Mini Quizzes Sem 1 Flashcards
1
Q
The pulmonary arteries carry:
A. oxygenated blood to the lungs
B. deoxygenated blood to the myocardium & pericardium
C. deoxygenated blood to the lungs
D. oxygenated blood to the visceral & parietal pleura
E. deoxygenated blood to the diaphragm
A
The pulmonary arteries carry:
C. deoxygenated blood to the lungs
2
Q
Which one of the following is most likely to lead to the reduction in the lumen diameter of arterioles in the skin and gastrointestinal tract?
A. Reduction in sympathetic outflow.
B. Strenous physical activity.
C. Severe haemorrhage.
D. Consumption of a large meal.
E. High fever (39 degrees Celsius).
A
C. Severe haemorrhage.
3
Q
A pilosebaceous unit consists of:
A. hair follicle, apocrine gland, sebum
B. erector pili muscle, sebaceous gland, melanin
C. dermal papillae, sebaceous gland, melanin
D. keratinocyte, apocrine gland, melanin
E. hair follicle, sebaceous gland, sebum
A
A pilosebaceous unit consists of:
E. hair follicle, sebaceous gland, sebum
4
Q
Which one of the following is the most appropriate term for a gene for a particular trait that is only expressed in the presence of another gene of the same kind?
A. dominant gene.
B. codominant gene.
C. incompletely dominant gene.
D. recessive gene.
E. corecessive gene.
A
D. recessive gene.
5
Q
An embolus from the left atrium is most likely to lodge in the:
A. right side of the brain
B. aortic arch
C. superior vena cava
D. pulmonary trunk
E. right coronary artery
A
An embolus from the left atrium is most likely to lodge in the:
A. right side of the brain
Left atrium –> Mitral valve –> Left ventricle –> Aortic valve –> Aorta –> either vertebral or internal carotid arteries supply brain
6
Q
Which one of the following will lead to an increase in local blood flow in a particular tissue?
A. Increase in pO2
B. Decrease in pO2
C. Increase in pCO2
D. Decrease in pCO2
E. Decrease in [H+]
A
Which one of the following will lead to an increase in local blood flow in a particular tissue?
B. Decrease in pO2
7
Q
Which one of the following is the correct formula for calculation of a patient’s stroke volume?
A. end diastolic volume - end systolic volume
B. end systolic volume – end diastolic volume
C. heart rate x end diastolic volume
D. heart rate x total peripheral resistance
E. mean arterial BP – end systolic volume
A
Stroke Volume = EDV-ESV
A. end diastolic volume - end systolic volume
8
Q
Glucose is exported from liver cells by:
A. Glucose-6-phosphatase system
B. Insulin release from the pancreas
C. Gluconeogenesis
D. Bile excreted from hepatocytes
E. Free fatty acids
A
Glucose is exported from liver cells by:
A. Glucose-6-phosphatase system
B. Insulin release from the pancreas
C. Gluconeogenesis
D. Bile excreted from hepatocytes
E. Free fatty acids
9
Q
Polydactylism is a dominant trait that results in extra fingers and toes in humans. A polydactyl man marries a woman with 10 fingers and toes. They have a child that has a normal number of digits. The phenotype of the man’s father is unknown, but his mother has a normal phenotype. What are the genotypes of the married couple?
A. woman Dd, man dd
B. woman DD, man dd
C. woman dd, man DD
D. woman dd, man Dd
D. woman DD, man Dd or dd
A
D. woman dd, man Dd
10
Q
Changes in which one of the following layers of blood vessels are involved in regulating blood flow?
A. tunica media
B. tunica intima
C. tunica adventitia
D. tunica mucosa
E. tunica insalata
A
Changes in which one of the following layers of blood vessels are involved in regulating blood flow?
A. tunica media - contains smooth muscle
B. tunica intima
C. tunica adventitia
D. tunica mucosa
E. tunica insalata
11
Q
Biological oxidation-reduction reactions always involve:
A. direct participation of oxygen.
B. formation of water.
C. mitochondria.
D. transfer of electron(s).
E. transfer of hydrogens.
A
Biological oxidation-reduction reactions always involve:
A. direct participation of oxygen.
B. formation of water.
C. mitochondria.
D. transfer of electron(s).
E. transfer of hydrogens = Acid/Base Reaction
12
Q
Which two nerves conduct the impulses for the flexion of the arm and extension of the wrist respectively?
A. Radial and ulnar
B. Radial and median
C. Musculocutaneous and radial
D. Musculocutaneous and ulnar
E. Musculocutaneous and median
A
C. Musculocutaneous and radial
Flexion of arm = Anterior compartment (brachialis, biceps brachii, and brachioradialis) = Musculocutaneous
Extension of wrist = Posterior compartment of the forearm = radial nerve.
13
Q
Blood Pressure is a function of:
A. mean arterial pressure – capillary pressure
B. cardiac output x total peripheral resistance
C. cardiac output x mean arterial pressure
D. systolic pressure – diastolic pressure
E. systolic pressure – mean arterial pressure
A
Blood Pressure =
B. Cardiac output x total peripheral resistance
14
Q
Hypoglycemia will cause which of the following clinical signs and symptoms:
A. Trembling, fever, sweatiness
B. Weight loss, sweatiness, abdominal pain
C. Trembling, sweatiness, tachycardia
D. Pallor, hypotension, sweatiness
E. Polyuria, abdominal pain, fever
A
C. Trembling, sweatiness, tachycardia
15
Q
Which one of the following symptoms and signs are most commonly found in patients with severe shock?
A. thirst and high urine output
B. thirst and low urine output
C. increased heart rate and increased blood pressure
D. increased heart rate and reduced respiratory rate
E. pallor plus reduced respiratory rate
A
Which one of the following symptoms and signs are most commonly found in patients with severe shock?
A. thirst and high urine output
B. thirst and low urine output - thirsty because want to increase blood volume + won’t pee because don’t want to deplete blood volume further
C. increased heart rate and increased blood pressure
D. increased heart rate and reduced respiratory rate
E. pallor plus reduced respiratory rate
16
Q
Consider an organism whose karyotype shows it to have a total of 60 chromosomes. How many chromosomes would be contained in the sperm of this organism?
A. 30
B. 60
C. 90
D. 120
E. 180
A
A. 30
Sperm = gamete = haploid (n) = half the no. of chromosomes
Somatic cells = diploid (2n) = full DNA
17
Q
A homologous pair of sister chromatids possesses how many copies of the alleles for each locus?
