Smooth Muscle

Question 1

Where is tonic smooth muscle most likely to be located?
A. Small intestine
B. Blood vessels
C. Large Intestine
D. Urinary bladder
E. Oesophagus

Answer 1

B

Question 2

What is a key difference between smooth and skeletal muscle?
A. Smooth muscle is faster to contract than skeletal
B. Smooth muscle cells are able to coordinate contraction but skeletal cannot
C. Smooth muscle does not have actin but skeletal muscle does
D. Skeletal muscle has the ability to increase force whereas smooth muscle cannot
E. Skeletal muscle contraction is initiated by calcium and smooth muscle is not

Answer 2

B

Question 3

What is the role of gap junctions in smooth muscle cells?
A. Provide a barrier between neighbouring cells
B. Functions similarly to T tubules in allowing the action potential to travel down cell membrane
C. Allow rapid spread of electrical signals to neighbouring cells
D. Anchor the filament actin within cell
E. Provide a gap between the cell

Answer 3

C

Question 4

Which receptors are responsible for release of calcium from the sarcoplasmic reticulum in smooth muscle cells?
A. DHP receptors
B. IP3 receptors
C. Receptors on sodium channels
D. Receptors on potassium channels
E. Both DHP and IP3 receptors

Answer 4

B

Question 5

What will stop smooth muscle contraction?
A. Binding sites on actin being covered by tropomyosin
B. Calcium unbinding to troponin
C. Myosin light chain kinase (MLCK) activity decreasing
D. Increase in calcium entering cell
E. Additional action potential

Answer 5

C