دكتور عظام صنعاء: دليل شامل للبحث عن أفضل رعاية لعظامكم ومفاصلكم
دكتور عظام صنعاء: الدليل النهائي والشامل لصحة مثالية للعظام والمفاصل مع الأستاذ الدكتور محمد هطيف - خبير جراحة العظام والمفاصل والعمود الفقري الرائد (+967 774203774)
مقدمة: أهمية الرعاية المتخصصة لصحة العظام والمفاصل في صنعاء ودور الخبير الموثوق
هل تجد نفسك تتألم من آلام مستمرة ومزعجة في عظامك أو مفاصلك، تلك الآلام التي تعكر صفو حياتك اليومية وتحد من قدرتك على أداء أبسط المهام؟ هل بلغ بك البحث عن استشاري متميز وخبير في مجال جراحة العظام والمفاصل في صنعاء، طبيب يمزج ببراعة بين الخبرة العلمية العميقة، والكفاءة العملية الفائقة، والتفاني الصادق في خدمة ورعاية مرضاه؟ إذا كانت إجابتك بنعم، فاعلم أنك قد وصلت إلى وجهتك المنشودة، وأن هذا الدليل هو بوابتك نحو رعاية صحية مثالية.
يقدم لكم هذا الدليل الشامل والمتكامل كافة المعلومات الضرورية والمفصلة التي تحتاجون إليها
Hydroxylation of vitamin D to 25-hydroxyvitamin D occurs in the:
1) Liver
3) Thyroid
2) Kidney
5) Small intestine
4) Parathyroid hormone
Vitamin D is hydroxylated to 25-hydroxyvitamin D in the liver. The vitamin is further hydroxylated to 1,25 dihydroxyvitamin D in the mitochondria of the proximal tubules of the kidney.
Correct Answer: Liver
652. (785) Q2-1046:
Which of the following serum levels is the best indicator of body stores of vitamin D3:
1) 7-dehydrocholesterol
3) 25 hydroxyvitamin D3
2) 1,25 dihydroxyvitamin D3
5) Parathyroid hormone levels
4) 24,25 dihydroxyvitamin D3
A serum 25 hydroxyvitamin D3 level is the best indicator of body stores of vitamin D3.
Remember that 1,25 dihydroxyvitamin D3 is the active metabolite and 24,25 dihydroxyvitamin D3 is the inactive form.Correct
Answer: 25 hydroxyvitamin D3
653. (786) Q2-1047:
At which of the following sites is 25 hydroxyvitamin D3 converted into the active hormone 1,25 dihydroxyvitamin D3:
1) Skin
3) Kidney
2) Liver
5) Small intestine
4) Parathyroid hormone
Vitamin D3 is converted into its active form in the proximal tubules of the kidney. The active form is 1,25 dihydroxyvitamin D3. Remember that the liver performs the conversion to 25 hydroxyvitamin D3 and the kidney further hydroxylates to 1,25
dihydroxyvitamin D3. Correct Answer: Kidney
654. (787) Q2-1048:
Which of the following causes the conversion of 1,25 dihydroxyvitamin D3 into the inactive metabolite 24,25 dihydroxyvitamin
D3:
1) Ultraviolet light
3) Liver 1 alpha-hydroxylase
2) Enzymes in the mitochondria of the kidney proximal tubules
5) Decreased serum calcium level
4) Decreased serum parathyroid hormone
Increased serum calcium, increased serum phosphate level, and decreased parathyroid hormone all convert vitamin D to its inactive from â 24,25 dihydroxyvitamin D3.
Elevated serum parathyroid hormone and decreased calcium and phosphorus levels will increase conversion to the active form â
The active form of vitamin D has which of the following effects on end organs:
1) Vitamin D strongly stimulates intestinal absorption of calcium and phosphorus.
3) Vitamin D stimulates renal mitochondria to hydroxylate 25 hydroxyvitamin D.
2) Vitamin D inhibits osteoclastiCresorption of bone.
5) Vitamin D promotes urinary excretion of phosphorus.
4) Vitamin D increases renal fractional resorption of filtered calcium.