A. 1
B. 2
C. 4
D. 6
E. 8
A
A homologous pair of sister chromatids = chromosomes that have replicated but still have other pair so…
A. 1
B. 2
C. 4
D. 6
E. 8
18
Q
The major carrier of chemical energy in all cells is:
A. acetyl triphosphate.
B. adenosine monophosphate.
C. adenosine triphosphate.
D. cytosine tetraphosphate.
E. uridine diphosphate.
A
The major carrier of chemical energy in all cells is:
A. acetyl triphosphate.
B. adenosine monophosphate.
C. adenosine triphosphate.
D. cytosine tetraphosphate.
E. uridine diphosphate.
19
Q
The Frank-Starling law of the heart states that
A. increasing the filling time will decrease the force of contraction by the ventricles
B. the right and left ventricles must pump equal amounts of blood with each heart beat
C. a healthy heart will pump out all the blood that entered during the previous diastole.
D. the greater the preload on cardiac muscle fibers, the greater the force of contraction will be
E. the ventricular filling pressure will depend on the compliance of the heart
A
Frank-Starling Law
D. the greater the preload on cardiac muscle fibers, the greater the force of contraction will be
20
Q
If total peripheral resistance remains constant, what will be the effect of a decrease in heart rate on mean arterial pressure, and why?
A
This would lead to a decrease in MAP because Cardiac Output will decrease.
MAP = CO x TPR
Cardiac Output = the amount of blood ejected into the aorta in 1 minute.
CO = HR x SV
21
Q
If the heart rate remains constant, what will be the effect of an increase in total peripheral resistance on mean arterial pressure, and why?
A
This would lead to an increase MAP (because Cardiac Output will remain constant)
MAP = CO x TPR
CO = HR x SV
MAP = HR x SV x TPR
22
Q
List two chromosomal abnormalities that will result in Down Syndrome:
A
Chromosomal abnormalities resulting in Down Syndrome:
- Trisomy 21
- Robertsonian translocation
23
Q
List four clinical features of Down Syndrome:
A
Clinical Features of Down Syndrome
- Short stature with relatively short limbs.
- Slanted eyes with prominent epicanthic folds.
- Small rounded head.
- Folding of ear helix.
- Small flattened nose.
- Small mouth and jaw resulting in tongue protrusion.
- Intellectual impairment
- Short spade-like hands with a single palmar crease.
- Brushfield’s spots.
- Hypotonia in the newborn.
24
Q
A 45 year old man presents to his GP six days after surgical removal of a skin lesion from his forearm. The sutures are still in place and the area around the incision is tender, red, warm, swollen and oozing a small amount of pus. This presentation is consistent with a wound infection.
How does the inflammatory response to infection produce the local signs and symptoms of this patient?
A
Inflammation is induced by chemical mediators released from cells in response to injury. These mediators stimulate vascular changes and leucocyte recruitment to the area. Vasodilation and increased blood flow cause the redness and heat (1 mark). Changes in vascular permeability allow plasma fluid and proteins to leave the circulation, contributing to oedema/swelling and tenderness (1 mark). Leucocyte activation allows elimination of pathogens and the formation of exudate (pus) (1 mark).
25
Draw a diagram showing the differences in chromosome behaviour during prophase of mitosis and prophase 1 of meiosis.
**Mitosis - Prophase**
* Chromosomes condense + become visible
* Chromosomes appear as 2 sister chromatids held together at the centromere
* Cytoskeleton is disassembled: spindle beings to form
* Golgi + ER are dispersed
* Nuclear envelope breaks down
**Meiosis**
* Similar to mitosis but the sister chromatids do not separate
* Crossing over occurs
* Homologous chromosomes pair then separated afterwards
**Meiosis - Prophase 1 -** Homologous chromosomes pair up and exchange fragments in the process of crossing over. Each chromosome still has two sister chromatids, but the chromatids of each chromosome are no longer identical to each other.
26
List 6 factors which can affect the rate of an enzyme-catalysed reaction:
_Factors affecting the rate of an enzyme-catalysed reaction:_
1. Concentration of substrate
2. Concentration of the enzyme
3. Concentration of the product
4. pH
5. Temperature
6. Co-factors
27
Alcohol is the main cause of deaths on Australian roads. Based on the International Evaluation Literature, list up to 5 effective strategies available for the control of alcohol abuse in the community:
1. Minimum legal purchase age
2. Government monopoly of retail sales
3. Restriction on hours or days of sale
4. Outlet density restrictions
5. Alcohol tax
6. Random Breath Testing
7. Lower Blood Alcohol Concentration (BAC) limits
8. Brief interventions for hazardous drinkers (or brief medical advice)
9. Administrative license suspension
10. Graduated licensing for novice drivers
28
Complete this diagram of the general route usually taken by the blood from the heart, to the systemic circulation, pulmonary circulation and then returning to the heart:
29
List four possible types of shock.
Types of Shock = HOCSAN
1. Hypovolemic
2. Obstructive
3. Cardiogenic
4. Septic
5. Anaphylactic
6. Neurogenic
30
A 19 year old man is brought to the Emergency Department with a laceration to his femoral artery after a workplace accident with a chainsaw. He is pale, cold and clammy, with a pulse of 130 bpm and BP 90/50. He is assessed to be in Class III hypovolaemic shock due to blood loss.
What are the general principles of fluid balance management for this patient?
1. Restoration of circulating volume
2. Using intravenous route
3. Consider the 3:1 principle of fluid replacement when using crystalloid and blood products
Aim is to return BP to normal by:
* Increasing intravascular volume
* Lower HR by increasing SV (CO = SV x HR)
* Increase tissue perfusion by increasing capillary BP
31
Define Active transport across a cellular membrane.
**Active transport** = movement across a cellular membrane against an electrochemical or concentration gradient requiring energy / ATP
32
What process is being shown in the diagram below?
**Exocytosis** = the process of moving materials from within a cell to the exterior of the cell.
requires energy = a type of active transport.
33
Give 3 examples of when exocytosis occurs in the human body.
**Examples of Exocytosis in the Body**
1. Secretion of hormone
2. Release of neurotransmitters
3. Release of cellular waste
34
Define patient autonomy.
**Patient autonomy** = the right of competent patient to make informed decisions about their own medical care.
35
What is the Duty of Care of a Doctor?
**Duty of Care**
A registered medical practitioner has an obligation to adhere to a standard of reasonable care to patients in the confines of a patient-doctor relationship.
Duty of care is both an ethical and a legal concept.
36
Which one of the following medications irreversibly binds to H+ / K+ ATPase?
