Muscle Flashcards
Where is skeletal muscle?
What microstructure?
Voluntary or involuntary?
On bones by tendons
striated/striped
Both
Where Cardiac Muscle?
What microstructure?
Voluntary or involuntary?
In the heart
stirated
involuntary
Where is smooth muscle?
What microstructure?
Voluntary or involuntary?
Walls of hollow organs
Non-sirated
Involuntary
What are the points of attatchment of skeletal muscles called?
Wich mooves the least?
Origin and insterion
Origin mooves the least
What is a group of sk muscles that work together called?
synergists
What is a prime moover and fixator?
- Prime moover is the muscle that makes the main moovment
- A fixator stabalizes the main moover
What are pairs of muscles that oppose to eachother called?
antagonists
What needs to happen for a muscle to uncontract?
- A muscle or gravity pulling it back to it’s original position
What type of skeletal muscle is powerfull with a small range of moovment?
Parallel muscle
What type of skeletal muscle is less powerful but has a broader range of moovment?
Unipennate
Name 2 special properties of muscle cells
The are multinuclate
they ar rich in mitocondria and glycogen
What gives muscles their stratified structure?
the arrangement of MYOFIBRILS (the contractile proteins) within the cell
What is the outermost layer of dense fibrous
connective tissue that encloses the whole muscle called?
Fascia or Epimysium
What is the connective tissue that encloses a bundle of muscle cells called?
What is each bundle called?
Perymisium
FASCICLE
What is the loose connective tissue within the perrymisium called?
Endomysium
MUSCLE CELLS – each muscle cell is packed with myofibrils,
mainly ______and _______. The myofibrils are arranged in a
repeating structure called a _________.
Actin and myosin
Sarcomere
Where does a motor nerve and muscle cell meet?
Neuromuscular junction
What chemical is released when a signal is recieved at the neuromuscular junciton?
neurotransmitter (acetylcholine)
What does Acetylcholene do?
What does this cause?
It binds to a receptor on the muscle cell
Change in ion pemeability wich changes the voltage acorss the cell membrane
What is initiated when the voltage reaches threshold
Action Potential
Via what does the action potenital propogate in to the muscle cell?
T-tubles
The action potential causes _______ to release its ___stores.
sarcoplasmic reticulum
Ca++
What do the released Ca++ bind to?
What does this then bind to?
What does this cause?
- Troponin
- TROPOMYOSIN
- Causes the tropomyosin to moove aside and expose the myosin binding sites on the actin
What happens when the myosin actin sites on the actin are exposed?
What provides the energy?
Myosin binds to acting and myosin mooves relative to actin. The myosin heas then unbinds and straightens
ATP
What happens when the nerve signal stops?
- the Ach signals stop
- Troponin gives up Ca++
- Myosin binding sites are covered up again
- Muscle relaxes, but stays the same length
What is the force of the contraction of a muscle dependent on? (2)
a) The amount of overlap between the actin and myosin (more overlap more strength)
b) the frequency of stimulation (affecting the amount of Ca++ released
What happens when a muscle in in the Tetanus state?
Relaxation phase is eliminated
In TETANUS the sarcoplasmic reticulum has no time to remove Ca++ and the high Ca++ makes the contraction continuous
Where can a muscle get ATP from if ATP runs out?
From ceratine phosphate
What is the process of producing ATP in the mitochondria called?
What does this require?
What happens if there is not enough of this?
Glycolysis and the TCA cycle
Oxygen
Lactic acid
