1 Chapter 32 Integumentary, Skeletal, and Muscular Systems

2 Sect 32.2 –

32.2 The Skeletal System 3 Objectives Distinguish between the bones of the axial and appendicular skeletons. Distinguish between the bones of the axial and appendicular skeletons. Describe how new bone is formed. Describe how new bone is formed. Summarize the functions of the skeletal system. Summarize the functions of the skeletal system.

32.2 The Skeletal System 4 Main Idea The skeleton provides a structural framework for the body and protects internal organs such as the heart, lungs, and brain. The skeleton provides a structural framework for the body and protects internal organs such as the heart, lungs, and brain.

32.2 The Skeletal System 5 Structure of Skeletal System Skeletal system Skeletal system ◦ composed of connective tissue, such as  bone  cartilage  ligaments ◦ functions  supports the body  protects internal organs  provides for movement  stores mineral reserves  provides a site for blood cell formation

32.2 The Skeletal System 6 Structure of Skeletal System The skeleton The skeleton ◦ is an endoskeleton ◦ makes up < 20% of body mass ◦ is composed of 206 bones ◦ has two divisions  axial skeleton  appendicular skeleton

32.2 The Skeletal System 7 Structure of Skeletal System Axial skeleton (80) Axial skeleton (80) ◦ includes  the skull □ ossicles  the vertebral column □ hyoid  the chest □ ribs □ sternum

32.2 The Skeletal System 8 Structure of Skeletal System Appendicular skeleton (126) Appendicular skeleton (126) ◦ includes the bones of the  shoulder girdle  arms  hands  pelvic girdle  legs  feet

32.2 The Skeletal System 9 Structure of Skeletal System Bone Bone ◦ is a connective tissue ◦ are classified as  long  short  flat  irregular ◦ all bones have same basic structure  compact bone on the outside  spongy bone on the inside

32.2 The Skeletal System 10 Structure of Skeletal System Compact bone Compact bone ◦ found on the outside of all bones ◦ is dense and strong ◦ it provides  strength  protection

32.2 The Skeletal System 11 Structure of Skeletal System Running the length of compact bone Running the length of compact bone ◦ tube-like structures  called osteons □ aka Haversian systems  contain □ blood vessels □ nerves  contain osteocytes □ bone cells

32.2 The Skeletal System 12 Structure of Skeletal System Spongy bone Spongy bone ◦ is less dense  contains many cavities  filled with bone marrow ◦ found in  center of □ short bones □ flat bones  ends of long bones ◦ is surrounded by compact bone ◦ does not have Haversian systems

32.2 The Skeletal System 13 Structure of Skeletal System Skeleton has two types of marrow Skeleton has two types of marrow ◦ red marrow ◦ yellow marrow ◦ red marrow is found in the  humerus  femur  sternum  ribs  vertebrae  pelvis ◦ yellow is found in rest of the bones

32.2 The Skeletal System 14 Structure of Skeletal System Bone marrow Bone marrow ◦ red marrow  produces blood cells □ red □ white  children’s bones have more red marrow □ than adults ◦ yellow marrow  used to store fat

32.2 The Skeletal System 15 Structure of Skeletal System Ossification Ossification ◦ = formation of bone ◦ osteoblasts  = cells that make bone  convert cartilage into bone ◦ after the age of 25, the adult skeleton  is entirely composed of bone  except for □ tip of the nose □ outer ears □ discs between the vertebrae □ lining of movable joints

32.2 The Skeletal System 16 Structure of Skeletal System Remodeling of bone is continual life- long process Remodeling of bone is continual life- long process ◦ old bone is replaced by new bone ◦ osteoclasts  = cells that breakdown bone  followed by osteoblasts □ which form new bone ◦ bone growth depends on sev factors  nutrition  physical exercise

32.2 The Skeletal System 17 Structure of Skeletal System Repair of bone Repair of bone ◦ fracture  = any break in the continuity of bone  three most common types □ simple frx □ compound frx □ stress frx

32.2 The Skeletal System 18 Structure of Skeletal System Simple frx Simple frx ◦ = bone ends do not penetrate the skin

32.2 The Skeletal System 19 Structure of Skeletal System Compound frx Compound frx ◦ = bone ends exposed to outside of body

32.2 The Skeletal System 20 Structure of Skeletal System Stress frx Stress frx ◦ = break in the surface of a bone

32.2 The Skeletal System 21 Structure of Skeletal System Repair of bone Repair of bone ◦ begins almost immed after the frx ◦ the area becomes inflammed □ or swollen ~ which may last 2-3 weeks ◦ within 8 hours  a clot between the ends of the frx bones □ this clot becomes a ‘soft callus’ ~ = a mass of cartilage ◦ frx bone must be kept immobile  soft callus is weak tissue

