Download original University of PORT-HARCOURT (UNIPORT) Physiology Past Questions and Answers below for your practice. We discovered 169 repeated questions from 2008 to 2013. Read it below and download your complete copy now.
This product contains physiology past MCQ for students of the following departments in UNIPORT:
- Medicine and Surgery
- Nursing Science
- Medical Radiography
- Human Anatomy
- Medical Laboratory Science
1. Which of the following values is closest to the resting membrane potential of mammalian cells?
a. -20 mV
b. -60 mV
c. +60 mV
d. +20 mV
e. +30 mV
Correct answer: (b) -60 mV
• The resting membrane potential of mammalian cells is negative and is around -50 to -70 mV in many cells.
• Nerve and muscle cells generally have more negative membrane potentials than other cells (in the region of -70 to -90 mV).
2. The amount of tension generated by a skeletal muscle:
a. Is increased by summation
b. Is greatest when the muscle is between 100 and 120% of its optimal resting length
c. Is increased by recruiting more motor units
d. All of the above
Correct answer (d) All of the above
• Summation is the increase in tension that results when a muscle fiber is unable to relax between twitches. Individual twitches overlap and produce a continuous, smooth contraction of increasing strength. Summation requires increasing stimulus frequency. At low frequency, the muscle fiber will relax before the next stimulus impulse occurs.
• Recruitment is increasing the number of motor units responding to a single stimulus, which results in the increase in tension in whole muscle Recruitment requires increasing stimulus amplitude. Below threshold stimulus, there is no response from the muscle. As stimulus amplitude increases, only the muscle fibers with the lowest threshold initially respond and contract. As the stimulus amplitude continues to increase, an increasing number of motor units will be recruited so that the strength of the contraction, or tension, increases as well. Once all motor units in a muscle have been recruited, an increase in the stimulus amplitude will not result in any increase in tension. The contraction of a whole muscle can produce strong, weak or intermediate contractions depending upon how many motor units are stimulated.
3. The cell organelle, which increase their number by self-replication are:
a. Endoplasmic reticulum
b. Golgi apparatus
Correct answer: (d) Mitochondria
• Mitochondria (and chloroplasts) are self-replicating organelles. They are produced only by growth and division of pre-existing mitochondria (or chloroplasts).
• Mitochondria and chloroplasts contain DNA genomes with a small number of functional genes.
o Mitochondrial DNA = mtDNA
o Chloroplast DNA = cpDNA
4. The risk of osteoporosis is increased
A. In people between 60 and 90 years of age as compared with people between 40 and 50 years of age.
B. In males as compared with females.
C. During prolonged periods of bedrest.
D. When both ovaries are removed in a premenopausal woman.
E. During treatment with adrenal glucocorticoids.
A. True – Bone density declines, particularly after 60.
B. False – The risk is considerably greater in females, especially after the menopause.
C. True – Normal calcification requires exposure of the bone to gravitational and other stress.
D. True – This leads to an artificial menopause and a considerably increased risk.
E. True – These lead to breakdown of bone collagen thereby reducing bone strength.
5. Blood eosinophils
A. Have agranular cytoplasm.
B. Are about a quarter of all leukocytes.
C. Are relatively abundant in the mucosa of the respiratory, urinary and alimentary tracts.
D. Release cytokines.
E. Increase in number in viral infections.
A. False – They have eosinophilic granules (eosinophilic granulocytes).
B. False – Only 1–4 per cent of white cells are eosinophils.
C. True – They are involved in mucosal immunity.
D. True – Interleukin 4 and platelet activating factor (PAF).
E. False – Their number increases in parasitic infections and allergic conditions.