## Footnote
A. β2 agonist
B. Corticosteroid
C. H1 antagonist
D. H2 antagonist
E. Proton pump inhibitor
Which one of the following medications irreversibly binds to H+ / K+ ATPase?
A. β2 agonist
B. Corticosteroid
C. H1 antagonist
D. H2 antagonist
**E. Proton pump inhibitor**
37
Which one of the following sites in the gastrointestinal tract is most responsible for the digestion of protein?
A. Stomach only
B. Stomach and caecum
C. Small intestine and caecum
D. Stomach and small intestine
E. Small intestine only
Which one of the following sites in the gastrointestinal tract is most responsible for the digestion of protein?
A. Stomach only
B. Stomach and caecum
C. Small intestine and caecum
**D. Stomach (pepsin) and small intestine**
E. Small intestine only
38
Which one of the following layers of the skin is responsible for thermoregulation through vascular control?
A. Epidermis
B. Dermis
C. Hypodermis
D. Deep Fascia
E. Aponeurosis
Which one of the following layers of the skin is responsible for thermoregulation through vascular control?
A. Epidermis
**B. Dermis**
C. Hypodermis
D. Deep Fascia
E. Aponeurosis
39
What major structure lies immediately posterior to the head of the pancreas?
A. Transverse mesocolon
B. Inferior vena cava
C. Bile duct
D. Left kidney
E. Spleen
What major structure lies immediately posterior to the head of the pancreas?
A. Transverse mesocolon
**B. Inferior vena cava**
C. Bile duct
D. Left kidney
E. Spleen
40
A 23-year-old man severs his musculocutaneous nerve in an industrial accident. Which one of the following muscles is likely to be affected?
A. Triceps brachii
B. Deltoid
C. Pectoralis minor
D. Brachialis
E. Trapezius
A 23-year-old man severs his musculocutaneous nerve in an industrial accident. Which one of the following muscles is likely to be affected?
A. Triceps brachii = radial nerve
B. Deltoid = axillary nerve
C. Pectoralis minor = Medial pectoral nerve
**D. Brachialis**
E. Trapezius = accessory nerve (CN XI) (motor)
41
A 55-year-old man presents with epigastric pain after taking ibuprofen long-term on a daily basis. Gastroscopy reveals a gastric ulcer. Which one of the following is the most likely mechanism through which ibuprofen causes this condition?
A. Ibuprofen binds to H+/K+ ATPase and inhibits the proton pump
B. Ibuprofen increases gastric acid secretion by stimulating histamine release from enterochromaffin-like cells
C. Ibuprofen reduces the production of prostaglandins formed by COX 1 and reduces the integrity of the gastric mucosal barrier
D. Ibuprofen reduces the release of acetylcholine from post-ganglionic parasympathetic nerve fibres
E. Ibuprofen stimulates parietal cells to secrete more hydrochloric acid
C. Ibuprofen reduces the production of prostaglandins formed by COX 1 and reduces the integrity of the gastric mucosal barrier
42
A 46-year-old woman is treated with penicillin for a skin infection. The condition does not improve after 48 hours. Which one of the following is the most likely mechanism for the organism's resistance to this antibiotic?
A. inhibition of nucleic acid synthesis
B. Inhibition of folate metabolism
C. Beta-lactamase activity
D. inhibition of neuraminidase
E. Decreased host immunity
A. inhibition of nucleic acid synthesis = Sulphonamides + Trimethoprim
B. Inhibition of folate metabolism = Sulphonamides + Trimethoprim
**C. Beta-lactamase activity** --\> Penicillins = β-lactam antibiotic + β-lactamase = enzyme that breaks down beta lactam ring thus inactivates antibiotic
D. inhibition of neuraminidase = antiviral replication
E. Decreased host immunity
43
A 44-year-old man experiences dyspepsia and burning sensation radiating up to his neck following a large meal. He experiences relief of symptoms after taking ranitidine. Which one of the following is the mechanism of action of ranitidine in the treatment of this man's condition?
A. Exerts a bactericidal effect on Helicobacter pylori
B. Increases bicarbonate ion secretion by gastric mucosal cells in the stomach
C. Increases pepsinogen release in the stomach by increasing the stimulant effects of gastrin on parietal cells
D. Inhibits the action of histamine at H2 receptors on parietal cells and reduces the secretion of gastric acid
E. Reduces gastric acid secretion by inhibiting the enzyme cyclooxygenase 1 (COX 1)
D. Inhibits the action of histamine at H2 receptors on parietal cells and reduces the secretion of gastric acid
Ranitidine (Zantac) = an H2 histamine receptor antagonist that works by blocking histamine, thus decreasing the amount of acid released by cells of the stomach.
44
Which one of the following mechanisms is most important in facilitating the release of glucose from liver cells?
A. Glucose-6-phosphatase
B. Insulin release from the pancreas
C. Gluconeogenesis
D. Bile excretion
E. Synthesis of free fatty acids
**A. Glucose-6-phosphatase =** an enzyme that hydrolyzes glucose 6-phosphate, resulting in the creation of a phosphate group and free glucose. Glucose is then exported from the cell via glucose transporter membrane proteins.
B. Insulin release from the pancreas --\> insulin causes uptake of glucose from blood into liver/cells
C. Gluconeogenesis = the production of glucose from non-carboyhydrate sources
D. Bile excretion = breaks down fats into fatty acids, which can be taken into the body by the digestive tract.
E. Synthesis of free fatty acids
45
A 21-year-old woman presents with tiredness. Her blood tests show iron and vitamin deficiencies caused by intestinal malabsorption. The damage to which one of the following structures is most consistent with this clinical picture?
A. hepatocytes
B. villi and microvilli
C. longitudinal and circular muscle layers
D. beta cells
E. haustra
A. hepatocytes = liver cells
**B. villi and microvilli** = finger-like projections that mainly occur as extensions on the lumen of the intestine = increase the absorptive surface area of the lumen.
C. longitudinal and circular muscle layers
D. beta cells = a type of cell found in pancreatic islets that synthesize and secrete insulin and amylin
E. haustra = small pouches caused by sacculation, which give the colon its segmented appearance.
46
A 73-year-old man presents with a non-healing ulcer in his right leg. A histological biopsy is taken to exclude malignancy. The pathologist's report concludes that the specimen is consistent with chronic inflammatory response. Which one of the following cells would you expect to find as a dominant feature in microscopy?
