Set 8 Flashcards
Diagram the pathway by which the cochlea communicates a signal to the primary auditory cortex.
Cell bodies of the spiral ganglia (in the cochlea) -> cochlear nuclei -> contralateral superior olivary nucleus -> lateral lemniscus -> inferior colliculus -> medial geniculate body
Homocystinuria is one of the few diseases that can result in subluxation of the lens. What are the different causes of homocystinuria? How does the treatment differ for each?
METHIONINE CYSTATHIONINE —> CYSTEINE
3 types, all AR
1) Cystathionine synthase deficiency. Treatment: decreased methionine, increased cysteine, increased B12 and folate in diet
2) Decreased affinity of cystathionine synthase for pyridoxal phosphate (cofactor). Treatment: increase B6 and increase cysteine in diet
3) Homocysteine methyltransferase (methionine synthase deficiency). Treatment: increased methionine in diet
Findings: Increased homocysteine in urine, intellectual disability, osteoporosis, tall stature, kyphosis, lens subluxation (downward and inward), thrombosis, and athersclerosis (stroke and MI)
What also presents with subluxation of the lens?
Marfan syndrome
A 34-year-old obese white woman develops urinary retention after undergoing a laparoscopic cholecystectomy. Which cholinergic agonist can be used to treat post-op ileus and urinary retention? What conditions can be made worse by using cholinomimetic agents?
Bethanechol - Direct cholinergic agonist. Activates bowel and bladder smooth muscle, resistant to AChE. Used for postoperative ileus, neurogenic ileus, and urinary retention.
Neostigmine - Indirect cholinergic agonist (cholinesterase inhibitor - increases ACh at cleft)
Watch for exacerbation of COPD, asthma and peptic ulcers when giving to susceptible patients
A 20-year-old Italian woman complains of weakness and fatigue. A CBC reveals a microcytic, hypochromic anemia with a normal iron panel. What type of thalassemia does this patient most likely have? What is the structure of HbH? What disease results in HbH production? What is the structure of Hb Bart’s? What disease results in Hb Bart’s production?
*Italian/Greece/Spain - Beta thalassemia (alpha - African and Asian)
Not making enough hemoglobin -> anemia
Normal - Hemoglobin A (2 alpha and 2 beta)
HbH: 3 allele deletion a-thalassemia. Very little a-globin. Excess B-globin forms B4 (HbH) -> beta globins pair up because they don’t have partners (a)
Hb Barts: 4 allele deletion a-thalassemia. No a-globin. Excess y-globin forms y4 (Hb Barts). Incompatible with life (causes hydrops fetalis)
Cis vs. Trans alpha thalassemia - which is associated with which race?
Cis - Asian
Trans - African
A 23-year-old man undergoes a splenectomy due to splenic rupture from blunt abdominal trauma. What would you expect to find on this patient’s peripheral RBC smear after the splenectomy?
Howell-Jolly Bodies - basophilic nuclear remnants found in RBC and usually removed by the splenic macrophages (little dark dots in RBCs)
Asplenic patients are susceptible to which encapsulated organisms? What vaccines for these encapsulated organisms should be given to asplenic patients?
Splenic dysfunction: decreased IgM -> decreased complement activation -> decreased C3b opsonization -> increased susceptibility to encapsulated organisms
(SHiNE SKiS)
Streptococcus pneumonia, Haemophilus influenza type B, Neisseria meningitidis, Escherichia coli, Salmonella spp., Klebsiella pmeumoniae, Group B streptococci
Give: H. influenzae, N. meningitidis and S. pneumoniae vaccinces
For what conditions is hyperbaric oxygen therapy particularly helpful?
- Severe CO poisoning
- Decompression sickness
- Arterial gas emboli
- Gas gangrene (Clostridium perfringens)
- Osteomyelitis
- Acute MI
What is the pressure in the potential spaces of the body including the pleural cavity, the joint spaces, and the pericardial cavity?
Pleural cavity: -7 to -8 cm H20
Joint spaces: -3 to -5 cm H20
Pericardial cavity: -5 to -6 mmHg
Negative pressure draws fluid in
What increases contractility?
- Catecholamines (increased activity of Ca2+ pump in sarcoplasmic reticulum)
- Sympathetic stimulation
- Increased intracellular Ca2+
- Decreased extracellular Na+ (decreased activity of Na+/Ca2+ exchanger)
- Digitalis/Digoxin (blocks Na+/K+ pump -> increases intracellular Na+-> decreased Na+/Ca2+ exchanger activity -> increased intracellular Ca2+)
What decreases contractility?
- B1-blockade (decreased cAMP)
- Heart failure with systolic dysfunction
- Acidosis
- Hypoxia/hypercapnea (decreased PO2/increased PCO2)
- Non-dihydropyridine Ca2+ channel blockers (Verapamil and diltiazem)
- Decreased intracellular Ca2+
- Increased extracellular Na+
What affects SV?
Contractility
Afterload
Preload
SV CAP
A 48-year-old man presents to your office with a persistent cough that has begun to become bloody. CXR reveals a coin lesion within the lung parenchyma. Further work-up reveals that the patient has the most common type of lung cancer in non-smokers. Which cancer is this? What other lung cancers are not associated with smoking? Which lung cancers are associated with smoking, and where are they located, centrally or peripherally?
Bronchial adenocarcinoma is the most common lung cancer in nonsmokers. Bronchioalveolar adenocarcinoma and malignant mesothelioma are also seen in non-smokers.
Squamous cell carcinoma and Small cell carcinoma are located Sentral (central). Large cell carcinoma and adenocarcinoma are located peripherally.
How does standard deviation differ from standard error of the mean? (FA14 p56) (FA15 p53) Which one is used in calculating confidence intervals?
Standard deviation = how much variability exists from the mean in a set of values
Standard error of mean = an estimate of how much variability exists between the sample mean and the true population mean (SD/square root of n). AKA how well will a mean of a sample predict the mean of the population. Larger SD = larger SEM, larger n = smaller SEM.
SEM is used for CI
