Unit 2 Skeletal System Part 1A (2) PDF

Unit 2: Skeletal System Objectives Identify major bony landmarks Summarize bone tissue Differentiate between axial and appendicular skeleton Describe three main types of joints Identify examples of 6 synovial joints Review Skeleton is made of cartilage and bone ○ Cartilage: con...

Unit 2: Skeletal System Objectives Identify major bony landmarks Summarize bone tissue Differentiate between axial and appendicular skeleton Describe three main types of joints Identify examples of 6 synovial joints Review Skeleton is made of cartilage and bone ○ Cartilage: connective tissue that gives flexibility ○ Bone: hard form of connective tissue Support Protection Movement Storage Blood Supply Production Review Bones are covered in periosteum ○ Nourish the external portion of skeletal tissue ○ Provide attachment site for ligaments and tendons Bone types: ○ Compact Dense, hard, tightly packed tissue Found in shafts of long bones and outer layer of other bones Contains units called osteons (haversian systems) Contain mature bone cells (osteocytes) that form concentric circles around a central (haversian) canal, containing blood vessels ○ Spongy Arranged in bars and plates called trabeculae Irregular holes between trabeculae make the bone lighter and provide space for red bone marrow, which produces red blood cells Review Bone types: ○ Long Bones ○ Flat Bones ○ Irregular ○ Sesamoid Bone Development ○ Ossification starts in embryonic period (8 weeks) ○ Finishes around age 20 Review Vasculature and Innervation ○ High level of vascularization Enters through nutrient foramina to supply the bone marrow, spongy bone, and deep portions of compact bone Osteocytes are supplied through the haversian system ○ Innervation Periosteum is supplied by fibers that can carry pain signals Inside of the bone limited amount of fibers that can detect pain Vasomotor fibers regulates blood flow through the bone marrow https://app.jove.com/embed/player?id=10863&t=1&s=1&fpv=1 https://app.jove.com/embed/player?id=14150&t=1&s=1&fpv=1 Regional Anatomy The Skeleton (1 of 2) Two main sections of the skeleton ○ Axial skeleton Bones of the bony thorax, spinal column, hyoid bone, bones of the middle ear, and skull; they protect the body organs and total 80 bones The Skeleton (2 of 2) Two main sections of the skeleton ○ Appendicular skeleton Bones of your arms, legs, hips, and shoulders and total 126 bones ○ Half of the bones in your body are found in the hands and feet. Figure 6–10 Axial Skeleton Axial Skeleton Axial Skeleton Ribs Ribs The Spinal Column (2 of 4) The individual bones (vertebrae) are numbered and classified according to the body region in which they are located. ○ 7 cervical vertebrae, 12 thoracic, 5 lumbar, 5 sacral (mid-buttocks), and 3 to 5 coccygeal (tailbone) Learning Hint To remember the number of vertebrae in each region, think of 7 days in a week for cervical, 12 months in a year for thoracic, and 5 vertebrae in the lumbar area—the same as the number of digits on your hand. Another way of remembering is you have breakfast at 7 (cervical), lunch at 12 (thoracic), and dinner at 5 (lumbar). Figure 6–13 The Spinal Column (3 of 4) Spinal curvature ○ Initial curvature begins in the newborn period. It is concave, like a fetal position. ○ Curvature changes as infant learns to hold its head up and begin to walk, curving in the opposite direction. The Spinal Column (4 of 4) Spinal curvature ○ From about age 2 onward, the vertebral column will present with a secondary curvature in the neck, primary in the upper back, secondary in the lower back, and primary in the mid buttocks and tail bone region. Appendicular Skeleton Upper and Lower Extremities (1 of 5) The appendicular region consists of the arms and legs. These areas perform most of the body’s movement. Upper and Lower Extremities (2 of 5) The arms and legs are of similar construction. ○ One large bone humerus in the arm; femur in the legs) ○ Two smaller bones in the forelimb (radius and ulna in the arms; tibia and fibula in the legs) ○ Multiple bones (carpals in the wrist; tarsals in the ankle) Upper and Lower Extremities (3 of 5) The arms and legs are of similar construction. ○ Five single bones (metacarpals in the hand; metatarsals in the foot) and digits made of multiple bones (phalanges) Upper and Lower Extremities (4 of 5) Both the arms and legs are attached to the axial skeleton via the pectoral and pelvic girdles, respectively. ○ Pectoral girdle consists of the clavicle and scapula ○ Pelvic girdle consists of the pelvic bones (ischium, ilium, and pubis) Upper and Lower Extremities (5 of 5) The pelvic girdle is different for women than men. ○ Women have a greater pubic angle that facilitates childbirth and