Parathyroid hormone, 1,25 dihydroxyvitamin D, and calcitonin have the following effects on end organs:
Parathyroid hormone
Kidney
1. Stimulates 1,25 dihydroxyvitamin D formation
2. Increases fractional resorption of filtered calcium
3. Promotes urinary excretion of phosphorus
Bone
1. Stimulates osteoclast resorption of bone
1,25 dihydroxyvitamin D
Intestine
1. Stimulates small intestine absorption of calcium and phosphorus
Calcitonin
Bone
1. Inhibits osteoclastiCresorption of bone
Correct Answer: Vitamin D strongly stimulates intestinal absorption of calcium and phosphorus.
660. (793) Q2-1054:
The net effect of increased parathyroid hormone action on calcium and phosphorus concentration in the extracellular fluid and serum is:
1) Increased calcium, increased phosphate
3) Decreased calcium, decreased phosphate
2) Increased calcium, decreased phosphate
5) Transient decrease in serum calcium
4) Increased calcium, no effect on phosphate
Parathyroid hormone, the active form of vitamin D (1,25 dihydroxyvitamin D), and calcitonin each have a net effect on calcium and phosphorus concentrations in extracellular fluid and serum:
The net effect of 1,25 dihydroxyvitamin D3 on the calcium and phosphate concentration of the extracellular fluid and serum is:
1) Increased calcium, increased phosphate
3) Decreased calcium, decreased phosphate
2) Increased calcium, decreased phosphate
5) Transient decrease in serum calcium
4) Increased calcium, no effect on phosphate
Parathyroid hormone, the active form of vitamin D (1,25 dihydroxyvitamin D), and calcitonin each have a net effect on calcium and phosphorus concentrations in extracellular fluid and serum:
The net effect of calcitonin on the calcium and phosphorus concentrations in the extracellular fluid and serum is:
1) Increased calcium, increased phosphate
3) Decreased calcium
2) Increased calcium, decreased phosphate
5) Transient decrease in serum calcium
4) Increased calcium, no effect on phosphate
Parathyroid hormone, the active form of vitamin D (1,25 dihydroxyvitamin D), and calcitonin each have a net effect on calcium and phosphorus concentrations in extracellular fluid and serum:
In which of the following osteonecrotiCconditions does the marrow cavity become packed with abnormal cells:
1) Caisson disease
3) Renal transplantation
2) Gaucher disease
5) ChroniCcorticosteroid administration
4) Pancreatitis
There are two conditions that cause osteonecrosis secondary to the marrow cavity becoming packed with abnormal cells â
Gaucher disease and sickle cell disease. There is probable occlusion of the intraosseous arteries with both of these conditions.
With Gaucher disease, the marrow cavity is filled with Gaucher cells (macrophages filled with cerebroside). In sickle cell disease, the marrow cavity is filled with sickled red blood cells.
Correct Answer: Gaucher disease
664. (862) Q2-1125:
Which of the following cells die in osteonecrosis:
1) Osteocytes only
3) Osteoblasts, osteocytes, hematopoietiCcells, capillary endothelial cells, and lipocytes
2) Osteoblasts and osteocytes only
5) Osteoblasts only
4) Osteoblasts and osteoclasts only
There is complete death of all the elements inside the bone in osteonecrosis: osteoblasts, osteocytes, hematopoietiCcells, capillary endothelial cells, and lipocytes.
In animal models, there are no histologiCchanges after the first week, but during the second week, there is evidence of death of all marrow cells. The osteocytes shrink and the lacunae are empty. The fat in the marrow dies and there is release of lysosomes. The pH is lower and the released calcium forms an insoluble soap with the saponified free fatty acids.
Correct Answer: Osteoblasts, osteocytes, hematopoietiCcells, capillary endothelial cells, and lipocytes
665. (863) Q2-1126:
The increased radiographiCbone density in osteonecrosis is most likely secondary to:
1) Calcification of the necrotiCbone marrow
3) Creeping substitution on the dead trabeculae
2) Insoluble soap from released calcium and free fatty acids
5) NecrotiCcortical bone
4) Resorption of the Haversian canal bone
The majority of the increased radiographiCbone density in osteonecrosis is caused by new bone formation laid down on the necrotiCbone trabeculae. This occurs through the process of creeping substitution.
There is calcification of the necrotiCmarrow and insoluble soap formation from the combination of the free fatty acids and released calcium. However, this does not cause the majority of the increased radiodensity.
There is resorption of the Haversian canal bone, but this results in decreased radiodensity on the radiograph rather than increased radiodensity.
