CR EOYS1 Flashcards
Decsribe the structure of NOSs xx
NOS: oxidoreductase homodimer enzymes:
- Oxygenase domain: binding for NADPH, FMN & FAD
- Reductase domain: binding for BH4, heme and L’arginine (substrate
- Calmodulin binding site: in between reductase and oxidase domains
What happens to NOS if there is / isn’t BH4 present?
BH4 present: causes dimerisation and proper catalytic activity for NO formation
BH4 absence: causes monomer, becomes a superoxide
For the formation of NO using NOS, what substrates are essential? [3]
Which co-factors are essential? [5]
For the formation of NO using NOS, what substrates are essential? [3]
- L-arginine
- O2
- NADPH
Which co-factors are essential? [5]
- FAD
- FMN
- BH4
- haem
- calmodulin.
OXYGEN is essential for the synthesis. Because of the oxygen requirement, NO synthesis is inhibited in hypoxic tissue
Explain MoA of endothelial NO synthase creating NO
- Normally: eNOS associates with Caveolin 1 in caveolae (invaginations of plasma membrane) this inhibits calmodulin complex (CaM) binding to eNOS
- Shear stress promotes wall stretching, which promotes the dissociation of eNOS from caveolae
- This allows eNOS release into the cytoplasm and its activation (through binding of a Ca2+/ calmodulin (CaM) complex)
- M2-muscarinic acetylcholine receptor activation or other stimulation initiates an influx of Ca2+ that binds to calmodulin.
- eNOS dissociates from Cav1 and then combines to Ca/CaM.
- eNOS is activated leading to synthesis of NO.
[] shear stress favors the activation of eNOS by releasing endothelium-dependent agonists.
What are they? [4]
Increased shear stress favors the activation of eNOS by releasing endothelium-dependent agonists.
Agonists stimulated NO formation:
* Acetylcholine (M3muscarinic)
* Bradykinin
* Substance-P
* Adenosine
What can endothelial dysfunction be caused by? [4]
Consumptive processes that transform bioavailable NO into other species:
- Reactive oxygen species such as -O2 reacts readily with NO forming peroxynitrite (ONOO−)
- Uncoupling of NOS: BH4 insufficiency results in uncoupled NOS, which produces superoxide anions instead of NO
Deficiencies in production of NO in the endothelium:
- Reduced bioavailability of l-arginine o
- Presence of its inhibitor, asymmetric dimethyl-l-arginine (ADMA)
Describe the pathophysiology behind acute bronchitis (e.g. caused by respiratory synctial virus)
Epithelial cells: 1st line of defence
RSV: binds and invades mucosal lining via epithelial cells
Epithelial cells switch on immune response after recognised through Toll-like receptor (TLR)-3 and retinoic acid-inducible gene (RIG)-I-like receptors
Cellular infection triggers the release of early inflammatory mediators (e.g.interferons (IFNs) and tumour necrosis factor (TNF)-α) and chemokines (e.g.CXCL8 and CXCL11).
A) Innate: Macrophages and Neutrophils, e.g. PMN polymorphonuclear leukocytes cells recruited PMNs)
B) Acquired: Dendritic cell, triggering B and T cells: CD4, CD8 and primed T cells
Name the signs of pneumonia [4]
Name a complication that pneuomonia a risk factor for !!
Signs:
- Tachypnoea
- Tachycardia
- Hypoxia
- Hypotension
- Fever
- Confusion
Can lead to sepsis
How do you diagnose acute bronchitis?
Diagnosis by exclusion:
- Cough >3 weeks
- If signs of consolidation (on CXR), airway obstruction, fever, increase RR, increase HR: NOT acute bronchitis
- If no: is there currently an outbreak of influenza pertusis (whooping cough)?
- If no: Acute bronchitis
How does hypertension damage the heart?
What effect does HTN have on SVR? [1]
State the cardiac remodelling that initially occurs because of HTN [1]
State the effect on heart performance of chronic HTN [2]
HTN leads to increased systemic vascular resistance compared to normal in HTN.
Initially leads to HTN leads toleft ventricular hypertrophy (initially protective, but long term is damaging) to overcome increased afterload:
Chronic HTN leads to diastolic and (eventually) systolic dysfunction: there is less space to in ventricle to pump blood out. This leads to dilated cardiomyopathy/congestive heart failure
what can left ventricular hypertrophy lead to? [3]
Dilated cardiomyopathy/congestive heart failure
If increased cardiac muscle is not well perfused myocardial ischaemia and myocardial infarction can follow.
Conducting system also impacted: increasing risk arrythmias
What are the BP ranges for isolated diastolic HTN (BP)? [1]
Abstract. In various guidelines, isolated diastolic hypertension is defined as diastolic blood pressure >80 or >90mmHg in individuals with normal systolic blood pressure.
