Table of Contents
In locomotion and movement :
Movement refers to a change in the body position. It is a fundamental characteristic of living beings.
Locomotion is the movement of body parts that leads to change place.
The reduction in force of contraction of muscle after prolonged stimulation is called muscle fatigue. This happens due to the accumulation of lactic acid. It is produced by glycolysis in the absence of O2 [MHCET 2011].
I-band is considered as a light band and contains a protein actin. It has a dark membrane called Z-line (M-line) which is an elastic fiber. It is also called Z-disc or Dobie’s. The part of the myofibril between two successive Z-lines is called sarcomere (functional unit of contraction) [WB JEE 2014].
The pectoral girdle is the bony or cartilaginous structure in the vertebrates to which the anterior limbs (pectoral fins, forelegs or arms) are attached. In mammals, it consists of two dorsal scapulae (shoulder blades) attached to the backbone and two scapulae (shoulder blades) attached to the backbone and two venereal clavicles (collar bones) attached to the sternum (breastbone) [AIPMT 2010].
Each half of pectoral girdle consists of suprascapular, scapula, coracoid, precoracoid, epicoracoid and para glenoid cartilage. The clavicle is a slender rod, separated from the coracoid by a wide gap called coracoid foramen. Posteriorly scapula forms the upper half of a deep cup-like depression the glenoid cavity for articulation with the humerus bone of forelimbs [DUMET 2011].
Gliding joint is a type of synovial joint, found between carpal bones and tarsal bones [CBSE AIPMT 2014].
The Zygomatic bone also called cheekbone or molar bone. It is a diamond-shaped bone below and lateral to the orbit (eye-socket). The parietal bones are bones in the human skull which, when joined together form the sides and roof of the cranium. Sphenoid bone is a prominent, irregular, wedge-shaped bone at the base of the skull. The sphenoid bone is also known as the keystone of the cranial floor because it is in contact with all of the other cranial bones [EAMCET 2014].
Synovial Joints – Locomotion and Movement
Synovial joints are characterized by the presence of a fluid-filled synovial cavity between the articulating surfaces of the two bones. Such an arrangement allows considerable movement. These joints help o, locomotion and many other movements. Ball and socket joint (between the humerus and pectoral girdle), Hinge joint (Knee joint), Pivot joint (between atlas and axis), Gliding joint (between the carpals) and Saddle joint (between carpal and metacarpal of thumb) are some examples [NEET 2013].
Each arm consists of one humerus, one radius, one ulna, 8 carple ones, 5 metacarpal bones and 5 digits(14 phalanges). The pelvic girdle is formed of two innominate bones. Each innominate bone consists of ilium and pubis. The bones found in legs are the femur, tibia, fibula, patella, tarsal bones, metatarsal ones and 5 digits [UP CPMT 2012].
Osteoporosis – Locomotion and Movement
Osteoporosis is an age-related disease in which bone loose minerals and fibers from the matrix causing decreased bone mass and higher chances of fractures with advancing age. Major causative factors of osteoporosis are an imbalance of hormones like calcitonin of thyroid, parathormone of parathyroids, sex hormones and deficiencies of calcium and vitamins [CBSE AIPMT 2012].
Osteoporosis is caused by the decreased level of estrogen. It is caused both the early and late forms of osteoporosis in postmenopausal women. Osteoporosis is thinning or weakening of bones which makes them fragile and more likely to break. Women have low estrogen level when they are transitioning through menopause [NEET-II 2016].
A sarcomere is the basic unit of a muscle’s cross-striated myofibril. Sarcomeres are multi-protein complexes composed of three different filament systems [UP CPMT 2010, Pb PMET 2012].
Pelvic girdle consists of two coxal bones. Each coxal bone is formed by the fusion of three bones – ilium, ischium, and pubis (Kerala CEE 2011).
The kinesin, myosin and dynein proteins of skeletal muscle involve ATPase activity. This cause the contraction of skeletal muscles, propelling the action of cilia and flagella and the intracellular transport of organelles [BHU 2010].