Organization Cell (ex=muscle cell) Tissues (many of the same types of cells ex muscle tissue) Organ...
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Transcript of Organization Cell (ex=muscle cell) Tissues (many of the same types of cells ex muscle tissue) Organ...
Organization
• Cell (ex=muscle cell) • Tissues (many of the same types of cells ex
muscle tissue)• Organ (many tissues that work together ex
heart)• Organ system level (many organs work
together ex circulatory system)• Organism level (many organ systems work
together)
Bones and ligaments
Bone Structure
• Compact bone – hard outer surface
• Spongy bone – Swiss cheese like matrix interior. To cushion impact.
• Bone marrow – source of red and white blood cells
• Haversian Canals – blood vessel canals through compact bone
osteoporosis
• Disease of the bone, causes of which are largely unknown.– Mineral deficiencies promote
disease, especially Calcium.– Decrease in bone density– Predominantly older women– Prevention – Get plenty of
Calcium at a young age, exercise helps build bone strength
Joints – 4 types
• Ball and socket – all directions– Shoulder and hips
• Pivot joints – twist around– Arm, vertebrae
• Hinge joints – lever or hinge action– knees, fingers, toes
• Gliding – slide past one another– Wrist, ankle
Ligaments
• TOUGH connective tissue that links bones to bones
Ligaments
• Connect bone to bone (joints)
Tendons
• Collagen connective tissue that links bone to muscle. When muscle contracts, pulls on tendon, moves bone.
Muscles and Muscular Contraction
3 types of muscle cells
• Smooth muscle – internal organ walls, blood vessels (enables dilation and contraction)– Sheets of cells, all
acting in concert– Many work together to
squeeze– Involuntary muscle
• Cardiac Muscle– Only found in heart– Striated– Involuntary– group of cells contract
together
• Skeletal Muscle•Voluntary muscle• Multinucleated•Striated•The muscles in your arms, legs, etc.
Skeletal cont…
• Structure:
MuscleFasicleMyofiber (cell) Myofibril (with
many sarcomeres)Myofilaments
• Many myofibers connected lengthwise through entire fiber
• Many mitochondria• Many nuclei (why? The multiple
nuclei arise from the fact that each muscle fiber develops from the fusion of many cells (called myoblasts).
Skeletal cont…
• Sarcomere (small part of myofibril)– Made up of thin
(Actin) and thick (Myosin) filaments
– Thin slide across thick
Contraction – Sliding Filament Theory
• When muscle contracts its shortens. When muscle relaxes it DOES NOT lengthen beyond relaxed state
• Actin and Myosin slide across one another (they do not shorten or lengthen)
• Myosin head binds actin and pulls it, causing sliding. Requires help of Calcium and _______.ATP
Actin/Myosin animation