Muscles

Question 1

What are the three main types of muscle tissues? (2 groups)

Answer 1

STRIATED MUSCLE:
-Skeletal Muscle
-Cardiac Muscle

SMOOTH MUSCLE:

Question 2

What are some characteristics of striated muscle? (3)

Answer 2

1) Single axis of contraction (1 direction)

2) Fast (controlled by nerves & connected end-to-end so cumulative effect output)

3) Voluntary bodily movements (acts on endo/exoskeleton)

Question 3

What are some characteristics of smooth muscle? (3)

Answer 3

1) Multiaxial contraction (3D)

2) Slow

3) Acts on itself (internal organs –> involuntary peristaltic movement like stomach)

Question 4

Explain the myosin-actin cycle?

Answer 4

1) rest state (not connected)

2) ATP hydrolysed to ADP, cross bridge formed (muscle activated ca2+ increases)

3) power stroke (P released triggers myosin head pivot, pulling actin, ATP released)

4) detatchment (new ATP binds to myosin head, detatched from actin)

5) reactivation (ATP decomposes to ADP & Pi causing myosin head to recock into position.

Question 5

If you stimulate a single motor neuron what will happen?

Answer 5

It will result in the activation of a single motor unit (a motor neuron and the muscle fibers it innervates).

This causes a small, localized muscle contraction, a twitch.