|1 Crore+ students have signed up on EduRev. Have you?|
Select the correct statement with respect to disorders of muscles in humans [NEET Kar. 2013]
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.
The H-zone in the skeletal muscle fibre is due to : [NEET 2013]
Central part of thick filament, not overlapped by thin filaments is called the ‘H’ zone. ‘H’ zone is also called Hensen’s Line.
Select the correct statement with respect to locomotion in humans : [NEET 2013]
Vertebral column has 12th 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
The characteristics and an example of a synovial joint in humans is : [NEET 2013]
(d) Fluid cartilage Knee joint
between two bones,
The atlas and the occipital bone form the atlanto-occipital joint, which allows neck flexion. The atlanto-axial joint is a compound synovial joint. A synovial joint is a freely moveable joint, differing from other types of joints due to the presence of synovial fluid, which lubricates the joint. Most of the main joints (hands, feet, and other regions in the appendicular skeleton) are synovial joints. So, the correct answer is option B.
Which one of the following pairs of chemical substances is correctly categorized? [2012M]
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.
Select the correct statement regarding the specific disorder of muscular or skeletal system :- 
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.
Three of the following pairs of the human skeletal parts are correctly matched with their respective inclusive skeletal category and one pair is not matched. Identify the non-matching pair. [2011M]
Glenoid cavity is found in pectoral girdle.
Elbow joint is an example of: 
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.
Which one of the following items gives its correct total number? 
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 two in number
(3) Floating ribs - These are 4 in number.
In human body, which one of the following is anatomically correct? 
Floating ribs are 2- pairs (11th and 12th pair) which are not attached to sternum
An acromian process is characteristically found in the: 
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.
Which of the following pairs, is correctly matched? 
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).
What will happen if ligaments are cut or broken? 
Ligaments are specialized connective tissues which connect bones together; hence if they are cut or broken the bone will become unfixed.
Which statement is correct for muscle contraction? 
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.
What is sarcomere? 
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.
Which one of the following is a skull bone ? 
Atlas is the first cervical vertebra. Coracoid is part of the pectoral girdle. Pterygoid is a small bone articulated with palatine.
The joint found between sternum and the ribs in humans is 
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 is a 
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.
Tendon is made up of 
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.
Which of the following is the contractile protein of a muscle? [1998, 2006]
Contractile proteins of muscle are actin and myosin, the main components of the thin and thick filaments, respectively.
The lower jaw in mammals is made up of 
Dentary is tooth bearing membrane bone of lower jaw of the vertebrates-one on each side, that supports the teeth. In mammals the dentary is the sole bone of the lower jaw. The dentary bone is relativley short comma shaped bone.
Total number of bones in the hind limb of man is
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.
The number of floating ribs in the human body, is 
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.
Which is part of pectoral girdle? 
Glenoid cavity is a shallow concavity on the lateral side of pectoral girdle in which the head of humerus fits making the shoulder joint.
Which ion is essential for muscle contraction? 
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 function in 
Long bones gives us support as well as their bone marrow (the peripheral part) synthesizes (in adults) the blood and its cells.
Number of cervical vertebrae in camel is 
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 occurs in 
A deltoid ridge is present along the ventral side of humerus (bone of upper arm - Brachium) which provides the insertion to muscles.
Extremities of long bones possess cartilage 
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 
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'.