Christie Flashcards
What cofactors are required for muscle contraction?
ATP and Ca2+
True or False: In smooth muscle, the contractile proteins attached to Z bands.
False
What binds calcium ions within the smooth endoplasmic reticulum of skeletal muscle cells?
calsequestrin
Which type of muscle has the longest contraction time?
Skeletal muscle
In cardiac muscle, what determines the amount of calcium released from the sarcoplasmic endoplasmic reticulum in Ca2+ -induced Ca2+ release?
The amount of Ca2+ previously stored in the sarcoplasmic endoplasmic reticulum
The size of the inward Ca2+ current during the plateau of the action potential
Which of the following statements about smooth muscle is false?
- Contractile mechanism differs from that of skeletal muscle
- ATP is hydrolyzed very slowly
- It does not fatigue or “tetanize”
- contracts more slowly than skeletal muscle
- calcium ions bind to troponin
Calcium ions bind to troponin
Which of the following statements about botulinium toxin is true?
- causes spastic paralysis
- cleaves synaptobrevin
- causes irreversible binding of the pre-synaptic vesicles with the membranes of the motorneurons
- none of these statements are true
Cleaves synaptobrevin
Acetylcholine receptors of skeletal muscle are
nicotinic
Where do cardiac action potentials originate?
sino-atrial node
Which of the following blocks the myosin-binding sites in actin?
- tropomyosin
What causes rigor mortis?
unavailability of ATP
which of the following statements abbout Guillain-Barre syndrome is false
- acute-onset
- immune-mediated
- demyelinating disease
- noted for descending paralysis
- most cases preceded by an acute, influenza-like illness
Noted for descending paralysis
Ducheenne-Becker muscular dystrophy has which type of inheritance?
X-linked
Which of hte following statements about Becker muscular dystrophy (are) true?
- Due to a frame-shift mutation
- Due to a point mutation
- More severe disease than Duchenne muscular dystrophy
- Less severe disease than Duchenne muscular dystrphy
- Both A & C
- Both B & D
Both B & D
- Due to a point mutation
- Less severe disease than Duchenne muscular dystrophy
Which of the following statements about Duchenne muscular dystrophy (are) true?
- Due to a frame-shift mutation
- Due to a point mutation
- More severe disease than Becker muscular dystrophy
- Less severe disease than Becker muscular dystrophy
- Both A & C
- Both B & D
Both A and C
- Due to a frameshift mutation
- More severe disease than Becker muscular dystrophy
Which of the following statements about amytrophic lateral sclerosis (ALS) is true?
- Sporadic ALS is more common than familial ALS
- Primary pathology is due to muscle damage
- Commonly emerges in third decade
- Affects women more often than men
- Most affected individuals only have lower motor neuron involvement
- Sporadic ALS is more common than familial ALS
Which of the following statements about multiple sclerosis is false?
- Lesions predominantlyin the gray matter of the brain
- autoimmune origin
- most common of the demyelinating diseases
- lesions are seperated in space
- characterized by distinct episodes of neuroogic deficits, seperated in time
- Lesions occur predominatelly in the gray matter of the brain
What is the most common cause of peripheral neuropathies?
Diabettes Mellitus
_______ is a systemic autoimmune disease that typically presents with proximal muscle weakness and skin changes with a bimodal age distribution.
Dermatomyositis
Which the following is not a common cause of metastatic bone tumors?
- Prostate
- Thyroid
- Breast
- Lung
- Skin
Skin
Complete the following sentence- “osteosarcoma is a malignant tumor of mesenchymal cells characterized by _____.”
direct formation of osteoid by tumor cells
Gnathic chondrosarcomas have a predilection for which one of the following sites?
Anterior Maxilla
Which of the following statements about rhabdomyosarcoma is false?
- Malignant neoplasm characterized by skeletal muscle differentiation
- More common in young children than in teenagers and adults
- Most frequent site is the head and neck
- Most head and neck lesions are pleomorphic rhabdomyosarcomas
Most head and neck lesions are pleomorphic rhabodymyosarcomas
Which of the following statements about synovial sarcoma is false?
