Lecture 27 Flashcards
The function of skeletal muscle:
- Posture, movement, heat
- On-demand individual-specific
The function of cardiac muscle:
- Pumping bloof
- Continuous
- All at once
- Build pressure
At the connection of two myocytes in cardiac muscle you’ll find….
- An intercalated disc
- Inside the intercalated disc you’ll find z discs
How do myocytes in the cardiac muscle connect?
- Gap junction (electrical)
- Desmosome (mechanical)
In the right atrium ______ cells are located. The depolarisation wave is initiated in the ______ node and travels to the _____ node.
- Pacemaker
- Sinoatrial (SA) node
- Atrioventricular (AV) node
What is the order of depolarisation in the heart?
- Atria
- Septum
- Apex
- Ventricles (via purkinje fibres)
- FURTHER DEPOLARISATION up ^^^
- Fully depolarised, contraction!
The smooth muscle cell has no ____ cells which means it’s not ____. There are ____ length changes. Single-unit smooth muscle cells also have ____ ____ like cardiac muscle. Which means that action potentials can reach other cells through them.
- Sarcomeres
- Striated
- Large
- Gap junctions
Smooth muscle cells can be found in the ____ _____.
- Digestive tract
In a multi-unit smooth muscle cell they are ______ innervated by neurons.
- Individually
Relaxation of the smooth muscle cells = ______. The opposite of this is ______.
- Vasodilation
- More blood flow
- Decrease resistance
- Vasoconstriction
Smooth Muscle: Excitation-Contraction
- Action potential / hormones make Calcium ride
- C2+ binds to calmodulin
- Ca-calmoduo\lin complext activates MLCK
- MLCK activates MLC which activates cross bridge
- Myosin filament regulated
Skeletal cells have …… cells
- Long, cylindrical, multinucleate
Cardiac muscle cells have….cells
- Mononucleate
- Branching
Smooth muscle tissues has …….cells
- Mononucleate
- Spindle-shaped
In skeletal and cardiac muscle, ____ and myosin organised along an _____ therefore stronger _____ along the axis. ____ filament regulated. Needs calcium to bind to ____.
- Actin
- Axon
- Force
- Thin
- Troponin
In smooth muscle, actin and _____ arranged in various directions so are ____. ___ filament regulated. ____ needed for calmodulin.
- Myosin
- Weak
- Thick
- Calcium
In which types of muscle can action potentials be spread from cell to cell?
- Cardiac
- Smooth (only in single-unit)
Which types of muscles do we have control over?
- Skeletal
What type of muscle do we not have control over? (Involuntary)
- Cardiac
- Smooth
Speed of contraction for muscle types…
- Skeletal (fast)
- Cardiac (slow)
- Smooth muscle (very slow)
Important info to remember:
- Why do we need muscle?
- Structure
- Mechanism of contraction
- Energy source for contraction of skeletal muscle
- Twitch and tetanus
- Skeletal muscle fibre types
- Structural/functional differences of all muscle types
