Skeletal System Unit 6.4 (6 th Edition) Chapter 7.4 (7 th Edition) 1
Learning Objectives Understand the five functions of bones (physiology) Classify the four major types of bones Identify the major parts (anatomy) of a bone Identify the components of the axial and appendicular divisions of the skeleton Identify the main bones of the human skeleton Identify major joints and describe their motion Describe the main diseases of the skeletal system (pathophysiology) Distinguish between the major bone fractures 2
Fun Facts About the Human Skeleton Adult humans have 206 bones You are born with 300 bones Bones fuse together as you age As human develops in mother s womb, majority of skeleton is cartilage, not yet ossified bone The strongest and longest bone in the femur (thigh) The smallest bone is the stapes bone in the ear Ounce for ounce, bone is stronger than steel and reinforced concrete However, in a given year, doctors around the world treat tens of millions of broken bones! One out of 20 people have an extra rib 3
26 bones in head eventually fuse together with the exception of the mandible. 4
Cervical Rib attaches posteriorly at C7 and can be floating Or attach anteriorly to the first rib. 5
Bone Functions (Physiology) Framework support the body s muscles, fat, and skin Protection surround vital organs to protect them Levers muscles attach to bones to help provide movement Blood Cell Production produce red and white blood cells and platelets Storage store most of calcium supply of body 6
Types of Bones 7
Bone Anatomy Diaphysis long shaft of bone medullary cavity contains yellow marrow (fat cells) Epiphysis ends of long bone contains red marrow Red Marrow produces red blood cells produces platelets some white blood cells used to diagnose blood diseases Periosteum tough membrane on outside of bone aids in bone growth, repair, nutrition 8
Two Divisions of the Skeleton Axial Skeleton main trunk of body skull spinal column ribs breastbone Appendicular Skeleton extremities of body shoulder girdle arm bones pelvic girdle leg bones 9
Bones of the Skull Know the Yellow Highlighted Bones 10
Division of Spinal (Vertebral) Column Spinal Column made of 26 bones called vertebrae bones protect spinal cord provide support for head and trunk Intervertebral Disks pads of cartilage tissue separate the vertebra act as shock observers permit bending & twisting motion 11
Increase Mobility Decreased Stability Cervical smaller, more mobile Thoracic larger, less mobile Lumbar largest, minimal mobility 12
Ribs & Breastbone Ribs 12 pairs called costae attached to thoracic vertebrae on dorsal surface True Ribs first 7 pairs of ribs attached directly to sternum on front of body False Ribs next 5 pairs of ribs first three pairs of false ribs attach to cartilage of the rib above last two pairs of false ribs are called floating ribs because they do not attach to front of body 13
Bones of the Skeleton 14
Joints Joints areas where 2+ bones join Ligaments connective tissue bands help hold long bones at joints Tendons tough connective tissue cords one way skeletal muscles attach to bone Four Main Types of Joints classified according to degree of movement arthr/o = joint diarthroses- moveable (hip, elbow, knee) amphiarthroses- partially moveable (ribs to vertebrae) synarthroses- immoveable (cranium) 15
Diathroses (Moving) Joints Three Major Joint Parts articular cartilage bursa (joint capsule) synovial (joint cavity) Ball and Socket shoulders, hips Hinge knees, elbows Pivot radius, ulna Gliding vertebrae 16
Diseases & Abnormal Conditions Arthritis inflammation of the joints Osteoarthritis most common form of arthritis chronic disease due to aging commonly affects knees and hips symptoms are stiffness, pain, aching, limited range of motion no cure, but treatments include: anti-inflammatory medications, heat/ cold application, steroid injections, and rest Rheumatoid arthritis affects joints and connective tissues 3 times more common in women than men occurs between 35 and 45 years of age can case scar tissue formation and atrophy of bone and muscle tissue results in deformity and immobility rest, anti-inflammatory medications, and surgery 17
Diseases & Abnormalities Continued Bursitis inflammation of bursae (small, fluid-filled sacs surrounding joints) common in shoulders, elbows, hips, or knees Dislocation when bone is forcibly displaced from a joint common in shoulders, fingers, knees, and hips Sprain twisting action tears ligaments at joint common in wrists and ankles Osteomyelitis bone inflammation usually caused by pathogenic organism abscess is formed within the bone and accumulation of pus Osteoporosis increased porosity or softening of bones caused by hormone deficiency lack of calcium, and sedentary lifestyle Ruptured (Herniated) Disk occurs when an intervetrebral disk ruptures/protrudes out of place 18
Abnormal Curvatures of the Spine Causes poor posture congenital (at birth) defects structural defects of vertebrae malnutrition Kyphosis hunchback or rounding of spine at the back of thoracic area Scoliosis side-to-side, or lateral, curvature Lordosis swayback inward curvature of lumbar region 19
Bone Fractures Definition crack or break in a bone Greenstick bone bends & is split causing a crack/incomplete break common in kids Simple or Closed complete break of the bone with no damage to skin Compound or Open bone breaks and ruptures through the skin with increased infection risk Impacted broken bone ends jam into each other Comminuted bone fragments/splinters into 2+ pieces Spiral bone twists and results in one or more breaks Depressed broken piece of skull bone moves inward Colles breaking and dislocation of distal radius that causes bulge at wrist 20
Bone Fractures Continued 21