Muscle Flashcards
3 basic forms of movement
Amoeboid movement,
Muscle contraction
Ciliary and flagellar bending.
Locations , anatomy, Neural control and function of skeletal, cardiac and smooth muscles
Skeletal: skeleton, striated, voluntary, movement, heat production
Smooth: Hollow organs, not striated, involuntary, movement/control organ size.
Cardiac: Heart, Striated(difficult to see), involuntary, contraction of the heart.
What’s a fascicles and which connective tissue surrounds it
A group of muscle fibres is called a fascicle and its surrounded by perimysium
What are the specialised membranes within a muscle cell and their function?
The sarcoplasmic reticulum (SR) is an intracellular membrane network which is important in regulating [Ca2+]
Transverse tubules ( T tubules)
Describe the organisation of a sarcomere
2 dark lines called “Z line” define the boundaries of the sarcomere.
“M line” is a dark line at the centre
On either side of the “Z line” there is the “I band” (spans 2 sarcomeres) which is light and contains mostly thin filaments.
“A band” is the area between two “I bands” composed of mostly thick filaments portion of “A band” contains thin filaments which overlap from the “I band”
the portion of the “A band” which contains only thick filaments is called “H band”
What are the thick filaments of sarcomeres
Mostly Myosin
What are the thin filaments of sarcomeres
Mostly Actin
How are the origin and insertion of a muscle determined and how are they connected to the muscle
The origin is the side of the muscle nearest the core of the body, the insertion is the other side
Which connective tissue surrounds muscle fibres
endomysium
Which connective tissue surrounds the whole muscle
epimysium
What causes striations in skeletal muscles
The organised arrangement of myofibrils and the specific arrangement of thick and thin filaments within the myosin.
What is present on the myosin head
ATP binding site. Actin Binding site
What is present on the myosin neck and their functions
Essential light chain - maintain the head in the correct orientation and regulatory light chain - “regulating the activity of the head”
Structure if thin filaments
2 chains of actin wrapped around each other, 2 proteins called tropomyosin run in the grooves between the 2 actins. troponin is a complex composed of 3 actin molecules.
What experiment did Hugh Huxley carry out and what did it show
It proved the sliding filament theory using an electron microscope.in the 1950s