Why does obesity increase BP? [3]
- increased oxidative stress damages endothelium of BV: stiffer
- increased RAAS system
- increases sympathetic system
which all influence CVD and CKD, which themselves contribute to BP
What specifically about obesity causes increase in HTN? [1]
High leptin levels increase activity of RAAS and sympathetic NS
Anti-hypertensives:
Which of the following class of drug does indapamide fall into?
ACE inhibitors:
Angiotensin-II receptor antagonists
Calcium-channel blocker
Diuretics
Beta-blockers
Which of the following class of drug does indapamide fall into?
ACE inhibitors:
Angiotensin-II receptor antagonists
Calcium-channel blocker
Diuretics thiazide-like diuretic
Beta-blockers
Which of the following class of drug does enalapril fall into?
ACE inhibitors:
Angiotensin-II receptor antagonists
Calcium-channel blocker
Diuretics
Beta-blockers
Which of the following class of drug does enalapril fall into?
ACE inhibitors:
Angiotensin-II receptor antagonists
Calcium-channel blocker
Diuretics
Beta-blockers
Which of the following class of drug does losartan fall into?
ACE inhibitors:
Angiotensin-II receptor antagonists
Calcium-channel blocker
Diuretics
Beta-blockers
Which of the following class of drug does losartan fall into?
ACE inhibitors:
Angiotensin-II receptor antagonists
Calcium-channel blocker
Diuretics
Beta-blockers
Which of the following would you use to deliver 24 – 30% O2 (maximum flow rate of 4L/min) for mild hypoxia?
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
Which of the following would you use to deliver 24 – 30% O2 (maximum flow rate of 4L/min) for mild hypoxia?
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
Which of the following would you use to deliver for patients with chronic obstructive pulmonary disease (COPD) due to the risk of type 2 respiratory failure.
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
Which of the following would you use to deliver for patients with chronic obstructive pulmonary disease (COPD) due to the risk of type 2 respiratory failure.
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
Which of the following would you use to deliver approximately 70% O2 when used with a 15L oxygen flow rate.
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
Which of the following would you use to deliver approximately 70% O2 when used with a 15L oxygen flow rate.
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
7Which of the following would you use to deliver 30 – 40% O2 (flow rate 5-10 L/min)
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
Which of the following would you use to deliver 30 – 40% O2 (flow rate 5-10 L/min)
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
Which of the following would used to treat patients with a significant degree of hypoxia (moderate to severe).
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
Which of the following would used to treat patients with a significant degree of hypoxia (moderate to severe).
Nasal cannulae
Simple face mask
Non-rebreather mask
Venturi mask
What mmHg would systolic [1] and diastolic [1] blood pressure indicate have pneumonia? [2]
- SBP < 90
- DBP < 60
The larynx lies in which vertebral layers? [1]
C3-C6
The vocal cords attach posteriorly to which of the following?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilage
Thyroid cartilage
The vocal cords attach posteriorly to which of the following?
Cricoid cartilage
Cuneiform cartilage
Epiglottis
Arytenoid cartilages
Thyroid cartilage
Palsy to which nerve causes reduced gag reflex?
Superior laryngeal nerve, external branch
Superior laryngeal nerve, internal branch
Recurrent layngeal nerve, bilateral damage
Recurrent layngeal nerve, unilateral damage
Palsy to which nerve causes reduced gag reflex?
Superior laryngeal nerve, internal branch
Why is DCLO raised in asthma Ptx?
Expiration is decreased, so air is trapped in the lungs.
Have a lot of blood vessel recruitment
How do you calculate VO2? [1]
What is the name of the equation? [1]
Fick equation:
VO2 = Q x (CaO2-CvO2)
Qis thecardiac outputof the heart (blood flow to muscle)
CaO2is the arterial oxygen content
CvO2is the venous oxygen content
(CaO2– CvO2) is also known as thearteriovenous oxygen difference.
What happens to the levels of paO2 in arterial blood during high levels of exercise?
At high levelss of exercise the paO2 in the arterial blood declines slightly
During exercise, changes in autonomic factors (inhibition of parasympathetic and increase in sympathetic) are controlled by WHAT?
Central command: area in brain that mediates autonomic responses (increase in sympathetic / decrease in parasympathetic) to exercise.
Happens at same time as brain tells muscles to move: e.g. The increase in heart rate, even within the first beat, is proportional to the force developed
Once begun, chemical and metabolic tweaks to the system: chemoreceptors, baroreceptors
What would DCLO be expected to be in COPD & asthma patients?
