Ch 6 SKELETAL SYSTEM How many bones do you have in your body?
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Transcript of Ch 6 SKELETAL SYSTEM How many bones do you have in your body?
Ch 6 SKELETAL SYSTEM
How many bones do you have in your body?
Label what you can
FUNCTIONS1. SUPPORT– provides framework for body, support for
soft tissues, attachment for tendons of skeletal muscles
FUNCTIONS2. PROTECTION– of internal organs (brain,
heart and lungs, spinal cord)
FUNCTIONS3. LEVERAGE– muscles contract and
pull on bones to provide movement
FUNCTIONS4. MINERAL STORAGE– contribute to bone
strength, stored calcium and phosphorus can be distributed to body at will (need Ca2+ for nerve impulses to cross synaptic cleft)
FUNCTIONS5. BLOOD PRODUCTION– red marrow
produces blood cells
Functions6. ENERGY STORAGE– yellow marrow
stores lipid (Energy reserve)
Types of BonesA. LONG BONES– longer than they are wide; curved;
strong-absorb stress at several different pointsEXAMPLES: femur, tibia, ulna, humerus, fingers, toes
Types of BonesB. SHORT BONES– as wide as they are tall;
EXAMPLES: wrist and ankle bones
TYPES OF BONESTYPES OF Short bonesSESAMOID BONES – small; usually located in
tendons (where there is a lot of physical stress) of hands, feet and knees; variable (#, ossification)
EXAMPLES: knee cap (everyone has)
fabella
TYPES OF BONESC. FLAT BONES– thin spongy bone sandwiched between
two layers of compact bone; protective; forms large surface area for muscle attachment; site of blood production in adults
EXAMPLES: cranial, sternum, rib, scapula, ilium
TYPES OF BONESD. IRREGULAR BONES– complex shapes
EXAMPLES: vertebrae, some facial bones, heel, ischium
TYPES OF BONESE. SUTURAL BONES– small bones b/w joints
of some cranial bones; variable (#)
HISTOLOGY (OSSEOUS TISSUE)Composition: 1/3 COLLAGEN FIBERS (protein); function: FLEXIBILITY +
STRENGTH
2/3 MINERAL SALTS (mainly Ca & P); function : HARDNESS
Connective Tissue
Cells Matrix
Fibers Ground Substance
Connective Tissue
Cells Matrix
Fibers Ground Substance
Histology (Osseous Tissue): Cell Types:1. Osteoprogenitor (Osteogenic) Cells: stem cells (only
bone cells that divide), precursors of osteoblasts2. Osteoblasts: Bone building cells (secrete collagen;
mineral salts deposited in collagen framework = calcification)
3. Osteocytes:– mature bone cells that maintain daily cellular activities of bone; most numerous
4. Osteoclasts: huge multinucleated cells; break down bone & allow for growth, maintenance & repair (lysosomal enzymes + acids digest protein & minerals = resorption (reg. Blood Ca2+)
Histology (Osseous Tissue): Cell Types:
Osteoprogenitor Cells Osteoblasts Osteocytes
• What is the hardest substance in the body?
What spongy bone looks like.Video Links:
Short clip of Osteoblasts and Osteoclasts http://www.youtube.com/watch?v=78RBpWSOl08
Explanation of how bone is remodeled: http://www.youtube.com/watch?NR=1&v=0dV1Bwe2v6c&feature=endscreen
• Bone Remodeling: • http://www.youtube.com/watch?v=0dV1Bwe
2v6c
• Rank Ligand: http://www.youtube.com/watch?NR=1&v=GpMV197xZXc&feature=endscreen
LONG BONE GROSS ANATOMY (Ex: HUMERUS)
Each bone is an ORGAN With its own osseous tissue, cartilage, dense connective tissue, epithelial tissue, adipose tissue and nervous tissue
LONG BONE GROSS ANATOMY
DIAPHYSIS – long, main portion of bone (shaft)
LONG BONE GROSS ANATOMY
EPIPHYSIS – proximal and distal ends of bone (heads)
LONG BONE GROSS ANATOMY
METAPHYSIS – region where diaphysis meets epiphysis
LONG BONE
ARTICULAR CARTILAGE– thin layer of hyaline cartilage covering ends (epiphyses) of bones that contact other bones (@ articulation/joint), reduces friction, absorbs shock @ freely moveable joints
LONG BONE GROSS ANATOMY PERIOSTEUM– dense, white fibrous covering (dense irregular conn. tissue) around surface of bone – protects, nourishes, repairs, allows for growth, allows for attachment of tendons (& muscle) and ligaments
LONG BONE GROSS ANATOMY (Ex: HUMERUS)PERIOSTEUM– dense, white fibrous covering
1.FIBROUS OUTER LAYER: OUTER LAYER: tendon (muscle) and ligament attachment and provides route for vascular and nervous tissue2. CELLULAR INNER LAYER: growth & remodeling; osteoprogenitor cells, osteoblasts, & osteoclasts
LONG BONE GROSS ANATOMY
LONG BONE GROSS ANATOMY (Ex: HUMERUS
MEDULLARY CAVITY – cavity containing yellow marrow (fat cells – energy storage) in adults
LONG BONE GROSS ANATOMY (Ex: HUMERUS)
ENDOSTEUM – lining of medullary cavity containing osteoprogenitor cells, osteoblasts, & osteoclasts