UWorld Exam 1 Section 3 Flashcards
Describe the pathogenic course of pulmonary HTN
1) Injury to pulmonary endothelium
2) Narrowing of pulmonary vascular bed with resultant RV hypertrophy
3) Accelerated vascular injury secondary to increased pulmonary arterial pressure
4) Further rise in RV afterload
5) Dilation of RV
What is the enzyme responsible for the first step of beta- oxidation of fatty acids
Acyl-CoA dehydrogenase
What is the enzyme responsible for the first step in fatty acid synthesis
Acetyl-CoA carboxylase
What are the substrates of CYP450
Always Think When Outdoors:
A - Anti-epileptics
T - Theophylline
W - Warfarin
O - OCPs
What are the inducers of CYP-450
Corona, Guiness, ‘N’ PBRS induce Chronic alcoholism
C - Carbamazepine
G - Griseofulvin
N - Nevirapine
P - Phenytoin
B - Barbiturates
R - Rifampin
S - St. John’s Wort
Chronic alcoholism
What are the inhibitors of CYP-450
SICKFACES.COM:
S - Sodium valproate
I - Isoniazid
C - Cimetidine
K - Ketoconazole
F - Fluconazole
A - Acute alcohol abuse
C - Chloramphenicol
E - Erythromycin (macrolides)
S - Sulfonamides
C - Ciprofloxacin
O - Omeprazole
M - Metronidazole
Describe the Internal Ribosome Entry and it’s function in eukaryotic translation
Eukaryotic translation is initiated when the small ribosomal subunit bind the 5’ cap of mRNA (facilitated by initiation factors, IF) and scans for the AUG start codon within the Kozak consensus sequence
Internal ribosome entry is an alteranative method used by apoptotic cells whereby a distinct nucleotide sequence (usually in the 5’ untranslated region) allows translation to begin in the middle of mRNA
Most frequent site of involvment in Crohn disease
Terminal ileum
What disease is characterized by decreased mineralization of osteoid
Osteomalacia
What disease is characterized by excessive bone resportion out of proportion to new bone formation
Osteoporosis
Differentiate between compact and trabecullar bone
Compact - dense, hard, outer bone shell
Trabecullar - inner cancellous/spongy bone separated by interconnecting marrow spaces
What are the 2 main microscopic forms of bone
Woven - immature, first bone to be laid down during fetal osteogenesis and following a fracture. Will be later remodelled to lamellar bone
Lamellar - stronger bone containing regular, parallel collagen fibers and sheets
What disease is characterized by the abnormal fomation of lamellar bone
Paget disease of the bone
What nerve may be complicated in dilation of the aortic arch, and which muscles may be affected?
L recurrent laryngeal nerve
May lead to paralysis of most of the intrinsic laryngeal muscles (posterior cricoarytenoid, lateral cricoarytenoid, oblique arytenoid, transverse arytenoid, thyroarytenoid) - responsible for sound production
Does no innervate the cricothyroid
What is the only DNA virus that replicates in the cytoplasm
Poxvirus
What is the abnormal heart sound associated with an atrial septal defect?
Widely split S2
What is achalasia and what is the cause?
Esophageal motility disorder characterized by the absence of esophageal peristalsis in the distal esophagus and lower esophageal sphincter (LES) that is unable to relax
Due to damaged ganglion cells of the myenteric plexus
Describe the location and deficits of Broca’s and Wernicke’s area
Broca:
- located in inferior frontal gyrus of the dominant (usually left) hemisphere
- lesion = expressive aphasia (slow speech consisting primarily of nouns and verbs - agrammatism); speech is punctated by pauses; preserved speech comprehension; patients are aware of their expressive language dysfunction
Wernicke:
- located in the caudal superior temporal gyrus
- lesion: receptive (sensory) aphasia; fluent aphasia (speech flows but is meaningless); patients are unaware of their problem
What are some examples of unmyelinated neuron fibers (aka group C nerve fibers)
Those responsible for slow pain (dull, burning, or visceral pain), heat sensation, olfaction, and postganglionic autonomic NS axons
Are preganglionic autonomic nerve fibers myelinated or unmyelinated?
Myelinated
Describe the components of MHC class II and what parts are expressed vs. not expressued during antigen processing
During antigen processing within the cell, the invariant chain brings the alpha and beta chains of MHC II together
The invariant chain is then removed from the MHC-invariant complex and replaced by an external protein
The MHC-peptide comples (containing a-chain, b-chain, and external protein) is then expressed at the cell surface
What are clinical symptoms of iron deficiency anemia other than weakness and fatigue?
Glossal pain, dry mouth, atrophy of the tongue papilla, alopecia
What is pagophagia and what disease is it specific for?
Craving for ice
Specific for iron deficiency
