Joints Questions in English

(B) Movement of organs occurs due to the pulling of bones caused by the force generated by contracting muscles.
The mandibular joint is designed for power, specifically during the $CLENCHING$ $OF$ $TEETH$.
It is a synovial joint formed between the head of the mandible and the mandibular fossa and articular tubercle of the temporal bone.

(D) The correct match is the Gliding Joint between the zygapophyses of vertebrae.
In a gliding joint,the articular surfaces of the bones are flat or slightly curved,which allows the bones to slide or glide over each other.
Cartilaginous joints are found between adjacent vertebrae in the vertebral column,not in cranial sutures.
Hinge joints allow movement in one plane,such as in the elbow or between phalanges,not between vertebrae.
Fibrous joints are immovable joints found in the cranial sutures,not between phalanges.

(C) Synovial fluid is present in freely movable joints,also known as synovial joints.
The synovial membrane secretes synovial fluid,which acts as a lubricant to reduce friction between the articulating surfaces of the bones.
Additionally,it provides nourishment to the articular cartilage.

(D) 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 for considerable movement. These joints are freely movable. Examples include ball and socket joints,hinge joints,pivot joints,gliding joints,and saddle joints. Therefore,all the given statements are correct.

(C) Pivot joint: One bone rotates around another.
$e.g.$,radius over ulna.
Gliding joint: Two bones can glide over each other; surfaces are flat or curved.
$e.g.$,wrist / tarsal bones.
Saddle joint: The convex end of one bone fits into the saddle-like depression of the other bone.
$e.g.$,human thumb and carpals.
Angular joint: Allows movement in two planes.
$e.g.$,between metacarpals and phalanges.

(C) The Assertion is incorrect because maximum movement is possible at the $diarthroses$ (synovial) joints,not $amphiarthroses$ joints.
$Amphiarthroses$ are cartilaginous joints that allow only limited or slight movement.
The Reason is correct because synovial joints contain synovial fluid,which acts as a lubricant to provide almost frictionless movement.
Therefore,the Assertion is incorrect,but the Reason is correct.

(N/A) The pubic symphysis is a cartilaginous joint located at the midline of the body.
It is formed by the junction of the two halves of the pelvic girdle ventrally.
This joint contains fibrous cartilage,which provides limited movement and helps in absorbing shock during activities like walking or running.

(A) The vertebral column consists of several vertebrae that are connected by cartilaginous joints.
Specifically,the intervertebral discs,which are composed of fibrocartilage,are located between the adjacent vertebrae.
These discs act as shock absorbers and allow for limited movement of the vertebral column.
Therefore,cartilage is the tissue present between the adjacent bones of the vertebral column.

(B) The joints are classified based on their mobility:
$1$. Fibrous joints $(P)$ do not allow any movement and are known as immovable joints $(I)$. Example: Sutures in the skull.
$2$. Cartilaginous joints $(Q)$ allow limited or slight movement due to the presence of cartilage between bones,known as slightly movable joints $(II)$. Example: Joints between adjacent vertebrae.
$3$. Synovial joints $(R)$ are characterized by a fluid-filled synovial cavity,allowing for significant movement,known as freely movable joints $(III)$. Example: Ball and socket joint,hinge joint.
Therefore,the correct matching is $(P-I), (Q-II), (R-III)$.

(A) The joint between the frontal bone and the parietal bone is a type of fibrous joint known as a suture.
Fibrous joints are characterized by the presence of dense fibrous connective tissue that holds the bones together.
These joints are immovable (synarthrosis) and provide protection to the brain by firmly interlocking the bones of the cranium.
Therefore,the correct option is $A$.

(C) The joint between the first vertebra (atlas) and the second vertebra (axis) is known as the atlanto-axial joint.
This joint is a type of pivot joint.
Pivot joints are a sub-category of synovial joints,which allow for rotational movement (such as shaking the head 'no').
Therefore,the correct answer is a synovial joint.

(C) The correct matches are as follows:
$P$. Ball and socket joint is found between the humerus and pectoral girdle $(V)$.
$Q$. Hinge joint is found in the elbow $(I)$.
$R$. Pivot joint is found between the atlas and axis vertebrae $(IV)$.
$S$. Gliding joint is found between the carpals $(II)$.
$T$. Saddle joint is found between the carpal and metacarpal of the thumb $(III)$.
Therefore, the correct sequence is $(P-V), (Q-I), (R-IV), (S-II), (T-III)$.

(C) Synovial joints are characterized by the presence of a fluid-filled synovial cavity between the articulating surfaces of the two bones.
This fluid,known as synovial fluid,reduces friction between the articular cartilages and allows for considerable movement.
Fibrous joints do not allow any movement,and cartilaginous joints allow only limited movement; neither contains a fluid-filled cavity.

(C) The correct matching is as follows:
$A$. Cartilaginous Joint: These joints are found between adjacent vertebrae in the vertebral column $(A-II)$.
$B$. Ball and Socket Joint: This joint is found between the humerus and the pectoral girdle,allowing for rotational movement $(B-IV)$.
$C$. Fibrous Joint: These joints do not allow any movement and are found between the flat skull bones,which fuse end-to-end with the help of dense fibrous connective tissues $(C-I)$.
$D$. Saddle Joint: This joint is found between the carpal and metacarpal of the thumb,allowing for greater range of motion $(D-III)$.
Therefore,the correct sequence is $A-II, B-IV, C-I, D-III$.

(C) The correct matching is:
- $A$. Fibrous joints: These joints do not allow any movement. They are found in the flat skull bones, which fuse end-to-end with the help of dense fibrous connective tissues in the form of sutures $(A-III)$.
- $B$. Cartilaginous joints: These joints are present between the adjacent vertebrae in the vertebral column and permit limited movements $(B-I)$.
- $C$. Hinge joints: This is a type of synovial joint present in the knee, which helps in locomotion $(C-IV)$.
- $D$. Ball and socket joints: This is a type of synovial joint present between the humerus and the pectoral girdle, allowing rotational movement $(D-II)$.
Therefore, the correct sequence is $A-III, B-I, C-IV, D-II$.

(B) Joints are points of contact between bones or between bones and cartilages.
$1$. Fibrous joints do not allow any movement (e.g.,sutures in the skull).
$2$. Cartilaginous joints allow limited movement due to the presence of cartilage between bones (e.g.,between vertebrae).
$3$. 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 for considerable movement. These joints help in locomotion and many other movements.
Therefore,the correct option is $B$.

(B) The joint present between the head of the humerus and the glenoid cavity of the pectoral girdle is known as the $Ball-and-Socket$ joint.
In this type of joint,the rounded head of one bone fits into the cup-like cavity of another bone.
This arrangement allows for multi-axial movement,including rotation,which provides a wide range of motion to the shoulder joint.

(D) The correct answer is $D$.
The knee joint is an example of a hinge joint.
$A$ hinge joint is a type of synovial joint that allows movement primarily in one plane,similar to the hinge of a door.
It is characterized by the presence of a fluid-filled synovial cavity between the articulating surfaces of the two bones,which facilitates smooth movement.