Ch. 5 - Skeletal System

1. Ch. 5 - Skeletal System • Parts of the skeletal system • Bones (skeleton) • Joints • Cartilages • Ligaments • Function of Bones • Support of the body • Protection of soft organs • Movement due to attached skeletal muscles • Storage of minerals and fats • Blood cell formation • Divided into two divisions • Axial skeleton • Appendicular skeleton

2. Bones of the Human Body • The adult skeleton has 206 bones • Marrow – found inside of bone • Two basic types of bone tissue • Compact bone • Dense & looks smooth • Covers outside of bone • Spongy bone • Inside of bone • Many open spaces

3. Classification of Bones on the Basis of Shape

4. Classification of Bones • Long bones • Typically longer than wide • Have a shaft with heads at both ends • Contain mostly compact bone • Examples: Femur, humerus • Short bones • Generally cube-shape • Contain mostly spongy bone • Examples: Carpals, tarsals

5. Flat bones • Thin and flattened • Usually curved; made of compact bone • Thin layers of compact bone around a layer of spongy bone • Examples: Skull, ribs, sternum • Irregular bones • Irregular shape • Made mostly of spongy bone • Do not fit into other bone classification categories • Example: Vertebrae and hip

6. Gross Anatomy of a Long Bone • Diaphysis • Shaft; largest section of bone • Composed of compact bone • Physis • Growth plates of bone • Made of cartilage • Epiphysis • Ends of the bone • Outside made of compact • Surrounding mostly of spongy bone

7. Articular cartilage • Covers the external surface of the epiphyses • Made of hyaline cartilage • Decreases friction at joint surfaces • Medullary cavity • Cavity of the shaft • Contains yellow marrow (mostly fat) in adults • Contains red marrow (for blood cell formation) in infants

8. Bone Growth • Epiphyseal plates allow for growth of long bone during childhood • New cartilage is continuously formed • Older cartilage becomes ossified • Cartilage is broken down • Bone replaces cartilage • Bones are remodeled and lengthened until growth stops • Bones change shape somewhat • Bones grow in width

10. Bone Fractures • A break in a bone • Types of bone fractures • Closed (simple) fracture – break that does not penetrate the skin • Open (compound) fracture – broken bone penetrates through the skin • Bone fractures are treated by reduction and immobilization • Realignment of the bone

12. Repair Bones • Hematoma (blood-filled swelling) is formed • Break is splinted by fibrocartilage to form a callus • Fibrocartilage callus is replaced by a bony callus • Bony callus is remodeled to form a permanent patch

13. Axial Skeleton • Forms the longitudinal part of the body • Divided into three parts • Skull • Vertebral column • Bony thorax

14. Skull • Two sets of bones – cranium and facial bones. • Cranium – used to protect & enclose the brain • Frontal bone • Parietal bone • Temporal bone – made of 5 bone markings • External auditory meatus – makes up ear drum • Styloid process – attachment of mandible • Zygomatic process – joins cranium to check bone • Mastoid process – attachment of neck muscle; also makes up sinuses • Jugular foramen – passage for jugular vein to the brain • Occipital bone – It forms the formen magnum so the spinal cord can connect with brain; it also makes up the occipital condyles which allows cranium to set on vertebrae

15. Sphenoid bone – makes up the eye orbits & more sinus cavities • Ethmoid bone – forms roof of nasal cavity • Facial bones • Bones are joined by sutures • Only the mandible is attached by a freely movable joint

16. Facial Bone • Mandible – lower jaw; largest & strongest facial bone; moveable bone which allows your mouth to chew & speak • Maxillae – upper jaw; allow for chewing • Palatine bone • Zygomatic bone – cheekbone; makes up eye socket • Lacrimal bone – used to serve the passage way for tears

17. Nasal bone – bridge of nose • Vomer bone • Inferior Conchae • Hyoid bone – this bone does not connect with any other bone; located under the mandible; functions as a movable boase for the tongue & attachment point for neck muscles

18. Vertebral Column • Main purpose is to support the body • 24 total vertebra which consist of 7 cervical which includes atlas & axis, 12 thoracic & 5 lumber • Vertebrae separated by intervertebral discs • The spine has a normal curvature • Herniated disk is a cartilage disk that has slipped out between vertebrae causing pressure on nerves

19. Vertebra Structures & Functions • Body – weight bearing • Vertebral arch • Vertebral foramen – canal of spinal cord • Transverse process • Spinous process • Superior & inferior articular process

20. Cervical Vertebrae • Atlas – receives the occipital condyles; allowing you to nod “yes” • Axis – allows the head to rotate side to side

21. Thoracic Vertebrae – the vertebrae which receives the ribs • Lumbar Vertebrae – receives the most weight of body

22. Sacrum – connects the vertebrae to the pelvic bone • Coccyx – the human “tailbone” which is the remains of the human tail

23. Bony Thorax – sternum, ribs, & thoracic vertebra Protects the major organs of the body: heart, lungs & blood vessels. • Made-up of three parts • Sternum • Ribs • Thoracic vertebrae

24. Appendicular Skeleton • Limbs (appendages) • Pectoral girdle • Pelvic girdle

25. The Pectoral (Shoulder) Girdle • Composed of two bones • Clavicle – collarbone; helps hold arm away from thorax • Scapula – shoulder blade • These bones allow the upper limb to have exceptionally free movement

26. The arm is formed by a single bone • Humerus • The forearm has two bones • Ulna • Radius • The hand • Carpals – wrist • Metacarpals – palm • Phalanges – fingers

27. Bones of Pelvic Girdle • Hip bones • Composed of three pair of fused bones • Ilium • Ischium • Pubic bone • The total weight of the upper body rests on the pelvis • Protects several organs • Reproductive organs • Urinary bladder • Part of the large intestine

28. The thigh has one bone • Femur – thigh bone • The leg has two bones • Tibia • Fibula • The foot • Tarsus – ankle • Metatarsals – sole • Phalanges – toes

29. Joints • Articulations of bones • Functions of joints • Hold bones together • Allow for mobility • Ways joints are classified • Functionally • Structurally • Types of Joints • Synarthroses – immovable joints; sutures of skull • Amphiarthroses – slightly moveable joints; connected by cartilage disk; pelvic & vertebrae • Diarthroses – freely moveable joints

30. Types of Joint Movements • Glid or plane joints – slip movement; wrist & feet • Hinge joints – allows up & down movement; knee & elbows • Pivot joints – rolling or twisting movement; wrist & ankle • Condyloid joint – movement one direction; fingers & toes • Ball-and-socket joint – shoulder & hip • Saddle joint – rotational movement; thumb

31. Ligaments • Medial Ligament (MCL) • Anterior & Posterior Cruciate Ligament (ACL & PCL) • Collateral ligament • Side ligament; connect tibia & fibula to femur

32. Inflammatory Conditions Associated with Joints • Bursitis – inflammation of a bursa usually caused by a blow or friction • Tendonitis – inflammation of tendon sheaths • Arthritis – inflammatory or degenerative diseases of joints • Over 100 different types • The most widespread crippling disease in the United States

33. Clinical Forms of Arthritis • Osteoarthritis • Most common chronic arthritis • Probably related to normal aging processes • Rheumatoid arthritis • An autoimmune disease – the immune system attacks the joints • Symptoms begin with bilateral inflammation of certain joints • Often leads to deformities • Gouty Arthritis • Inflammation of joints is caused by a deposition of urate crystals from the blood • Can usually be controlled with diet