Practice Questions Flashcards
What structures occupy the quadrangle space?
Axillary nerve and posterior circumflex humeral artery
What structure makes up the superior border of the triangular interval?
Teres major M
A 39 yo male presents to office with trouble medially rotating his humerus. What rotator cuff muscle is likely implicated?
Subscapularis (medial rotation)
In vertebrates, the signal passes through the neuromuscular jxn via which of the following NTs?
Acetylcholine
Approximately 1/2 of major joint dislocations seen in ER are of the shoulder. Partial dislocation of the shoulder is referred to as subluxation. The glenohumeral joint is most likely to dislocate in what direction?
Anterior and inferior direction
Brachial plexus injuries, or lesions, can occur as a result of shoulder trauma, tumors or inflammation. The rare Parsonage-Turner Syndrome causes brachial plexus inflammation without obvious injury, but with disabling symptoms. Injury to the posterior cord of the brachial plexus would most likely cause dysfunction which of the following maneuvers?
Abduction of the arm at the shoulder joint
A 15 yo African Am presents with developing ‘light blotchy patches’ on his arm. His mother said they started months ago and are getting worse. The physician suspects an autoimmune process involving melanocytes. Which of following conditions?
Vitalgo
During first 3 to 4 weeks of a pregnancy, specific cells in a developing baby curl up and their edges fuse together to form a narrow tube that becomes the foundation of the spinal canal, brain and the bone/tissues around them. This neural tube fusing process is usually complete by 28 days of pregnancy (gestation) before many women know they are pregnant. Neural tube defect. Defects caused by failure of the neural tube to close completely during fetal development and are called?
Encephalocele
In 2nd week of pregnancy, called gastrulation, specialized cells on the dorsal side of gets begin to fuse and form neural tube. When the neural tube does not close completely, an NTD develops. Soon after neural tube closure, future brain can be distinguished. The most caudal of the 3 primary brain vesicles is which of the following?
Rhombencephalon
The nervous system consists of the brain, spinal cord and complex network of neurons. This system is responsible for sending, receiving and interpreting information from all parts of the body. The nervous system monitors and coordinates internal organ function and responds to changes in the external environment. This system can be divided into 2 parts: CNS and PNS. One of the subdivisions of PNS is in charge of voluntary actions and conscious perceptions. In this subdivision of the PNS:
One neuron comes in, one neuron goes out
In all bilateral animals, the mesoderm is one of the 3 primary germ layers in the very early embryo. The other 2 layers are ectoderm (outside layer) and endoderm (inner layer) with mesoderm in the middle. The type of mesoderm responsible for forming the urogenital system is the
Intermediate mesoderm
……so many fucking words…. The mesoderm which is precursor to sclerotome, myotome and dermatome is the
Paraxial mesoderm
From their initial location within the somite, the sclerotome cells migrate medially towards the notochord. These cells meet the sclerotome cells from the other side to form the vertebral body. From this ventral body, sclerotome cells move dorsally and surround the developing spinal cord, forming vertebral arch. Other cells move distally to the costal process of thoracic vertebrae to form the ribs. Vertebrae are formed by the sclerotomes. The differentiation of the lumbar, sacral and coccygeal vertebrae is due to:
Hox 10
Calcium is involved in the skeletal muscle contraction in several ways. It is released and resequestered, it enters the bouton for NT release and is involved elsewhere. Calcium is sequestered into the sarcoplasmic reticulum by which of the following protein molecules
SERCA
Sarcoplasmic reticulum Ca2+ ATPase
A baby that is born with a limb defect will have an upper or lower limb that did not properly form while in utero. There are a variety of types of congenital limb defects that your child could experience. Sirenomelia is a congenital limb abnormality in which:
There is a fusion of the lower limbs
A longitudinal cut of muscle is observed to have the following characteristics: striations, nuclei at side, rectangular shape and large sized cells. Which type is being observed?
Skeletal muscle
Myofilaments are long tubular structures inside of muscle cells that are made up of shorter contractile sections called sarcomeres. In myofilament organization, which of the following elements most notably control length of actin?
Nebulin
The contraction signal is spread rapidly along the fiber by means of the T-tubule system, which signals the rapid release of calcium ions from the sarcoplasmic reticulum (SR). A skeletal muscle fiber type which uses type I myosin ATPase and is slowly oxidative is a
Red skeletal muscle fiber
Action potentials are of great importance to the functioning of the brain since they propagate info in the nervous system to the CNS and propagate commands initiated in the CNS to the periphery. Consequently, it is necessary to understand thoroughly their properties. To answer the question of how action potentials are initiated and propagated, we need to record the potential between the inside and outside of nerve cells using intracellular recording techniques. For every neural action potential:
There is one muscle action potential
An immune response to post-synaptic nicotinic receptors is the cause of which of the following conditions?