NecrotiCbone that has not gone through the repair process appears normal on the plain radiograph (neither bone resorption or creeping substitution has occurred).
Correct Answer: Creeping substitution on the dead trabeculae
666. (864) Q2-1127:
A 20-year-old college student sustains a closed distal one-third tibia fracture when he falls while skiing. Which of the following would be the most common fracture pattern and mechanism:
1) Short spiral fracture â torsion
3) Transverse fracture â pure bending
2) Oblique fracture â uneven bending
5) Segmental fracture â four-point bending
4) Oblique fracture with a butterfly fragment â bending and compression
This college student has sustained a low-energy twisting injury, also known as a boot-top injury. The fracture pattern is a short spiral fracture and the mechanism of injury is torsion loading of the tibia.
The other patterns included:
Oblique fracture â uneven bending: This type of injury typically occurs following motorcycle accidents when the tibia is subjected to uneven bending forces.
Transverse fracture â pure bending: This fracture is typical of a soccer injury because the tibia is subjected to pure bending forces.
Oblique fracture with a butterfly fragment â bending and compression: This is a common fracture that occurs with low- and high-speed injuries. These fractures may occur from car bumpers and motorcycles.
Segmental fracture â four-point bending: This pattern is typical of high-energy injury, such as a pedestrian being struck by a car bumper.
Correct Answer: Short spiral fracture â torsion
667. (865) Q2-1128:
A 45-year-old man is struck by the bumper of a fast moving car. He has an open tibia fracture. Which of the following would be the most common fracture pattern and mechanism:
1) Short spiral fracture â torsion
3) Transverse fracture â pure bending
2) Oblique fracture â uneven bending
5) Segmental fracture â four-point bending
4) Oblique fracture with a butterfly fragment â bending and compression
The mechanism in this patient is four-point bending. A segmental fracture is common. The other patterns included:
Oblique fracture â uneven bending: This type of injury typically occurs following motorcycle accidents when the tibia is subjected to uneven bending forces.
Transverse fracture â pure bending: This fracture is typical of a soccer injury because the tibia is subjected to pure bending forces.
Oblique fracture with a butterfly fragment â bending and compression: This is a common fracture that occurs with low- and high-speed injuries. These fractures may occur from car bumpers and motorcycles.
Short spiral fracture â torsion: This mechanism is usually from a low velocity skiing injury. Correct Answer: Segmental fracture â four-point bending
668. (866) Q2-1129:
A 25-year-old soccer player sustained a closed tibia fracture when his planted leg was struck by another player. Which of the following would be the most common fracture pattern and mechanism:
1) Short spiral fracture â torsion
3) Transverse fracture â pure bending
2) Oblique fracture â uneven bending
5) Segmental fracture â four-point bending
4) Oblique fracture with a butterfly fragment â bending and compression
A transverse fracture is secondary to a pure bending force. The other patterns included:
Oblique fracture â uneven bending: This type of injury typically occurs following motorcycle accidents when the tibia is subjected to uneven bending forces.
Segmental fracture â four-point bending: This injury most commonly follows a high-energy injury, such as a pedestrian being struck by a car bumper.
Oblique fracture with a butterfly fragment â bending and compression: This is a common fracture that occurs with low- and high-speed injuries. These fractures may occur from car bumpers and motorcycles.
Short spiral fracture â torsion: This mechanism is usually from a low velocity skiing injury. Correct Answer: Transverse fracture â pure bending
669. (867) Q2-1130:
Which of the following would be a high-energy injury:
1) Transverse tibia fracture after a soccer injury
3) Femur fracture from a bullet with a 1,200 ft/seCmuzzle velocity
2) Ulna shaft fracture secondary to being struck by a bat
5) Short spiral tibia fracture after a skiing injury
4) Segmental fracture from a car bumper
An injury caused by a car bumper is a high-energy injury.
All of the other distracters are low-energy injuries. Note that the cutoff for muzzle velocity between low- and high-energy injuries is 2,000 to 2,500 ft/sec.
