Skeletal System PDF

Skeletal System Skeletal system What is the skeletal system? The skeletal system is composed of 206 bones that, along with cartilage, tendons, and ligaments, make up the framework or skeleton of the body. 80 bones of the axial skeleton 126 bones of the appendicular skeleton Dr. Ali Mohammed Skeletal...

Skeletal System Skeletal system What is the skeletal system? The skeletal system is composed of 206 bones that, along with cartilage, tendons, and ligaments, make up the framework or skeleton of the body. 80 bones of the axial skeleton 126 bones of the appendicular skeleton Dr. Ali Mohammed Skeletal system Axial skeleton : The skeleton can be divided into two main parts. The axial skeleton consists of 80 bones. The primary bones of the axial skeleton are the skull, spine, ribs and sternum (thorax). Anterior means front; posterior means back. This is an anterior view of the skeleton. Dr. Ali Mohammed Skeletal system Appendicular skeleton : The appendicular skeleton consists of 126 bones. The primary bones of this skeleton are the shoulder or pectoral girdle, arms, hands,pelvic girdle, legs, and feet. Dr. Ali Mohammed Skeletal system Functions of bones: Bones are composed of about 50% water and 50% a solid, calci ed, rigid substance known as osseous ssue. 1. Bones provide shape, support, and the framework of the body. 2. Bones protect internal organs. 3. Bones serve as a storage place for minerals such as salts, calcium, and phosphorus. ti fi Dr. Ali Mohammed Skeletal system 4. Bones play an important role in hematopoiesis the forma on of blood cells that takes place in bone marrow. 5. Bones provide a place to a ach muscles. 6. Bones make movement possible through ar cula on (manner in which the parts come together at a joint). ti ti tt ti Dr. Ali Mohammed Classifications of bones Classifications of bones by shape : Bones can be classi ed by shape. 4 of those classi ca ons are: A-LONG bones include the femur (thigh), bia (larger shin), bula (smaller shin bone), humerus (upper arm), radius (larger forearm), and ulna (smaller forearm). ti ti fi Dr. Ali Mohammed fi fi Skeletal system Skeletal system B-SHORT bones include the carpals of the wrist and tarsals of the ankle. Dr. Ali Mohammed Skeletal system C-FLAT bones include the skull, sternum (breastbone), and scapula (shoulder bone). Dr. Ali Mohammed Skeletal system D-IRREGULAR bones include the vertebrae (spine), and pelvic. Dr. Ali Mohammed Skeletal system Bone structure: Epiphysis - growing end Diaphysis - sha Periosteum-outside covering Medullary- inner space containing bone marrow Endosteum- lining of medullary cavity The features in this long bone illustrate those found in all bones. ft Dr. Ali Mohammed Skeletal system Joints : A joint is a place where two or more bones connect. The manner in which they connect determines the type of movement allowed at that joint. A synarthrosis is a joint that allows no movement. An example would be a cranial suture. Dr. Ali Mohammed Skeletal system Joints : A amphiarthrosis is a joint that allows slight movement. An example would be a vertebra. A diarthrosis is a joint that allows free movement in a variety of direc ons, such as knee, hip, elbow, wrist, and foot. ti Dr. Ali Mohammed Skeletal system The vertebral column : The vertebral column is composed of separate bones called vertebrae, connected to form four spinal curves. A curve has more strength than a straight line, so can support the weight of the body and provide balance needed to walk. Dr. Ali Mohammed Skeletal system The vertebral column : The cervical curve contains the first 7 vertebrae; The thoracic curve contains the next 12; The lumbar curve contains 5. The sacral curve does not contain vertebrae. It contains the sacrum and coccyx (KOCK siks) or tailbone. Dr. Ali Mohammed Skeletal system The male and female pelvis : The pelvis is the lower por on of the trunk of the body. The hip bones, sacrum, and coccyx form the pelvic basin. Hip bones include the ilium (Ĭl ee um), pubis (PYU bus), and ischium (ISS kee um). The male pelvis is shaped like a funnel and is heavier and stronger than the female. The female pelvis is oval to round, and wider than the male. Male Female ti Dr. Ali Mohammed Skeletal system Bone growth and resorption : Bone is continually remodeled. It is broken down by osteoclasts in a process called resorption, and formed again by osteoblasts. Bone formation and healing slow down as part of the aging process. Dr. Ali Mohammed Skeletal system Osteoporosis is an age-related loss of bone mass or density. Dr. Ali Mohammed Skeletal system Microscopic Structure : Bone cells are called osteocytes Osteocytes transport nutrients and wastes The extracellular matrix of bone is largely collagen and inorganic salts Collagen gives bone resilience Inorganic salts make bone hard Dr. Ali Mohammed Skeletal system Homeostasis of Bone Tissue : Bone Resorp on – ac on of osteoclasts and parathyroid hormone PTH Bone Deposi on – ac on of osteoblasts and calcitonin Occurs by direc on of the thyroid and parathyroid glands ti ti ti ti ti Dr. Ali Mohammed Skeletal system Factors Affecting Bone Development, Growth and Repair: Deficiency of Vitamin A – retards bone development Deficiency of Vitamin C – results in fragile bones Deficiency of Vitamin D – rickets, osteomalacia Insufficient Growth Hormone – dwarfism Excessive Growth Hormone – gigantism, acromegaly Insufficient Thyroid Hormone – delays bone growth Sex Hormones – promote bone formation; stimulate ossification of epiphyseal plates Physical Stress – stimulates bone growth Dr. Ali Mohammed Skeletal system Blood Cell Formation : Blood Cell Formation Also known as hematopoiesis Occurs in the red bone marrow Dr. Ali Mohammed Skeletal system Inorganic Salt Storage : Inorganic Salt Storage Calcium Phosphate Magnesium Sodium Potassium Dr. Ali Mohammed