A. Neutrophils
B. Macrophages
C. Lymphocytes
D. Basophils
E. Eosinophils
**Chronic Inflammation**
## Footnote
A. Neutrophils
**B. Macrophages**
C. Lymphocytes
D. Basophils
E. Eosinophils
47
The ankle joint consists of the distal ends of the Tibia and Fibula articulating with which one of the following bones?
A. Navicular
B. Cuneiform
C. Talus
D. Calcaneus
E. Metatarsal
The ankle joint consists of the distal ends of the Tibia and Fibula articulating with which one of the following bones?
A. Navicular
B. Cuneiform
**C. Talus**
D. Calcaneus
E. Metatarsal
48
Several people who went on a picnic together developed vomiting and diarrhoea from eating potato salad contaminated with Staphylococcus aureus enterotoxin. Which one of the following mechanisms is most likely to counteract the effects of this toxin?
A. antibody binding and neutralization of the toxin.
B. antibody opsonization and phagocytosis of S. aureus.
C. antibody opsonization and phagocytosis of the toxin.
D. B cell binding to S. aureus.
E. cytotoxic T cell binding and lysis of S. aureus.
A. antibody binding and neutralization of the toxin.
49
Which one of the following triads of clinical signs is most commonly associated with inflammation?
A. redness, swelling, heat
B. discharge, pus, bleeding
C. pain, itchiness, paraesthesia
D. necrosis, granulation, scarring
E. fever, tachycardia, hypotension
**A. redness, swelling, heat**
5 Cardinal Signs of Inflammation
1. Redness (rubor)
2. Swelling (tumour)
3. Heat (calor; only applicable to the body' extremities)
4. Pain (dolor)
5. Loss of function (functio laesa).
50
Which one of the following mechanisms best explains the role of capsules as important virulence factor in bacteria?
A. Prevents entry of antibiotics
B. Enables bacteria to bind to fibroblasts and epithelial cells
C. Inhibits uptake by phagocytic cells
D. Facilitates invasion across epithelial surfaces
E. Toxic to endothelial cells
Capsules as important virulence factor in bacteria?
A. Prevents entry of antibiotics
B. Enables bacteria to bind to fibroblasts and epithelial cells
**C. Inhibits uptake by phagocytic cells**
D. Facilitates invasion across epithelial surfaces
E. Toxic to endothelial cells
51
Describe how blood flow to the skin assists in thermoregulation.
**Blood flow/Thermoregulation of Skin**
* The sympathetic nervous system is responsible for innervation of human skin circulation
* It allows for vasoconstriction and vasodilation in response to temperature changes.
52
What is the response of the skin when there is an INCREASE in body temperature?
* An increase in body temperature results in increased blood flow to the skin (vasodilation) to increase heat loss to the environment
* An increase in body temperature will stimulate sweat secretion and promote evaporative heat loss
53
List the two principal features of the skin that protect the body from physical insults from the environment.
**Skin Defences**
1. A stratified epithelium providing protection from abrasion
2. UV absorbing pigment / melanin protects against UV damage heat loss to the environment
3. Anti-microbial defences such as sebum and Keratin
54
List the three principal types of skin receptors.
**Principal types of skin receptors**
1. mechanoreceptors
2. thermoreceptors
3. pain receptors / nociceptors
55
A 44-year-old man presents with a 3-month history of epigastric discomfort. Endoscopy showed an ulcer in the duodenum. Biopsy did not show features of malignancy. The CLO test was positive.
List the two most appropriate medications for the effective treatment of this condition and briefly explain how they work.
CLO test positive = H.pylori bacteria present
**Treatment for Ulcer**
1. Proton pump inhibitor / H2 receptor antagonist -- inhibiting/suppressing acid secretion in stomach
2. Antibiotics (e.g. amoxicillin/metronidazole/clarithromycin) - eradication of H. pylori
* (Antacid - decrease acidity)
56
For each of the listed hormones list one of its actions.
## Footnote
(i) gastrin
(ii) gastric inhibitory peptide
(iii) secretin
(iv) cholecystokinin
**(i) gastrin**
1. Increased release of HCL
2. Increased release of pepsinogen
3. Stimulate protein digestion
4. Increased GIT motility
5. Relaxes pyloric sphincter
**(ii) gastric inhibitory peptide**
1. Reduced gastric secretion
2. Reduced gastric motility and emptying
3. Reduced gastric activity
4. Stimulates insulin secretion
**(iii) secretin**
1. Stimulates release of pancreatic juice
2. Reduced gastric motility
3. Reduced gastrin
**(iv) cholecystokinin**
1. Stimulates release of pancreatic juice
2. Stimulates release of bile
3. Promotes digestion in the small intestine
4. Decreased gastric activities
57
A man suffering from a common cold sneezes into the air as he walks past. The aerosols are inhaled by a passer-by.
List the three mechanisms of host defence against the potential pathogens.
**Respiratory Defences**
1. Nasal Clearance (Sneezing, blowing, and swallowing)
2. Tracheobronchial clearance (mucociliary transport action)
3. Alveolar clearance (alveolar macrophages)
58
A 76-year-old man presents with fever, cough and dyspnoea. Chest x-ray shows lobar consolidation in the left lower lobe. List the commonest microbiological cause of this condition and its gram status.
Gram positive streptococcus pneumoniae (pneumococcus)
59
What role does saliva have in the chemical digestion of carbohydrates?
As a source of salivary amylase/a-amylase/ptyalin digests starch into simpler oligosaccharides
60
Describe the pathogenesis of Giardia lamblia infection.
List 8 points.
**Pathogenesis - Giardia lamblia infection**
1. Cyst ingestion in contaminated water or food
2. Excystation in stomach and duodenum in the presence of acid and pancreatic enzymes
3. Trophozoite multiply in small bowel
4. Trophozoite enters large bowel
5. Encystation occurs in the presence of neutral PH and secondary bile salts
6. Encystation is a continuous process, the trophozoite attaches to an enterocyte
7. Secretory vesicles appear, cyst wall proteins secreted, new cysts made with new antigenic differences
8. Epithelial injury is caused by the trophozoite which induces cell apoptosis
61
A 27-year-old woman presents one week after caesarean section. She is concerned about her wound and thinks it may be inflamed.
List up to 5 features that one would expect to find in the wound that are consistent with acute inflammation.
**Cardinal Signs of Inflammation**
1. Rubor (red)
2. Calor (heat)
3. Tumour (swelling)
4. Dolor (pain)
5. Functio laesa (loss of function)
62
What is the role of complement in acute inflammation?
List 4 points.
