Muscle Flashcards
What are the three types of muscle?
Smooth, cardiac & skeletal
What is the role of skeletal muscle?
It attaches via tendons to bone
Where is cardiac muscle found?
Only in the heart
What is the role of smooth muscle?
It lines blood vessels and some organs (ie. intestines)
Approximately how many muscles exist in the human body?
650+
The autonomic nervous system controls what muscle types?
Cardiac & smooth muscle
What muscle type does the somatic nervous system control?
Skeletal
Name the muscle types that are multinucleated and striated
Cardiac & skeletal
What muscle type is branched and has intercalated discs?
Cardiac
Name the three connective tissues of muscle
Epimysium, perimysium & endomysium
What cells can smooth muscle tissue regenerate from?
Pericytes
Can cardiac muscle regenerate?
No
Hypertrophy is the…
Increase of cell size
What cells repair skeletal muscle?
Satellite cells
What are skeletal muscle fibre bundles called?
Fascicles
What surrounds the myofibrils?
Sarcoplasm
What are sarcomeres?
Contractile units of muscle fibres composed of actin & myosin filaments
Muscle cells are also known as?
Muscle fibres/myocytes
What type of cell is skeletal muscle derived from?
Myoblast
Name the muscle cell membrane
Sarcolemma
What is the muscle cell cytoplasm called?
Sarcoplasm
What is the endomysium?
The innermost CT layer of muscle that wraps around individual muscle fibres
What is the role of the sarcoplasmic reticulum?
It stores & regulates calcium ions intracellularly
Describe the location and role of T tubules
They are extensions of sarcolemma that aid muscle contractions within fibres by conducting electrical impulses
What is the epimysium?
A dense irregular fibrous CT that covers the entire skeletal muscle. It protects muscles from friction against other muscles during movement
What is the role of the perimysium?
It is a thin CT that wraps around bundles of muscle fibres (fascicles)
Describe the morphology of skeletal muscle cells
It is unbranched and tubular
Myofibrils are composed of…
Bundles of myofilaments (actin & myosin)
How do sarcomeres shorten?
Myosin heads interact with actin filaments / the actin filaments are attached to Z lines
What causes the striations of muscle?
The alternating zones of thin & thick filaments
Describe the role of tropomyosin
A regulatory protein that prevents involuntary contraction
What is the role of ATP in muscle contraction?
Allows the myosin head to detach from actin
Name the binding site of calcium in muscle
Troponin
How do tropomyosin and troponin work together in the muscle?
They prevent the binding of myosin to actin during the resting state
Thin filaments are composed of…
Actin, troponin & tropomyosin
What types of muscles do gap junctions help with coordinated function?
Cardiac & smooth
Describe the filaments of skeletal muscle tissue
Thick & thin filaments overlap each other within A band of sarcomere
What is extensibility?
Ability of muscle tissue to be stretched without being damaged
Describe the structure of smooth muscle cells
They are unbranched, unstriated & have a single nucleus
What are the three cell junctions in intercalated discs?
Desmosomes, fascia adherens & gap junctions
