Chapter 3 THE SKELETAL SYSTEM Structures and Functions

Chapter 3 THE SKELETAL SYSTEM

Structures and Functions of the Skeletal System Consists of… ◦Bones ◦Bone marrow ◦Cartilage ◦Joints ◦Ligaments ◦Synovial membrane & Synovial fluid ◦Bursa

Functions o. Bones act as framework of the body o. Support and protect the internal organs o. Joints+Muscles & Ligaments & tendons = movement o. Calcium stored in bones (needed for nerve and muscle function) o. Red bone marrow important in forming blood cells

Structure of a bone o. Periosteum: outermost covering o. Compact bone: Hard bone – outer o. Spongy one: lighter bone – inner o. Red bone marrow: within spongy bone, hemopoietic tissue, makes red/white blood cells, hemoglobin, thrombocytes o. Hem/o= blood, -poietic = pertaining to formation o. Yellow bone marrow: In spongy bone of medullary cavity of long bones – fat storage area

Cartilage o. Smooth rubbery connective tissue that acts as a shock absorber between bones. o. Outer ear and tip of nose o. Articular cartilage: ends of bones/joints

Anatomic Landmarks of Bones o. Diaphysis: shaft of long bone o. Epiphyses (ep-PIF-ih-seez): Wide ends of long bones. Singular - epiphysis o. Foramen: Opening in a bone through which blood vessels, nerves and ligaments pass o. Process: normal projection on the surface of a bone that serves as an attachment for a muscle or tendon.

Joints o. AKA Articulations o. Place of union between two or more bones.

Types of Joints Fibrous: Inflexible, AKA sutures; found in skull Cartilaginous (kar-tih-LADJ-ih-nus): only slight movement, bones connected entirely by cartilage. Found ribs/sternum, pubic bones Synovial: 2 bones articulate (come together) and move in a variety of directions ◦ Ball and socket: hips and shoulders ◦ Hinge: knees and elbows

Synovial Joints Synovial fluid: acts as a lubricant to make the movement smooth Ligaments: connect bone to bone/cartilage Bursa: sac that acts as a cushion to ease movement in areas of high friction like the shoulder, elbow, knee

The skeleton Axial Skeleton includes 80 bones of the… ◦ Skull ◦ Ossicles of the middle ear ◦ Hyoid bone (throat between chin and thyroid) ◦ Rib cage ◦ Vertebral column Appendicular skeleton includes 126 bones … ◦ Upper extremities (shoulders, arms, forearms, wrists and hands ◦ Lower extremities (hips, thighs, legs, ankles, feet)

Bones of the skull 8 bones of the cranium (part of the skull that protects the brain) Frontal (1) Parietal (2) Occipital (1) Temporal (2) (has the external auditory meatus… ear holes) Sphenoid (1) Ethmoid (1)

Bones of the face Nasal bones (2) Zygomatic bones (2) Maxillary bones (2) Palatine (2) Lacrimal (2) Mandible (1) (Only movable bone of the skull) ALSO: Inferior conchae (2) and Volmer (1)

Thoracic Cavity (AKA Rib Cage) 1. Ribs (costals) 2. Sternum(breast bone) ◦Upper: Manubrium ◦Middle: Sternum body ◦Lower: Xiphoid process (cartilage) 3. Upper spinal column from neck to the diaphragm

Shoulders (pectoral girdle) and Arms Clavicle (collar bone) Scapula (shoulder blade) ◦ Acromion – extension of the scapula that forms the high point of the shoulder Humerus Radius- Thumb side Ulna – Pinkie side ◦ Olecranon (oh-LEK-rah-non) process (funny bone) upper end of ulna, forms point of elbow.

Wrists, hands and fingers Carpals (8) ◦wrist Metacarpals (5) ◦Palms of hands Phalanges (14) ◦fingers

Spinal Column AKA vertebral column 26 vertebrae (VER –the-bray singular: vertebra VER-the-bruh) Cervical (First set of 7) ◦ C 1 -C 7; form neck Thoracic (second set of 12) ◦ T 1 -T 12; ribs attached here Lumbar (Third set of 5) ◦ L 1 -L 5; inward curve of the lower spine Sacrum: Triangle shaped bone at base of spine Coccyx: Tailbone

Structure of Vertebrae o. Anterior portion AKA body of the vertebra – solid – provides strength o. Posterior AKA lamina – attachment points for muscles and tendons o. Vertebral foramen – opening in the middle for spinal cord o. Intervertebral Disks made of cartilage, cushion and absorb shock between vertebrae

Pelvic Girdle Pubic Bones: 3 bones fused together after birth ◦ Ilium (hips) ◦ Ischium (sit bones) ◦ Pubis (below bladder) Pubic symphysis ◦ Cartilaginous joint connecting R and L pubic bones Acetabulum AKA hip socket ◦ Large circular cavity on each side of pelvis that articulates with the head of the femur to form the hip joint

Legs and Knees Femur (thigh bone) Knees ◦ Patella (kneecap) ◦ Popliteal space – behind the knee Lower legs ◦ Tibia (shinbone, larger) ◦ Fibula (smaller) Malleoli (singular malleolus) ◦ Rounded bony projection on the tibia and fibula on the sides of each ankle joint.