Correct Answer: Segmental fracture from a car bumper
670. (868) Q2-1131:
Which of the following is a high-energy injury:
1) Comminuted distal radius fracture after a fall on an outstretched hand
3) Humerus fracture from a bullet with a 2,900 ft/seCmuzzle velocity
2) Comminuted radial head fracture after a fall
5) Transverse tibia fracture after a soccer injury
4) Ulna shaft fracture from a bat
Gun shot injuries with a muzzle velocity greater than 2,500 ft/seCare high-energy injuries. These injuries cause cavitation in the soft tissues. Often the projectiles yaw, increasing the amount of soft tissue damage. High-velocity injuries require aggressive debridement. Low-velocity projectiles have a muzzle velocity that is less than 1,500 ft/sec. There is minimal soft tissue damage such that debridement of the wound edge is all that is required.
Correct Answer: Humerus fracture from a bullet with a 2,900 ft/seCmuzzle velocity
671. (869) Q2-1132:
In which of the following fractures is the load to failure the lowest:
1) Transverse tibia fracture after a soccer collision
3) A short spiral humerus fracture after throwing a baseball from home to second base
2) Segmental tibia fracture after an automobile-pedestrian accident
5) A humerus fracture from a bullet with a muzzle velocity of 2,700 ft/sec
4) A comminuted spiral tibia fracture after a skiing injury
The lowest load to failure in long bones occurs with pure torsional forces. A long bone is weakest when loaded in pure torsion. Throwing may cause a humerus fracture through pure torsional loading. The skiing injury is also a torsional injury, however, the comminution indicates a greater amount of energy storage by the bone prior to failure.
Correct Answer: A short spiral humerus fracture after throwing a baseball from home to second base
672. (870) Q2-1133:
A hematoma located at a bone fracture site forms a:
1) Fibrin scaffold formation for mechanical stability
3) Production of matrix vesicles to initiate mineralization
2) Source of signaling molecules, such as interleukins 1 and 6
5) Source of matrix vessels for protease and phosphatase production
4) Source of perivascular cells as progenitors of osteoblasts
The hematoma at a bone fracture site is believed to serve as a source of signaling molecules to control cellular events. Inflammatory cells produce cytokines, such as interleukin 1 and 6, and platelets in the clot release transforming growth factor- beta (TGF-B) and platelet derived growth factor (PDGF).
An old theory was that the hematoma served as a fibrin scaffold and added mechanical stability.
The hypertrophied chondrocytes produce matrix vesicles that control mineralization. The hypertrophiCcartilage cells are invaded by blood vessels that bring in the perivascular cells, which are the progenitors of the osteoblasts.
Correct Answer: Source of signaling molecules, such as interleukins 1 and 6
673. (871) Q2-1134:
Which of the following fractures occurs through a single application of force:
1) A minimally displaced femoral neck fracture in a long distance runner
3) A fifth rib fracture in a collegiate rower
2) A second metatarsal fracture in a Naval Academy midshipman
5) A proximal one-third posterior tibial cortex fracture in a long distance runner
4) A short spiral humerus fracture in a baseball catcher
The femoral neck fracture, metatarsal fracture, rib fracture, and the tibial fracture are stress fractures that result from repetitive loading.
In contrast, the humeral fracture in the baseball catcher is secondary to failure of the humerus secondary to a pure torsional force. Long bones are at their weakest when loaded in pure torsion.
Correct Answer: A short spiral humerus fracture in a baseball catcher
674. (872) Q2-1135:
Which of the following statements is true concerning the vascularity at a fracture site:
1) Periosteal blood vessels are capable of supplying the endosteal region.
3) Reamed intramedullary rods do not significantly interrupt endosteal blood supply.
2) Fracture site blood flow peaks at 2 weeks.
5) In animal studies, blood flow is greater at 42 days in rodded vs. plated tibias.
4) In animal studies, blood flow is greater at 120 days in plated vs. rodded tibias.
In the normal long bone, the periosteal vessels supply the outer one-third of the cortex. The nutrient artery enters at the diaphysis of a long bone and has ascending and descending vessels that supply the inner two-thirds of the cortex.
Important points to remember:
The periosteal blood supply cannot supply the inner two-thirds of the cortex even if the endosteal blood supply has been interrupted, as in intramedullary reaming.
Blood flow markedly drops at the fracture site at the time of the fracture and peaks at 2 weeks.
Intramedullary reamed rods destroy the endosteal blood supply. In dog experiments, the blood supply is reconstituted to normal in 120 days.
In dog experiments, the blood supply is decreased in both plated and rodded tibias at 42 and 90 days. The decrease is greater in the rodded tibias.