Myasthenia gravis
Which of the following conditions is best described as an immune response to pre-synaptic voltage-gated channels in which symptoms improve with use throughout the day?
Lambert-Eaton Syndrome
Depolarization within the T-tubule causes a conformational change in the DHP receptor which consequently causes:
Ryanodine receptors to open, releasing Ca2+ from the sarcoplasmic reticulum
For an isometric contraction for skeletal muscle to occur the following must take place
The muscle length stays the same but there is an increase in force
A med student is trying to study and cook at the same time. Accidentally places hand on hot stove. Pain is fast and sharp and before realizes burn, he pulled hand away. The fiber which is most involved in this acute accident is the
A-delta fibers
The same medical student has rough night. Accidentally hits shin on coffee table. 5 minutes after there is a small lump and dull throbbing coming from leg. Student cheers because knows how dull pain is being transmitted.
C fibers
An anterior/ventral displacement of a vertebra onto an adjacent vertebra most commonly associated with L5 displacing on the sacrum is known as
Spondylolisthesis
When lateral masses of C1 are compressed between the occipital condyles and the axis of C2 resulting in the fracturing of the anterior and/or posterior arches of C1, this is known as
Jefferson or Burst fracture
Identify the cells in the photograph
-
Chondroblasts in elastic cartilage
A pt in ER with penetrating wound to axillary region. Pt is an electrician who was working and fell onto a metal steak which penetrated his side. The most likely resultant long term symptom secondary to nerve damage of the region would be:
Winged scapula
In a pt with a fracture at distal end of humerus, most likely neurological damage will be to
Median nerve
Which troponin complex binds actin and inhibits myosin binding?
Troponin I
Pharm question
……
20 yo with history of osteoporosis presents to ER after fall on outstretched hand, injury to R wrist. Wrist swollen and rates pain 8 out of 10. No loss of sensation or loss of circulation. See radiograph. What is diagnosis?
Colles fracture
Identify the neural tube
1
Middle structure on first image
Using same image, identify the cranial neuropore and the caudal neuropore respectively
7,8
- top of the second image in the very middle
- very bottom of second image in the very middle
What event marks the beginning of gastrulation?
The formation of the primitive streak on the surface of the epiblast
What cell line is the source of all three germ layers?
Epiblast
What is the normal function of E-cadherin and what compound down regulates it?
Normally binds epiblast cells together, it is down regulated by FGF8
Muscles have different functions which one internally rotates the humerus, pulls upper extremities toward midline and extends toward the back?
Latissiumus dorsi
Which muscle functions to medially rotate the humerus in the glenoid fossa?
Subscapularis
What is the function of the Teres Minor?
Rotates the humerus laterally
Aspirin demonstrates which of the following as its mechanism of action through which pathways
Irreversible acetylation of the cyclooxygenase enzyme
The tendon of the ______ enters the shoulder joint capsule via the inter tubercular sulcus?
Long head of the biceps brachii
Which cytokine produced by Tregs can inhibit the effector activities of T-lymphocytes?
IL-10
Injury to the posterior cord of the brachial plexus would most likely cause weakness in which of the following?
Abduction of the arm at the shoulder joint
70 yo female complains of bilateral knee pain that worsens during the day. She is a seamstress and her hands become more painful during the day with distal joints the worst. Exam reveals tenderness at distal interphalangeal joints and also redness. Most likely diagnosis.
Osteoarthritis
Release of a chemical by the alpha-motor neuron, that activates a muscle specific kinase that if not released ultimately leads to the death of the skeletal muscle cell is which of the following
Agrin
The inhibitory action of ______ receives molecular signals from the notochord that block it and induces neural formation is which of the following?
BMF-4
What is the primary function of the pectorals minor muscle?
Stabilize the scapula
Your best friend calls about med for tension HA. Discover treated recently for GI bleed. Which would you now recommend?
Acetaminophen
Dr. Karius is very thirsty for Diet Pepsi. She sees it sitting on table and goes to pick it up. When she goes to lift it, the load doesn’t affect her muscles until the muscle contraction begins. This is an example of
Afterload
The tendon of which muscle makes up the most lateral border of the anatomical snuff box?
Abductor pollicus longus muscle
You got this!!!
YOU are amazing.
An inhibitory postsynaptic potential
Hyperpolarizes the postsynaptic membrane by opening CT channels
A drug completely blocks Na+ channels in nerves. Which of the following effects on action potentials would be expected?
Block the occurrence of action potentials
21 yo patient has a lesion of upper trunk of brachial plexus (Erb-Duchenne paralysis). Which is most likely diagnosis
Arm tending to lie in medial rotation
27 yo pt presents with an inability to draw scapula forward and downward because of pectorals minor. Most likely cause of condition?
