Electrical excitation in a muscle fibre most directly causes:
(1) Movement of tropomyosin
(2) Attachment of the cross bridges to actin
(3) Release of Ca+2 from sarcoplasmic reticulum
(4) Splitting of ATP
The energy for muscle contraction is most directly obtained from:
(1) Phosphocreatine
(2) ATP
(3) Anaerobic respiration
(4) Aerobic respiration
Put the following phrases in proper order to describe what occurs at the neuromuscular junction to trigger muscle contraction:
I. | Receptor sites on sarcolemma. |
II. | Nerve impulse. |
III. | Release of Ca+2 from sarcoplasmic reticulum |
IV. | The neurotransmitter acetylcholine is released |
V. | Sarcomere shorten |
VI. | Synaptic cleft |
VII. | Spread of impulses over sarcolemma on T-tubules |
1. II, IV, I, VI, VII, III, V
2. II, IV, VI, I, VII, III, V
3. I, II, III, IV, V, VI, VII
4. VII, VI, V, IV, III, II, I
Go through the following diagram describing muscle contraction:
Now identify A to E:
(1) A - Cross bridge, B - Cross bridge formation, C - Breaking of cross bridge, D - Sliding (rotation), E - ATP
(2) A - Cross bridge, B - Cross bridge formation, C - Sliding / rotation, D - Breaking of cross bridge, E - ATP
(3) A - Cross bridge, B - Breaking of Cross bridge, C - sliding / rotation, D - Cross bridge formation, E - AMP
(4) A - Cross bridge, B - Cross bridge formation, C - Sliding / rotation, D - ADP, E - Breaking of cross bridge
The muscle band that remains unchanged during muscle contraction and relaxation of the skeletal muscle is:
(1) I
(2) A
(3) H
(4) Z-line
The compound or pigment acting as an oxygen store in skeletal muscles is:
(1) Myoglobin
(2) Haemoglobin
(3) Myokinase or ATP
(4) Cytochrome
I. Number of mitochondria less.
II. Number of mitochondria more
III. Sarcoplasmic reticulum is abundant
IV. Myoglobin content high
V. Sarcoplasmic reticulum moderate
VI. Aerobic muscles
VII. Depend on anaerobic respiration for energy
VIII. Less myoglobin content
A. Red muscles B. White muscles
Identify above (I to VIII) traits as characteristic of A and B types of muscles:
(1) A - I, III, VII, VIII; B - II, IV, V, VI
(2) A - II, IV, V, VI; B - I, III, VII, VIII
(3) A - I, III, IV, VII; B - II, V, VI, VIII
(4) A - II, V, VI, VIII; B - I, III, IV, VII
How many bones make up the human skeleton?
(1) 948
(2) 96
(3) 796
(4) 206
Number of bones in human axial skeleton is:
(1) 80
(2) 106
(3) 206
(4) None of these
Match Column-I with Column-II:
Column-I Column-II (Number of bones)
A. Cranium / Brainbox I. 22
B. Skull (Cranial and facial bones) II. 8
C. Face III. 14
D. Hind limb IV. 12 pairs
E. Ribs V. 30
(1) A - I, B - II, C - III, D - V, E - IV
(2) A - II, B - I, C - III, D - V, E - IV
(3) A - I, B - II, C - III, D - IV, E - V
(4) A - V, B - IV, C - III, D - II, A - I