The oxygen tension is low in the fracture hematoma and in the newly formed cartilage and bone. The oxygen tension is highest in the fibrous tissue. The hypoxiCstate favors cartilage formation.
Correct Answer: Fracture site blood flow peaks at 2 weeks.
675. (873) Q2-1137:
Which of the following statements is true concerning molecular events at the site of a healing fracture:
1) Type II collagen production is lowest during the first 2 weeks.
3) Periosteal type III collagen serves as a substrate for migration of osteoprogenitor cells and capillary ingrowth.
2) Type I collagen production is highest during the first 2 weeks.
5) Types V and XI collagen control the maturation of mineralization crystals.
4) Type IX collagen initiates mineralization of type II collagen.
Important points to remember concerning molecular events at the fracture site:
Type II collagen production is highest during the first 2 weeks. Cartilage is the first tissue produced at the fracture site. The chondrocytes hypertrophy and release matrix vesicles that prepare the extracellular matrix for mineralization of the cartilage. Blood vessels grow into the hypertrophied cartilage cells and perivascular cells become osteoblasts and begin mineralization. This is the exact same process that occurs at the growth plate with formation of the primary and secondary spongiosa.
Type I collagen production is low during the first 2 weeks as cartilage is initially formed. Type I collagen production is highest as the cartilage is mineralized later.
Periosteal type III collagen serves as a substrate for the migration of osteoprogenitor cells and capillary ingrowth. Type IX collagen contributes to the mechanical stability of type II collagen.
Types V and XI collagen regulate the growth and orientation of types I and II collagen fibrils.
Correct Answer: Periosteal type III collagen serves as a substrate for migration of osteoprogenitor cells and capillary ingrowth.
676. (874) Q2-1138:
Which of the following statements is true concerning the molecular events involved in fracture healing:
1) Osteonectin plays a role in early ossification.
3) Osteopontin plays no role in normal bone remodeling.
2) Osteocalcin inhibits intramembranous bone formation.
5) Osteonectin is found in proliferating and hypertrophiCchondrocytes rather than extracellular matrix.
4) Fibronectin inhibits cell migration and adhesion.
There are several noncollagenous proteins that are important in bone repair and regeneration:
Osteonectin â The gene for osteonectin is expressed at the onset of both intramembranous and enchondral ossification. It may play a role in the regulation of cell function in the early stages of ossification.
Osteocalcin â Osteocalcin is expressed in the fracture callus only by osteoblastiCcells. This protein may have a role in intramembranous subperiosteal bone formation.
Osteopontin â This protein is found in the extracellular matrix and is important in cellular attachment. It is found in osteocytes and osteoprogenitor cells. Osteopontin may play a role in bone remodeling.
Fibronectin â This protein plays a role in early fracture healing and is found in the fracture hematoma within 3 days. Fibronectin mediates adhesion and migration. It is found in the fibrous portions of provisional matrices and in cartilage matrix. The potential role for this protein is the establishment of provisional fibers in cartilaginous matrices.
Correct Answer: Osteonectin plays a role in early ossification.
677. (933) Q2-1220:
Which of the following is not a clinical sign of rickets?
1) Irritability
3) Localized bone pain
2) Frontal bossing
5) Enlarged epiphyses
4) Short stature
Localized bone pain is not a common finding in rickets. In contrast, in osteomalacia, bone pain is very common. The features of rickets that one should remember include:
Elevated PTH (phosphorus lower range of normal, 1/3 low) Neuromuscular syndrome
Easy fatigue, weakness, older than you seem
Bone mineral density - excellent marker of the disease - low in distal radius (cortical bone) and normal at vertebra (cancellous bone)
Treatment - neck exploration and removal of the parathyroid adenoma
Correct Answer: Tetany
679. (935) Q2-1222:
Which of the following is the most likely origin for the greater medullary artery (Adamkiewicz artery):
1) Lower cervical segmental
3) Middle thoraciCsegmental
2) Upper thoraciCsegmental
5) Upper lumbar segmental
4) Lower thoraciCsegmental
The major part of the blood supply of the spinal cord is provided by the medullary or radicular arteries. The only feeder for the lower thoraciCspine cord is the greater medullary artery or artery of Adamkiewicz (T9-T11).
One should remember that in the thoraciCspine the right-sided approach is preferred to avoid the aorta and segmental artery of
Adamkiewicz.
