Anatomy
what muscle does the parotid duct pierce?
Buccinator
What are the 4 key steps in primary haemostasis
Vasoconstriction: The injured blood vessel immediately narrows to reduce blood loss and shear stress. This is driven by local nerve reflexes and endothelin secreted by the damaged endothelium.
Platelet Adhesion: Circulating platelets adhere to exposed subendothelial collagen. This critical tethering step is mediated by the von Willebrand factor (vWF), which binds to the GP1b receptor on the platelet surface.
Platelet Activation: Once attached, platelets undergo a shape change (extending projections) and degranulate. They release active substances from dense granules (ADP, serotonin, calcium) and secrete thromboxane A₂ to recruit and activate additional platelets.
Platelet Aggregation: Activated platelets express the (GP2b\3a) receptor. Fibrinogen acts as a bridge, linking these receptors between adjacent platelets to build the primary platelet plug.
What is the therapeutic class and mechanism of doxycycline?
tetracycline. It is bacteriostatic and primarily works by binding reversibly to 30S ribosomal subunits.
What is the golden standard for Malaria PoCT?
Malaria Blood Smear
thick vs thin blood smear: A thick smear acts as a concentration technique to detect parasites efficiently. A thin smear uses a single layer of blood to identify the exact species of the parasite
What features will you want to assess on palpation of the thyroid gland?
Size
Shape – diffusely enlarged versus nodule present
If a nodule is present – assess size, location, tenderness, consistency, mobility
Feel inferior margin – if absent, this may suggest retrosternal extension
Tenderness – suggests thyroiditis, occasionally may be due to a bleed into a cyst or carcinoma
Mobility/tethering – suggests carcinoma
Presence of a thrill – suggests hyperthyroidism
what are the features of Tetralogy of Fallot
▪ Right ventricular outflow tract (RVOT) obstruction
▪ Malalignment ventricular septal defect (VSD)
▪ Overriding aorta
▪ Concentric RV hypertrophy
Name 5 actions of the thyroid hormone
• Increased protein synthesis
• Increased basal metabolic rate and heat production
• Increased O2 consumption
• Greater carbohydrate and lipid catabolism
• Enhanced synthesis of cholesterol (in liver)
• Activation of the SNS
• Permissive effect on catecholamines
• Increased cardiac output
• Increased respiratory rate
• Increased mental alertness
A patient was prescribed a drug to manage his deep vein thrombosis. It works by competitively inhibiting vitamin K epoxide reductase. What is this drug?
(bonus question: What is the role of vitamin K in clotting?)
Warfarin: Warfarin competitively inhibits vitamin K epoxide reductase, an enzyme responsible for activating vitamin K in the body. By blocking this process, warfarin prevents the liver from producing functional versions of several crucial blood clotting factors
The primary physiological role of Vitamin K is to catalyze the γ-carboxylation of glutamic acid residues on Factors II, VII, IX, and X. This structural change enables calcium binding, membrane attachment, and the ultimate activation of the coagulation cascade. We need calcium to bind as when platelets are activated they are negatively charged. the clotting factors are also negatively charged so we need a strongly positive ion (Ca2+) to allow the clotting factors to cling to the site of injury
What's the difference between grading and staging a neoplasm?
Stage - describes size of a tumour & how far it has spread from origin
▪ Stage 0 to 4
▪TNM system - uses letter & numbers
T: tumour size (1 for small, 4 for large)
N: for lymph nodes (0 = no lymph nodes have
cancer, 3 means many do)
M: metastases, whether cancer has spread to
another body part (0 = no spread, 1 = spread)
Grade - describes appearance of the cancerous cells
• 1 – cancer cells resemble normal cells & aren't growing rapidly
• 2 – don't look like normal cells & growing faster than normal cells
• 3 – look abnormal & may grow or spread more aggressively
What is the pain pattern for pericarditis?
Pain from friction of inflamed pericardium rubbing. Sharp, stabbing behind sternum, towards left. Worse on coughing, lying, deep breathing.
Name all the branches of the External Carotid Artery
Some Anatomist Like Freaking Out Poor Medical Students
Superior thyroid, Ascending Pharyngeal, Lingual, Facial, Occipital, Posterior Auricular, Maxillary, Superficial Temporal
What type of jaundice do newborns commonly get, conjugated or unconjugated? Why?
Unconjugated hyperbilirubinemia. The little munchkins don’t have their hepatic and blood-transport
systems fully matured yet and their livers aren’t as effective at conjugating and excreting bilirubin.
