Muscle part 3.pdf

Muscle Part 3 Skeletal Muscle Characteristics: 1. Voluntary: controlled by the motor nervous system, capable of quick forceful contractions. Cells can be extensive (very long) as they can reach one meter in some animals. 2. Skeletal muscle cells are unbranched, striated, multinucleat...

Muscle Part 3 Skeletal Muscle Characteristics: 1. Voluntary: controlled by the motor nervous system, capable of quick forceful contractions. Cells can be extensive (very long) as they can reach one meter in some animals. 2. Skeletal muscle cells are unbranched, striated, multinucleated (syncytia). Nuclei are peripherally placed. 3. location/function: conscious movement of the muscles that are connected to the bone via tendons ( what type of tissue makes up tendons?) dense regular CT. 4. Muscle cell = muscle fiber. 5. Sarcomere= actual contractile apparatus and made up of actin & myosin. Skeletal Muscle Epimysium= Dense irregular CT surrounding the whole muscular organ. Perimysium= CT of fibrous sheaths surrounding each fascicle. ( contain blood vessels and neurons) Fascicle= package of muscle fibers Endomysium= Areolar (loose) CT surrounds individual muscle fibers (muscle cells) that contains tiny capillaries and individual neurons providing innervation and nutrient to muscle fibers. Sarcomere= contractile functional unit from one z-line to the next z-line. Myofilaments= actin & myosin Skeletal Muscle Skeletal Muscle Muscle contraction and relaxation occur by the: Sliding Filament Model (theory) by a series of molecular events called the cross-bridge cycle as seen in the following video. Myofilaments (Actin and Myosin) Comparison between the 3 types of muscles: Comparison between the 3 types of muscles: