review Flashcards
Alpha-fetoprotein (AFP) and acetylcholinesterase (AChE) levels in amniotic fluid are elevated and AFP levels in maternal serum are elevated. Ultrasound shows increased amniotic fluid volume (polyhydramnios).
anencephaly
due to failed rostral neuropore closure
Diagnosis is based on findings of a small dimple or tuft of hair in the lumbosacral region
Spina bifida occulta - closed NTD
vertebral arch(es) - derived from sclerotome, typically in the lumbosacral region - form incompletely while the neural tissues and meninges are intact
In the developing spinal cord, the neuroepithelial cells of the neural tube form the _____ layer, which will become the gray matter, and the _____ layer, which will become the white matter. Additionally, the _____ layer contains the ____ plate, which develops into the sensory dorsal horn, and the _____ plate, which develops into the motor ventral horn.
In the developing spinal cord, the neuroepithelial cells of the neural tube form the mantle layer, which will become the gray matter, and the marginal layer, which will become the white matter. Additionally, the mantle layer contains the alar plate, which develops into the sensory dorsal horn, and the basal plate, which develops into the motor ventral horn.
[feel the Air with the Alar plate, Bust it with the Basal plate]
risk factor for holoprosencephaly
alcohol consumed during pregnancy - causes defective SHH signaling
defective closure of rostral vs caudal neuropore causes…
rostral —> anencephaly
caudal —> neural tube defect
this should make sense if you think of the directions !
patient with a herniated nucleus pulpous at C5-C6 may:
feel paresthesia (tingly, prickly sensation) or numbnness in the thumb.
feel paresthesia (tingly, prickly sensation) or numbnness in the pinky finger.
lose some function in flexion of the distal interphalangeal joints.
lose some function in the ulnar nerve.
lose some function in the intrinsic muscles of the hand.
feel paresthesia (tingly, prickly sensation) or numbnness in the thumb.
The ventral ramus of the C6 spinal nerve contains different nerve fiber types including:
postganglionic sympathetic.
postganglionic parasympathetic.
pregnaglionic parasympathetic.
preganglionic sympathetic.
postganglionic sympathetic.
Ventral rami of spinal nerves carry different fiber types, including somatic motor, somatic sensory, and POSTGANGLIONIC SYMPATHETIC. Presynaptic sympathetic neurons are only present at T1-L2 so they are not present at this level.
A 36-year-old is being evaluated for left-hand weakness. On examination it is found that he also has numbness in the left C8 dermatome. This might indicate a lesion to the:
ventral root.
ventral ramus
dorsal root ganglia.
dorsal ramus.
ventral ramus
Ventral ramus is correct because it is the only choice that contains both motor and sensory components that innervate the hand. The dorsal ramus supplies sensory and motor to a limited region along the midline of the back.
which nerve contributes to each of the following functions of the thumb?
a. 2 extensors: EPL, EPB
b. 2 flexors: FPL, FPB
c. 2 abductors: APL, APB
d. adductor pollicis
e. opponens pollicis
2 extensors: EPL, EPB (both radial nerve)
2 flexors: FPL, FPB (both median nerve)
2 abductors: APL, APB (radial nerve for APL, median nerve for APB)
1 adductor pollicis. (ulnar nerve)
1 opponens pollicis (median nerve)
A fracture at the medial epicondyle of the humerus may result in the inability to:
flex the metacarpophalangeal joints with extension of the interphalangeal joints for digits 2 and 3.
adduct the fingers.
feel sensation in the 3rd digit.
flex the distal interpgalangeal joint of the index finger.
abduct the thumb.
adduct the fingers.
ulnar nerve may be injured at the medial epicondyle of the humerus. ulnar nerve supplies most of the intrinsic hand muscles, except the median nerve supply to 2LOAF muscles. The palmar interosseus muscles adduct the digits (PAD).
A cyclist experiences sensory loss and motor loss in the left hand. You suspect that your patient has ulnar canal syndrome due to compression of the ulnar nerve as it courses through Guyon’s canal at the wrist. Which of the following movements may be associated with this?
inabilityto abduct the thumb
weakness in extension of metacarpophalngeal joints with flexion of interpahalngeal joints of medial four digits
inability to adduct the fingers
hypothesia in thee lateral 3-½ digits
inability to fleex the distal interphalangeal joint of digits 4 and 5
inability to adduct the fingers
Compression of the ulnar nerve in Guyon’s canal affects deep ulnar nerve supply to most of the intrinsic hand muscles (except 2LOAF) and superficial nerve supply to the medial 1-1/2 digits and hand. Therefore, the palmar interosseus muscles that adduct the fingers are compromised.
Thumb abduction is not affected because of recurrent median nerve supply to the APB and deep posterior interosseus nerve supply to the APL. The medial half of the FDP is supplied by the ulnar proximal to Guyon’s canal, so flexion of DIP still occurs in all digits.
which of the rotator cuff muscles is a medial rotator?
subscapularis
Sign of benediction is associated with a _____ nerve injury.
Sign of benediction is associated with a median nerve injury.
In evaluating your patient’s hand you ask him to hold a piece of paper between his index and middle fingers while you pull on the paper. Which of the following nerve/muscle combinations are you assessing with this test?
ulnar nerve and 1st dorsal interosseous muscle
median nerve and 1st lumbrical muscle
ulnar nerve and 1st palmar interosseous muscle
anterior interosseous nerve and flexor digitorum profundus of the index finger
median nerve and adductor pollicis muscle
ulnar nerve and 1st palmar interosseous muscle
Keeping the paper between the index and middle fingers requires the patient to adduct (palmar interossei muscles PAD) the index finger and abduct (dorsal interossei muscles DAB) the middle finger. Both muscle groups are Ulnar nerve innervated and the 1st palmar interosseous muscle adducts the index finger.
