Tag: human muscular system

Questions Related to human muscular system

Muscles containing large amounts of myoglobin are likely to be found in a

  1. Marathon runner

  2. 100 m sprinter

  3. High jumper

  4. Gymnast


Correct Option: A
Explanation:

In the marathon runners, the skeletal muscles are of the type of slow twitch. These type of muscles are known for the prolonged activity and so contain a large amount of myoglobin which carries the oxygen to the muscle fibers. They need slow and continuous supply of oxygen which is provided by the slow twitch muscle fibres. 

Thus, the correct answer is 

Muscle activity causes

  1. Increase in body temperature

  2. Decrease in BMR

  3. Decrease in venous return

  4. Reduction in blood and lymph flow


Correct Option: A
Explanation:

Muscle activity causes an increase in body temperature. During muscle contraction, the stored energy which is ATP breaks down into ADP and Pi to produce energy that is required for muscle activity. This is an exothermic reaction which causes an increase in body temperature. when skeletal muscles contract the myofibrils slide past each other and this friction generates the heat which also causes an increase in body temperature in fewer levels. So, the correct answer is 'Increase in body temperature'.

Which of the following type of cell junction make up an intercalated disc?

  1. Fascia adherens

  2. Desmosomes

  3. Gap junctions

  4. All of the above


Correct Option: D
Explanation:

Cardiac cells are connected to each other by intercalated discs. Cardiac muscle cells have three distinct types of intercellular junctions, namely gap junctions, desmosomes, and fascia adherens. All these junctions are located in the intercalated disc.  Hence, all these cell junction make up an intercalated disc of cardiac cells. 

Thus, the correct answer is 'All of the above.'

State whether the following statements are true or false.
The strongest muscle in the body is present in the jaw.

  1. True

  2. False


Correct Option: A
Explanation:

The strongest muscle based on its weight is the masseter. With all muscles of the jaw working together it can close the teeth with a force as great as 55 pounds on the incisors on the molars.

So, the correct option is 'True'.

The strongest muscle of the body is found in:

  1. Wrist

  2. Thigh

  3. Jaws

  4. Fingers


Correct Option: C
Explanation:

The strongest muscle based on its weight is the masseter. With all muscles of the jaw working together it can close the teeth with a force as great as 55 pounds on the incisors on the molars.


So, the correct option is 'Jaws'.

One myosin filament in the myofibril of skeleton muscle fibres is surrounded by how many actin filaments.

  1. $8$

  2. $2$

  3. $6$

  4. $4$


Correct Option: C
Explanation:
Sarcomeres contain the contractile proteins myosin and actin, which are the proteins that bind during muscle contraction. Six actin filaments surround each myosin filament, and each actin filament is surrounded by three myosin filaments—an arrangement that gives muscle its striated appearance under magnification.
So, the correct option is '6'.

For muscle-building anabolic steroids we can say that:

  1. They are relatively risk free to use

  2. They have side effects that outweigh their benefits

  3. They increase muscular strength and endurance

  4. Both (b) and (c)


Correct Option: D
Explanation:
Anabolic steroids are synthetic, or human-made, variations of the male sex hormone testosterone. The proper term for these compounds is anabolic-androgenic steroids. "Anabolic" refers to muscle building, and "androgenic" refers to increased male sex characteristics. Some common names for anabolic steroids are Gear, Juice, Roids, and Stackers. Health care providers can prescribe steroids to treat hormonal issues, such as delayed puberty. Steroids can also treat diseases that cause muscle loss, such as cancer and AIDS. But some athletes and bodybuilders misuse these drugs in an attempt to boost performance or improve their physical appearance.  Misuse of anabolic steroids might lead to negative mental effects, such as paranoid (extreme, unreasonable) jealousy, irritability, and aggression (“roid rage”),delusions—false beliefs or ideas, impaired judgment etc. Aside from mental effects, steroid use commonly causes severe acne. It also causes the body to swell, especially in the hands and feet.

So, the correct answer is 'Both (b) and (c)'.

Which of the following ions are necessary in the chemical events of the muscle contraction?

  1. Sodium and Potassium

  2. Sodium and Magnesium

  3. Calcium and Magnesium

  4. Sodium and Calcium


Correct Option: C
Explanation:

For contraction of muscles, a stimulus is required 

Impulse is generated when an action potential is initiated, the muscles then shortens in length and trigger sarcoplasmic reticulum to release calcium ions into the interior of muscle and they bind to troponin, thus causing tropomyosin shift from the face of actin filaments to which myosin head need to bind to produce contraction. Thus, Calcium plays important role in muscle contraction Magnesium plays important role in muscle regulation.
So, the correct answer is 'Calcium and Magnesium'

Cori's cycle operates in

  1. Liver

  2. Muscles

  3. Blood

  4. Both A and B


Correct Option: D
Explanation:

The Cori cycle (lactic acid cycle), refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is metabolized back to lactate. 

Polio disease affects

  1. Skeleton

  2. Nervous system

  3. Muscles and spinal cord

  4. Skeleton and muscular system


Correct Option: B,C
Explanation:

Polio is a viral disease, which affects the spinal cord causing muscle weakness and paralysis. The polio virus enters the body through the mouth, usually from hands contaminated with the stool of an infected person.