31 Years NEET Previous Year Questions: Locomotion & Movement - 1 - NEET MCQ

Myasthenia gravis is a chronic autoimmune muscular disease. It causes 
breakdown of neuromuscular junction due to which the brain loses control over muscles. The symptoms may include drooping eyelids, difficulty in swallowing muscle fatigue, difficult breathing and inability to control facial expressions.

Central part of thick filament, not overlapped by thin filaments is called the ‘H’ zone. ‘H’ zone is also called Hensen’s Line. 

Vertebral column has 12^th or acicvertebrate. The joints between adjacent vertebrae is cartilaginous joint which permits limited movements. Progesterone is secreted by corpus luteum which supports in pregnancy in females

Synovial joints are distinguished by the existence of a synovial cavity filled with fluid between the surfaces of two bones that articulate with each other. These joints facilitate movement, aiding in locomotion and various other activities. Examples of synovial joints include the ball and socket joint found between the humerus and the pectoral girdle, the hinge joint present in the knee, the pivot joint located between the atlas and axis vertebrae, the gliding joint between the carpals, and the saddle joint between the carpal and metacarpal bones of the thumb.

Troponin and myosin are the proteins of striated muscles. They help in muscle contraction.

Thymosin is the hormone released from thymus and helps in stimulating the growth of certain immune cells. Calcitonin is also a hormone released from parafollicular cells of the thyroid gland.

Prolactin is a hormone released by the pituitary gland. Pepsin is a protein-digesting hormone secreted in the stomach.

Rhodopsin is a derivative of vitamin D. Secretin a hormone released into the bloodstream by the duodenum (especially in response to acidity) to stimulate secretion by the liver and pancreas.

So the correct option is C.

Major causative factors of osteoporosis are imbalances of hormones like calcitonin of thyroid, parathormone of parathyroids, and sex hormones and deficiencies of calcium and vitamin D.

Glenoid cavity is found in pectoral girdle.

Elbow joint is an example of hinge joint. The elbow is a hinge joint; it can open and close like a door. Hinge joint is a form of diarthrosis (freely movable joint) that allows angular movement in one plane only, increasing or decreasing the angle between the bones e.g. elbow joint, knee joint etc.

In humans, the total number of ribs are fourteen. These are of three types : 
(1) True ribs -These are 7 in number. 
(2) False ribs - These are 3 in number 
(3) Floating ribs - These are 2 in number.

Floating ribs are 2- pairs (11^th and 12^th pair) which are not attached to sternum

Each half of pectoral girdle has two bones i.e. clavicle and scapula. A spine like, acromian process is attached to scapula for articulation with clavicle bone.

Hinge joint : elbow joint, knee joint, ankle joint, inter phalangeal joint.
Gliding joint : Intercarpal joint, intertarsal joint, sternoclavicular joint and joint between pre and post zygapophysis of adjacent vertebra.
Fibrous joint (Synarthroses) : Joints of cranium - bones. Joints between teeth and Jaw bones.
Cartilaginous joint (Amphiarthroses): Joints between mammalian vertebrae and two innominate bones (pubic symphysis).

Ligaments are specialized connective tissues which connect bones together; hence if they are cut or broken the bone will become unfixed.

When Ca⁺ ions combine with troponin contraction of muscles initiates. During Contraction the Z lines come closer  together and the sarcomere becomes shorter. The length of A band remains constant. I bands shortens  and H-band  narrows.

Darks bands on the myofibril form A-band. Middle part of A-band contains light zones-Hensen line (H-lines). Light  band on myofibril is called I-band. Middle part of I-band contains Z-lines. Sarcomere is part between two Z-lines.

Atlas is  the first cervical vertebra. Coracoid is part of the pectoral girdle. Pterygoid is a small bone articulated  with palatine.

In angular joint articulating surface of one bone is oval and convex whereas that of the other is elliptical and concave, it allows movement only in  two directions e.g. Wrist. Fibrous joints are unmovable joints e.g. Sutures of skull. Cartilaginous joints have little motility due to disc of  fibrocartilage between the articular ends. In gliding joints articulate end of both the bones are either flat or curved to allow gliding movements. e.g. between carpels and wrist.

Ligament contain both yellow elastin fibres and collagen fibres. The latter are arranged in a manner to allow for stretching.  Ligaments help in binding bone to bones.

Tendons are made of inelastic white fibrous connective tissue. A tendon (or sinew) is a tough band of fibrous connective tissue that connects muscle to bone or muscle to muscle and is designed to withstand tension. Tendons are similar to ligaments except that ligaments join one bone to another. Tendons and muscles work together and can only exert a pulling force.

Contractile proteins of muscle are actin and myosin, the main components of the thin and thick filaments, respectively.

In mammals, the lower jaw is primarily made up of the dentary bone, which is the largest and most significant bone of the lower jaw, responsible for holding the teeth. The mandible refers to the entire lower jaw structure, which in many vertebrates is made of multiple bones, but in mammals, it consists largely of a single dentary bone.

Each hind limb contain 30 bones namely 1 femur in the thigh, 1 petala in the knee, 1 tibia and 1 fibula in the lower leg, 7 tarsals in the ankle, 5 metatarsals in the sole and 14 phalanges in toes.

In a human body, there are two pairs of floating ribs. i.e., 11th and 12th pairs. These ribs are not attached to either to sternum or the cartilage of another rib. They protect the kidneys.

Glenoid cavity is a shallow concavity on the lateral side of pectoral girdle in which the head of humerus fits making the shoulder joint.

Movement of Ca²⁺ out in sarcoplasmic reticulum controls the making and breaking of actin and myosin complex actomyosin due to which muscle contraction and relaxation takes place. Albert Szent Gyorgyi worked out biochemical events of muscle contraction.

Long bones gives us support as well as their bone marrow (the peripheral part) synthesizes (in adults) the blood and its cells.

All mammals have 7 cervical vertebrae in their neck (it is one of the typical mammalian characters). Though they become long in camel & giraff but the number is 7 only. As whale is also a mammal it also possess the same 7 cervical vertebrae.

A deltoid ridge is present along the ventral side of humerus (bone of upper arm - Brachium) which provides the insertion to muscles.

Hyalin Cartilage forms the ‘cushions’ or ‘pads’ upon the articular surfaces at the joints of long bones and called ‘articular cartilage’. Its role in adult body is to withstand forces of compression and torsion at the joints.

Sella turcica is depression in the skull in the area of the pituitary gland.
It is a saddle shaped (bent down at the sides so as to give the upper part a rounded form) depression in the sphenoid bone of the skull.
The pituitary gland is present in the inferior portion of the sella turcica.
So, the correct answer is 'Depression in the skull in the area of pituitary gland'.