**Complement function in Acute Inflammation**
Improve mediation of :
1. Opsonization
2. Cell activation
3. Chemotaxis
4. Cell killing via Membrane Attack Complex
63
A 65-year-old woman is admitted to hospital with community acquired pneumonia and is commenced on intravenous antibiotic therapy. After 48 hours she is no better. Blood culture bottle grows multiple drug resistant strain of streptococcus.
List up to 3 genetic mechanisms leading to antibiotic resistance in bacteria.
**Genetic mechanisms leading to antibiotic resistance**
1. Genetic mutation
2. Expression of a latent resistance gene
3. Acquisition of genes or DNA segments with resistance determinants
64
A 65-year-old woman is admitted to hospital with community acquired pneumonia and is commenced on IV antibiotic therapy. After 48 hours she is no better. Blood culture bottle grows multiple drug resistant strain of streptococcus.
List one empiric antibiotic that is most likely to have been given to this patient. Assume she has no known risk factors for multiple drug resistant pathogens.
Ampicillin / Penicillin
65
If two medications have been shown to be orally bioequivalent explain what this means.
**The oral bioavailability of a drug** = the percentage (fraction) of the unchanged drug which reaches the systemic circulation following oral administration
* Two products are considered to be orally bioequivalent if the rate and extent of the oral absorption of the active ingredient from each product is basically the same
* Both products will produce such similar plasma concentrations of the same active ingredient that their therapeutic effects should be identical
66
Which of the following is most correct? Glucose is exported from liver cells by:
A. Glucose-6-phosphatase system
B. Insulin release from the pancreas
C. Gluconeogenesis
D. Bile excreted from hepatocytes
E. Free fatty acids
A. Glucose-6-phosphatase system
67
In March 2009 the Government of Mexico communicable disease surveillance system identified several cases of influenza-like illness in otherwise healthy young adults. The number of cases rose steadily and by 23 April there were almost 900 cases and 62 deaths throughout Mexico. The virus in this outbreak had not been previously detected in humans. Which one of the following is the most correct reason for defining this episode as an epidemic?
## Footnote
A. Large number of cases in this population
B. A high case-fatality rate
C. Person-to-person spread was observed
D. Common source for the outbreak
E. Frequency of disease was higher than expected
E. Frequency of disease was higher than expected
**An epidemic** = the rapid spread of disease to a large number of people in a given population within a short period of time.
68
Which structures pass through the thoracic plane/sternal angle/Angle of Louis?
Sternal Angle = RATPLANT
* R: rib 2
* A: aortic arch
* T: tracheal bifurcation
* P: pulmonary trunk
* L: ligamentum arteriosum
* A: azygos vein drains into SVC
* N: nerves
* loop of recurrent laryngeal nerve
* parasympathetic: contributions to the cardiopulmonary plexuses
* sympathetic: branches of the cardiopulmonary splanchnic nerves
* T: right-to-left movement of the thoracic duct
69
A 57-year-old man is diagnosed with pancreatic tumour following an evaluation of his symptoms and laboratory findings that are consistent with obstruction of the common bile duct. Which one of the following represents the symptoms and laboratory findings that one would expect to find in this patient?
* A. Pale stools, itchy skin, elevated plasma bilirubin (conjugated)
* B. Normal stools, jaundice, elevated plasma bilirubin (unconjugated)
* C. Dark urine, pain after eating a fatty meal, decreased plasma bilirubin (conjugated)
* D. Jaundice, abdominal tenderness, decreased urinary bilirubin
* E. Dark stools, pain after eating a fatty meal, elevated plasma bilirubin (unconjugated)
Obstruction of the common bile duct = EDIT THIS SLIDE - types of jaundice
A. Pale stools, itchy skin, elevated plasma bilirubin (conjugated)
70
Which one of the following parts of the brain has a central role in the regulation of feeding behaviour and appetite?
A. Precentral gyrus
B. Hypothalamus
C. Pineal gland
D. Medulla oblongata
E. Frontal lobe
**B. Hypothalamus**
Neurons involved in the homeostatic regulation of feeding are located mainly in the hypothalamus and brainstem.
71
Which one of the following statements best describes the role of insulin?
A. reducing blood glucose levels after food has been eaten
B. increasing blood glucose levels after food has been eaten
C. increasing blood glucose levels between meals
D. sustaining adequate glucose levels between meals
E. reducing blood glucose levels before food is eaten
_Role of insulin_
**A. reducing blood glucose levels after food has been eaten**
* After you eat, carbohydrates break down into glucose which enters bloodstream. The pancreas responds by producing insulin, which allows glucose to enter the body's cells to provide energy.
* Store excess glucose for energy. After you eat — when insulin levels are high — excess glucose is stored in the liver in the form of glycogen.
* Between meals — when insulin levels are low — the liver releases glycogen into the bloodstream in the form of glucose.
72
Glycolysis in adipose tissue produces pyruvate that is predominantly further metabolised to:
A. Acetyl-CoA
B. Carbon dioxide
C. Ethanol
D. Glucose-6-phosphate
E. Lactate
Glycolysis in adipose tissue produces pyruvate that is predominantly further metabolised to:
**A. Acetyl-CoA**
B. Carbon dioxide
C. Ethanol
D. Glucose-6-phosphate
E. Lactate
73
A 23-year-old medical student presents for review of his immunisation status before he starts his clinical placements. His serology shows that he has immunity against hepatitis B (HBV). He is not sure whether he had vaccination for hepatitis B in the past. Which one of the following is the most appropriate test to distinguish between natural post-infection immunity and post-vaccination immunity?
## Footnote
A. HBV surface antigen (HBsAg)
B. Antibody to HBV core antigen (anti-HBc)
C. Antibody to HBsAg (anti-HBs)
D. HBV e antigen (HBeAg)
E. HBV DNA
**B. Antibody to HBV core antigen (anti-HBc)**
74
A 25-year-old man fasts from food over a 48-hour period. During this time he only consumes water and vitamins. During the fast, which one of the following is the greatest source of fuel for the brain?
A. triglycerides
B. lactate
C. ketone bodies
D. fatty acids
E. cholesterol
It typically takes 2–4 days to enter ketosis
**C. ketone bodies -** Fatty acids do not serve as fuel for the brain, because they are bound to albumin in plasma and so do not traverse the blood-brain barrier. In starvation, ketone bodies generated by the liver partly replace glucose as fuel for the brain.
75
Which of the following is most correct? Glucose is exported from liver cells by:
A. Glucose-6-phosphatase system
B. Insulin release from the pancreas
C. Gluconeogenesis
D. Bile excreted from hepatocytes
E. Free fatty acids
**A. Glucose-6-phosphatase system =** an enzyme that hydrolyzes glucose 6-phosphate, resulting in the creation of a phosphate group and free glucose. Glucose is then exported from the cell via glucose transporter membrane proteins.