DCLO reduced in COPD & asthma patients
DCLO reduced in COPD but raised in asthma patients
DCLO reduced in asthma but raised in COPD patients
DCLO raised in COPD and asthma patients
What would DCLO be expected to be in COPD & asthma patients?
DCLO reduced in COPD & asthma patients
DCLO reduced in COPD but raised in asthma patients
Low KCO: seen in COPD with emphysema due to alveolar destruction (usually normal in chronic bronchitis) with an obstructive pattern on PFT.
DCLO reduced in asthma but raised in COPD patients
DCLO raised in COPD and asthma patients
A 69-year-old male presents with pleuritic chest pain and shortness of breath. He is normally fit and well. On examination, he is alert, orientated and conversing with you. He is febrile (38.4) and tachycardic (105bpm) but other observations are within normal limits. A chest x-ray demonstrates left lower zone consolidation.
Blood tests are as follows:
Urea: 8mmol/L
Creatinine: 115 µmol/l
WCC: 13 10^9/l
Hb: 130 g/l
An ECG is performed showing sinus rhythm with some ventricular ectopics.
A diagnosis of community-acquired pneumonia is made.
What is this patient’s CURB-65 score?
3
2
4
1
5
2
CURB-65 is a scoring system used to grade the severity of pneumonia:
Confusion
Urea > 7
Respiratory rate ≥ 30
Blood pressure <90mmHg systolic or ≤60mmHg diastolic
Aged ≥ 65 years old
Which of the following is the correct name for the piece of equipment shown in the image?
Nasal cannulae
Venturi mask
Nasopharyngeal airway
Reservoir mask
Hudson mask
Which of the following is the correct name for the piece of equipment shown in the image?
Nasal cannulae
Venturi mask
Nasopharyngeal airway
Reservoir mask
Hudson mask
Which of the following treatments of pneumonia causes toxic optic neuropathy?
Rifampicin
Isoniazid
Ethambutol
Pyrazinamide
Which of the following treatments of pneumonia causes toxic optic neuropathy?
Rifampicin
Isoniazid
Ethambutol
Pyrazinamide
An 82-year-old lady presents to the hospital with a fever and confusion.
A CXR is performed showing a right-sided basal pneumonia. Her blood tests reveal a urea of 12mmol/L. Her observations are shown below:
Oxygen saturation 94% on air
Heart rate 120 bpm
Blood pressure 110/57 mmHg
Respiratory rate 28 breaths per minute
Temperature 38.1oC
What is her CURB 65 score?
2
3
5
4
1
An 82-year-old lady presents to the hospital with a fever and confusion.
A CXR is performed showing a right-sided basal pneumonia. Her blood tests reveal a urea of 12mmol/L. Her observations are shown below:
Oxygen saturation 94% on air
Heart rate 120 bpm
Blood pressure 110/57 mmHg
Respiratory rate 28 breaths per minute
Temperature 38.1oC
What is her CURB 65 score?
2
3
5
4
1
She would score for confusion, urea, diastolic blood pressure and age, bringing her total score to 4.
A 36-year-old Norwegian female presents with a 4-month history of gradually progressive shortness of breath, a non-productive cough and fatigue. She also reports painful red lesions on her shins. She has no significant medical/surgical history and is on no regular medications. She has no family history of note. She is a non-smoker and non-drinker. She is married and works as a classroom assistant. Her review of systems is otherwise unremarkable.
She is afebrile and her vital signs are within normal limits. Respiratory examination is normal. On inspection of the lower limbs, there are tender erythematous nodules on the anterior aspects of her lower legs bilaterally.
Given the most likely underlying diagnosis, what is the most likely cause of the skin lesions on her lower limbs?
Necrobiosis lipoidica
Pyoderma gangrenosum
Acanthosis nigricans
Erythema multiforme
Erythema nodosum
Erythema nodosum
The most likely underlying diagnosis is sarcoidosis, given this patient’s Scandinavian ancestry, age, female gender and constellation of non-specific symptoms and signs. Erythema nodosum (painful, blue-red nodules most commonly affecting the shins) is associated with sarcoidosis. Other causes of erythema nodosum include TB, streptococci and certain drugs (eg. sulfonamides, dapsone, COCP).
Which of the following is not part of Weldeyer ring?
Pharyngeal
Tubal
Lingual
Tonsular
Palatine
Which of the following is not part of Weldeyer ring?
Pharyngeal
Tubal
Lingual
Tonsular
Palatine
What is the earliest and most notable physiological change seen in patients experiencing hypovolemic shock?
TachypneaTachypnea
Hypotension
Altered mental status
Tachycardia
Tachycardia
Which of the following conditions does not contribute to shock by increasing tissue demand for oxygen and nutrients?
