In describing the cellular components of skeletal muscle, several specialized terms are used such as the plasma membrane of skeletal muscle is called the sarcolemma; its cytoplasm is known as sarcoplasm; the endoplasmic reticulum is called the sarcoplasmic reticulum. The term motor unit is used to describe a group of muscle fibers innervated by a single motor nerve, the fibers within a single motor unit contract simultaneously (Van and Marleen,2000). Each muscle cell is surrounded by a sarcolemma and has many nuclei occurring at intervals along its length. The nuclei are displaced peripherally within a cross section of the sarcoplasm while a large number of longitudinal myofibrils, groups of arranged contractile proteins, occupy most of the center space(Tortora and Derrickson,2011). Based on nerve stimulation studies, skeletal muscles are divided into two muscle fiber types, the first type is called Slow-twitch muscle fibers which mainly rely on aerobic metabolism.
Deep Fascia connective tissue with dense irregular tissue that lines the body wall and limbs. Muscle Cell muscle fibers that are elongated and striated and multinucleated. A skeletal muscle fiber is actually embryonic cells that have fused together to form one large cell with multiple nuclei. Perimysium dense
A)osteogenic cells B)osteoblasts C)osteocytes D)endosteum cells E)osteoclasts Feedback: Correct! 5 CORRECT The basic structural unit of compact bone is termed ________________. A)lamellae B)periosteum C)endosteum D)osteon E)canaliculi Feedback: Correct! 6 CORRECT Which large multinucleate cells found in bones secrete enzymes to reabsorb matrix? A)osteoclasts B)osteocytes C)osteoblasts D)osteoprogenitors E)chondrocytes Feedback: Correct!
The muscle tissue has four main properties; Excitability, Contractibility, Extensibility and Elasticity. Excitability; The ability to respond to stimuli. Contractibility; The ability to contract. Extensibility; The ability to stretch without causing a tear. Elasticity; The ability to be able to return to normal shape.
The axial skeleton includes the skull, spinal column, ribs and sternum. The appendicular skeleton includes all upper and lower extremities, the shoulder girdle and the pelvic girdle. Bones come in four main shapes, long, short, flat and irregular and are composed of webs of collagen fibers reinforced with calcium and phosphorous. The collagen provides flexibility while the minerals provide tensile strength. The axial skeletal makes up the upper structure of the skeletal system.
Flat bones provide protection for the internal organs including the brain, heart, lungs, liver and kidneys. The flat bone is made up of two layers of compact bone with a layer of spongy bone in the middle. 3) The epiphyseal plate is located in the metaphysis of the long bones which is found between the epiphysis and diaphysis. The epiphyseal plate is made up of hyaline cartilage. The cartilage makes it possible for the diaphysis to grow in length, thus the epiphyseal plate is also known as the growth plate.
Section 17.3- The muscular system makes movement possible Vocabulary 1. Muscular system- The muscles of the body that together with the skeletal system, function to produce movement 2. Skeletal muscle – A muscle that attaches to the skeleton 3. Voluntary muscle- A muscle that can be moved at will 4. Smooth muscle- Muscle that performs involuntary movement and is found inside certain organs such as the stomach 5.
What is a tendon made of? Tendons are made of dense, regular connective tissue. This form of connective tissue consists of densely packed bundles of collagen fibres. These fibres all run parallel to each other in the direction of the pull that is generated on the tendon What are agonistic muscles? Agonistic muscles are a classification used to describe a muscle that causes specific movement or possibly several movements to occur through the process of its own contraction.
Describe the function of a ligament and of a tendon. -Fasciae are the fibrous connective tissue sheets that wrap around muscle bundles to hold them in place. Ligaments are strong, flexible bands (or cords) that hold bones firmly together at the joints. Tendons are white, glistening bands that attach skeletal muscles to the bones. 5.)