1 / 47

Skeletal System

Skeletal System. Chapter 7 Dr. Katherine Harris. Bones are alive!. Bone consists of a variety of active, LIVING tissues: Bone tissue Cartilage Dense connective tissue Blood Nervous tissue. Functions of Bone. Organs of the skeletal system Provide points of attachment for muscles

easter
Download Presentation

Skeletal System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Skeletal System Chapter 7 Dr. Katherine Harris

  2. Bones are alive! • Bone consists of a variety of active, LIVING tissues: • Bone tissue • Cartilage • Dense connective tissue • Blood • Nervous tissue

  3. Functions of Bone • Organs of the skeletal system • Provide points of attachment for muscles • Protect & support softer tissues • House blood-producing cells • Store inorganic salts • Form passageways for blood vessels and nerves

  4. Bone and Muscle • Both bone and muscle are living tissue • separately neither is able to produce movement • Muscular tissue contracts (gets shorter) • when the muscle shortens, it pulls on the bone • Bones are held together by joints, most of which permit movement between the bones • pulling on one bone causes movement at the accompanying joint

  5. Body Movement • Bones and Muscles interact as levers.

  6. Blood Cell Formation • Hematopoiesis

  7. Bone Marrow • The central canal of the long bone houses the marrow • blood cells form in red marrow • energy (fat) is stored in yellow marrow

  8. Bone Classification • Bones are classified by their shapes • Long bones • Short bones • Flat bones • Irregular bones • Sesamoid (round) bones

  9. Anatomy of a Typical Bone • Dense compact bone surrounds the organ and spongy bone comprises the inner support • The ends of the bones, or epiphyses, include the epiphyseal plate, an area of cartilage where long bones continue to grow during childhood and adolescence • when bones cease growing, this cartilage is replaced by bone, leaving the epiphyseal line • Wherever two bones meet, you will find a layer of hyaline cartilage • this articulating cartilageprevents bone from grinding against bone at a joint

  10. Bone Tissue • Two types of bone tissue • Compact – dense • Spongy – lighter and less dense than compact bone

  11. Compact Bone • Compact bone material usually occurs at the edges of the bone and is composed of many individual osteons • the central canal of the osteon houses the blood and nerve supply for the bone tissue Osteon – concentric rings of matrix made by osteocytes and formed surrounding a central canal.

  12. Spongy Bone • Spongy bone is less organized than compact bone and lacks osteons • Instead, spongy bone has trabeculae, or struts, that form in response to stress

  13. Bone Development & Growth • The skeletal system begins to form during the first few weeks of prenatal development • Bones continue to develop and grow into adulthood

  14. Bone Formation • Bones are a form of connective tissue produced by immature bone cells called osteoblasts • There are three types of cells that contribute to bone homeostasis. • Osteoblasts are bone-forming cells • Osteoclasts resorb or break down bone • Osteocytesare mature bone cells • An equilibrium between osteoblasts and osteoclasts maintains bone tissue.

  15. Bone Formation = Ossification • Ossification is the process of bone formation • 2 types of ossification • Most bones are endochondral(formed within cartilage) • Intramembranous (cartilage is not involved)

  16. Bone Formation • Intramembranous ossification forms the flat bones of the skull, clavicle, and mandible • bone is laid down within embryonic connective tissue • bones form deep in the dermis of the skin and thus are often called dermal bones

  17. Bone Formation • Bones grow longer and thicker • growth occurs at the outer surface of the bone • cells within the membrane that covers the bone, the periosteum, differentiate into osteoblasts and begin to add matrix to the exterior • accumulating matrix entraps these osteoblasts, which mature into osteocytes, creating new bone tissue around the exterior of the bone

  18. Bone Formation

  19. Bone Remodeling • Bones are dynamic structures, constantly being remodeled and perfected to suit the needs of the body, and continuously making subtle changes in shape and density • Bones cease growing in length at maturity, but continue to change shape throughout life

  20. Bone Remodeling: Blood Calcium • When the blood calcium level rises, the osteoblasts create new matrix, removing excess calcium from the blood. • When the blood calcium level drops, osteoclasts go to work to release stored calcium to the blood.

  21. Osteoporosis • Bone = bank • Calcium = money • The more you have in your account before age 30, the less likely you are to develop osteoporosis! • Calcium rich foods: • Dairy products -- milk, cheese and yogurt • Dark green leafy vegetables — broccoli and spinach • Calcium fortified foods -- orange juice, cereal and bread • Nuts -- almonds

  22. Avoiding Osteoporosis • Get at least 30 minutes of exercise daily • A portion should be weight bearing exercise • Consume enough daily calcium (1000-1200 mg) • Consume enough daily vitamin D (200 IU) • Avoid tobacco & alcohol consumption

  23. The human skeleton is composed of 206 bones The Skeleton

  24. The skeleton is divided into: the axial skeleton(the central axis of the body) the appendicular skeleton (the appendages and girdles holding them to the central axis) The Skeleton

  25. Cranial Bones • Cranial bones surround and protect the brain • the parietal and temporal bones are paired • parietal bones protect the upper sides of the head • temporal bones protect the middle sides of the head and support the ears • the frontal bone, occipital bone, ethmoid, and sphenoid are single bones • All 8 cranial bones are held together by fixed joints called sutures

  26. Facial Bones • The 14 facial bones protect the entrances to the respiratory and digestive systems, and the sensory organs. • Two facial bones are single, and 12 occur in pairs.

