Appendicular skeleton Questions in English

(D) fracture of the distal end of the $Radius$ bone,in which the distal fragment is displaced posteriorly,is known as Colles' fracture. This type of injury typically occurs when a person falls on an outstretched hand.

(A) In the human skeleton,each hindlimb (leg) consists of $30$ bones.
The bones of the hindlimb are as follows:
$1$. Femur (thigh bone): $1$ per leg ($2$ total).
$2$. Patella (kneecap): $1$ per leg ($2$ total).
$3$. Tibia and Fibula (shank bones): $2$ per leg ($4$ total).
$4$. Tarsals (ankle bones): $7$ per leg ($14$ total).
$5$. Metatarsals (sole bones): $5$ per leg ($10$ total).
$6$. Phalanges (digits): $14$ per leg ($28$ total).
Therefore,for a single limb,the number of tarsals is $7$,metatarsals is $5$,and phalanges is $14$.

(A) The human skeletal system is divided into two parts: the axial skeleton and the appendicular skeleton.
The axial skeleton consists of the skull,vertebral column,ribs,and sternum.
The appendicular skeleton consists of the bones of the limbs along with their respective girdles (pectoral and pelvic girdles).
The pectoral girdle supports the forelimbs,and the pelvic girdle supports the hindlimbs.
The appendicular skeleton is composed of $126$ bones in total.

(A) The scapula is a large,triangular,flat bone located in the dorsal part of the thorax between the $2^{nd}$ and $7^{th}$ ribs.
Its dorsal surface features a slightly elevated ridge known as the spine,which projects as a flat,expanded process called the acromion.
The clavicle articulates with the acromion.
Below the acromion,there is a depression called the glenoid cavity,which articulates with the head of the humerus to form the shoulder joint.
The clavicle is a long,slender bone with two curvatures,commonly referred to as the collar bone.

(B) The forearm consists of two bones: the inner $Radius$ and the outer $Ulna$. The $Ulna$ is longer and thicker. At the elbow joint,the $Ulna$ projects beyond the $Radius$ as an $Olecranon$ process. This process contains a deep,subterminal $Sigmoid$ notch,which articulates with the $Trochlea$ of the $Humerus$ to form a hinge joint.

(A) The head of the humerus bone articulates with the glenoid cavity of the scapula to form the shoulder joint.
This is a ball-and-socket type of synovial joint that allows for a wide range of movement.

(C) The longest bone of the human body,located in the thigh,is the $Femur$. It is also the strongest and heaviest bone in the human skeleton.

(A) The correct matches are as follows:
$(a)$ Tarsal: These are the ankle bones,numbering $7$ per limb.
$(b)$ Phalanges: These are the toe bones,numbering $14$ per limb.
$(c)$ Metatarsal: These are the bones of the sole,numbering $5$ per limb.
$(d)$ Femur: This is the thigh bone,which is the longest bone in the body,numbering $1$ per limb.
Therefore,the correct sequence is $a(iii), b(i), c(iv), d(ii)$.

(D) The deltoid ridge (also known as the deltoid tuberosity) is a roughened,$V$-shaped area located on the lateral surface of the shaft of the humerus bone. It serves as the site of attachment for the deltoid muscle,which is responsible for the abduction of the arm at the shoulder joint. Therefore,the correct option is $D$.

(C) The olecranon fossa is a deep triangular depression found on the posterior surface of the distal end of the humerus bone.
It accommodates the olecranon process of the ulna during the extension of the forearm at the elbow joint.

(B) The coxal bone (hip bone) is formed by the fusion of three bones: ilium,ischium,and pubis.
The obturator foramen is a large opening in the hip bone,which is located between the ischium and the pubis bones.
While the ilium,ischium,and pubis fuse to form the acetabulum,the obturator foramen specifically lies between the ischium and the pubis.

(D) The acetabulum is a cup-shaped socket located on the lateral surface of the hip bone (coxal bone). It is formed by the fusion of three bones: the ilium,the ischium,and the pubis. These three bones meet at the acetabulum to provide a socket for the head of the femur,forming the hip joint.

