the skeletal system. parts of the skeletal system bones (skeleton)—206 bones in human body...
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The Skeletal System Slide 2 Parts of the skeletal system Bones (skeleton)206 bones in human body Joints Cartilages Ligaments Two subdivisions of the skeleton Axial skeletonskull, vertebral column and thoracic cage Appendicular skeletonpectoral girdle, upper limbs, pelvic girdle and lower limbs Slide 3 Axial Skeleton Pubic or Coxal Bone Pubis illium ischium Talus Slide 4 The Skull Mandibular condyle Slide 5 Axial SkeletonSkull Two sets of bones Cranium Facial bones Bones are joined by sutures Only the mandible is attached by a freely movable joint Slide 6 The Skull Slide 7 Axial SkeletonSkull Skull: at birthnot completely developed Cranial bones separated by fibrous membranes called fontanels or soft spots They allow for compression in birth canal They are eventually replaced wit bones and become sutures. Slide 8 Slide 9 Sinuses Hollow portions of bones surrounding the nasal cavity Functions of paranasal sinuses Lighten the skull Give resonance and amplification to voice Slide 10 Hyoid bone The only bone that does not articulate with another bone Serves as a moveable base for the tongue Aids in swallowing and speech Slide 11 Axial SkeletonVertebral Column Extends from the skull to the pelvis Composed of vertebrae (24) Supports the head and trunk of the body Protects the spinal cord Slide 12 Types of vertebrae Cervical (7) Thoracic(12) Lumbar(5) Sacrum (1) Coccyx (1) Axial SkeletonVertebral Column Slide 13 Supports the shoulder girdle and arms Protects the visceral organs in chest and upper abdomen Made of Ribs (12 pair2 float) Sternum (1 long bone with 3 divisions) Axial SkeletonThoracic Cage Slide 14 Appendicular Skeleton Slide 15 Appendicular SkeletonPectoral Girdle Supports arms Made of Clavicle (2) Scapula (2) Humerus (upper arm) Radius (lower arm) Ulna (lower arm, elbow) Olecranon process (on ulna) Handcarpals (wrist), metacarpals (hand) and phalanges (fingers) Slide 16 Appendicular SkeletonPelvic Girdle 2 coxal bones that come together to form the pelvis Strong stable support for vertebral column Attaches lower limbs to axial skeleton Made of Ilium Ischium Pubis Slide 17 Gender differences of the pelvis Slide 18 Femur (thigh) Patella (kneecap) Tibia (lower leg-shin) Fibula (lower leg-lateral) Foottarsals (ankle), metatarsals (foot) and phalanges (toes) Calcaneus (heel bone- large tarsal) Talus-where tibia articulates with tarsals Appendicular SkeletonLower Limbs Slide 19 Types of bones Long Bones Short Bones Flat Bones Irregular Bones Slide 20 Long Bones Parts of a long bone Epiphysis: end of the bone that forms a joint with another bone Epiphyseal disk: dark line at epiphysis where growth takes place Articular cartilage: cartilage that covers the ends of bones. Serves to cushion and decrease friction Slide 21 Long Bones Diaphysis: the main shaft of the bone Medullary Cavity: contains bone marrow, a specialized soft connective tissue Red bone marrow makes RBCs, WBCs and platelets Yellow bone marrow stores fat Periosteum: tough vascular covering of the bone that functions to form and repair bone tissue Slide 22 Long Bones Compact bone: tightly packed tissue that makes up the diaphysis; very strong Spongy bone: spongy inner portion of the bone that makes up the epiphysis; helps reduce the weight of the bone; provides strength at the ends of bones. Slide 23 Microscopic Structures of Bones Slide 24 Microscopic Structure of Bones Osteocytes: mature bone cells that are arranged around canals called Haversian canals Haversian canals hold blood vessels and nerves. Osteocytes secrete calcium and phosphorus that form extracellular matrix that is very hard. Slide 25 Lamellae-layers of calcified matrix Lacunae- holes in lamella where bone cells are Canaliculus-canals so bone cells can touch each other. Slide 26 Microscopic Structure of Bones Types of bone cells Osteoblasts: bone forming cells Osteoclasts: bone destroying cells break down bone for remodeling and release calcium in response to parathyroid Slide 27 Formation of the Human Skeleton In embryos, the skeleton is primarily hyaline cartilage During development, much of this cartilage is replaced by bone Cartilage remains in isolated areas Bridge of the nose Parts of ribs Joints Slide 28 Bone Growth (Ossification) Epiphyseal plates allow for lengthwise growth of long bones during childhood New cartilage is continuously formed Older cartilage becomes ossified Cartilage is broken down Enclosed cartilage is digested away, opening up a medullary cavity Bone replaces cartilage through the action of osteoblasts Slide 29 Bone Growth (Ossification) Bones are remodeled and lengthened until growth stops Bones are remodeled in response to two factors Blood calcium levels Pull of gravity and muscles on the skeleton Bones grow in width (called appositional growth) Slide 30 Long Bone Formation and Growth Figure 5.4a, step 1 Bone starting to replace cartilage In an embryo Bone collar Hyaline cartilage model (a) Slide 31 Long Bone Formation and Growth Figure 5.4a, step 2 Bone starting to replace cartilage In a fetusIn an embryo Growth in bone length Blood vessels Hyaline cartilage New center of bone growth Medullary cavity Bone collar Hyaline cartilage model (a) Slide 32 Long Bone Formation and Growth Figure 5.4a, step 3 Bone starting to replace cartilage Epiphyseal plate cartilage Articular cartilage Spongy bone In a childIn a fetusIn an embryo New bone forming Growth in bone width Growth in bone length Epiphyseal plate cartilage New bone forming Blood vessels Hyaline cartilage New center of bone growth Medullary cavity Bone collar Hyaline cartilage model (a) Slide 33 Broken Bones Fracturebreak in a bone Fracturebreak in a bone Types of bone fractures Closed fracturebreak that does not penetrate the skin Open fracturebroken bone penetrates through the skin Bone fractures are treated by reduction and immobilization Slide 34 Steps to healing broken 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 Slide 35 Types of Breaks Greenstick Fracture incomplete fracture, only one side of the bone is broken, causes bone to bend, common in children Slide 36 Types of Breaks Hairline fracture-- incomplete fractureit is a crack that does not break all the way through Slide 37 Types of Breaks Transverse simple fracturecomplete fractureoccurs when the bone is broken into two fragments and the break is straight across Slide 38 Types of Breaks Oblique simple fracturecomplete fractureoccurs when bone is broken into 2 fragments and the break is at an angle Slide 39 Types of Breaks Spiral simple fracturecomplete fractureoccurs when the bone is broken into 2 fragments and the break is at an angle that is twisted Slide 40 Types of Breaks Comminuted complete fractureit is a break that has many fragments Slide 41 Types of Breaks Compression fracture bone is crushed, common in skull and vertebral column