Musculoskeletal System (Part A-2) Module 7 -Chapter 10 Overview Muscles Attachments Bones Bone types Surface features of bones Divisions of the skeletal system Joints or Articulations Susie Turner, M.D. 1/8/13 Sternum Bones of Thorax (Rib Cage) Breastbone Ribs (12 pairs attached to spine) 1-7 are True ribs Attached directly to sternum 8-12 are False ribs Do not attach directly to sternum Floating ribs (11,12) Not attached at all 1
Vertebral Column Formed from 26 vertebrae Support body Provides protective canal for spinal cord Attachment site for ribs and muscles Consists of vertebrae, sacrum, and coccyx Separated by intervertebral discs Vertebrae Vertebra Building blocks of spine Vertebral arch Posterior part that protects the spinal cord. Vertebral foramen Hole for spinal cord Intervertebral foramen Hole formed between 2 vertebrae Spinal nerves pass here. 2
General Structure of the Vertebrae (Compare to the structure of a house-walls, roof & basement) a. Pedicles (walls) b. Lamina (roof) Protects cord from back c. Spinal process (chimney) Can feel thru skin d. Transverse process (window air units) Protrudes horizontally on both sides e. Body (basement) Circular main area that is weight bearing. Intervertebral Discs Flat round plates between vertebra For cushioning Two components Anulus fibrosus Outer rings made of fibers & cartilage Nucleus pulposus Gelatinous center 3
Vertebral Sections & Numbers Cervical Neck 7 C1 (atlas) Supports skull Allows you to nod head yes C2 (axis) Allows you to nod no Thoracic Chest 12 Supports chest & serves as an articulation point for the ribs Lumbar Lower back 5 Carries most of the weight of the torso Sacral High butt 5 fused Coccygeal Tailbone 4 fused Appendicular Skeleton Composed of 126 bones Includes appendages & the pectoral, and pelvic girdle Attach the limbs to the axial skeleton. Enables the body to move your limbs 4
Upper Extremity Bones Clavicle Scapula Humerus Radius Ulna Carpals Metacarpals Phalanges Shoulder Girdle Formed by the Clavicle & Scapula Clavicle (2) Collar bone Scapula (2) Shoulderblade Pectoral Girdle 5
Upper Limb Humerus Bone of arm Radius/Ulna Bones of forearm Carpals (8) Bones of wrist Metacarpals Hand (Palm area) Roman Numerals I-IV Phalanges/Digits Thumb Pollex Thumb First Finger Index Fifth Finger Little Finger Digiti Minimi Hand & Fingers 6
Bones of the Lower Extremity Hip Bones or Os Coxae Ilium Ischium Pubis Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges Pelvis Includes hip bones plus sacrum and coccyx Does not mean same as pelvic girdle 7
Pelvic Girdle Composed of 2 Hip Bones or Os Coxae Also called Innominate Bone Means No name Each composed of 3 bones that fuse together in childhood. Ilium Ischium Pubis The Pelvic (Hip) Girdle Supports the trunk Protects the abdominal organs within its basin Attaches the lower extremities to the body 8
Pelvic Girdle Symphysis Pubis Joint where 2 pubic bones come together Acetabulum Name for deep socket of hip joint. Means little vinegar cup Differences in Female and Male Pelvis Male Pelvis Female Pelvis Female Pelvis Differs from male in size and shape Shallower but wider in all directions Specialized in child bearing Male Pelvis Female Pelvis 9
Lower Extremity Femur Bone of the thigh Longest, largest & strongest bone of body Patellae Kneecap Protects the knee joint Tibia/Fibula Bones of the leg Tibia Shinbone Fibula Small Lateral bone Ankle Tarsal Bones-7 Calcaneous Heel bone Largest Tarsal Bone Metatarsals Roman Numbers I- IV Phalanges/Digits Toes Big Toe Hallux Ankle & Foot 10
Articulations Joints Allow for body movement Point where bones meet Various degrees of mobility Classification of Joints Based on amount of mobility at joint 3 types Synarthroses Immovable joints Ex; Skull sutures Amphiarthroses Slightly movable joints Ex; Between ribs & sternum Diarthrosis Freely movable joints Ex; Knee joints 11
Synovial Joint All diarthrotic joints also synovial joints Contain a joint cavity & synovial membrane Synovial Membrane Secretes synovial fluid for lubrication & nutrition of joint cartilage. Joint Capsule Sleeve-like extension of the periosteum Binds articulating bones together Ligaments Hold bones together Synovial Joint 12
Synovial Joint Bursae Flattened fibrous sacs Lined with synovial membrane Common at sites where ligaments, skin, muscles or tendons rub against a bone 13