(C) The girdle bones are part of the appendicular skeleton,which includes the pectoral and pelvic girdles.
$Clavicle$ is a bone of the pectoral girdle.
$Ischium$ and $Pubis$ are bones of the pelvic girdle.
$Ileum$ is a part of the small intestine in the digestive system,not a bone.

(C) The Assertion is correct: The tibia is the larger,stronger,and medial bone of the lower leg,while the fibula is the thinner,lateral bone.
The Reason is incorrect: The projection on the inner side of the ankle is called the medial malleolus,which is part of the tibia. The lateral malleolus is the projection on the outer side of the ankle,which is part of the fibula. Therefore,the statement in the Reason is factually wrong.

(B) The collar bone is scientifically known as the $Clavicle$.
It is a long,slender bone with two curvatures that connects the sternum to the scapula,forming part of the pectoral girdle.

(C) The bones of the human arm (forelimb) are categorized as follows:
$P$. Arm (Humerus): $1$ bone $(IV)$
$Q$. Forearm (Radius and Ulna): $2$ bones $(V)$
$R$. Wrist (Carpals): $8$ bones $(I)$
$S$. Palm (Metacarpals): $5$ bones $(II)$
$T$. Digits (Phalanges): $14$ bones $(III)$
Therefore,the correct matching is $(P-IV), (Q-V), (R-I), (S-II), (T-III)$.

(B) The $Femur$,also known as the thigh bone,is the longest,heaviest,and strongest bone in the human body. It extends from the hip to the knee and supports the weight of the body during movement.

(C) The question refers to the shape of a specific bone. Among the options,the 'Cup-shaped' description typically refers to the acetabulum of the pelvic girdle,which forms a socket for the head of the femur. However,if referring to a specific bone like the patella or a sesamoid bone,'Cup-shaped' is the most descriptive morphological term provided in the options compared to the names of specific bones (Tarsal,Carpal,Humerus).

(A) The correct matching is as follows:
$P$. Thigh: Contains the femur,which is $1$ long bone per leg $(III)$.
$Q$. Shank: Contains the tibia and fibula,which are $2$ bones per leg $(IV)$.
$R$. Knee cap: Contains the patella,which is $1$ cup-shaped bone per leg $(V)$.
$S$. Ankle: Contains $7$ tarsal bones per leg $(I)$.
$T$. Metatarsals: Contains $5$ bones per leg $(VI)$.
$U$. Phalanges: Contains $14$ bones per leg $(II)$.
Therefore,the correct sequence is $(P-III, Q-IV, R-V, S-I, T-VI, U-II)$.

(A) In the provided diagram,the labels represent the following bones:
$P$ represents the clavicle (collar bone).
$Q$ represents the scapula (shoulder blade).
$R$ represents the humerus (bone of the upper arm).
$S$ represents the radius/ulna (bones of the forearm).
The pectoral girdle consists of two bones: the clavicle $(P)$ and the scapula $(Q)$.
Therefore,the correct answer is $P$ and $Q$.

(B) In the given diagram of the human hind limb:
$P$ represents the Femur, which is the thigh bone and the longest bone in the body.
$Q$ represents the Patella, which is the knee cap bone.
$R$ represents the Fibula, which is the thinner, lateral bone of the lower leg.
Therefore, the correct identification is $P = \text{Femur}$, $Q = \text{Patella}$, and $R = \text{Fibula}$.

(D) The glenoid cavity is a shallow,pyriform articular surface located on the lateral angle of the scapula.
It articulates with the head of the humerus to form the glenohumeral joint,which is a ball-and-socket joint.
This joint allows for a wide range of movement of the arm.

(C) The $Clavicle$ (also known as the collarbone) is a long,slender bone that connects the arm to the trunk of the body. It is characterized by having two distinct curvatures: a medial curvature that is convex anteriorly and a lateral curvature that is concave anteriorly. This $S$-shaped structure helps in transmitting forces from the upper limb to the axial skeleton.

