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DAT ch 10
bio- muscle and locomotion from coursesaver notes
Question | Answer |
---|---|
Cartilage | type of connective tissue that is softer and more flexible than bone; ear, nose, joints; formed from mesenchyme tissue - chondrocytes - produce collagen, ground substance, & elastin fibers |
Bone | mineralized connective tissue that is hard and elastic; compact and spongy |
Compact Bone | dense bone that does not appear to have cavities; bone matrix is deposited in osteons with a central microscopic channel called a Haversian canal surrounded by concentric circles of bony matrix called lamellae |
Spongy Bone | less dense and consists of an interconnecting lattice of bony spicules; filled with red / yellow bone marrow; (yellow is full of adipose tissue) |
epiphyseal plates | where bone growth occurs in long bones |
Osteoblasts | BUILD bone; mature into osteocytes |
Osteoclasts | destroy bone; bone resorption |
Endochondral Ossification | existing cartilage is replaced by bone; LONG bones |
Intramembranous Ossification | messenchymal (embryonic, undifferentiated) connective tissue is transformed into and replaced by bone |
Axial Skeleton | skull, vertebral column, and rib cage |
Appendicular Skeleton | bones of the appendages and pectoral and pelvic girdles |
Sutures | immovable joints; hold skull together |
Ligaments | connect bone-to-bone |
Tendons | muscle-to-bone |
Origin | point of attachment of stationary bone |
Insertion | point of attachment of movable bone |
Sacromere | is composed of thin filaments (actin) and thick filaments (myosin) |
Contraction | action potential conducted along sarcolemma and T system => into muscle fiber => sarcoplasmic reticulum release Ca+ ions => contraction of sacromere |
During contraction ___ bands reduce in size //___ band does not | A,H & I |
Strength of contraction can be increased by | recruiting more muscle fibers |
Simple Twitch | response of a single muscle fiber to brief stimulus; latent, contraction, relax ‑Latent period – time b/w stimulation and onset of contraction; lag ‑Contraction ‑Relaxation – absolute refractory period; unresponsive to stimulus |
Tetanus | continuous contractions; so frequent that the muscle cannot relax; stronger than twitch |
Tonus | state of partial contraction |
Skeletal Muscle | voluntary movement; each fiber is multinucleated; striations of light/dark bands; mitochondria is very abundant |
Smooth Muscle | involuntary movement; myogenic; ONE central nucleus; LACK striations; ex lining of bladder, uterus, digestive tract |
Cardiac Muscle | striated appearance (sacromeres); myogenic; one or TWO central nucleus |
Myogenic | capable of contracting without stimulation from nerve cells |
tropomyosin | on actin - blocks the attachment site for the myosin crossbridge, thus preventing contraction |
troponin | attached to the protein tropomyosin and lies within the groove between actin filaments. calcium attaches to it and makes it change shape and expose active myosin binding sites on the actin filaments. This forms cross bridges and contraction of the muscle |