Muscle Up!

Lights, Camera, Action Potential

100

This ion movement is responsible for repolarization in cardiomyocytes and cardiac nodal cells. (Name ion and direction). 

K⁺ moving out of cells

200

These are the ion channels that are responsible for the pacemaker potential in cardiac nodal cells.

F-type votage-gated Na⁺ channels

300

These ion channels are responsible for the plateau phase in cardiomyocytes.

L-type Ca²⁺ channels

400

Movement of these two ions creates the plateau phase and prolongs the action potential in cardiomyocytes. (Name ions and direction of movement)

K⁺ moving out

Ca²⁺ moving in

500

This is the only depolarization phase in any action potential that is not created by Na⁺ but by Ca²⁺.

Depolarization phase in cardiac nodal cells. 

Show Me What You're Made Of

100

This protein makes up thick filaments.

Myosin

200

These are the three proteins in skeletal and cardiac muscle thin filaments.

Actin, troponin, and tropomyosin.

300

This structure includes gap junction and other cell-cell junction, is only found in cardiac muscle, and can be seen under a microscope. 

Intercalated discs

400

These two binding sites are on myosin heads in thick filaments.

ATP-binding site and actin-binding site

500

This section of the sarcomere has thick filaments. 

A band

Flex Your Knowledge

100

This skeletal muscle fiber type has the highest endurance, slowest contraction speed, and least power.  

Slow oxidative (type 1)

200

This occurs in skeletal muscle fiber membrane after acetylcholine binds to nicotinic receptors. This then triggers an action potential. 

End plate potential (EPP)

300

This will be used to produce ATP when a professional sprinter is running a 100-meter race. (Name metabolic process and fuel molecule/s). 

Glycolysis of glucose from glycogen or blood glucose. 

400

This is the protein that senses an action potential in T-tubules. 

DHP receptor

500

DAILY DOUBLE

These are the 4 ion channels involved in excitation-contraction coupling in skeletal muscle. (Name in correct order starting from arrival of action potential to terminal end of lower motor neuron)

Voltage-gated Ca²⁺ channels (releases Ach in neuromuscular junction)

Nicotinic receptor (causes EPP)

Voltage-gated Na⁺ channels (causes AP)

Ryanodine receptor (releases Ca²⁺ from SR to cytosol and causes contraction)

This or That?

100

This muscle type lacks troponin. 

Smooth muscle

200

This muscle type in stimulated by acetylcholine binding to nicotinic receptors.

Skeletal muscle. 

300

These muscle types are regulated by the autonomic nervous system. 

Smooth and cardiac muscle

400

These two muscle cell types have pacemaker potential. (Be as specific as possible). 

Cardiac nodal cells.

Single-unit smooth muscle cells. 

500

This muscle type is striated and has a long refractory period. 

Cardiac muscle. 

We'll Cross That Bridge When We Get To It

100

Binding of Ca²⁺ to this protein starts the cross-bridge cycle in skeletal and cardiac muscle. 

Troponin

200

Phosphorylation of myosin by this enzyme starts the cross-bridge cycle in smooth muscle.

Myosin light chain kinase (MLCK). 

300

This is caused by ATP binding to cross bridge. 

Cross-bridge detaches from actin. 

400

This event triggers the powerstroke step in the cross-bridge cycle. 

Release of ADP

500

This event starts cross-bridge cycling and causes contraction in all three muscle types.

Rise in cytosolic Ca²⁺