76
A 16-year-old girl has recently been diagnosed with Anorexia Nervosa. Her mortality rate in the next 10 years is closest to:
A. \< 1%
B. 1-5%
C. 10-20%
D. 30-40%
E. \> 50%
A 16-year-old girl has recently been diagnosed with Anorexia Nervosa. Her mortality rate in the next 10 years is closest to:
A. \< 1%
B. 1-5%
**C. 10-20%**
D. 30-40%
E. \> 50%
77
Which one of the following statements best describes the role of glucagon?
A. reducing blood glucose levels after food has been eaten
B. increasing blood glucose levels after food has been eaten
C. increasing blood glucose levels between meals
D. sustaining adequate glucose levels between meals
E. reducing blood glucose levels before food is eaten
**D. sustaining adequate glucose levels between meals**
78
The hormone secreting cells are easily identifiable at the electron microscopic level because they have prominent and distinctive features. What are they?
A. granules
B. mitochondria
C. Golgi apparatus
D. crystalline bodies
E. nuclear chromatin pattern
The hormone secreting cells are easily identifiable at the electron microscopic level because they have prominent and distinctive features. What are they?
**A. granules**
B. mitochondria
C. Golgi apparatus
D. crystalline bodies
E. nuclear chromatin pattern
79
A 34-year-old patient with obesity requests dietary advice. List 5 principal food groups that would be recommended.
**Recommended Food Groups**
1. Grain products
2. Animal- (meat/fish/eggs) or plant- (nuts, legumes) derived sources of protein
3. Dairy OR Dairy- or non-dairy sources of calcium
4. Vegetables
5. Fruits
80
When the glucose is delivered to the liver, the liver will consume what it needs to sustain its functions. List up to 3 examples of the fate of any glucose that is not directly oxidised by the liver.
Glucose not directly oxidised by the liver can...
1. Excess glucose can be stored as glycogen
2. It can be used to synthesise fatty acids
3. It is transported to extra-hepatic tissues via systemic circulation
81
Describe 4 possible outcomes for glucose 6-phosphate biochemically in the liver.
1. Conversion to liver glycogen
2. Dephosphorylation and release of glucose into bloodstream
3. Oxidation via the pentose phosphate pathway
4. Oxidation via glycolysis and the citric acid cycle
* Oxidation to acetyl-CoA, which then serves as precursor for synthesis of triacylglycerols, phospholipids, and cholesterol
82
Describe 4 possible outcomes for fatty acids in the liver.
1. Conversion to triacylglycerol or cholesterol esters for export in plasma lipoproteins
2. Conversion into hepatocyte phospholipids
3. Oxidation and conversion to ketone bodies for export to other tissues
4. Oxidation to acetyl-CoA, and further oxidation via citric acid cycle for ATP production
* Oxidation to acetyl-CoA, followed by synthesis of cholesterol from acetyl-CoA binding to serum albumin for transport to heart and skeleton
83
A 21-year-old man is diagnosed with a viral hepatitis (Hepatitis A) after travelling overseas.
A) Define hepatitis.
Hepatitis = inflammation of the liver
84
List 2 clinical features of hepatitis
**Clinical Features of Hepatitis**
1. Jaundice with dark urine and pale stools, anorexia, nausea, vomiting, diarrhoea
2. Constipation
3. Abdominal pain (right upper quadrant)
4. Systemic: fatigue, fever, malaise, muscle aches.
85
Outline two typical laboratory findings of hepatitis.
**Typical Laboratory Findings of Hepatitis**
1. Raised liver enzymes: AST and ALT
2. Presence of bilirubin in the urine; elevated serum bilirubin
3. Presence of virus in blood (and/or faeces)
4. Detectable virus-specific antibodies (IgM and/or IgG)
86
List 4 ways in which he may have contracted Hepatitis A.
**Hepatitis A Transmission = faecal-oral**
1. Person-Person contact - eg. sexual contact with an infected person, particularly oral-anal sex.
2. Contaminated drinking water or food
3. Not washing hands after toileting
4. Sharing of drink bottles, eating utensils & toothbrushes
87
The following viruses exhibit liver tropism, and can cause viral hepatitis. Complete the following table that summaries the main causes and features of viral hepatitis
88
Viral hepatitis can be diagnosed by serology or PCR techniques.
What is the difference between detecting serum antibodies to viral proteins (antigens) and detecting virus by PCR?
* **SEROLOGY:** The presence or absence of IgM &/or IgG specific to each of the viruses that cause viral hepatitis.
* Note: This only indirectly indicated the presence of the virus at some point in time.
* **MOLECULAR BIOLOGY:** Uses PCR (or RT-PCR) to detect the virus, e.g. virus shed in stool, or present in blood.
* Note: this directly confirms the presence (or absence) of viral particles.
89
# Fill in the blanks in the below paragraph about the synthesis and secretion of insulin.
Insulin is synthesised in the ....... as an inactive single polypeptide precursor. It is then packaged into ....... Proteolytic removal of the signalling sequence and formation of disulfide bonds leads to the formation of ..........
Proteolytic cleavage leads to secretion of both active insulin and ...........
Insulin is synthesised in the ***pancreas*** as an inactive single polypeptide precursor. It is then packaged into ***cytosolic*** ***vesicles***. Proteolytic removal of the signalling sequence and formation of disulfide bonds leads to the formation of ***proinsulin***.
Proteolytic cleavage leads to secretion of both active insulin and ***C peptide.***
90
Fill in the blanks in the following diagram showing the steps through which glucagon stimulates glycogenolysis.
91
Describe 4 processes through which the body maintains energy homeostasis during a period of fasting? Provide the name and a descriptive sentence for each process.
_Fasting State - Energy Sources_
1. **Glycogenolysis** = breakdown of glycogen to release glucose into the circulation.
2. **Glucose sparing** = usage of fatty acids by cells that are capable of doing so
3. **Gluconeogenesis** = synthesis of glucose from non-carbohydrate sources
4. **Increased ketogenesis** = increased production of ketone bodies
92
A 30-year-old man fasts as part of a fund-raising campaign. Describe the metabolic response to starvation by Day 3?
Eventually, the body depletes oxaloacetate by gluconeogenesis and there is a build up of acetyl-CoA.
The body then uses acetyl-CoA to produce ketone bodies as a fuel source.
93
Describe the stages of haem metabolism.
