Tag: human muscular system

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 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.

Stores of readily available glucose to supply the tissues with an oxidizable energy source are found principally in the liver, as glycogen. 

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.

• In a normal human adult male, the total weight of muscle is 30 kg.
• Muscle mass is important in determining healthy body composition. A person with a higher % of muscle mass finds it easier to move but needs more energy to do it. 
• The normal muscle mass percentage on the bodyweight lies between 38% and 54% for men and between 28% and 39% for women depending on age and physical activity level.
  
  Hence, option C is the answer.

Skeletal muscle is composed of muscle fibres which have smaller units called myofibrils. There are three types of proteins make up each myofibril; they are contractile, regulatory and structural proteins. By contractile proteins, we mean actin (thin filament) and myosin (thick filament).

When there is oxygen deficiency in the muscle cells, they undergo anaerobic respiration and start producing lactic acid. This lactic acid causes muscle fatigue. The muscle that has been contracted many times short intervals, exhaust its storage of ATP and glycogen and produces lactic acid. 

The biceps, also known as biceps brachii lies on the front of the upper arm between the shoulder and the elbow. The biceps brachii has two heads, or origins. Both heads originate on the scapula. The long head attaches to the supraglenoid tubercle of the scapula, which is just above the space where the humerus, or upper arm, enters the shoulder. The short head attaches to the coracoid process of the scapula. Both heads converge into one muscle, that runs the length of the humerus. The biceps brachii crosses the inside of the elbow and attaches at the radial tuberosity, which is a feature on the radius - one of the two bones (Ulna is other bone) in- the lower arm. In this way it attaches humerus with the radius and ulna.