Musculoskeletal Anatomy and Physiology: Bone, Joints, Ligaments, Tendons, and Muscle Practice Questions

25 multiple-choice questions on Musculoskeletal anatomy and physiology: bone, joints, ligaments, tendons, and muscle for paramedic and EMT students, from Chapter 38 (Orthopaedic Trauma). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. A patient asks why his badly sprained ankle may take longer to heal than a simple fracture. The best explanation is that ligaments:

   1. A. Are made of elastic cartilage
   2. B. Lack collagen fibers for repair
   3. C. Have poor blood supply
   4. D. Need surgery to heal
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   Answer: C. Have poor blood supply

   Ligaments and tendons have relatively little blood flow compared with bone, so severe sprains can heal slowly and sometimes incompletely. They are dense collagen rather than elastic cartilage, they repair by laying down new collagen, and most heal without surgery.

2. After a hard tackle, a player has pain where the collarbone meets the breastbone, the end of the clavicle feels sunken, and he has trouble swallowing. You should suspect:

   1. A. Posterior sternoclavicular dislocation
   2. B. Anterior sternoclavicular dislocation
   3. C. Displaced midshaft clavicle fracture
   4. D. Acromioclavicular separation at the shoulder
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   Answer: A. Posterior sternoclavicular dislocation

   In a posterior sternoclavicular dislocation the clavicle head is driven backward toward the trachea, esophagus, and great vessels, which can cause difficulty swallowing or breathing, hoarseness, or vascular injury. It is an emergency needing rapid transport. An anterior sternoclavicular dislocation leaves a bump rather than a hollow and does not press on the mediastinum, a midshaft clavicle fracture is felt along the bone rather than at the sternum, and an acromioclavicular separation is at the other end of the clavicle.

3. A 30-year-old has a fracture through the middle of the femoral shaft (diaphysis). The medullary canal at this site contains mainly:

   1. A. Synovial fluid
   2. B. Fatty yellow marrow
   3. C. Articular cartilage
   4. D. Growth plate cartilage
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   Answer: B. Fatty yellow marrow

   In adults the diaphysis is filled with fat-rich yellow marrow, which is why shaft fractures of the femur can release fat globules that cause fat embolism. Growth plate cartilage lies near the ends of the bone, not in the shaft.

4. A growth plate (Salter-Harris) fracture is possible in a 14-year-old but not in a 40-year-old because the growth plates of the long bones close:

   1. A. By about 6 years of age
   2. B. At the start of puberty
   3. C. In middle adulthood
   4. D. In late adolescence
   Show answer

   Answer: D. In late adolescence

   The physes of the long bones close (ossify) between about 14 and 19 years of age, earlier in girls than in boys, so a teenager can still fracture through a growth plate while an adult cannot. That is why joint-area injuries in children and young teens are treated as possible growth plate fractures even when they look like sprains. The plates are still open and growing at 6 years and at the start of puberty, when the growth spurt is driven by them. By middle adulthood they have been closed for decades.

5. The periosteum is clinically important in fractures because it:

   1. A. Stores most of the body's calcium
   2. B. Produces red blood cells
   3. C. Lubricates the joint surfaces
   4. D. Is richly supplied with nerves
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   Answer: D. Is richly supplied with nerves

   The dense nerve supply of the periosteum makes a fracture intensely painful, and its vessels contribute to bleeding and healing. Calcium is stored in the bone matrix itself, not in the periosteum.

6. A cyclist has a deformed middle-third clavicle fracture. Besides immobilizing it, you should check his:

   1. A. Grip strength in the other hand
   2. B. Pedal pulses and leg sensation
   3. C. Radial pulse and sensation
   4. D. Shoulder range of motion
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   Answer: C. Radial pulse and sensation

   The subclavian artery and vein and the brachial plexus run beneath the clavicle, so a displaced fracture can injure them. Check distal pulses, motor function, and sensation in the arm before and after immobilization. Testing the uninjured hand or the legs does not assess the vessels and nerves at risk, and moving the shoulder through its range of motion displaces the fracture.

