Skeletal System MCQ for RRB & SSC and other Competitive exams
51
What is the name of the opening at the base of the skull through which the spinal cord passes?
RRB/SSC/UPSC
Medium
✓ Answer:
B
Foramen Magnum
The Foramen Magnum (Latin: great opening) is the large oval opening at the base of the occipital bone through which: the spinal cord passes (continuing from the brainstem/medulla oblongata), vertebral arteries pass into the skull, and the accessory nerve (CN XI) passes. It is the largest foramen in the skull. The occipital condyles on either side of the foramen magnum articulate with the Atlas (C1) at the atlanto-occipital joint.
52
What is the name given to the shaft (middle portion) of a long bone?
RRB/SSC/UPSC
Medium
✓ Answer:
C
Diaphysis
Parts of a long bone: Diaphysis = the shaft (long, cylindrical middle portion) - made of compact bone surrounding the medullary cavity (yellow marrow in adults). Epiphysis = the two ends (proximal and distal) - made of spongy bone covered by thin compact bone and articular cartilage. Metaphysis = the flared region between diaphysis and epiphysis - contains the growth plate (epiphyseal plate) in growing bones. Articular cartilage = hyaline cartilage covering the joint surfaces of epiphyses.
53
Which of the following is the correct statement about the knee joint?
RRB/SSC/UPSC
Medium
✓ Answer:
B
The knee joint is the largest and most complex joint in the body
The Knee joint (Tibiofemoral joint) is the largest and most complex joint in the human body. It is primarily a hinge joint (allowing flexion and extension) but also allows slight rotation when flexed. The knee has: 4 major ligaments (ACL, PCL, MCL, LCL), 2 menisci (Medial and Lateral - fibrocartilage shock absorbers), Patellofemoral joint (kneecap-femur joint), and Multiple bursae (fluid-filled sacs). The knee is the most commonly injured joint due to its complexity and exposure to high mechanical stresses.
54
Which of the following is the correct statement about the floating ribs?
RRB/SSC/UPSC
Medium
✓ Answer:
B
Floating ribs (11th and 12th) are not attached to the sternum at all
Classification of ribs: True ribs (1-7) = Directly attached to sternum via their own costal cartilage. False ribs (8-10) = Attached to the cartilage of the 7th rib (not directly to sternum). Floating ribs (11-12) = NOT attached to sternum at all - they only connect to the thoracic vertebrae at the back and are free (floating) at the front. Floating ribs are shorter than other ribs and only attach posteriorly to the thoracic vertebrae T11 and T12.
55
Which of the following bones is NOT part of the cranium?
RRB/SSC/UPSC
Medium
✓ Answer:
C
Mandible
The Cranium consists of 8 bones that encase and protect the brain: Frontal (1), Parietal (2), Temporal (2), Occipital (1), Sphenoid (1), and Ethmoid (1). The Mandible (lower jaw) is a facial bone - NOT a cranial bone. It is the only movable bone of the skull and holds the lower teeth. The 14 facial bones include: Mandible, Maxillae (2), Zygomatic (2), Nasal (2), Lacrimal (2), Palatine (2), Inferior nasal conchae (2), and Vomer (1).
56
What is the name given to softening of the cartilage under the kneecap?
RRB/SSC/UPSC
Hard
✓ Answer:
B
Chondromalacia Patellae
Chondromalacia Patellae (Runner's Knee) is a condition where the cartilage on the undersurface of the patella (kneecap) softens and deteriorates, causing: Anterior (front) knee pain (especially when going up/down stairs or sitting for long periods), grinding or clicking sensation in the knee, and swelling around the kneecap. Common in young athletes, runners, and cyclists. Causes: overuse, muscle imbalance, poor patellar tracking. Treatment: physiotherapy, quadriceps strengthening, activity modification, and sometimes surgery.
57
The acetabulum is a part of which bone?
RRB/SSC/UPSC
Medium
✓ Answer:
C
Hip bone (Os coxae)
The Acetabulum is the cup-shaped socket on the lateral surface of the hip bone (os coxae). It is formed by the fusion of three bones: Ilium (contributes the upper portion), Ischium (contributes the lower and posterior portion), and Pubis (contributes the anterior and medial portion). The head of the femur (ball) fits into the acetabulum (socket) to form the hip joint (coxofemoral joint) - a ball and socket joint. Acetabulum means little vinegar cup in Latin.
58
What is the name of the process where old bone is broken down and new bone is formed?
RRB/SSC/UPSC
Medium
✓ Answer:
B
Bone remodelling
Bone Remodelling is the continuous process of bone resorption (breakdown) followed by bone formation throughout life. It involves: Osteoclasts (resorb/break down old bone) and Osteoblasts (form new bone to replace it). Purpose of remodelling: Repair microdamage and fractures, Adapt bone to mechanical stresses, Regulate blood calcium levels, and Replace old bone with new, stronger bone. Approximately 10% of the skeleton is replaced each year. Imbalance (more resorption than formation) leads to osteoporosis.
59
Which of the following is the correct statement about bone marrow transplantation?
RRB/SSC/UPSC
Hard
✓ Answer:
B
Bone marrow transplant replaces diseased bone marrow with healthy stem cells to restore blood cell production
Bone Marrow Transplantation (BMT) / Haematopoietic Stem Cell Transplantation (HSCT) is a procedure that replaces diseased or damaged bone marrow with healthy haematopoietic stem cells to restore normal blood cell production. Used to treat: Leukaemia, Lymphoma, Myeloma (blood cancers), Aplastic Anaemia (bone marrow failure), and Thalassaemia, Sickle Cell Anaemia (genetic blood disorders). Types: Autologous (patient's own cells) and Allogeneic (donor's cells - requires HLA matching).
60
Which of the following bones forms the upper arm?
RRB/SSC/UPSC
Easy
✓ Answer:
C
Humerus
The Humerus is the single bone of the upper arm, extending from the shoulder joint to the elbow joint. It articulates superiorly with the glenoid cavity of the scapula (glenohumeral joint - ball and socket) and inferiorly with the radius and ulna at the elbow joint (hinge joint). The humerus has several landmarks: greater and lesser tubercles (muscle attachment), deltoid tuberosity (deltoid muscle attachment), and the medial epicondyle (where ulnar nerve passes - the funny bone sensation).