Block 27 Flashcards
Systemic arterial pressure during inspiration fall
Pulsus paradoxus
- pulsus paradoxus refers to an exagerated drop in the systolic BP during inspiration.
- its detected by inflating BP cuff above systolic BP and gradually deflating it
-the difference between the systolic BP at which kortokff sounds first become audible during expiration and the pressure at which they are heared throughout all the phases of respiration quantifies pulsus paradoxus.
asthma and COPD are the most frequent causes of pulsus paradoxus in the absence of significant pericardial disease
Physiological changes done to relieve COPD excacerbation
Acute obstructive pulmonary excacerbation is treated with beta agonist, which produces relaxation of bronchial smooth muscles by stimulating the beta 2 adrenergic receptor.
-the receptor is a Gs protein coupled protein coupled receptro that activates adenylyl cyclase and increase intracellular cAMP concentration.
Types of incontenece
- Stress (decreased urethral sphincter tone with urethral hypermotility, present with leakage with couging lifting and sneezing).
- Urge (detrusor hyperactivity, present as sudden overwhelming urge to urinate)
- Overflow (impaired detrusor contractility, bladder outlet obstruction, presents with incomplete emptying and persistent involuntary dribbling.
Voltage gated calcium channels in neurons
When the action potential reaches the axon terminal, voltage gated calcium channels open and allow the influx of calcium which is essential for the fusion and release of neurotransmitter vesicles into the synaptic cleft.
-GABAPENTIN is anticonvulsant that act by inhibiting presynaptic voltage gated calcium channels.
Diphenoxylate
Is an opoid antidiarrheal agent structually related to mepiridine. It binds ti mu receptors in GI tract and slows motility.
-to discourage abuse its given along with atropine which produces adverse symptoms if taken in high doses.
Congenital long QT syndrome
- usually due to potassium channels mutation that contribute to outward rectifying potassium current.
- decreased outward K+ flow due to K+ channel mutation leads to prolongation of AP duration and QT interval.
- this may predispose to development of life threatining arrythmias (torsades de pointes)
Dimpling in breast cancer is due to
- Malignant invasion of the suspensory ligament.
- invasive breast carcinoma typically presents as an irregularly shaped adherent breast mass.
- overlying skin retraction (dimpling) signal involvement of suspensory ligaments of the breast (cooper ligament), malignant infiltration of these ligaments causes fibrosis and shortening, leading to traction on the skin with distortion in breast contour.
If a drug is secreted in the liver what is the main condition of a drug to be
High lipophillic (lipid soluble) allows drug to cross cellular barriers more easily and enter hepatocytes.
Chronic bronchitis biopsy results
- Thickened bronchial walls
- Neutrophilic infiltrates
- Mucus gland enlargement
4, patchy squamous metaplasia of bronchial mucosa.
Migratory thrombophelibits
- usually raise the suspicion for cancer
- hypercoagulability is a very common paraneoplastic syndrome seen in adenocarcinoma of pancreas, colon and lung,this is due to the production of thromboplastin like substance capable of causing chronic intravascular coagulation that can disseminate and tend to migrate.
- migratory thrombophlebitis known as trusseau syndrome.
Raltegravir
- integrase inhibitor
- inhibts ability of Ds HIV DNA to integrate into host cell chromosome —> thus in the absence of integration, viral genome transcription by host cellular machinery and eventually degraded by nucleases.
In femoral neck fracture increase risk for ?
-increase femoral head risk for osteonecrosis if its blood supply interrupted. The blood supply to the femoral head derives mainly from the ascending cervical and retinacular branches of the medial cicumflex artery .
Asplenic sepsis
- usually patients have a history of previous trauma that lead to spleen resection
- sepsis with encapsulated organs leads to life threatining infection (s.pneumoniae sepsis …)
P53 deficiency
Is one of the few tumor suppressor gene (along with rb) its absence leads to neoplasm formation
PrP stands for
If it changes the neuron from a-helical secondary structure to b-pleated sheet isoform
- PrP stands for prion protein
- its normally found in neurons and has an a helical structure. If the conversion of a helix into ß-pleated sheet occurs, the protein becomes resistant to protease —> prion disease if accumulated.
Pneumonia stages
- Congestion
- Red hepatization
- Gray hepatization
- Resolution
Nuclear factor kappa B
Also stands for NF-kB
- is part of the family of transcription factors that performs a critical role in the immune response to infection and inflammation.
- in inflammatory cells NF-kB is normally present in latent state inactivated by IkB protein bound to it.
- activation of IkB kinase(in infection) leads to ubiquitination and destruction of IkB with release of NF-kB.
- once free NF-kB —> enter nucleus —> promotes synthesis of inflammatory proteins —?> also stimulates more unbinding of NF-kB
Krukenbrg tumor
Biopsy
-gastric tumor that has metastasized to the ovary.
-histologic feature is nests of signet ring cells.
- the appearance is a result of large amounts of mucin displacing the nucleus.
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Mechanism in which hepatitis B leads to hepatocellular carcinoma
- not very much clear, however integration of viral DNA into the cellular genome of the host is considered a trigger of neoplastic changes.
- the viral protein HBX —> increased IGF I and II —> cell proliferation.
- another effect is suppression of p53.
Class 1B antiarrythmic indication
- these are the weakest sodium channel blockers compared to other class I antiarrythmics
- they predominantly binds to sodium channels in the inactivated state, and dissociation from the channels occurs so rapidly that they have negligible effect on QRS duration on normal cardiac tissues.
- ischemic myocardium has higher than normal resting membrane potential which delays voltage dependent recovery of sodium channels from the inactivated to resting state. —> that allow IB agents to bind to it.
- thus class IB is used in ischemia induced ventricular arrythmia (especially after MI)
