ANAPHY LECTURE MODULE 2 (SKELETAL, ARTERIAL SYSTEM)

• Functions of the Skeletal System


  • Support
  • Protection
  • Movement
  • Storage
  • Blood cell production (hematopoiesis)
• Support


  • Rigid strong bones for bearing weight and is the major supporting tissue of the body
  • Cartilage provides a firm yet flexible support within certain structures (ex. nose and external ears)
  • Ligaments are strong bands of fibrous connective tissue that attach to bone and hold them together
• Protection


  The hardness of the bone contributes to its ability to protect the vital organs of the body from injury (ex. cranial bones protect the brain)
• Movement


  Skeletal muscles attach to bones by tendons. When muscles contract, they pull on bones and together they produce movement
• Storage


  • Fat is stored in the internal cavities of bones
  • Stores several minerals especially calcium and phosphorus
  • Important in maintaining homeostasis of minerals in the blood with minerals stored in the bone are released in response to body's demand
• Blood cell production (hematopoiesis)


  Many bones contain cavities filled with bone marrow that gives rise to blood cells and platelets
• OSTEOLOGY


  The study of bone structure and treatment of bone disorder
• BONE OSSIFICATION (OSTEOGENESIS)


  It refers to the formation of bone by osteoblast
• Types of Bone Ossification

  • Intramembranous Ossification
  • Endochondral Ossification
• Intramembranous Ossification


  • A process of bone development from fibrous membrane
  • It is involved in the formation of the flat bones of the skull, the mandible and clavicles
• Endochondral Ossification


  • A process of bone development from hyaline cartilage
  • All of the bones of the body, except for the flat bones of the skull, mandible and clavicles are formed through endochondral ossification
• Bone Growth


  • Appositional Growth
  • Endochondral Growth
• Appositional Growth


  • It refers to the formation of new bone on the surface of existing bone
  • Appositional growth results as osteoblasts deposit new bone matrix on the surface of bones between the periosteum and the existing bone matrix
  • Responsible for the increase in width or diameter of long bones and most growth of other bones
• Endochondral Growth


  • It refers to the growth of cartilage in the epiphyseal plate and its eventual replacement by bone
  • Responsible for the increase in the length of the bone
  • Bones continue to grow in length until early childhood, the rate of growth is controlled by hormones
• Bone Remodeling


  1. Resorption - during which osteoclasts digest old bone

  2. Reversal - when mononuclear cells appear on the bone surface

  3. Formation - when osteoblasts lay down new bone until the resorbed bone is completely replaced
• Bone Remodeling


  • It involves the removal of old bone by cells called osteoclast and the deposition of new bone by osteoblast
  • It occurs in all bone
  • Responsible for: Bone growth, Changes in bone shape, Adjustment of bone to stress, Bone repair, Calcium ion regulation
• Bone Repair (Healing)


  1. When a bone is broken, a clot forms in the damaged area

  2. Callus forms, the zone of tissue repair between the two bone fragments

  3. Osteoblasts enter the callus and form cancellous bone

  4. The cancellous bone is slowly remodeled to form compact bone and the repair is complete
• Bone and Calcium Homeostasis

  • Bone serves as the major storage site for calcium
  • The movement of calcium in and out of bone helps determine blood calcium levels
  • Calcium moves into bone as osteoblasts build new bone
  • Calcium move out of bone as osteoclasts break down bone
  • Calcium homeostasis is maintained by parathyroid hormone and calcitonin
• ACHONDROPLASIA is a form of short-limbed dwarfism where the problem is not in forming cartilage but in converting it to bone
• OSTEOGENESIS IMPERFECTA is a genetic disorder that results from a lack of protein collagen producing very brittle bones that are easily fractured
• Bone and Joint Disorders

  • RICKETS
  • OSTEOMALACIA
  • OSTEOMYELITIS
  • OSTEOPOROSIS
  • SCOLIOSIS
  • ARTHRITIS
  • OSTEOARTHRITIS
  • RHEUMATOID ARTHRITIS
  • GOUTY ARTHRITIS
  • BURSITIS
• RICKETS


  • Bones of children are inadequately mineralized causing softened, weakened bones
  • Bowed legs and deformities of the pelvis, skull, and rib cage are common
  • Caused by insufficient calcium in the diet, or by vitamin D deficiency
• OSTEOMALACIA


  • Bones are inadequately mineralized causing softened, weakened bones
  • Main symptom is pain when weight is put on the affected bone
  • Caused by insufficient calcium in the diet, or by vitamin D deficiency
• OSTEOMYELITIS


  • Infection in bone caused by Staphylococcus bacteria
  • The bacteria can enter a bone by the bloodstream, injuries and surgery
• OSTEOPOROSIS


  • Group of diseases in which bone reabsorption outpaces bone deposit
  • Spongy bone of the spine is most vulnerable
  • Occurs most often in postmenopausal women
  • Bones become so fragile that sneezing or stepping off a curb can cause fractures
• SCOLIOSIS


  • Lateral curvature of the central part of the spine
  • The condition is brought on by: congenitally malformed vertebra, chronic sciatica, paralysis of muscles on one side of the backbone, poor posture
• ARTHRITIS


  • It literally means "joint inflammation", however some forms could affect the skin and internal organs
  • It is marked by pain, stiffness and swelling of the affected joint
  • It may include one or several joints
• OSTEOARTHRITIS


  • Commonly known as "wear and tear" arthritis
  • A degenerative joint disease in which the cartilage that covers the ends of the bones in the joint deteriorates
  • Symptoms include: pain, restriction of movement, formation of hard nobs
• RHEUMATOID ARTHRITIS


  An active chronic inflammatory autoimmune disease affecting synovial membrane
• GOUTY ARTHRITIS


  A disease associated with an inborn error of uric acid metabolism
• BURSITIS


  An acute or chronic inflammation of the bursa (a small sac filled with fluid and located at friction points)
• Fracture


  • It refers to a break in a bone
  • Common types of fractures include simple, compound, compression, comminuted and greenstick
• Articulation or Joint


  The physical connection between two bones
• Functions of Joints


  • Holds bones together
  • Allows movement
  • Makes bone growth possible
• Arthrology


  The science that deals with the study of joints
• Functional Classification of Joints

  • Synarthrosis (immovable joint)
  • Amphiarthrosis (slightly movable joint)
  • Diarthrosis (freely movable joint)
• Structural Classification of Joints


  • Based on the major connective tissue type that binds the bones together and whether there is a fluid filled joint capsule
• Fibrous Joints


  • The bones are united by fibrous connective tissue
  • They allow little or no movement
• Types of Fibrous Joints

  • Sutures
  • Syndesmoses
  • Gomphoses
• Sutures


  • Fibrous joints between the bones of the skull
  • Immovable due to interlocking junctions between the bones and short numerous connective fibers