Locomotion and Movement Test 3

Actin filament help in contraction and relaxation of muscles. Actin filament are found in all eukaryotic cells but it is absent in nematode sperms.

Most skeletal muscles are attached to bones by bundles of collagen fibers known as tendons. A skeletal muscle refers to multiple bundles (fascicles) of cells joined together called muscle fibers. The fibers and muscles are surrounded by connective tissue layers called fasciae.

Hinge joint occurs between humerus and radioulnar.
A hinge joint is a common class of synovial joint that includes the ankle, elbow and knee joints. Hinge joints are formed between two or more bones where the bones can only move along one axis to flex or extend. The elbow is a hinged joint made up of three bones which are the humerus, ulna and radius.

Myology is the branch of biological science in which different aspects of muscles are studied.

Myograms is diagnostic test of health and functionality of a person’s muscle. In the given myograms, a. shows staircase effect, b. shows summation and c. shows tetanus that leads to fatigue.

Synovial joints are characterised by the presence of a fluid filled synovial cavity between the articulating surfaces of the two bones. Saddle joint (between carpal and metacarpal of thumb)

• Each organised skeletal muscle in our body is made of a number of muscle bundles or fascicles held together by a common collagenous connective tissue layer called fascia.
• Each muscle bundle contains a number of muscle fibres.
• A characteristic feature of the muscle fibre is the presence of a large number of parallelly arranged filaments in the sarcoplasm called myofilaments or myofibrils.
• The portion of the myofibril between two successive ‘Z’ lines is considered as the functional unit of contraction and is called a sarcomere.

Myoglobin is an iron and oxygen binding protein found in the muscle tissue of mammals. Presence of myoglobin in blood stream may be due to muscle injury of Ravi due to accident or sudden jerk.

The X-ray of knee shows gout in the knee. Gout is a kind of arthritis. It can cause an attack of sudden burning pain, stiffness and swelling in joint.

Pivot joint: Between atlas and axis called atlanto-axial joint.

The vertebral column is differentiated into cervical (7), thoracic (12), lumbar (5), sacral (5-fused) and coccygeal (4-fused) regions starting from the skull.

Gliding joint (between the carpals).

Muscles are attached to bones by tendon and bones are attached with another bone by ligaments. Tendon and ligaments are types of connective tissue.

At the base of human skull a large hole is present that allows brain to continue with the spinal cord. This hole is called foramen magnum.

Fibrous joint is present in skull bone, hinge joint is present in knee, ball and socket joint is present in shoulder and forelimb and ellipsoid joint is present in wrist of human beings.

A functional G-actin molecule in its free state is bound to magnesium ion and ATP. G-actin molecule forms a bridge between the muscle fibres for sliding.

The axial skeleton comprises 80 bones distributed along the main axis of the body.

Osteoporosis is an age-related disorder characterised by decreased bone mass. It is mainly caused by decreased level of estrogen in blood. Osteoporosis may leads to increased chances of fracture.

Each meromyosin has two important parts, a globular head with a short arm and a tail.

• The synovial membrane is the membrane that lines the articular surfaces of the bones of the synovial joint. Its secretes a watery fluid that lubricates and cushions the joint. It reduces the friction during movement.
• Tendon is a cord of strong fibrous collagen tissue that connects muscles to bones and doesn't secrete any fluid. 
• The ligament is a band of flexible fibrous connective tissue that connects bone to bone and doesn't secret any fluid. 
• Cartilage is a tough and flexible material that acts as a cushion between the bones of joints and doesn't secret any fluid.