Feet and Toes Tarsals (7 - ankle bones) ◦Talus (articulates with tibia and fibula ◦Calcaneus (heel bone) ◦ Largest tarsal Metatarsals (foot bones where toes are attached) Phalanges (toes)

Medical Specialties Orthopedic surgeon ◦ Physician specializing in the dx and tx of diseases and disorders of bones, joints and muscles ◦ Orth/o straight/normal/correct, ped foot, ic pertaining to Podiatrist ◦ Physician specializing dx and tx of the foot ◦ Pod foot, -iatrist specialist

Pathology of Joints Arthrosclerosis – Stiffness of the joints often seen in elderly Chondromalacia – abnormal softening of cartilage ◦ Chondr/o cartilage, -malacia abnormal softening Chondroma – slow-growing benign tumor of cartilage ◦ Chondr cartilage, -oma tumor Costochondritis – Inflammation of the cartilage that connects to the sternum ◦ Cost/o rib, chondr cccartilage, -it is inflammation

More Joint Pathology Hallux valgus (HAL-ucks VAL-guss) – AKA bunion; abnormal enlargement of the joint at the base of the great toe Synovitis: Inflammation of the synovial membrane – d/t arthritis, trauma or infection Hemarthrosis – blood within a joint ◦ Hem blood, arthr joint, -osis abnormal condition/disease Subluxation- partial displacement of a bone from its joint Dislocation – Complete displacement of a bone from its joint

Arthritis Osteoarthritis “OA” (AKA wear and tear arthritis) – wearing away of articular cartilage in joints ◦ Oste/o bone, arthr joint, -itis inflammation Spondylosis – spinal osteoarthritis Spondyl - vertebrae, -osis - abnormal condition/disease Gouty Arthritis – AKA gout – excess uric acid deposits in feet/leg joints Rheumatoid arthritis “RA” chronic autoimmune disorder in which the joints and some organs of other body systems are attacked Ankylosing spondylitis – form of RA – inflammation of joints between vertebrae Juvenile RA – Autoimmune disorder affecting children <16 yrs old.

Spinal Column Lumbago - low back pain ◦ Lumb lumbar, -ago diseased condition Spondylolisthesis- forward slipping movement of the body of one of the lower lumbar vertebrae on the vertebrae below it. ◦ Spondyl/o vertebrae, -listhesis slipping Spina bifida – congenital defect that occurs during early pregnancy when the spinal canal fails to close completely around the spinal cord to protect it.

Curvatures of the Spine Kyphosis (AKA humpback or dowager’s hump) ◦ Abnormal increase in the outward curvature of the thoracic spine ◦ Kyph hump, -osis abnormal condition/disease Lordosis (AKA swayback) ◦ Abnormal increase in the forward curvature of the lumbar spine ◦ Lord bent backward, -osis abnormal condition/disease Scoliosis ◦ Abnormal lateral curvature of the spine ◦ Scoli curved, -osis abnormal condition/disease

Bones Craniostenosis – malformation of the skull due to premature closure of the cranial sutures ◦ Carni/o skull, -stenosis abnormal narrowing Fibrous Dysplasia – bone disorder of unknown cause that destroys normal bone structure and replaces it with fibrous (scarlike) tissue Osteitis (oss-tee-EYE-tis) – inflammation of the bone

Bones continued… Osteomalacia – AKA Adult rickets. Abnormal softening of bones in adults (usually caused by < vitamin D, calcium or phosphate) ◦ Oste/o bone, -malacia abnormal softening Osteomyelitis – inflammation of the bone marrow and adjacent bone. Often bacterial ◦ Oste/o bone, myel bone marrow, -itis inflammation

More bone pathology Osteonecrosis – death of bone tissue d/t insufficient blood supply ◦ Oste/o bone, -necrosis tissue death Paget’s disease – excessive breakdown of bone tissue, followed by abnormal bone formation. Periostitis (pehr-ee-oss-TYE-tis)– inflammation of the periosteum (shin splints) ◦ Peri- surrounding, ost bone, -it is inflammation Rickets – defective bone growth in children resulting from < Vitamin D Talipes (TAL-ih-peez) – AKA clubfoot – any deformity of the foot involving the talus (ankle bones)

Bone Tumors Primary bone cancer: rare malignant tumor that originates in the bone Secondary bone cancer: tumors in the bone caused by a metastasis from other organs (breast/lung cancer) Myeloma: cancer of red bone marrow ◦ Myel bone, -oma tumor Osteochondroma: benign bony projection covered with cartilage ◦ Oste/o bone, chondr cartilage, -oma tumor