7. After twisting on a planted foot, a 24-year-old says his knee keeps locking and he cannot fully straighten it. This most suggests a tear of the:

   1. A. Fibula
   2. B. Meniscus
   3. C. Medial collateral ligament
   4. D. Bursa in front of the kneecap
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   Answer: B. Meniscus

   The menisci are C-shaped cartilage pads in the knee, and a torn fragment can catch in the joint, causing locking or inability to fully extend. Splint in a position of comfort and refer. A collateral ligament sprain causes pain and instability on that side but not mechanical locking, an inflamed bursa in front of the kneecap causes swelling there, and the fibula lies outside the knee joint.

8. A 30-year-old with no prior hip problems has a hip dislocation after a crash. Because the normal adult hip is a deep, stable joint, this injury implies:

   1. A. Great force; other injuries
   2. B. Weak bone more than force
   3. C. An isolated hip injury
   4. D. Ligament laxity from sports
   Show answer

   Answer: A. Great force; other injuries

   The native adult hip is held in a deep socket by strong ligaments and muscles, so dislocating it takes high energy, and patients often have associated acetabular, femur, knee, pelvic, or internal injuries. In a patient with no prior hip problems it should not be put down to weak bone or lax ligaments, and it is rarely isolated. A prosthetic hip, by contrast, can dislocate with minor movement.

9. The elbow (humeroulnar joint) and the interphalangeal joints of the fingers are examples of:

   1. A. Ball-and-socket joints
   2. B. Hinge joints
   3. C. Gliding joints
   4. D. Fibrous joints
   Show answer

   Answer: B. Hinge joints

   Hinge joints allow flexion and extension in one plane. Ball-and-socket joints such as the shoulder add rotation and motion in all directions.

10. The joint between the first and second cervical vertebrae that allows the head to rotate side to side is a:

    1. A. Hinge joint
    2. B. Saddle joint
    3. C. Fibrous joint
    4. D. Pivot joint
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    Answer: D. Pivot joint

    The dens of C2 acts as a pivot around which the ring of C1 turns. The thumb's carpometacarpal joint is the classic saddle joint, which allows opposition rather than rotation.

11. The sutures of the skull and the pubic symphysis differ from the knee in that they:

    1. A. Allow little or no motion
    2. B. Contain synovial fluid
    3. C. Are held by tendons alone
    4. D. Rotate in all planes
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    Answer: A. Allow little or no motion

    Fibrous joints such as sutures are essentially immovable, and the cartilaginous pubic symphysis moves only slightly. Synovial fluid is the feature of freely movable joints like the knee.

12. The smooth tissue that covers the ends of bones within a joint and reduces friction is:

    1. A. Periosteum
    2. B. Yellow marrow
    3. C. Articular cartilage
    4. D. Fibrous joint capsule
    Show answer

    Answer: C. Articular cartilage

    Hyaline articular cartilage gives a low-friction gliding surface and has no blood supply, so it heals poorly. Periosteum covers the bone shaft but stops at the joint surface.

13. A bursa is a fluid-filled sac whose main function is to:

    1. A. Reduce friction at joints
    2. B. Store calcium for the bone
    3. C. Anchor tendons to bone
    4. D. Produce new marrow cells
    Show answer

    Answer: A. Reduce friction at joints

    Bursae cushion points where tendons, muscles, or skin glide over bone, such as at the knee and olecranon. Tendon anchoring is done by tendon fibers inserting into the bone itself.

14. A muscle that straightens a joint, such as the triceps at the elbow or the quadriceps at the knee, is called a(n):

    1. A. Flexor
    2. B. Adductor
    3. C. Abductor
    4. D. Extensor
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    Answer: D. Extensor

    Skeletal muscles work in opposing pairs: extensors straighten a joint and flexors bend it. The biceps and hamstrings are flexors, the usual mix-up.

15. Which injury involves a bone of the appendicular skeleton?

    1. A. A sternum fracture
    2. B. A scapula fracture
    3. C. A sacral fracture
    4. D. A rib fracture
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    Answer: B. A scapula fracture

    The scapula is part of the shoulder girdle, which belongs to the appendicular skeleton with the pelvic girdle and limbs. The sacrum is part of the vertebral column and is axial, even though it forms the back of the pelvic ring.

16. Which bone is a sesamoid bone that develops within a tendon?

    1. A. Scaphoid
    2. B. Calcaneus
    3. C. Patella
    4. D. Clavicle
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    Answer: C. Patella

    The patella sits within the quadriceps tendon and improves its leverage over the knee. The scaphoid and calcaneus are short and irregular bones of the wrist and foot, not sesamoid bones.