(B) In a typical adult human,the pelvic girdle consists of two coxal bones. Each coxal bone is formed by the fusion of three bones: the ilium,ischium,and pubis.
In the embryonic stage,these three bones are separate. By adulthood,they fuse to form a single coxal bone on each side.
If these bones do not fuse,each side would consist of $3$ separate bones instead of $1$.
Therefore,the total count would increase by $2$ bones on each side (total $4$ additional bones).
Standard adult human skeleton = $206$ bones.
If fusion does not occur,the total = $206 + 4 = 210$ bones.

(A) The human skeletal system is divided into the axial and appendicular skeleton.
$1$. The Pectoral girdle consists of the Scapula and Clavicle,which support the upper limbs. Thus,option $A$ is correct.
$2$. The Pelvic girdle consists of two coxal bones; the Femur is the bone of the thigh,not part of the girdle itself.
$3$. The Rib cage consists of ribs and the sternum; cervical vertebrae are part of the vertebral column.
$4$. The palm consists of metacarpals,while carpals form the wrist.

(A) The pectoral girdle (shoulder girdle) consists of two bones: the clavicle and the scapula.
Each scapula is a large,triangular,flat bone situated in the dorsal part of the thorax between the $2^{nd}$ and $7^{th}$ ribs.
The scapula has a slightly elevated ridge called the spine,which projects as a flat,expanded process called the acromion.
Below the acromion is a depression called the glenoid cavity,which articulates with the head of the humerus to form the shoulder joint.
$Ilium$ and $Acetabulum$ are parts of the pelvic girdle,while the $Sternum$ is a bone of the axial skeleton.

(C) The human skeletal system is divided into two main parts: the axial skeleton and the appendicular skeleton.
$1$. The axial skeleton consists of $80$ bones,which include the skull,vertebral column,sternum,and ribs.
$2$. The appendicular skeleton consists of $126$ bones,which include the bones of the limbs (forelimbs and hindlimbs) and the girdles (pectoral and pelvic girdles).
Therefore,the correct option is $C$.

(B) The scapula is a large,triangular,flat bone located in the dorsal part of the thorax.
It extends between the level of the $2^{nd}$ and $7^{th}$ ribs.
This bone is part of the pectoral girdle and provides attachment points for various muscles that facilitate the movement of the upper limb.

(B) Statement $(a)$ is correct: The first seven pairs of ribs are attached directly to the sternum and are known as true ribs.
Statement $(b)$ is incorrect: The sternum is a flat bone on the ventral midline of the thorax,not the dorsal part.
Statement $(c)$ is correct: The scapula contains a prominent ridge called the spine,which extends into a flattened process known as the acromion.
Statement $(d)$ is incorrect: The glenoid cavity articulates with the head of the humerus,not the femur. The femur articulates with the acetabulum of the pelvic girdle.

(D) The pelvic girdle is a part of the appendicular skeleton.
It is composed of two coxal bones (hip bones).
Each coxal bone is formed by the fusion of three bones: the ilium,the ischium,and the pubis.
These three bones fuse together to form the acetabulum,which is the socket for the head of the femur.

(B) Based on the anatomical structure of the human pectoral girdle and upper limb:
$A$ points to the Clavicle (collar bone),which is a long,slender bone connecting the sternum to the scapula.
$B$ points to the Scapula (shoulder blade),a large,triangular bone located on the dorsal side of the thorax.
$C$ points to the Radius,which is the lateral bone of the forearm (on the thumb side).
$D$ points to the Ulna,which is the medial bone of the forearm (on the little finger side).
Therefore,the correct identification is $A \rightarrow$ Clavicle,$B \rightarrow$ Scapula,$C \rightarrow$ Radius,$D \rightarrow$ Ulna.

(B) Each coxal bone (hip bone) is formed by the fusion of three bones: the $ilium$,$ischium$,and $pubis$.
These three bones fuse together to form a single coxal bone in adults.
Therefore,the correct answer is $3$ bones.