Muscle Tissue Flashcards
what are the characteristics of muscle tissue and explain?
excitability: muscle cells can respond to stimulus, contractility: muscle cells can forcefully shorten, extensibility: muscle cells can be stretched (lengthen) and elasticity: muscle cells can recoil after shortening or lengthening.
list the types of muscle and where they are found
skeletal muscle found attached to bones, cardiac muscle found ONLY in the heart and smooth muscle found in organs of the digestive, respiratory, urinary, reproductive tracts, the walls of blood vessels and in the arrector pili muscle of skin
what is a fascicle?
single skeletal muscle that is composed of large bundles of muscle fibers
What are Myofibrils?
Each myofibril is a bundle of thick and thin myofilaments
What are sacromere?
It’s the functional contractile unit of a muscle fiber.
What are the other names for think and thin myofilaments?
Actin- thin myofilaments and myosin- thick myofilaments
What are sarcomeres made up of?
Myofilaments that are organized into repeating functional units
Whats the A band?
Its the dark band of sarcomeres that has overlapping thick and thin myofilaments
What is an I band?
It is the side of the A band that only contains thin myofilaments.
Whats H zone/band?
It is the middle of the A band that only contains thick myofilaments
What of the M line?
Its located in the middle of each H band/zone
Z line? and what protein do they contain?
They mark the boundary between adjacent sarcomeres and the protein is called actinins
What are the connective Tissues Associated with Muscle Tissue and they’re found
Epimysium- surrounds the entire muscle
Perimysium- a fibrous layer that divides the skeletal muscle into compartments, each muscle fascicle is wrapped by the perimysium layer
Endomysium- elastic connective tissue that surrounds the individual skeletal muscle cells (muscle fibers)
Myosatelite cells?
They are stems cells that help repair damaged muscle tissue
Skeletal muscle tissue is highly WHAT and highly WHAT?
vascularized and innervated.
Myoblasts and what they do?
It occurs during embryonic development, groups of embryonic cells and they fuse together to form a multinucleated cell called a muscle fiber
what happens to the myoblasts that does not fuse?
they remain in the endomysium and they form myosatellite cells
Sarcoplasm?
its the cytoplasm of the muscle fiber
What is myoglobin?
It is the protein responsible for storing oxygen
What’s a sarcolemma
The plasma membrane of a muscle fiber
What are T tubules and what’s their other name?
They form passageways through the muscle fiber and they are called transverse tubules
What’s a sarcoplasmic reticulum
They are a type of smooth endoplasmic reticulum that forms a tubular network around each myofibril