Correct Answer: Lower thoraciCsegmental
680. (936) Q2-1223:
The principle blood supply to the humeral head derives from:
1) The anterior humeral circumflex artery
3) The posterior humeral circumflex artery
2) Axillary artery
5) Subscapular artery
4) Acromial branch of thoracoacromial artery
The humeral head has been shown to be perfused primarily by the anterolateral ascending branch of the anterior circumflex artery. This branch runs parallel to the lateral aspect of the tendon of the long head of the biceps and enters the humeral head where the proximal end of the intertubercular groove meets the greater tuberosity. The posterior circumflex artery provides only the posterior portion of the greater tuberosity and a small posteroinferior part of the head
■Correct Answer: The anterior humeral circumflex artery
681. (937) Q2-1225:
A 4-year-old child injures his elbow and presents with swelling and limitation of voluntary movement. The radiographs show no obvious fracture, but it does show a Baumann angle of 71° and an elevation of the posterior fat pad. You tell the parents that this most likely represents:
1) A congenital anomaly with a valgus deformity of the elbow
3) A Salter I physeal separation
2) A medial epicondyle fracture
5) A variation of normal
4) An occult supracondylar fracture
Occult supracondylar fracture was the most common diagnosis assigned after careful study of a clinical series of elevated pediatriCposterior fat pads.
The value for Baumann angle is normally 73° ± 6°. Nothing in this description suggests a congenital anomaly. Medial epicondyle fractures are extremely rare before 9 years of age.
Although a Salter I physeal separation is a possibility, it is a rare injury.
With an elevation of the posterior fat pad, there is increasing recognition that a fracture exists. Correct Answer: An occult supracondylar fracture
682. (1049) Q2-1356:
The tibialis anterior muscle is principally innervated by which of the following nerve roots:
1) L1
3) L3
2) L2
5) L5
4) L4
The tibialis anterior muscle is primarily innervated by the L4 nerve root. The tibialis anterior muscle also receives innervation from the L5 nerve root. Patients with a weak or absent tibialis anterior muscle will have a drop foot or a steppage gait. The tibialis anterior muscle causes dorsiflexion and inversion of the foot and ankle
■Correct Answer: L4
683. (1050) Q2-1357:
The patellar tendon reflex is primarily transmitted through which of the following nerve roots:
1) L1
3) L3
2) L2
5) L5
4) L4
Although the patellar tendon reflex is primarily transmitted through the L4 nerve root, the L2 and L3 nerve roots also contribute to the fibers. There is a weak reflex if the L4 nerve root is completely cut, even if there are still L2 and L3 fibers. Patellar tendon reflex is seldom completely absent unless the patient has primary muscle or anterior horn lesions
■Correct Answer: L4
684. (1051) Q2-1358:
The skin on the medial aspect of the leg and great toe is innervated by which of the following nerve roots:
1) L2
3) L4
2) L3
5) S1
4) L5
It is important to remember the sensory dermatomes when examining patients. The medial aspect of the leg, foot, and great toe are supplied by the L4 nerve root. The tibial crest separates the L4 and L5 dermatomes on the leg.
Remember:
L4 Medial aspect of the leg, foot, and great toe
L5 Lateral aspect of the leg and toes 2 to 4
S1 Lateral aspect of the fifth toe
Correct Answer: L4
685. (1052) Q2-1359:
The extensor hallucis longus muscle is innervated by which of the following nerve roots:
1) L1
3) L3
2) L2
5) L5
4) L4
The extensor hallucis longus muscle is primarily innervated by the L5 nerve root. The L5 nerve root innervates the following muscles:
Extensor hallucis longus muscle
Extensor digitorum longus and brevis muscles
Gluteus medius muscle
Correct Answer: L5
686. (1053) Q2-1360:
The extensor digitorum longus and brevis muscles are primarily innervated by which of the following nerve roots:
1) L1
3) L3
2) L2
5) L5
4) L4
The extensor digitorum longus and brevis muscles are primarily innervated by the L5 nerve root. The L5 nerve root innervates the following muscles:
Extensor hallucis longus muscle
Extensor digitorum longus and brevis muscles
Gluteus medius muscle
Correct Answer: L5
687. (1054) Q2-1361:
The gluteus medius muscle is principally innervated by which of the following nerve roots:
1) L1
3) L3
2) L2
5) L5
4) L4
The gluteus medius muscle principally receives its innervation from the L5 nerve root through the superior gluteal nerve. Although the principal innervation is from L5, L4 and S1 nerve roots also contribute to the innervation
■Correct Answer: L5
688. (1055) Q2-1362:
Testing of the L5 nerve root is accomplished through the:
1) Patellar tendon reflex
3) Tibialis posterior reflex
2) Achilles tendon reflex
5) Beevor sign
4) Superficial anal reflex
There is not a well-defined reflex arCfor the L5 nerve root. The tibialis posterior reflex may be elicited at times, and this reflex is mediated through the L5 nerve root.
