A joint is a place at which two or more bones meet in the skeleton of the body. This place is called articulation.
Immovable joints have fibrous tissues between the bones. Such immovable joints are also found in the form of sutures. They are found between the bones of the skull (suture) and between the facial bones except at the joint of mandible.
There is a pad of fibrous-cartilage between the ends of the bones making up the joint which allows very slight movement. Example: joint of ribs and sternum.
Between two bones, there is a synovial cavity filled with synovial fluid. It lubricates the joints. They are again divided into different types which are as follows,
Ball and socket joints: In these joints, femur has a ball-like spherical end called head which fits into a cup like depression of the other bone called acetabulum. It helps in the free movement of bones. Example: shoulder joint and hip joint.
Hinge joints: In these joints, one bone is movable on another bone which remains fixed. In this joint, the bones move like a door or the lid of a box moving on a hinge (180o). Example: elbow, knee, etc.
Pivot or rotatory joints: In these joints, one bone shows the rotary movement on another bone which remains fixed. Examples: joint between atlas and axis vertebrae.
Gliding joint: In these joints, there is a slight gliding movement of one bone over another, usually through interposition of a pad of cartilage. Example: joint between carpels in wrist , tarsals in the ankle, etc.
In our body, movement is brought about by the combined effect of skeletal system and muscular system. The muscles connected with the skeleton are called skeletal muscles. Such muscles are connected with bone directly or by the means of a connective tissue called tendon. We know that in our body, movement is conducted by movable joints.
When the secretion of synovial fluid is stopped on knee joint of a person, join swells up and gives pain such that person can't walk easily.
Cartilage is the soft bones which are made up of living cells and are present at the joints of the bones. They are found in nose, ear etc.
Its functions are:
i) It absorbs the pain occurred in the different body parts.
ii) It protects the bones from vibration while walking, running etc.
At the old age the cartilage is eroded enough so that it cannot protect joints from vibration and cannot absorb the pain. Hence, the joints ache occurs while walking in an old age.
The place at which two or more than two bones join is called joint.
They are three types:
i) Fixed or immovable joints: Joint between bones of skull, joint in tooth sockets etc.
ii) Slightly movable joints: Joints of ribs and sternum
iii) Movable or perfect joints: Tarsal bones in the ankle, joints between upper and lower arm.
The joints which are allowed to move freely in various direction are called movable joints. They are of four types:
i) Ball and socket joints : Joint at shoulder
ii) Pivot joint : joint between atlas and axis, radius and ulna, tibia and fibula.
iii) Hinge joint: Joint in knee, elbow, fingers etc.
iv) Gliding joints : Joints in carpals, tarsal bone etc.
Bone marrow is of two types:
i) Yellow bone marrow: It produces white blood cells.
ii) Red bone marrow: It produces red blood cells.
The skeletal muscles are connected with bone directly or by connective tissue which is called tendon.
When biceps contracts, triceps muscle remains relaxed and when triceps muscle contracts, biceps muscle remains relaxed. Such method of oppositely working muscle is called antagonistic muscle.
The differences between tendon and ligament are as follows:
|i)It joins muscle to bone.||i) It joins bone together.|
|ii)It contains non elastic white fibre.||ii)It contains elastic yellow fibre.|
A joint is a place at which two or more bones meet in the skeleton of the body,this place is called ______.
none of the above
Immovable joints have fibrous tissues between the ______.