SKELETAL SYSTEM Functions of the Skeletal System Bones
SKELETAL SYSTEM
Functions of the Skeletal System • Bones are made of OSSEOUS TISSUE • Type of Connective Tissue • • Support and Protection Body movement Blood cell formation (bone marrow) Storage of inorganic materials (salt, calcium, potassium…. )
ORGANIZATION • About 206 bones • 2 Main Divisions – Axial & Appendicular
Axial Skeleton • • • Head, neck, trunk Skull Hyoid Bone Vertebral Column Thoracic Cage (ribs, 12 pairs) Sternum
Hyoid Bone
Appendicular Skeleton • Limbs & Bones that connect to the o Pectoral Girdle (shoulders) o Pelvic Girdle (hips)
BONE STRUCTURE - Long Bone 1. Epiphysis 2. Diaphysis 3. Articular Cartilage 4. Periosteum
Inside the Long Bone Medullary Cavity – hollow chamber filled with bone marrow Red Marrow (blood) Yellow Marrow (fat) Endosteum – lining of the medullary
Types of Bone Tissue Compact (wall of the diaphysis) Spongy (cancellous, epiphysis) * Assignment – Coloring of a Long Bone *Stanley the Skeleton (next slide)
Microscopic Structure MATRIX - where the bone cells live OSTEOCYTES - mature bone cells, enclosed in tiny chambers called LACUNAE OSTEOCYTES form rings (LAMELLAE) around a HAVERSIAN CANAL which houses blood vessels Osteocytes are linked by CANALICULI Haversian Canals are linked by VOLKMAN's CANALS
Compact Bone BONE COLORING!
Structure of a Long Bone Figure 6. 3 a-c
BONE DEVELOPMENT & GROWTH 1. Intramembranous bones – flat, skull 2. Endochondral bones – all other ALL BONES START AS HYALINE CARTILAGE, areas graduallly turn to bone PRIMARY OSSIFICATION CENTER (shaft) SECONDARY OSSIFICATION CENTER (ends)
Bone Development & Growth EPIPHYSEAL DISK (growth plate) is a band of cartilage between the epiphysis and diaphysis These areas increase bone length as the cells ossify Cartilage becomes OSTEOBLASTS become OSTEOCYTES
RESORPTION OSTEOCLASTS - dissolve bone tissue to release minerals, process is called RESORPTION
Bone Growth
Bone Growth * Assignment - Coloring of the Aging Hand
Types of Joints (articulations) 1. Synarthrotic (not moveable, aka sutures) 2. Amphiarthrotic (slightly moveable, vertebrae) 3. Diarthrotic (moveable joint, aka synovial joints)
Synovial fluid - fluid within the joints that helps to lubricate Types of Joints 1. 2. 3. 4. Ball and Socket Hinge Pivot Saddle
BONES OF THE SKULL 1. Frontal - anterior portion above eyes 2. Parietal - one on each side of the skull, just behind frontal bone 3. Occipital - forms the back of the skull and base of the cranium 4. Temporal - forms parts of the sides and base of cranium 5. Sphenoid - wedged between several other bones in anterior portion of the cranium 6. Maxilla - forms upper jaws 7. Mandible - lower jaws, only moveable bone of the skull 8. Zygomatic Bone - cheekbone
TOPOGRAPHY OF THE SKULL Foramen - refers to any tiny opening, nerves and blood vessels leave this opening to supply the face 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 bones 2. Lambdoidal - between occipital and parietal bones 3. Squamosal - between temporal and parietal bones 4. Sagittal - between parietal bones
Bones of the Skull & Sutures
Foramen Magnum * Assignment: Skull Labeling
Figure 6. 10
Figure 6. 10
The Rest of the Bones
Thoracic Cage
Vertebrae Neck = cervical Middle Back = thoracic Lower Back = lumbar
Pectoral Girdle
Bones of the Arm Ulna goes to pinky (P-U) Radius goes to thumb
Wrist Bones For test Carpels Metacarpals Phalanges *extra credit opportunity
Pelvic Girdle
Bones of the Leg
Bones of the Ankle For Test Calcaneous Tarsals Metatarsals Phalanges Assignment – Skeleton Labeling
Broken Bones
Upcoming Assignments • The Skeleton Mystery - read about a “crime scene” and reconstruct skeletons to identify the remains • Watch a Bones Episode • Identify Bones on a real skeleton • Lab Practical Test • Medical Imaging – learn how doctors view bones and diagnose problems
TEST INFORMATION • Test will cover everything in your notes and on the slides presented in class • Visit biologycorner. com for study aids • A second test will occur that covers the lab portion
Abnormal Bone Conditions • BONE SPURS: abnormal growth. Can occur on any bone (e. g. heel). • OSTEOPOROSIS: Increased activity of osteoclasts cause a break down bone, and the subsequent fewer minerals in the extracellular matrix make it fragile. The spongy bone especially becomes more porous. • Men get it as well as women. What’s the best way to prevent osteoporosis? Exercise! What does exercise do? Makes bones bigger. • The most common bone used for a bone graft is the iliac bone of the hip.
Osteoporosis Figure 6. 15
ABNORMALITIES OF THE SPINE • SCOLIOSIS is a lateral curve in the spine • KYPHOSIS is a hunchback curve • LORDOSIS is a swayback in the lower region. • ANKYLOSIS is severe arthritis in the spine and the vertebrae fuse.
SCOLIOSIS
LORDOSIS
ANKYLOSIS
FUN FACTS ABOUT BONES Bone is made of the same type of minerals as limestone. • Babies are born with 300 bones, but by adulthood we have only 206 in our bodies. • The giraffe has the same number of bones in its neck as a human: seven in total. • The long horned ram can take a head butt at 25 mph. The human skull will fracture at 5 mph.
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