Remember the other reflexes as well: Patellar tendon L4
Achilles tendon S1
Superficial anal reflex S2, S3, and S4
Beevor sign refers to asymmetry of the segmental innervation of the rectus abdominus muscles. This is noted when a patient performs a sit-up and unilateral segmental nerve root loss is noted
■Correct Answer: Tibialis posterior reflex
689. (1056) Q2-1363:
The skin on the lateral aspect of the leg and the dorsum of the foot between the second and fourth toes is innervated by which of the following nerve roots:
1) L1
3) L3
2) L2
5) L5
4) L4
The L5 dermatome covers the skin on the lateral leg and dorsum of the foot from the lateral border of the great toe to the medial border of the little toe.
Remember:
L4 Medial aspect of the leg, foot, and great toe
L5 Lateral aspect of the leg and toes 2 to 4
S1 Lateral aspect of the fifth toe
Correct Answer: L5
690. (1057) Q2-1364:
The peroneus longus and brevis muscles are innervated by which of the following nerve roots:
1) L3
3) L5
2) L4
5) S2
4) S1
The peroneus brevis and longus muscles are principally innervated by the S1 nerve root through the superficial peroneal nerve. Although the innervation is principally through the S1 nerve root, the nerve is derived from the L5 and S2 nerve roots, as well.
Remember that the muscles principally innervated by the S1 nerve root include: Peroneus longus and brevis muscles
Gastrocnemius-soleus complex
Gluteus maximus muscle
Correct Answer: S1
691. (1058) Q2-1365:
The medial and lateral gastrocnemius muscles principally receive their innervation through which of the following nerve roots:
1) L3
3) L5
2) L4
5) S2
4) S1
The medial and lateral gastrocnemius muscles are principally supplied by the S1 nerve root through the tibial nerve. There are also nerve fiber contributions from L5 and S2.
Remember that the muscles principally innervated by the S1 nerve root include:
Peroneus longus and brevis muscles Gastrocnemius-soleus complex Gluteus maximus muscle
Correct Answer: S1
692. (1059) Q2-1366:
The Achilles tendon reflex (ankle reflex) is transmitted through which of the following nerve roots:
1) L4
3) S1
2) L5
5) S3
4) S2
The Achilles tendon reflex is based upon the triceps muscle group (medial and lateral gastrocnemius muscles and soleus muscle)
and is transmitted through the S1 nerve root. Remember:
Patellar tendon reflex L4
Posterior tibial reflex L5
Achilles tendon reflex S1
Correct Answer: S1
693. (1060) Q2-1367:
Which of the following groups of nerve roots innervate the intrinsiCmuscles of the foot:
1) L2, L3, and L4
3) L4, L5, and S1
2) L4 and L5
5) S2 and S3
4) L5, S1, and S2
The intrinsiCmuscles of the foot are innervated by the S2 and S3 nerve roots. These muscles are difficult to test. Clawing of the toes occurs with intrinsiCmuscle paralysis.