**Heme metabolism**
1. When RBCs become senescent they are phagocytosed by cells of the reticuloendothelial (RES) stem macrophages and the haemoglobin is degraded.
2. The globin component is degraded to amino acids.
3. Haem is first oxidised to bilverdin by haem oxygenase-1 with the release of Iron
4. Bilverdin is oxidised to bilirubin
5. Bilirubin is released into plasma where it is largely bound to albumin
6. Bilirubin is conjugated and excreted into the bile
7. In the GIT bilirubin is catabolised by the gut microflora to urobilinogen, the fate of which is 3 fold
1. most is reabsorbed and returned to the liver and can be re-excreted
2. some of the reabsorbed urobilinogen reaches the kidneys where it is excreted as urobilin
3. some is oxidised further to stercobilin and excreted in the faeces
94
A 16-year-old girl is diagnosed with type I diabetes mellitus
How may this _chronic_ disease impact on this girl’s life in the _short term_?
List 3 examples
**DM - Type 1 - Short Term Impacts**
1. Coming to terms with having a chronic illness
2. Learning to give herself insulin
3. Having to eat & exercise regularly
4. More prone to infections
5. Hyperlipidaemia / dyslipidaemia
6. Lack of energy
7. Hypoglycaemia if misses a meal / has too much insulin/ too much exercise or alcohol
8. Diabetic ketoacidosis – can be caused by intercurrent infections / missing dose of insulin
95
A 16-year-old girl is diagnosed with type I diabetes mellitus
How may this _chronic_ disease impact on this girl’s life in the _long_ term?
List 3 examples
**DM - Type I - Long Term Impacts**
1. Microvascular- retinopathy
2. Nephropathy / chronic renal failure
3. Sensory neuropathy (pain & numbness in feet/ painless ulcers prone to infection, which may lead to amputation)
4. Macrovascular- cardiovascular disease
5. Peripheral vascular disease (claudication, DVT, may lead to amputation).
6. Autonomic neuropathy (impotence in men, constipation, postural hypotension).
96
The diverse repertoire of antibody specificities is:
A. encoded entirely by germ-line genes
B. the result of somatic rearrangement of a limited number of germ-line genes
C. encoded by genes located on a single chromosome
D. generated after the B cell first encounters antigen
E. driven by the interaction of a naive B cell with a helper t cell (TH)
The diverse repertoire of antibody specificities is:
A. encoded entirely by germ-line genes
**B. the result of somatic rearrangement of a limited number of germ-line genes**
C. encoded by genes located on a single chromosome
D. generated after the B cell first encounters antigen
E. driven by the interaction of a naive B cell with a helper t cell (TH)
97
Which one of the following substances is required for the splicing of introns in nuclear mRNA primary transcripts?
## Footnote
A. guanine nucleoside or nucleotide.
B. endoribonucleases.
C. polynucleotide phosphorylase.
D. RNA polymerase II.
E. small nuclear ribonucleoproteins (snurps).
Which one of the following substances is required for the splicing of introns in nuclear mRNA primary transcripts?
## Footnote
A. guanine nucleoside or nucleotide.
B. endoribonucleases.
C. polynucleotide phosphorylase.
D. RNA polymerase II.
**E. small nuclear ribonucleoproteins (snurps).**
98
Sulphonamide antibiotics stop bacterial growth by inhibiting:
## Footnote
A. bacterial nucleic acid synthesis
B. folic acid synthesis
C. bacterial wall synthesis
D. DNA synthesis
E. cell wall synthesis
Sulphonamide antibiotics stop bacterial growth by inhibiting:
## Footnote
A. bacterial nucleic acid synthesis
**B. folic acid synthesis**
C. bacterial wall synthesis = penicillins + cephalosporins (β-Lactams)
D. DNA synthesis
E. cell wall synthesis
99
The Ig A molecule:
A. Crosses the placenta via the Fc portion
B. Can be secreted into mucus and intestinal juices to fight infection
C. Is produced in early phase infections and activates complements easily
D. Is secreted in high concentrations in the atopic individual
E. crosses the blood brain barrier
_The Ig A molecule:_
## Footnote
A. Crosses the placenta via the Fc portion = IgG
**B. Can be secreted into mucus and intestinal juices to fight infection**
C. Is produced in early phase infections and activates complements easily = IgM
D. Is secreted in high concentrations in the atopic individual = IgE (allergies)
E. crosses the blood brain barrier = IgG
100
In a standard haematological stain, a lymphocyte is identified as:
## Footnote
A. Having a lobed nucleus with purple granules
B. A lobed nucleus with red / orange granules
C. A lobed nucleus with dark blue granules
D. A small cell with large darkly staining nucleus
E. A large cell with darkly staining irregular nucleus & no granules
In a standard haematological stain, a lymphocyte is identified as:
## Footnote
A. Having a lobed nucleus with purple granules
B. A lobed nucleus with red / orange granules
C. A lobed nucleus with dark blue granules
**D. A small cell with large darkly staining nucleus**
E. A large cell with darkly staining irregular nucleus & no granules
101
Which one of the following second messengers regulates the secretion of chloride from chloride ion channels in the luminal membrane of epithelial cells?
A. Cyclic GMP
B. Cyclic AMP
C. IP3
D. Calcium
E. Protein Kinase C
Which one of the following second messengers regulates the secretion of chloride from chloride ion channels in the luminal membrane of epithelial cells?
A. Cyclic GMP
**B. Cyclic AMP**
C. IP3
D. Calcium
E. Protein Kinase C
102
The sodium-potassium exchange pump located in the basolateral membrane of epithelial cells
## Footnote
A. actively transports potassium into cells.
B. osmotically moves sodium into cells.
C. actively transports water out of cells.
D. moves chlorine out of cells.
E. actively transports sodium into cells.
The sodium-potassium exchange pump located in the basolateral membrane of epithelial cells
## Footnote
**A. actively transports potassium into cells.**
B. osmotically moves sodium into cells.
C. actively transports water out of cells.
D. moves chlorine out of cells.
E. actively transports sodium into cells.
103
The process of transcription:
A. produces mRNA from the DNA template
B. produces an amino acid chain from the mRNA template
C. occurs in the cytoplasm
D. forms new protein
E. forms DNA from the RNA template
The process of transcription:
**A. produces mRNA from the DNA template**
B. produces an amino acid chain from the mRNA template = False - translation
C. occurs in the cytoplasm = False - transcription occurs in the nucleus & translation occurs at ribosome in cytoplasm
D. forms new protein = False - translation
E. forms DNA from the RNA template
104
Which one of the following types of immunoglobulin can cross the placenta?
