Actin filaments are found in all eukaryotic cells but reportedly absent in :
Actin filament help in contraction and relaxation of muscles. Actin filament are found in all eukaryotic cells but it is absent in nematode sperms.
Skeletal muscle bundles [fascicles] are held together by a common connective tissue layer called:
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.
Which joint occurs between humerus and radioulna?
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.
Study of muscles is called :
Myology is the branch of biological science in which different aspects of muscles are studied.
From the following figure infer :
(a) = ?, (b) = ? and (c) = ?
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.
Read the following :
i. The synovial joints ischaracterised by the presence of a fluid filled synovial cavity between the articulating surfaces of the two bones.
ii. Saddle is a type of synovial joint
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)
The correct organisation of skeletal muscle is :
Myoglobin was the first protein to have its three-dimensional structure revealed. Ravi was diagnosed with myoglobin in his bloodstream. This had occurred due to :
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 following X-ray shows :
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.
What is the type of movable joint present between the atlas and axis?
Pivot joint: Between atlas and axis called atlanto-axial joint.
The vertebral formula of human is :
The vertebral column is differentiated into cervical (7), thoracic (12), lumbar (5), sacral (5-fused) and coccygeal (4-fused) regions starting from the skull.
The joint present between the carpals is
Gliding joint (between the carpals).
Muscles are attached to bones via :
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 skull, a large hole is present which allows brain to continue with the spinal cord. That hole is called :
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.
Match the following :
a) Fibrous joint
b) Hinge joint
c) Ball and socket joint
d) Ellipsoid joint
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 :
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.
Axial skeleton consists of
The axial skeleton comprises 80 bones distributed along the main axis of the body.
Read the following statements and view carefully the figure :
i. Osteoporosis is an age-related disorder characterised by decreased bone mass. Osteoarthritis is shown in the following figure.
ii. The above figure shows gouty arthritis which is caused by inflammation of joints.
iii. Decreased levels of estrogen is a common cause for increased chances of fractures.
iv. Inflammation of joints is caused by decreased levels of calcium ions in body fluids.
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.
A meromyosin molecule doesn’t contain :
Each meromyosin has two important parts, a globular head with a short arm and a tail.
Which one of the following membranes secretes a watery fluid that lubricates and cushions the joint?