Pain
FeverIncorrect response
Infection
Respiratory distress
Respiratory distress
750 - 1500 ml of blood loss would indicate which stage of shock?
Class I
Class II
Class III
Class IV
750 - 1500 ml of blood loss would indicate which stage of shock?
Class I
Class II
Class III
Class IV
< 750ml of blood loss would indicate which stage of shock?
Class I
Class II
Class III
Class IV
Class I
1500 - 2000 ml of blood loss would indicate which stage of shock?
Class I
Class II
Class III
Class IV
1500 - 2000 ml of blood loss would indicate which stage of shock?
Class I
Class II
Class III
Class IV
> 2000 ml of blood loss would indicate which stage of shock?
Class I
Class II
Class III
Class IV
Class IV
Explain three examples that could cause obstructive shock xx [2]
PE
Tension pneuomothorax air gets trapped in pleural space: compresses against vena cava and heart: stops blood flow into right side of heart: reduced preload: reduced CO
Cardiac tamponade :accumulation of pericardial fluid: causes increas in intrapericardial pressure which reduceds cardiac filling
Explain 3 examples of distributive shock x
Sepsis: dysregulated host response to infection where bacteria in blood release chemicals causing uncontrolled hypotension
Anaphylactic shock: allergic response to antigen: IgE mediated mass degranulation releasing histamines: vasodilation and capillary leaking
Neurogenic shock: loss of sympathetic tone and thus unopposed parasympathetic response driven by the vagus nerve. Consequently, patients suffer from instability in blood pressure,
What is cardiogenic shock?
Name 4 causes of cardiogenic shock xx [4]
Failure of the heart to pump blood
Occurs as a result of ventricular dysfunction (esp. LV)
Causes:
* Acute myocardial infarction leading to ventricular dysfunction
* Arrhythmias
* Valvular rupture
* Decompensated heart failure
Explain the compensatory mechanisms for haemorrhagic shock [3]
Baroreceptors detect drop in arterial pressure
Activates sympathetic stimulation:
- Constriction of small arterioles increasing total peripheral resistance thereby maintaining BP
- Veins and venous reservoirs constrict, maintaining venous return
- Increased heart rate and contractility to maintain cardiac output
CNS ischaemia results in increased noradrenaline and adrenaline secretion from adrenal medulla
Name 3 long term compensatory mechanisms of shock [3]
- There is (by an unknown mechanism) stimulation of albumin and other plasma protein synthesis in the liver.
- Increased fluid absorption from GI tract
- Fibroblasts surrounding the kidney tubules are sensitive to hypoxia and release increased amounts of erythropoietin: Red cell production
CO = [] X []?
BP = [] x []?
CO = HR X SV
BP = CO x Systemic vascular resistance
What are the overall physiological consequences of shock ? [3]
- Increased afterload
- Reduced systemic vascular resistance (Failure to maintain peripheral vasoconstriction)
-
Decreased CO
i) reduced preload
ii) reduced contactility
Describe the 4 classes of haemorrhagic shock
x
What is waldeyers ring? [4]
Waldeyer’s ring consists of four tonsillar structures:
- pharyngeal
- tubal
- palatine
- lingual
As well as small collections of lymphatic tissue disbursed throughout the mucosal lining of the pharynx (mucosa-associated lymphoid tissue, MALT).
What are the axillary lymph nodes? [3]
Where do they drain lymph from? [3]
Ddescribe their path to to L / R venous angle [2]
Humeral lymph nodes drain from upper limb
Pectoral lymph nodes drain from anterior chest wall (majority drains into here)
Subscapular lymph nodes drain from posterior chest wall (rotator cuffs etc)
Together: go to central –> apical –> supraclavicular –> left / right venous angle
Label the vert. layers of A-D
The laryngeal prominence occurs at which vertebral level
C3
C4
C5
C6
C7
The laryngeal prominence occurs at which vertebral level
C3
C4
C5
C6
C7
The carotid bifurication occurs at which vert. level?
C3
C4
C5
C6
The carotid bifurication occurs at which vert. level?
C3
C4 : carotid pulse can be palpated either side of thyroid cartilage
C5
C6
The cricoid cartilage occurs at which vert. level?
C3
C4
C5
C6
The cricoid cartilage occurs at which vert. level?
C3
C4
C5
C6
The thyroid gland occurs at which vert. level?
C3
C4
C5
C6
The thyroid gland occurs at which vert. level?
C3
C4
C5
C6: overlies cricoid cartilage
Thyroid gland overlies which laryngeal cartilage?
Thyroid cartilage
Cricoid cartilage
Epiglottis
Artyenoid cartilages
Thyroid gland overlies which laryngeal cartilage?
Thyroid cartilage
Cricoid cartilage
Epiglottis
Artyenoid cartilages
