upper armbone Articulates with the pectoral girdle Figure 8–5  Also called the antebrachium Consists of 2 long bones: –ulna (medial) –radius (lateral) Figure 8–6 ◦8 carpal bones: 4 proximal carpal bones 4 distal carpal bones allow wrist to bend and twist  The 5 long bones of the hand  Numbered I–V from lateral (thumb) to medial  Articulate with proximal phalanges  Thumb: ◦2 phalanges (proximal, distal)  Fingers: ◦3 phalanges (proximal, middle, distal)  Consists of 2 ossa coxae, the sacrum, and the coccyx  Stabilized by ligaments of pelvic girdle, sacrum, and lumbar vertebrae Figure 8–7  Also called hipbones Strong to bear body weight &stress of movement Each is made up of 3 fused bones: – ilium (articulates with sacrum) – ischium – pubis  Also called the hip socket Is the meeting point of the ilium, ischium, and pubis Articulates with head of the femur (Hip joint)) Figure 8–8 Figure 8–9  Female pelvis: –smoother –lighter –less prominent muscle and ligament attachments Figure 8–10  Enlarged pelvic outlet Broad pubic angle (> 100°) Less curvature of sacrum and coccyx Wide, circular pelvic inlet Broad, low pelvis Ilia project laterally, not upwards  Functions: ◦weight bearing ◦motion Note: leg = lower leg; thigh = upper leg  Femur (thigh) Patella (kneecap) Tibia and fibula (leg) Tarsals (ankle) Metatarsals (foot) Phalanges (toes) Figure 8–11  Also called the kneecap Formed within tendon of quadriceps femoris Figure 8–13  Also called the shinbone Supports body weight Larger than fibula Medial to fibula The Fibula Attaches muscles of feet and toes Smaller than tibia Lateral to tibia  Talus: Calcaneus (heel bone): – transfers weight to ground – attaches Achilles tendon  Also called the tarsus: – consists of 7 tarsal bones Figure 8–14a  5 long bones of foot Numbered I–V, medial to lateral Articulate with toes  Phalanges: – bones of the toes Hallux: – big toe, 2 phalanges (distal, proximal) Other 4 toes: – 3 phalanges (distal, medial, proximal)  Arches transfer weight from 1 part of the foot to another Figure 8–14b  Bones are arranged to form THREE strong arches, 2 longitudinal (medial & lateral)& 1 transverse  Ligaments & tendons help to hold the bones firmly in the arched position but still allow a certain amount of spriginess  Week arches are referred to as flat foot Articulations (Joints)  Holds bones together Allows bones to move All bones articulate with at least one other bone except the hyoid.  Functional classification: focuses on the amount of movement (synarthrosis, amphiarthrosis and diarthrosis) Structural classification:based on whether Fibrous, Cartilage or a joint cavity separates the bony regions at the joint. As a general rule, fibrous joints are immovable and synovial joints are freely movable.  Synarthroses No movements – Primarily axial skeleton – Bones connected with fibrous tissue ligament – Examples: Skull sutures and distal Tibia/Fibula  Amphiarthroses – Slightly movable – Axial skeleton – Connected by cartilage – Intervertebral joints, pubic symphysis  Diarthroses – freely movable – Also called synovial (fluid filled joint cavity) – Primarily found in the limbs – Plane of movement depends on the joint 1. Articular cartilage: hyaline 2. Joint Cavity: space filled with lubricating fluid 3. Fibrous Capsule: fibrous CT lined with a smooth synovial membrane 4. Reinforcing Ligament: can be inside or outside the joint capsule 5. Synovial Fluid: viscous and lubricating 6. Tendons sheath an elongated bursa that rapes around a tendon subjected to friction. 7. Menisci: cartilaginous discs  Dislocation: Bone is forced out of its position, Reduction is done by experts only Sprain: excessive stretch on a ligament Arthritis: inflammation of joints, may be -Acute: usually bacterial -Chronic: Rheumatoid ,Osteoarthritis and Gouty arthritis