  27. Inferior View of Skull

  28. Sagittal Section of Skull

  29. Vertebrae • These bones allow upright posture and protect vital organs of the thoracic cavity • There are 24 vertebrae, one sacrum, and three to five coccyx bones in the adult vertebral column • The sacrum is actually five fused vertebrae that form a solid base for the pelvic girdle • The tailbone, or coccyx, is our post-anal tail

  30. Vertebrae • A typical vertebra is composed of three parts • the vertebral body • the vertebral arch • the vertebral articular processes • serve as points of attachment between adjacent vertebra and sites for muscle attachment

  31. Vertebral Column • The vertebral column is divided into 5 regions • the cervical region • the thoracic region • the lumbar region • the sacrum • the coccyx • Moving down the column, the bodies of the vertebrae grow larger, because they must support more weight

  32. http://www.esurgeon.com/scripts/content/playmovie.html?filename=backpain&returnpath=anatomyandcauses/back.html&doctorname=%20%20&doctor=&page=backhttp://www.esurgeon.com/scripts/content/playmovie.html?filename=backpain&returnpath=anatomyandcauses/back.html&doctorname=%20%20&doctor=&page=back Vertebral Column • Between each vertebra is a pad of fibrocartilage called the intervertebral disc • the disc serves as a shock absorber, preventing vertebrae from rubbing against one another and crushing under the body's weight • allows limited motion between vertebrae

  33. Vertebrae • Vertebrae in different regions of the vertebral column have special characteristics.

  34. Sacrum & Coccyx • Sacrum • Composed of 5 fused vertebrae • Forms base of vertebral column • Rows of openings provide passageways for nerves and blood vessels

  35. Sacrum & Coccyx • Coccyx (tailbone) • Lowest part of vertebral column • Composed of 4 fused vertebrae

  36. Ribs and Sternum • 24 ribs, 1 pair attaches to each of the twelve thoracic vertebrae. • 7 true ribs • 5 false ribs • 2 floating ribs • The sternum, or breastbone, protects the anterior of the chest and has 3 parts: • Upper manubrium – articulates with clavicle • Middle body • Lower xiphoid process

  37. The Appendicular Skeleton • The appendicular skeleton includes all the bones that are attached, or appended, to the axial skeleton • the pectoral girdle • (shoulder bones) • the upper appendages • (arms and hands) • the pelvic girdle • (hips and pelvic bones) • the lower appendages • (legs and feet)

  38. The Pectoral Girdle and Upper Appendages • Human bodies have two pectoral girdles • each consisting of a clavicle and scapula • The upper appendages • the humerus is the longest and strongest bone in the upper appendicular skeleton • the ulna and radius make up the forearm • the elbow is the joint formed by the distal end of the humerus and the proximal ends of the radius and ulna • The carpals (wrist bones) are in two rows of four short bones • the metacarpals make up the structure of the hand • the phalanges (finger bones) are considered long bones

  39. Pelvic Girdle • The pelvic girdle • composed of the hip bones and lower vertebrae • denser, stronger, and less flexible than the appendicular girdle • The acetabulum is the curved recess that serves as a socket for the head of the femur • The pelvis is technically made of two large coxal bones (hip bones) which make up the pelvic girdle, plus the sacrum and the coccyx

  40. Right Hip Bone • The hip bone emerges from three bones that fuse in early puberty • the ilium • the ischium • the pubic bone • the femur articulates at the junction of these three bones

  41. Right Lower Limb • The femur is the longest and heaviest bone of the body. Makes up the upper leg. • The fibula and tibia are found in the lower leg. • The patella or knee cap is counted as a bone • The tarsals, metatarsals and phalanges form the feet and toes.

  42. Joints • Joints link the skeletal system together; they exist wherever two bones meet • Joints are classified by function or structure • Functionally, joints are • immovable or synarthrotic • semimovable or amphiarthrotic • freely movable or synovial(most common) • Structurally, a joint is considered a fibrous, cartilaginous, or synovial joint

  43. Fibrous Joints • Fibrous joints lie between bones that closely contact one another • A thin layer of dense connective tissue joins the bones, as in a suture between a pair of flat bones of the skull

  44. Cartilaginous Joints • Hyaline cartilage or fibrocartilage connect the bones of cartilaginous joints. • This type of joint is found between the vertebrae of the vertebral column

  45. Synovial Joints • Most common joint found within the skeletal system • Allow free movement and are more structurally complex than fibrous or cartilaginous joints. • Synovial fluid lubricates the joint.

  46. Lab This Week • Intro to the skeletal system, skull & vertebral column • Bring your textbook and lab manual • We’ll be covering Labs 12-14

More Related