17. The bone most commonly fractured in a fall onto an outstretched hand that is also at risk of avascular necrosis is the:

    1. A. Scaphoid
    2. B. Lunate
    3. C. Hamate
    4. D. Pisiform
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    Answer: A. Scaphoid

    The scaphoid's blood supply enters distally, so a waist fracture can leave the proximal part without circulation. The lunate is more often dislocated than fractured, making it the tempting but wrong choice.

18. After a fall on an outstretched hand, a 30-year-old has a swollen, deformed wrist. To test motor function of the median nerve, you should ask the patient to:

    1. A. Spread all the fingers apart against you
    2. B. Touch the thumb to the little finger
    3. C. Lift the wrist and fingers upward
    4. D. Bend the elbow against your hand
    Show answer

    Answer: B. Touch the thumb to the little finger

    The median nerve supplies the thenar muscles that bring the thumb across the palm, so touching the thumb tip to the little finger (opposition) tests it; it also carries sensation to the palm side of the thumb, index, and middle fingers. It is the nerve most often affected by distal radius fractures, as swelling compresses it in the carpal tunnel. Spreading the fingers apart uses the interosseous muscles, which the ulnar nerve supplies. Lifting the wrist and fingers tests extension, a radial nerve function. Bending the elbow uses the biceps (musculocutaneous nerve) and tells you nothing about the nerves crossing an injured wrist.

19. To test motor function of the peroneal (fibular) nerve in a patient with a knee injury, you should ask the patient to:

    1. A. Curl the toes downward
    2. B. Push the foot down on your hand
    3. C. Squeeze your fingers
    4. D. Lift the foot and toes upward
    Show answer

    Answer: D. Lift the foot and toes upward

    The peroneal nerve wraps around the fibular head and powers dorsiflexion; injury causes foot drop. Plantar flexion against your hand tests the tibial nerve, the tempting alternative.

20. Children's fractures usually heal faster than adults' mainly because children have:

    1. A. Less blood flow to their bones
    2. B. Denser, more brittle bone
    3. C. A thick, active periosteum
    4. D. No open growth plates
    Show answer

    Answer: C. A thick, active periosteum

    A child's periosteum is thick, well vascularized, and rich in bone-forming cells, so callus forms quickly. Children's bone is more flexible and less dense than adult bone, not more brittle.

21. Bone stores which mineral that is essential for nerve conduction and muscle contraction?

    1. A. Calcium
    2. B. Sodium
    3. C. Potassium
    4. D. Chloride
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    Answer: A. Calcium

    About 99% of the body's calcium is stored in bone and released under hormonal control. Potassium is mainly intracellular in muscle and other cells, not stored in bone.

22. The tough, fibrous sheet that wraps a group of muscles and limits how much they can swell is the:

    1. A. Bursa
    2. B. Fascia
    3. C. Periosteum
    4. D. Synovium
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    Answer: B. Fascia

    Fascia divides the limbs into compartments that cannot expand, which is the anatomic basis of compartment syndrome after fractures. The periosteum covers bone, not muscle groups.

23. The joint capsule of a synovial joint is lined by a membrane that secretes:

    1. A. Calcium for bone repair
    2. B. Red and white blood cells
    3. C. Lubricating fluid
    4. D. Collagen for the tendons
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    Answer: C. Lubricating fluid

    The synovial membrane produces viscous fluid that lubricates and nourishes articular cartilage. Blood cells come from red marrow, not the joint lining.

24. The femoral artery and nerve run closest to the skin surface in the:

    1. A. Back of the thigh near the knee
    2. B. Lateral thigh near the hip
    3. C. Popliteal fossa
    4. D. Groin, at the inguinal crease
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    Answer: D. Groin, at the inguinal crease

    The femoral vessels pass under the inguinal ligament in the femoral triangle, where the pulse is palpated. Behind the knee lie the popliteal vessels, a different segment that is at risk in knee dislocations.

25. The posterior tibial pulse, used to check distal circulation after a lower leg injury, is palpated:

    1. A. On top of the midfoot
    2. B. Behind the lateral malleolus
    3. C. At the front of the ankle
    4. D. Behind the medial malleolus
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    Answer: D. Behind the medial malleolus

    The posterior tibial artery runs behind the medial ankle bone. The dorsalis pedis pulse is felt on top of the foot, the other common distal pulse to check.