Phototherapy is usually very effective, and although this treatment can sometimes last a few days, bubby
usually just sleeps through the whole thing without a worry in the world.
patient undergoes orthopaedic surgery and
is prescribed Low-Molecular-Weight Heparin afterwards for venous thromboembolism prophylaxis.
1. Identify the therapeutic class
2. State the mechanism of action
Class: anticoagulant
Mechanism: LMWH is derived from unfractionated heparin by breaking it into shorter polysaccharide chains. These shorter chains alter its activity:
Factor Xa Inhibition: LMWH has a specific pentasaccharide sequence that binds to antithrombin III, causing a conformational change that rapidly neutralizes Factor Xa.
Thrombin (Factor IIa) Inhibition: Because the chains are too short to bind to both antithrombin and thrombin simultaneously, LMWH has a much weaker effect on thrombin compared to regular, unfractionated heparin
This disease is an autosomal dominant bleeding disorder that impacts a key glycoprotein in haemostasis. What disease am I?
Complete Blood Count (CBC): Platelet count and appearance are usually completely normal
Prothrombin Time (PT): normal
Activated Partial Thromboplastin Time (aPTT): prolonged
Platelet Function Analyzer (PFA-100/200): prolonged closure time
Von Willebrand Disease
o Quantitative – not enough
▪ Mild to moderate deficiency (Type I)
▪ Severe/absent VWF (Type III)
o Qualitative / functional defect (Type II)
▪ Unable to bind to collagen
▪ Unable to bind to GPIb
▪ Unable to bind factor VIII
Name 3 common causes for anaemia
Iron Deficiency, vitamin B12 deficiency, folate deficiency, Anaemia of Chronic Disease, blood loss
what is the arterial supply for the parathyroid gland
inferior thyroid arteries
What are some mechanisms for killing a pathogen after a macrophage has engulfed it?
Acidification/Low pH, oxygen free radicals, nitric oxide, antimicrobial peptides, enzymes and other
proteins to block/compete for binding sites etc. (don’t worry too much about how many of these
work just yet).
Name two possible drug treatment options for hyperthyroidism
thioureylenes: Carbimazole, Propylthiouracil
Iodine:Lugol’s solution (potassium iodide & iodine); Radioactive iodine
Macrocytic anaemia can be categorised into megaloblastic and non-megalo blastic. what are two causes for non-megaloblastic anaemia?
alcohol abuse, pregnancy, hypothyroidism, myelodyplastic syndrome
Which primary cancers are most often associated with metastatic spread to bone?
lung, prostate, breast, renal carcinoma
A 34 year old woman has just undergone an operation to remove her right thyroid lobe. In the recovery ward she notices her voice is a little weaker and hoarse. Why might this be?
• As part of the anaesthetic she would have had a endo-tracheal tube in her trachea that can cause some post operative hoarseness and weakness in speaking
• There may be some swelling/localized bleeding near the larynx as a result of the operation.
• The recurrent laryngeal nerve that is motor to the muscles of the larynx, runs near the thyroid gland. If this is irritated/damaged then the patient may experience vocal issues
haemoglobin undergoes part of its catabolism in the red blood cell. Haemoglobin splits into heme and globin wherein heme gets converted into biliverdin IXa which is converted bilirubin. Which two enzymes is involved in this process.
heme oxygenase, biliverdin reductase
What is the recommended drug treatment for uncomplicated malaria
Artemether 20mg + lumefantrine 120mg
Artemisinin Derivatives
Act rapidly on blood schizonts by generating reactive
free radicals that damage parasite structures e.g.
artesunate, artemether
Quinoline Antimalarials
Inhibit haeme detoxification in parasites, causing toxic
heme build-up and parasite death, though resistance is
common e.g. chloroquine, quinine, mefloquine,
lumefantrine
8-Aminoquinolines for Liver Stages
Eliminate dormant liver hypnozoites by causing
oxidative damage, preventing malaria relapse.
e.g. primaquine, tafenoquine
Explain how Hashimoto's Disease and Graves' Disease can cause a Goitre
Hashimoto’s disease: The immune system attacks the thyroid, leading to an underactive thyroid (hypothyroidism). The pituitary gland pumps out extra TSH (thyroid-stimulating hormone) to force the thyroid to produce more hormones, causing it to swell.
Graves’ disease: Antibodies trick the thyroid into producing excess hormones (hyperthyroidism), which forces the gland to grow
What is the significance of feeling for the consistency of a lymph node. What would a hard, soft or rubbery lymph node indicate?
hard: malignancy
soft: May be normal or due to a range of causes
rubbery: may suggest lymphoma