Ch. 10.1 Intro and anatomy of skeletal muscle Flashcards
What are the five functions of skeletal muscle?
Movement Body Posture Protection and Support Regulating elimination of material Heat
What’s another name for muscle cells?
Muscle fibers
Epimysium
Layer of dense irregular connective tissue that surrounds the whole muscle.
Perimysium
Layer of dense irregular connective tissue around each fascicle.
Endomysium
Layer of areolar connective tissue which surrounds each muscle fiber. These electrically insulate each muscle fiber.
What is a tendon made up of?
Epi, peri, and endomysium. Made of dense regular connective tissue. These are thick.
Aponeurosis-
Thin flattened sheet of dense regular connective tissue.
What is the function of tendons and aponeurosis?
Attaching muscle to skeletal component (bone or ligament) or to a fascia.
Deep fascia- location and function
Expansive sheet of dense irregular connective tissue external to the epimysium.
Separates individual muscle bundles, binds together muscles of a similar function, contains nerves, blood vessels, and lymph vessels, fills space between muscles.
Superficial fascia
Composed of areolar tissue and adipose connective
Separates muscle from skin.
What layers do skeletal muscles’ vascular penetrate?
Epimysium and perimysium, but stop at the endomyseium where they become capillaries and are the sight of gas exchange, waste pick up, and nutrient deposition.
Somatic motor neurons
Motor neurons that extend from the brain and spinal cord to control muscles.
What layers do axons extend through?
Epi, peri, and endomysium and almost make contact with individual muscles fibers.
Name of the gap between the somatic motor neuron axon and the muscle fiber
Neuromuscular junction
Sarcoplasm
Cytoplasm that is inside skeletal muscle fibers.
Myoblasts
Embryonic muscle cells that fuse together during development. This is the reason the skeletal muscle fibers are multinucleate.
What are the steps of the sodium potassium pump?
1) 3 NA+ ions from inside the cell bond to NA+ pump in the cell wall.
2) ATP is broken into ADP and additional phosphate on the protein which provides energy to change the pump’s shape.
3) This releases NA+ to the outside of the cell. And pump shape changes so NA+ can’t bond to pump while it is facing outside the cell.
4) 2 K+ ions bond to activate pump that is still facing the outside. The protein then changes shape again and the K+ is released to the inside of the cell.
What are the four properties of a muscle?
Excitability, conductivity, contractility, extensibility, elasticity
What are the general functions of a muscle?
Movement, posture, protection, joint stabilization, and heat generation.
What are satellite cells?
Adult stem cells that can help with muscle tissue repair if muscle is damaged.
Sarcolema
Plasma membrane of a skeletal muscle fiber.
Define t-tubules and their function.
Also called transversals tubules- these reach deep into the the skeletal muscle fiber to the sarcoplamic reticulum. Sarcoplasmis reticulum is the endoplasmic reticulum of the muscle cell.
What is the order of organization of muscle from largest to smallest.
Skeletal muscle, fascicle, muscle fiber, myofibril, myofiliment.
Sarcoplasmic reticulum
Internal membrane complex of the muscle. Segments of this fit around myofibrils like a sleeve. At either ends these sleeve segments are terminal cisternae.