a broad girdle to support the weight of the growing fetus. Pelvis and Shoulder Pelvis and Shoulder Hand Foot Bony Landmarks Bony Landmarks Cartilage and Ligaments Cartilage ○ Dense connective tissue Joint ○ Articulation between bones Ligaments ○ Connects bone to bone https://app.jove.com/embed/player?id=14058&t=1&s=1&fpv=1 Cartilage (1 of 2) A special form of dense connective tissue that can withstand a fair amount of flexing, tension, and pressure. ○ Examples: flexible parts of the nose and ears Makes a flexible connection between bones ○ Examples: between ribs and sternum, allowing chest flexion during deep breathing Cartilage (2 of 2) Acts as a cushion between bones. ○ Articular cartilage on ends of bones acts as a shock absorber, preventing the ends from grinding together ○ Bursa, secretes a lubricant called synovial fluid Figure 6–7 Joint types Synovial Joints ○ Surrounded by a joint capsule and lined with synovial fluid Fibrous Joints ○ Bones united by a fibrous tissue ○ Typically limited amount of movement Cartilaginous Joints ○ Give shock and absorption as well as flexibility https://app.jove.com/embed/player?id=14152&t=1&s=1&fpv=1 https://app.jove.com/embed/player?id=14059&t=1&s=1&fpv=1 Synovial Joints Plane Joints ○ Gliding or sliding Hinge Joints ○ Only Flexion and Extension movement Saddle Joints ○ Allows movement in 2 planes Condyloid Joints ○ flexion and extension, aDDuction and ABduction, circumduction Ball and Socket Joints ○ Movement in all planes Pivot Joints ○ Rotation Joints and Ligaments (1 of 10) Joint (articulation) ○ Necessary for movement ○ Place where two or more bones join together Ligaments ○ Permit joints to move ○ Tough, whitish bands that connect bone to bone Not same as tendons, which connect muscle to bone Joints and Ligaments (2 of 10) Joints may be classified by function ○ Immobile Skull sutures ○ Can move a little Pubic symphysis ○ Can move freely Elbow Joints and Ligaments (3 of 10) Joints may be classified by structure based on type of connective tissue. Fibrous joints ○ Held together by short connective tissue strands ○ Either immobile or slightly movable Example: sutures in the skull Joints and Ligaments (4 of 10) Cartilaginous joints ○ Held together by cartilage ○ Either immobile or slightly movable Examples: pubic symphysis and joints between the ribs and sternum Joints and Ligaments (5 of 10) Synovial joints ○ Joined by a joint cavity lined with a synovial membrane and filled with synovial fluid ○ All synovial joints are freely moving. Joints and Ligaments (6 of 10) Gliding joints ○ Flat, or slightly curved, plate-like bones found in your wrists and ankles ○ Slide back and forth Hinge joints ○ Found in knees and elbows ○ Typically one bone is cylindrical and other is a trough ○ Can either open or close Joints and Ligaments (7 of 10) Saddle joints ○ One bone shaped like a saddle and another bone similar to a horse’s back ○ Found in the base of the thumb ○ Rock up and down and side to side Joints and Ligaments (8 of 10) Ellipsoidal (condyloid) joints ○ Provide two axes of movement through the same bone, like the joint formed at the wrist with both the radius and ulna ○ Example: knuckles of the fingers Joints and Ligaments (9 of 10) Pivot joints ○ Act like a turnstile; can only rotate ○ A circular portion of one bone spins inside a ring- shaped portion of the other ○ Found in neck and forearm Joints and Ligaments (10 of 10) Ball-and-socket joints ○ Spherical articulation with cup-shaped socket on the other bone ○ Hips and shoulders ○ Can perform all types of movement, including rotation Figure 6–8 Movement Classifications (1 of 5) Flexion ○ Bending a joint and decreasing the angle between involved bones Extension ○ Straightening a joint Plantar flexion ○ Pointing toes down Movement Classifications (2 of 5) Dorsiflexion ○ Bending the foot up toward the body Abduction ○ Moving away from the body’s midline Adduction ○ Moving toward the midline of the body Movement Classifications (3 of 5) Inversion ○ Turning a foot inward toward the other foot Eversion ○ Turning a foot outward away from the opposing foot Movement Classifications (4 of 5) Supination ○ Turning a hand palm up Pronation ○ Turning a hand palm down Movement Classifications (5 of 5) Protraction ○ Drawing a part forward Retraction ○ Drawing backward Circumduction ○ Circular arm movement of a pitcher Rotation ○ Spinning on axis Figure 6–9 Planes of Motion Sagittal Plane: Cuts the body into left and right halves. Forward and backward movements. Coronal (or Frontal Plane): Cuts the body into front and back halves. Side-to-side movements. Transverse Plane: Cuts the body into top and bottom halves. Twisting movements. https://app.jove.com/embed/pl ayer?id=13858&t=1&s=1&fp v=1