- Characterized by the presence of the SS18-SSX fusion gene
- Characteristically found in older adults
- Oral tumors most often found in tongue and cheek
- Poor prognosis because the tumor has a higher rate of recurrence and metastasis
- Classic synovial sarcoma is a biphasic tumor
Characteristically found in older adults
True or False- The mean age at diagnosis for gnathic osteosarcomas is 33-39 years of age.
True
A child develops a neoplasm of hist left maxilla which is composed of malignant skeletal muscle cells. The lesion is most likely which one of the following?
rhabdomyosarcoma
A teenager develops a slow-growing mass in the tongue. Microscopically it is composed of a mixture of spindle and epithelial cells and has a SS18-SSX fusion gene. It is most likely which one of the following?
Synovial Sarcoma
What autoantibody is most typically found in drug-induced lupus?
Anti-histone
Which of the following statement(s) about lupus anticoagulants found in antiphospholipid syndrome is (are) true?
Both a and b
- In vivo, these autoantibodies induce a hypercoagulable state
- In vitro, these autoantibodies inhibit coagulation.
You see an elderly lady in your office for routine dental work. You notice that she has a drawn, mask-like appearnce of her face and telangiectasia on her lips and tongue. This appearance may be found in which of the following diseases?
Scleroderma
In scleroderma, which of the following causes the largest percentage of deaths?
Renal Failure
A 22-year-ld man has a sudden loss of vision in the right eye. On physical examination, there is a subluxation of the right crystalline lens. on auscultation of the chest, a mid-systolic click iis audible. An echocardiogram shows a floppy mitral valve and dilated aortic arch. The patients broth and his cousin are simarly affected. He is prescribed a beta-blocker. A genetic defect involving which of the following substances is most likely to be present in this patient?
Fibrillin-1
What type of inheritance does Marfan Syndromre have?
Autosomal Dominant
A 33-year old lady has a history of several spontaneous abortions with examination of the placenta revealing extensive areas of infarction. What abnormality/abnormalities might you see in her laboratory results?
Occasional prolonged PTT results
False-positive syphilis serologies
What is not typical of joints affected by osteoarthritis?
- inflammatory changes
- stiffness
- decreased mobility
- pain
Inflammatory changes
Which joint is affected by rheumatoid arthritis but not by osteoarthritis?
MCP
Part of the increased mortality in rheumatoid arthritis is due to which of the following?
- GI bleeding due to long term use of NSAIDS
- Infections secondary to steroid use
- Developement of reactive amyloidosis
- all of the above
All of the above
In which of the following diseases is bony ankylosis found?
Rheumatoid arthritis
True or False: The cause of most primary gout is unknown (idiopathic).
True
Tophi are seen most often in which one of the following diseases?
Gout
Which of the following hand lesions in the hands are typical osteoarthritis.
Both A and B
Heberden’s nodes
Bouchard’s nodes
The lesion shown in this illustration is most typical of which one of the following diseases?
Multiple sclerosis
The pathology shown in this illustration is typical of which of the following?
Amytrophic Lateral Sclerosis
The lesion shown in the illustration is composed of malignant cells producing osteoid. It is most likely which of the following?
osteosarcoma
Where did this tumor originate?
Medullary portion of the metaphysis
Which autoantibody/autoantibodies does this woman most likely have in her blood?
Anti-double stranded DNA (dsDNA)
Anti-smith (Sm)
. True or false – The condition shown in this illustration is only found in scleroderma.
False
The individual shown in this illustration has a defect in synthesis and/or synthesis of which of the following?
Collagen
This patient has osteoarthritis. What is the structure indicated by the arrow?
osteophyte
What is the lesion shown in the illustration called?
Podagra
The abnormality shown in this illustration is most typical of which one of the following?
osteoarthritis
