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SKELETAL SYSTEM. Functions of the Skeletal System. A. Bones are made of OSSEOUS TISSUE FUNCTIONS: 1.Support 2. Protection 3.Body movement 4. Blood cell formation (bone marrow) - hematopoiesis 5. Storage of inorganic materials (salt, calcium, potassium….).
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Functions of the Skeletal System A. Bones are made of OSSEOUS TISSUE FUNCTIONS: 1.Support 2. Protection 3.Body movement 4. Blood cell formation (bone marrow) - hematopoiesis 5. Storage of inorganic materials (salt, calcium, potassium….)
B. ORGANIZATION 1. About 206 bones 2. 2 Main Divisions – Axial & Appendicular
There is 2 basic types of osseus, or bone, tissue: a. COMPACT BONE – dense, looks smooth, homogeneous b. SPONGY BONE – composed of small needlelike pieces of bone and open space Classification of Bones:BASED ON SHAPE
2. Long bones – longer than they are wide, have shaft with heads at both ends; have mostly compact bone a. all limbs - ex, humerus and femur 3. Short bones – cube-shaped and contain mostly spongy bone. a. Wrist and ankle 4. Flat bones – thin, flattened, usually curved. a. Skull, ribs, sternum are flat 5. Irregular bones– do not fit into another category a. Vertebrae
Types of Bone Tissue 1. Compact (wall of the diaphysis) 2. Spongy (cancellous, epiphysis) - red marrow
Inside the Long Bone 1. Medullary Cavity – hollow chamber filled with bone marrow 2. Red Marrow - (red blood cell formation) 3. Yellow Marrow - (fat replaces much of the red marrow in diaphysis throughout childhood) 4. Endosteum– lining of the medullary
BONE STRUCTURE – 5 PARTS of a Long Bone Epiphysis – on each end Diaphysis – main body/shaft of bone Articular Cartilage – on ends for joint movement 4. Periosteum – outer covering 5. Medullary cavity – hollow chamber within diaphysis that connect to spaces in spongy bone. Filled with bone marrow.
* Assignment – Coloring of a Long Bone
Structure of a Long Bone Figure 6.3a-c
Review the Structure of a Long Bone Matching quiz at http://www.mhhe.com/biosci/ap/holehaap/student/olc2/chap07matching01.html
Axial Skeleton 1. Head, neck, trunk a. Skull b. Hyoid Bone c. Vertebral Column d. Thoracic Cage (ribs, 12 pairs including true and false and floating ribs) e. Sternum
Hyoid Bone – closely related to mandible and temporal bone • Unique that it is the only bone of the body that does not articulate directly with any other bone. • 2. Serves as a movable base for the tongue and attachment point for neck muscles that raise and lower the larynx when we speak and swallow. • 3. Is more prominent in males than females.
Appendicular Skeleton • Limbs & Bones that connect to the • Pectoral Girdle (shoulders) • Pelvic Girdle (hips)
Microscopic Structure – of Bone Growth and Development 1. MATRIX - where the bone cells live 2. OSTEOCYTES - mature bone cells, enclosed in tiny chambers called LACUNAE 3. OSTEOCYTES form rings (LAMELLAE) around a HAVERSIAN CANAL which houses blood vessels 4. Osteocytes are linked by CANALICULI 5. Haversian Canals are linked by VOLKMAN's CANALS
CompactBone BONE COLORING!
Test Yourself Find the... Haversian Canal Volkman's Canal Lamellae Spongy Bone Compact Bone
BONE DEVELOPMENT & GROWTH Intramembranous bones – are flat, ex. Skull 2. Endochondral bones – all other bones 3. ALL BONES start as hyaline cartilage, areas gradually turn to bone (through the process of OSSIFICATION) 4. PRIMARY ossification center (shaft) 5. SECONDARY ossification center(ends)
Bone Development & Growth 6. EPIPHYSEAL DISK (growth plate) is a band of cartilage between the epiphysis and diaphysis 7. These areas increase bone length as the cells ossify 8. Cartilage becomes OSTEOBLASTS become OSTEOCYTES
RESORPTION • Bone tissue is constantly being replaced as special cells called OSTEOCLASTS dissolve bone tissue from within the medullary cavity and releases minerals- a process called RESORPTION. • At the same time new bone tissue is being added to the outside of the bone. Assignment: Coloring of an Aging Hand
Function of Joints • Hold bones together securely • Give the rigid skeleton mobility.
Types of Joints (Also called Articulations!) Synarthrotic (not moveable, ex. sutures of the skull) Amphiarthrotic (slightly moveable, ex. vertebrae) 3. Diarthrotic (moveable joint, ex. synovial joints like knee or hips)
Synovial fluid - fluid within the joints that helps to lubricate Types of Joints: 1. Ball and Socket (example – shoulder/hip) 2. Hinge (example – knee) 3. Pivot (example – elbow) 4. Saddle (example – fingers)
BONES OF THE SKULL (Lab Test) 1. Frontal -2. Parietal - 3. Occipital -4. Temporal - 5. Sphenoid - 6. Maxilla - 7. Mandible - 8. Zygomatic -
More Bones of the Skull to know! 9. Lacrimal 10. Ethmoid 11. Nasal 12. External Auditory meatus 13. Mastoid process 14. Styloid Process 15. Temporo-mandibular joint 16. Sagittal suture 17. Lambdoid suture 18. Squamous suture 19. Coronal suture 20. Foramen magnum 21. Mental foramen
TOPOGRAPHY OF THE SKULL Foramen - refers to any tiny opening, nerves and blood vessels leave this opening to supply the face Mental Foramen
Suture - refers to any connection between large bones (in fetal skulls, these are called fontanels) Fissure - any wide gap between bones
Sutures 1. Coronal - between frontal and parietal bones2. Lambdoid- between occipital and parietal bones3. Squamous - between temporal and parietal bones4. Sagittal - between parietal bones
Foramen Magnum * Assignment: Skull Labeling
Fetal Skull • The adult skull represents only 1/8 of the total body length. • The newborn infant skull is only 1/4 as long as its entire body. • Areas of newborn’s skulls are still hyaline cartilage, called fontanels. (until age 2) • 4. The rhythm of the baby’s pulse can be felt in these “soft spots” 5. The largest fontanels are the anterior fontanel and posterior fontanel; which allows the skull to be compressed slightly during birth. 6. Allows the brain to grow and develop in the womb and infancy.
Vertebrae Neck = cervical (C1 – C7) Middle Back = thoracic (T1 – T12) Lower Back = lumbar (L1 – L5) Sacrum = 5 fused vertebrae Coccyx = tailbone
Bones of the Arm a. Humerus – upper arm b. Ulna goes to pinky (P-U or “UP”) c. Radius goes to thumb (RT)
Wrist Bones For test: a. Carpals b. Metacarpals c. Phalanges
Pelvic Girdle – Wider in females than malesSacrum – 5 fused vertebrae
Bones of the Ankle For Test: Calcaneous Tarsals Metatarsals Phalanges Assignment – Skeleton Labeling