Due in Lab

1. Skeletal System 33-34 2. Skeletal System 26 3. PreLab 6

Due next week in lab - Scientific America Article  Select one article to read and complete article summary  Cell Defenses and the Sunshine Vitamin (Summary in Case Study 19-20)  Skin Deep (Summary in Case Study 21-22)  Sex and the Secret Nerve (Instructor website)  The Naked Truth (Instructor website)

The Skeletal System

Introduction Cranium Skull Facial bones Clavicle Thoracic cage Scapula (ribs and Sternum sternum) Rib Humerus Vertebra Vertebral Radius column Ulna Sacrum Carpals

Phalanges Metacarpals Femur Patella Tibia Fibula

Tarsals Metatarsals (a) Anterior view Phalanges Functions 1. Support  For the body and soft organs 2. Protection  For brain, spinal cord and vital organs 3. Movement  Levers for muscle action 4. Mineral reservoir  Calcium and phosphorus 5. Hematopoiesis  Marrow cavities

Bone  Osseous tissue  Hydroxyapatite (85%)  Calcium carbonate (10%)  Inorganic minerals  Magnesium, sodium, fluoride  Organic material  Collagen  Chondroitin sulfate Bone consists of Endosteum multiple tissues

A single bone may be considered an organ

Yellow bone marrow

Compact bone Periosteum Perforating (Sharpey’s) fibers

Nutrient arteries

(c)

Figure 6.3c Articular cartilage

Compact bone Proximal epiphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined (b) by endosteum) Diaphysis

Bones are organs comprised of more than just osseous tissue

Distal epiphysis (a)

Figure 6.3a-b Bone Classification

Figure 6.2 General Bone Features Long bone anatomy (Humerus)  Diaphysis  Epiphysis  Metaphysis  Epiphyseal growth plate or line  Articular cartilage  Periosteum  Medullary cavity  Endosteum Articular cartilage

Compact bone Proximal epiphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined (b) by endosteum) Diaphysis

Anatomy of a long bone

Distal epiphysis (a)

Figure 6.3a-b Endosteum Outer layer of periosteum = dense irregular fibrous sheath

Yellow bone marrow

Compact bone Periosteum Perforating (Sharpey’s) fibers

Nutrient arteries

(c)

Figure 6.3c Articular cartilage

Compact bone Proximal epiphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined (b) by endosteum) Diaphysis

Epiphyseal line is a remnant of the epiphyseal plate

Distal epiphysis (a) Bone Histology  Components  Cells  Fibers  Ground substance

Bone Histology  Cells  Osteogenic (osteoprogenitor) cells  Stem cells in periosteum and endosteum → osteoblasts  Osteoblasts  Bone forming cells

(a) Osteogenic cell (b) Osteoblast

Stem cell Matrix-synthesizing cell responsible for bone growth

Figure 6.4a-b Bone Histology  Cells  Osteocytes  Mature bone cells  Maintain bone matrix  Osteoclasts  Break down (resorb) bone matrix  Related to macrophages

(c) Osteocyte (d) Osteoclast

Mature bone cell Bone-resorbing cell that maintains the bone matrix

Figure 6.4c-d

Spongy bone (diploë) Compact bone

Compact bone covers all spongy bone and the shafts Trabeculae of long bones

Figure 6.5 Bone Histology  Primary bone types  Compact  Spongy Articular cartilage

Compact bone Proximal epiphysis Spongy bone Epiphyseal line Periosteum Compact bone Medullary cavity (lined (b) by endosteum) Diaphysis

Distal epiphysis (a)

Figure 6.3a-b Compact Spongy bone bone

Central Perforating (Haversian) canal (Volkmann’s) canal Endosteum lining bony canals Osteon and covering trabeculae (Haversian system) Circumferential lamellae

(a) Perforating (Sharpey’s) fibers Lamellae Periosteal blood vessel Periosteum

Nerve Vein Artery Lamellae Central Canaliculi Lacuna (with canal osteocyte) Osteocyte Lacunae in a lacuna (b) (c) Interstitial lamellae

Figure 6.7a-c Artery with capillaries Structures in the Vein central Nerve fiber canal Lamellae

Collagen fibers run in different directions

Twisting force

Figure 6.6 Nerve

Vein Lamellae Artery Central Canaliculus canal Osteocyte Lacunae in a lacuna

(b)

Figure 6.3b Spongy bone (diploë) Compact bone

Trabeculae

Figure 6.5 Bone Histology  Bone marrow  Location  Medullary cavity and spaces between trabeculae Bone Histology  Bone marrow  Types  Red  Red blood cells  Hematopoiesis  Yellow  Replaces red with age  Fat storage  Gelatinous  Mostly water and protein

Skeletal System 17

Label the following

 Proximal epiphysis  Periosteum  Distal epiphysis  Endosteum  Epiphyseal line  Diaphysis  Articular cartilage  Nutrient artery  Spongy bone  Marrow  Compact bone  Perforating (Sharpey’s)  Medullary canal fibers

Turn in Skeletal System 19

Table 6.1 Skeletal System 19

Table 6.1 Table 6.1