Tag: the muscular system and digestive system in human beings

Questions Related to the muscular system and digestive system in human beings

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. 

A sheath of connective tissue that wraps around several muscle bundles forming a muscle is called 

  1. Sarcolemma

  2. Fascicle

  3. Endomysium

  4. Fascia


Correct Option: D

Which muscles move the fore limb?

  1. Brachialis

  2. Latis simus dorsi

  3. Dorsal scapularis

  4. Triceps brachii


Correct Option: A
Explanation:

The brachialis is a muscle in the upper arm that flexes the elbow joint.
The Latissimus dorsi is the larger, flat, dorsolateral muscle on the trunk, posterior to the arm.
The dorsal scapular is the nerve that is the right brachial plexus with its short branches, viewed from in front.
Triceps brachii is that large muscle on the back of the upper limb and is principally responsible for extension of the elbow joint (straightening of the arm).
Therefore, the correct answer is option A.

The cycle of reactions by which muscle lactic acid is transformed to muscle glycogen is known as

  1. Glycolactic cycle

  2. Glycolysis

  3. Cori cycle

  4. Krebs cycle


Correct Option: C
Explanation:

The Cori cycle (also known as 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 metabolised back to lactate.

One of the following is a set of antagonistic muscles. Select the wrong set.

  1. Fexor, Relaxor

  2. Abductor, Adductor

  3. Pronator, Supinator

  4. Elevator, Depressor


Correct Option: A

Flexation of thigh, knee and their rotation is facilatated by

  1. Biceps muscle

  2. Triceps muscle

  3. Sartorius muscles

  4. Shank


Correct Option: C
Explanation:

The sartorius muscle is the longest superficial muscle in the interior compartment of the human body. It is a two joint muscle that moves both hip and knee joint. It forms the lateral boundary of the femoral triangle and covers the abductor canal. It flexes the hip and knees and helps in the lateral rotation and thigh abduction. These all are necessary for the crossed leg position. So, the correct option is C.