32.2 The Skeletal System 22 Structure of Skeletal System Clot formation Clot formation

32.2 The Skeletal System 23 Structure of Skeletal System After about 3 weeks After about 3 weeks ◦ osteoblasts  form a callus around the frx site  callus is composed of spongy bone ◦ callus is still weak  so frx site must still be immobile  until remodeling occurs

32.2 The Skeletal System 24 Structure of Skeletal System Callus formation Callus formation

32.2 The Skeletal System 25 Structure of Skeletal System Remodeling Remodeling ◦ the spongy bone is replaced  by compact bone ◦ osteoclasts  remove the spongy bone that forms the callus ◦ while osteoblasts  produce strong compact bone

32.2 The Skeletal System 26 Structure of Skeletal System Remodeling Remodeling

32.2 The Skeletal System 27 Structure of Skeletal System Remodeling Remodeling ◦ bones require different amounts of time to heal  factors include □ age □ nutrition □ location □ severity of frx ◦ usual healing time  for young people – about 4-6 weeks  older adults – about 6 months

32.2 The Skeletal System 28 Joints Joint Joint ◦ = where 2 or more bones meet ◦ ligaments  tough bands of connective tissue  attach one bone to another bone □ holding joints together

32.2 The Skeletal System 29 Joints Joints usu classified Joints usu classified ◦ according to the movement allowed ◦ shape of bone ends ◦ 5 types of joints  ball-and-socket  pivot  hinge  gliding  suture

32.2 The Skeletal System 30 Joints Ball-and-socket joint Ball-and-socket joint ◦ composed of a  ball like surface of one bone  cuplike depression of another bone ◦ has the greatest range of motion ◦ examples  shoulder  hip

32.2 The Skeletal System 31 Joints Pivot joint Pivot joint ◦ primary movement – rotation ◦ example:  radio-ulnar joint □ just below the elbow

32.2 The Skeletal System 32 Joints Hinge joint Hinge joint ◦ convex surface of one bone  fits into concave surface of another ◦ allows back and forth movement  like the hinge of a door ◦ examples:  knee  elbow

32.2 The Skeletal System 33 Joints Gliding joint Gliding joint ◦ allows movements into 2 directions  side-to-side  back-and-forth ◦ examples:  wrist  ankle  between vertebrae

32.2 The Skeletal System 34 Joints Suture joint Suture joint ◦ non-movable joints ◦ joints between the 22 skull bones

32.2 The Skeletal System 35 Joints Osteoarthritis Osteoarthritis ◦ arthritis  = joint inflammation ◦ osteoarthritis  painful joint condition □ results from deterioration of the joint’s articular cartilage  articular cartilage □ cartilage that covers the ends of bones within a joint

32.2 The Skeletal System 36 Joints Osteoarthritis Osteoarthritis ◦ common condition found in  knees  hips  back/neck ◦ results from  wear and tear on a joint  common in athletes

32.2 The Skeletal System 37 Joints Osteoarthritis Osteoarthritis

32.2 The Skeletal System 38 Joints Rheumatoid arthritis Rheumatoid arthritis ◦ another form of arthritis ◦ exact cause unknown ◦ affected joints  lose strength and function  become □ inflammed □ swollen □ painful □ can become deformed

32.2 The Skeletal System 39 Joints Rheumatoid arthritis Rheumatoid arthritis

32.2 The Skeletal System 40 Joints Bursitis Bursitis ◦ bursae  = fluid-filled sacs  located near some joints  function: to □ decrease joint friction □ cushion the joint ◦ bursitis  = inflammation of a joint’s bursa  causes □ pain □ swelling □ reduced movement of joint

32.2 The Skeletal System 41 Joints Bursitis Bursitis

32.2 The Skeletal System 42 Joints Sprain Sprain ◦ injury to a  joint  or its ligaments ◦ usually occurs when joint is  forced beyond it range-of-motion (ROM)  twisted ◦ usually causes  pain  swelling of joint

32.2 The Skeletal System 43 Joints Sprain Sprain

32.2 The Skeletal System 44 Red blood cells, some kinds of white blood cells, and platelets are produced by Red blood cells, some kinds of white blood cells, and platelets are produced by a. red marrow. b. cartilage. c. yellow marrow. d. osteocytes. Question

32.2 The Skeletal System 45 The shoulder joint is an example of a The shoulder joint is an example of a a. hinge joint. b. ball-and-socket joint. c. pivot joint. d. gliding joint. Question

32.2 The Skeletal System 46 What are the living bone cells? What are the living bone cells? a. osteoclasts b. osteocytes c. cartilage d. bone marrow Question

32.2 The Skeletal System 47 Q U E S T I O N S ??