Following a surgical procedure in the axilla, your patient complains of reduced sensation along the lateral border of the forearm indicating inadvertent damage to the lateral cord of the brachial plexus. Which of the following functional deficits would this patient most likely present with?
weakness of abduction of the arm at the glenohumeral joint
weakness of lateral rotation of the arm at the glenohumeral joint
weakness of supination of the forearm
weakness of opposition of the thumb
weakness of extension of the forearm at the elbow
weakness of supination of the forearm
LATERAL CORD lesion resulting in reduced sensation from the lateral forearm indicates damage to nerve fibers traveling in the MUSCULOCUTANEOUS NERVE. SUPINATION of the forearm is the only action involving a muscle (biceps) innervated by the musculocutaneous nerve.
Examination of your patient reveals that he is unable to abduct his arm at the shoulder to a full 180 degrees. Injury of which of the following nerves might cause this finding?
medial pectoral nerve
dorsal scapular nerve
upper subscapular nerve
long thoracic nerve
musculocutaneous nerve
The LONG THORACIC NERVE supplies the SERRATUS ANTERIOR, which is involved in full abduction at the shoulder.
A patient presents due to low back pain. Your examination includes the sit-to-stand test, which reveals left quadriceps femoris weakness. This test is consistent with a diagnosis of:
compression of the ventral ramus of a sacral spinal nerve by a herniated nucleus pulposus.
stenosis of the vertebral canal at the level of the L5 vertebra.
a herniated nucleus pulposus at the lateral border of the anterior longitudinal ligament.
a herniated nucleus pulposus of the L4-5 intervertebral disc.
an arthritic bone spur narrowing the L3-4 intervertebral foramen.
an arthritic bone spur narrowing the L3-4 intervertebral foramen.
A weakness in the quadriceps femoris muscle may result with compression/injury to the femoral nerve or any of the spinal nerve segments (L2-L4) that comprise the femoral nerve. An arthritic bone spur narrowing the L3-L4 intervertebral foramen would impact the L4 spinal nerve that exits through this opening. Since L4 contributes to the femoral nerve this is the correct choice. An HNP of the L4-5 intervertebral disc would impinge on the L5 nerve so no effect on the femoral nerve or the muscles it innervates.
ANTERIOR LEG MUSCLES are innervated by the ______ and cause foot DORSIFLEXION. LATERAL LEG MUSCLES are innervated by the ______ and cause foot EVERSION.
ANTERIOR LEG MUSCLES are innervated by the DEEP FIBULAR NERVE and cause foot DORSIFLEXION. LATERAL LEG MUSCLES are innervated by the SUPERFICIAL FIBULAR NERVE and cause foot EVERSION. The COMMON FIBULAR NERVE divides into the deep and superficial below the knee. Injury to the common fibular nerve would compromise both foot dorsiflexion and eversion.
You are evaluating your patient’s gait in order to evaluate the integrity of the nerve supply to the lower limbs. You note that your patient enters the right stance phase with a toe strike. This finding is consistent with a lesion of his…
right deep fibular nerve
A toe strike when entering the stance phase of the gait cycle occurs when a patient can’t dorsiflex the foot. Since this case involves the patient’s right foot a right deep fibular nerve injury would weaken the right anterior leg muscles responsible for dorsiflexion.
A baseball player was hit by a pitch in the back of the thigh resulting in a large hematoma over the middle aspect of the semimembranosus muscle. The most likely source of the bleeding was from injury to branches of the…
profunda femoral artery (and its branches) is the chief blood supply to the entire thigh. The posterior thigh is supplied by perforating branches of the profunda femoral artery.
Excessive inversion of the foot is resisted by ligaments on the _____ side of the ankle. The _______ is on the _____ side of the ankle/foot and it is the most commonly torn ligament during an INVERTED ANKLE SPRAIN.
Excessive inversion of the foot is resisted by ligaments on the lateral side of the ankle. The ANTERIOR TALOFIBULAR LIGAMENT is on the LATERAL side of the ankle/foot and it is the most commonly torn ligament during an INVERTED ANKLE SPRAIN.
Ultrasonography indicates an obstruction in the posterior tibial vein of your patient. A thrombus in this vein is at risk of detaching and traveling to the lungs. The most direct course of the embolus through the lower limb would be from the: posterior tibial vein to the
fibular vein to the popliteal vein to the internal iliac vein.
great saphenous vein to the profunda femoral vein to the external iliac vein.
lesser saphenous vein to the great saphenous vein to the femoral vein.
popliteal vein to the femoral vein to the external iliac vein.
anterior tibial vein to the popliteal vein to the femoral vein.
popliteal vein to the femoral vein to the external iliac vein.
Immediately after intragluteal injection, a patient complains of foot drop and numbness, tingling, burning in the right leg down to the toes. Which nerve or division of the nerve is most likely affected?
The SCIATIC NERVE may be damaged during an intragluteal injection. Divisions of the sciatic nerve are tibial and common fibular nerve.
During a physical exam you have your patient stand on his right leg only and notice his pelvis tilts to the left. If the cause of your findings was a lesion of one of the collateral nerves of the lumbosacral plexus, which of the following other functional deficits would you expect to find with a lesion of that same collateral nerve?
weakened medial rotation at the hip joint
weakened extension at the hip joint
complete loss of flexion at the hip joint
complete loss of lateral rotation at the hip joint
weakened adduction at the hip joint
weakened medial rotation at the hip joint
Presentation indicates a weakness in HIP ABDUCTOR muscles, which are innervated by the SUPERIOR GLUTEAL NERVE. Those same muscles also are responsible for medial rotation at the hip.