Fracture of coracoid process
Man walks in with stab wound to the most medial side of the proximal portion of the cubital fossa. Which structure most likely damaged?
Median nerve
14 yo falls on outstretched hand and fractures scaphoid bone. The fracture most likely accompanied by a rupture of which artery?
Radial artery
The correct temporal sequence for events at the neuromuscular junction is
Release of Ach; action potential in the motor nerve; action potential in the muscle
At the muscle end plate, ACh causes the opening of
Na+ and K+ channels and depolarization to a value halfway between the Na+ and K+ equilibrium potentials
Which of the following temporal sequences is correct for excitation-contraction coupling in skeletal muscle.
Action potential in the muscle membrane; depolarization of the T tubules; release of Ca2+ from the sarcoplasmic reticulum (SR)
In skeletal muscle, which of the following events occurs before depolarization of the T tubules in the mechanism of excitation-contraction coupling?
Depolarization of the sarcolemma membrane
ATP is used indirectly for which of the following processes?
Absorption of glucose by intestinal epithelial cells
Which of the following causes rigorin skeletal muscle?
A decrease in ATP level
A woman with severe muscle weakness is hospitalized. The only abnormality in her laboratory values is an elevated serum K+ concentration. The elevated serum K+ causes muscle weakness because
Na+ channels are closed by depolarization
Which of the following growth differentiating factors is most important in somite differentiation?
WNT proteins
A birth defect in which the anterior abdominal wall musculature is deficient or absent, urinary tract anomalies are present and there is bilateral cryptorchidism is a triad of features defined as
Prune Belly Syndrome
During appendicular skeletogenesis, the upper limb rotates
90 degrees laterally
The horizontal connections of the Haversian canals in compact bone are known as
Volkmanns canal
Which of the following is the cell type which acts to phagocytose debris within a joint?
A-cells
Skier takes a tumble down a mountain, diagnosed with grade two shoulder separation, wants to know what that means. You explain that a grade two shoulder separation is defined as
Acromioclavicular partial tear
A construction worker who is constantly hammering overhead comes into office with recurrent pain in shoulder. Best long term help is to
Teach him to work with a more elevated technique, humorus being held at greater than 135 degrees instead of 90 degrees
Med student finally done with boards. Goes skiing, notice he has lost strength and it is harder for him to hold onto boat tow rope. He realizes he needs to strengthen the muscles responsible for his power grip. The muscle primarily responsible for this is the
Flexor digitorum profundus muscle
The nerve roots of the obturator nerve are
L2-L4
Pt presents with hyper-extensibility of joints and increased skin elasticity. What is etiology of this syndrome?
Mutation of type 4 collagen
Dinitrophenol (DNP) uncouples mitochondrial electron transport from ox phis by which mechanism?
Dissipating the proton gradient
Which of the following best supports the endosymbiotic theory of the evolutionary origin of mitochondria?
Mitochondrial and bacterial ribosomal functions are inhibited by the same antibiotics
Which of the following reactions is anapldrotic (replenishes intermediate pools) for the citric acid cycle?
Pyruvate + HCO3- + ATP –> oxaloacetate + ADP + Pi + H+
Donates electrons to mitochondrial cytochrome oxidase?
Cytochrome c
Accepts electrons from mitochondrial NADH dehydrogenase
Ubiquinone
An 18 yo female experiences vision loss about 6 years ago. Also has progressive external opthalmoplegia and neurosensorial hearing loss. Opthalmologic examination shows dystrophic features in the cornea and retina. A presumptive diagnosis of Kearns-Sayre syndrome is made pending further lab tests. Which family pedigree most consistent with this diagnosis?
D.
From mother to all off spring
Think of mito inheritance
A family has 3 children diagnosed with MERRF. The mother and affected children demonstrate classic manifestations of lactic acidosis and exercise intolerance. The second child in the family, II-2, has the same mutations as the affected individuals but is symptom free. Which of the following mechanisms explains the lack of symptoms in the proband?
Germ line mutation
6 yo presents with delayed developmental milestones corresponding to an 8 to 9 month old, hypotonia of all 4 limbs, gross motor delay and epilepsy. A muscle biopsy shows the accumulation of basophilic granules in the subsarcolemmal region and sarcoplasm that stain with Gomori Trichrome and a diagnosis of MELAS is confirmed. Which lab finding is consistent with this diagnosis?
Increases lactic acid
PMH of 6 yo male includes delayed developmental milestones, hypotonia of all limbs, poor head control, gross motor delay, epilepsy, elevated serum lactate levels. Symptoms were present at birth when he was ‘floppy and passive’ and have continued. Mitochondrial DNA analysis demonstrated a missense mutation in tRNALEU. Which of the following is most likely present in muscle biopsy from this patient?
Ragged red fibers