Remember the following nerve roots and the structures that they innervate:
• L5, S1 and S2 Hip extension: Gluteus maximus muscle
• L5, S1, and S2 Foot plantarflexion
• L5, S1 and S2 Foot eversion
• L4, L5, and S1 Hip abduction: Gluteus medius muscle
• L4, L5 Foot dorsiflexion
• L4, L5 Foot inversion
• L2, L3, and L4 Hip adduction
• L2, L3, and L4 Knee extension
• L1, L2, and L3 Hip flexion: Iliopsoas muscle
Correct Answer: S2 and S3
694. (1061) Q2-1368:
Perianal sensation is derived from which of the following nerve roots:
1) L2, L3, and L4
3) L5, S1, and S2
2) L3, L4, and L5
5) S2, S3, S4, and S5
4) S1, S2, and S3
Perianal sensation is derived from the S2, S3, S4, and S5 nerve roots. The sensory distribution is as follows:
• S4-S5 Innermost perianal ring
• S3 Middle perianal ring
• S2 Outermost perianal ring
Correct Answer: S2, S3, S4, and S5
695. (1062) Q2-1369:
Which of the following sensory segmental levels corresponds with the nipple line:
1) T2
3) T7
2) T4
5) T12
4) T10
It is important to know the sensory segmental levels to localize pathologiCprocesses. In addition to knowing the innervation of selected muscles and the deep tendon reflexes, a clinician should also know the sensory levels.
Remember:
• T4 Nipple line
• T7 Xiphoid process
• T10 Umbilicus
• T12 Groin
Correct Answer: T4
696. (1063) Q2-1370:
Which of the following sensory segmental levels corresponds to sensation at the xiphoid process:
1) T2
3) T7
2) T4
5) T12
4) T10
The skin over the xiphoid process area is innervated by the T7 nerve root.
It is important to know the sensory segmental levels to localize pathologiCprocesses. In addition to knowing the innervation of selected muscles and the deep tendon reflexes, a clinician should also know the sensory levels.
Remember:
• T4 Nipple line
• T7 Xiphoid process
• T10 Umbilicus
• T12 Groin
Correct Answer: T7
697. (1064) Q2-1371:
The skin over the umbilicus is innervated by which of the following sensory segmental levels:
1) T2
3) T7
2) T4
5) T12
4) T10
The skin of the umbilicus is innervated by the T10 sensory segmental level.
It is important to know the sensory segmental levels to localize pathologiCprocesses. In addition to knowing the innervation of selected muscles and the deep tendon reflexes, a clinician should also know the sensory levels.
Remember:
• T4 Nipple line
• T7 Xiphoid process
• T10 Umbilicus
• T12 Groin
Correct Answer: T10
698. (1065) Q2-1372:
The skin over the groin is innervated by which of the following sensory segmental levels:
1) T2
3) T7
2) T4
5) T12
4) T10
The skin over the groin is innervated by the T12 sensory segmental level.
It is important to know the sensory segmental levels to localize pathologiCprocesses. In addition to knowing the innervation of selected muscles and the deep tendon reflexes, a clinician should also know the sensory levels.
Remember:
• T4 Nipple line
• T7 Xiphoid process
• T10 Umbilicus
• T12 Groin
Correct Answer: T12
699. (1066) Q2-1373:
Which of the following levels of the spinal cord principally innervates the main flexor of the hip:
1) T10, T11, and T12
3) L2, L3, and L4
2) L1, L2, and L3
5) L5, S1, and S2
4) L4, L5, and S1
The iliopsoas muscle is the main flexor of the hip, and it receives principal innervation from the L1, L2, and L3 levels. Remember:
• L5, S1 and S2 Hip extension: Gluteus maximus muscle
• L5, S1, and S2 Foot plantarflexion
• L5, S1 and S2 Foot eversion
• L4, L5, and S1 Hip abduction: Gluteus medius muscle
• L4 and L5 Foot dorsiflexion
• L4 and L5 Foot inversion
• L2, L3, and L4 Hip adduction
• L2, L3, and L4 Knee extension
• L1, L2, and L3 Hip flexion: Iliopsoas muscle
Correct Answer: L1, L2, and L3
700. (1067) Q2-1374:
Which of the following segmental levels innervates the quadriceps muscle:
1) T10, T11, and T12
3) L2, L3, and L4
2) L1, L2, and L3
5) L5, S1, and S2
4) L4, L5, and S1
The quadriceps muscle is innervated by the femoral nerve from the L2, L3, and L4 segmental levels. Remember:
⢠L5, S1 and S2 Hip extension: Gluteus maximus muscle ⢠L5, S1, and S2 Foot plantarflexion
⢠L5, S1 and S2 Foot eversion
⢠L4, L5, and S1 Hip abduction: Gluteus medius muscle ⢠L4 and L5 Foot dorsiflexion
⢠L4 and L5 Foot inversion ⢠L2, L3, and L4 Hip adduction ⢠L2, L3, and L4 Knee extension