Osteoporosis vs. Osteopenia Osteoporosis: marked loss of bone density and an increase in bone porosity often associated with aging (oste/o bone, por small opening, -osis abnormal condition) Osteopenia: Thinner than average bone density; makes the patient at risk for developing osteoporosis (oste/o bone, -penia deficiency)

Fractures related to osteoporosis Compression fracture (AKA vertebral crush fracture) bone is pressed together on itself. Spontaneous or from injury. Leads to pain, ↓ height, spinal curvature (dowager’s hump) Colles’ Fracture: wrist fracture caused when a person tries to stop a fall by landing on the hands Osteoporotic hip fracture (AKA broken hip) spontaneous or from a fall, complications can lead to ↓function, ↓ mobility, ↓ independence or death

Fractures Open (AKA compound) bone is broken and there is an open wound in the skin … closed/simple/complete fractures do not have broken skin Comminuted: bone splintered or crushed Pathologic: bones weakened by disease break under normal strain. Spiral: bone twisted apart Crepitation AKA crepitus: grating crackling sound. Can be heard when ends of a broken bone move together

Diagnostics Radiograph: AKA x-ray – visualizes bone fractures and other abnormalities Arthroscopy: visual examination of the internal structure of a joint ◦ Arthr/o joint, -scopy visual examination using an athroscope Dual x-ray absorptiometry: low exposure radiographic measurement of the spine and hips to measure bone density. More accurate results than ultrasound which is used for screening purposes. ◦ (ab-sorp-shee-OM-eh-tree) German physicist Wilhelm Rontgen took the first medical x-ray of his wife’s hand in 1895. That’s her wedding ring!

Bone Marrow Transplant Used to treat certain types of cancer like leukemia, and lymphomas Stage 1: high intensity radiation and chemotherapy destroys both the cancer cells and the bone marrow Stage 2: Healthy bone marrow stem cells are transfused into the recipient’s blood. They migrate to the spongy bone and begin to multiply

Types of bone marrow transplants Allogenic: Originating within another ◦ Healthy bone marrow comes from a compatible donor Autologous: Originating within an individual ◦ Patients own bone marrow cells are harvested, cleaned, treated and stored before the remaining bone marrow is destroyed

Medical devices Orthotic: Mechanical appliance such as a leg brace or a splint that is specially designed to control, correct or compensate for impaired limb function Prosthesis (pros-THEE-sis): Substitute for a diseased or missing body part, such as a leg that has been amputated

Joints Arthrodesis: Surgical fusion of two bones to stiffen a joint such as an ankle, elbow or shoulder. Used to treat severe arthritis or a damaged joint ◦ Arthr/o joint, -desis bind together Arthrolysis (ar-THROL-ih-sis): Surgical loosening of an ankylosed joint. This can be either pathologic or therapeutic ◦ Arthr/o joint, -lysis loosening, breaking down Chondroplasty – surgical repair of damaged cartilage Synovectomy: surgical removal of a synovial membrane from a joint ◦ Synov synovial membrane, -ectomy surgical removal

Joint Replacement Arthroplasty – Based on word parts it means - surgical repair of a damaged joint ◦ Usually means surgically replacing a joint with an artificial joint (implant) ◦ knee replacement, hip replacement etc. Revision surgery – replacement of a worn out or failed implant

Spinal Column Percutaneous vertebroplasty: performed to treat osteoporosisrelated compression fractures ◦ Vertebr/o vertebra, -plasty surgical repair Laminectomy: surgical removal of a lamina or posterior portion of a vertebra ◦ Lamin lamina, -ectomy surgical removal

Bones Osteoclasis: (oss-tee-OCK-lah-sis) surgical fracture of a bone to correct a deformity ◦Oste/o bone, -clasis to break Osteorrhaphy: -(oss-tee-OR- ah-fee) surgical suturing or wiring together, of bones ◦Oste/o bone, -rrhaphy surgical suturing

Fracture treatment (Fx Tx) External fixation: Pins are placed through the soft tissues and bone so that an external appliance can be used to hold the pieces of bone firmly in place. Once healed, this is removed Internal fixation: a plate or pins are placed directly into the bone to hold the broken pieces in place and is not removed once healing is complete.

More fx tx Closed reduction AKA manipulation: the attempted realignment of the bone involved in a fracture or joint dislocation through manual manipulation Open reduction: Surgical procedure to realign broken bones.

Links to videos General overview of the skeletal system: http: //www. youtube. com/watch? v=J 8 x 6 t. ZI 2 h. VI http: //www. youtube. com/watch? v=UPrx. Qkjj. Ex. I (Bozeman Science) Fracture types http: //www. youtube. com/watch? v=t. XFFa. Md. NNJk Knee arthroscopy http: //www. youtube. com/watch? v=MOPn. EU 0 fe. KM