## Footnote
A. IgA
B. IgC
C. IgD
D. IgG
E. IgM
Which one of the following types of immunoglobulin can cross the placenta?
## Footnote
A. IgA
B. IgC
C. IgD
**D. IgG**
E. IgM
105
Huntington’s disease is an autosomal-dominantly inherited disease. A woman with one copy of the gene for Huntington’s disease marries a man who does not have the abnormal gene. Which one of the following is the likelihood that one of their offspring will be affected by Huntington’s disease?
A. 0%
B. 25 %
C. 50 %
D. 75 %
E. 100 %
**C. 50%**
Cc x cc = Cc, Cc, cc, cc
106
Which one of the following is the RNA responsible for bringing the amino acids to the “factory” site for protein formation?
## Footnote
A. mRNA
B. rRNA
C. ssRNA
D. tRNA
E. eRNA
Which one of the following is the RNA responsible for bringing the amino acids to the “factory” site for protein formation?
## Footnote
A. mRNA - messenger = carries genetic info of DNA from nucleus to ribosome in cytoplasm for protein synthesis
B. rRNA - ribosomal = associates with a set of proteins to form ribosomes. Complex structures which physically move along an mRNA molecule.
C. ssRNA
**D. tRNA**
E. eRNA
107
Sound waves are transmitted directly into the inner ear by movements of the:
## Footnote
A. Cochlea
B. Round window
C. Tympanic membrane
D. Auditory ossicles
E. Oval window
Sound waves are transmitted directly into the inner ear by movements of the:
**E. Oval window**
Sound wave – Tympanic membrane - transmitted to Stapes – Oval window - vibrates – pushes perilymph in scala vestibuli – to scala tympani – creates pressure waves in endolymph – result in vibration of basilar membrane – stimulation of receptors to generate nerve impulses for sound.
108
Outline the major functions of the adaptive immune system.
**Adaptive Immune System - Functions**
1. To recognise specific “non-self” antigens in the presence of “self”, during the process of antigen presentation.
2. To generate responses tailored to eliminate maximally specific pathogens or pathogen infected cells.
3. To develop immunological memory, in which each pathogen is “remembered” by a signature antigen.
109
A 44-year-old man requires a kidney transplant as a result of End Stage Renal Failure caused by Systemic Lupus Erythematosus.
The patient has one living sibling. What is the probability that this sibling is suitable as an organ donor?
One in four chance (25%)
110
A 44-year-old man requires a kidney transplant as a result of End Stage Renal Failure caused by Systemic Lupus Erythematosus.
The patient has one living parent. What is the most likely level of match between them?
Level of match = 50%
| (receive 1 copy from mum + 1 from dad)
111
What is the antigen system that plays the most significant role is transplantation rejection in humans?
HLA [major histocompatibility antigens]
112
List 2 forms of HLA antigens
MHC Class I and MHC Class II
113
Why is it difficult to find a tissue match between unrelated individuals?
There are many alleles for each of the Class I and Class II genes giving the population a large degree of heterogeneity [millions of HLA combinations] such that the chance of locating 2 near identical individuals is extremely low.
114
In Cystic Fibrosis, the secretions of the lung and pancreas are thickened. A. Briefly describe the mechanism by which this thick secretion occurs
The mutated CFTR gene causes dysfunction of the salt and water balance of secretions in these organs, causing secretions to be dehydrated and therefore thick.
115
Outline the pathological mechanisms by which chronic lung and pancreatic disease develops in cystic fibrosis.
**Lung**
Thick secretions reduce the muco-ciliary defence mechanism and
* obstructs airways
* This combination leads to destructive infections (bronchiectasis) of the lung parenchyma, leading to chronic lung disease.
**Pancreas**
* Thick secretions block the ducts of the pancreas,blocking the movement of digestive enzymes to the bowel.
* Duct obstruction causes damage and atrophy of pancreatic tissue reducing ability to produce digestive enzymes.
116
A 70-year-old man presents with a chronic non-healing ulcer in his leg. List up to 5 factors that could be impairing his wound healing. Provide a brief explanation for each factor.
1. **Immune status** – reduced immunity makes infection more likely
2. **Diabetes** – elevated blood glucose level may impair white cell function, and contribute to vascular disease
3. **Poor nutrition** – lack of essential vitamins and minerals for healing to occur
4. **Peripheral vascular disease** – contributing to lack of oxygen and nutrient supply to tissues for cell function
5. **Pain** - causes vasoconstriction
6. **Medication use** - Corticosteroids and other drugs depress immune function
117
Which study type is being described?
* Can provide true measure of risk
* Can study many disease outcomes
* Time-consuming and costly
* Can only study exposures measured at start of study
**Cohort studies**
118
Which study type is being described?
* Gold standard for evaluating interventions
* Investigator has control over research process
* Time-consuming and usually costly May be limited in generalisability
**Randomized controlled trials**
119
Which study is being described?
* Quick and easy to perform
* Useful for hypothesis generation
* Cannot provide causal conclusions to be drawn
* Subject to ecologic fallacy
Ecologic studies
120
Which study is being described?
* Quick and easy to perform
* Can study many risk factors
* Subject to recall bias
* Can study only one disease outcome at a time
Case-control studies
121
Which study is being described?
* Quick and easy to perform
* Useful for hypothesis generation
* Cannot show temporal relationships
* Not good for hypothesis testing
Cross-sectional Surveys
122
A 21-years-old, presents to her GP requesting the combined oral contraceptive. She asks her GP how the combined oral contraceptive pill [COCP] works as a contraceptive. Which one of the following is correct regarding the mechanism of action of the COCP?
A. Barrier method that hinders the passage of sperm
B. Anovulation due to reduced release of Follicle stimulating hormone
C. Cycle regulation allows more accurate timing of ovulation
D. Taken immediately before intercourse it prevents fertilisation
E. Impairs the motility of sperm
B. Anovulation due to reduced release of Follicle stimulating hormone
123
Which one of the following statements is most correct?
A. Morphine is an arpntagonist at opioid receptors
B. Enkephalins are exogenous peptides which produce analgesia
C. Naloxone is a competitive opioid antagonist
D. The actions of heroin mostly arise from it being metabolised to codeine
E. Significant tolerance does not develop to the constipating effects of opioids
**E. Significant tolerance does not develop to the constipating effects of opioids**
A. Morphine is an antagonist at opioid receptors
B. Enkephalins are exogenous peptides which produce analgesia
C. Naloxone is a competitive opioid antagonist
D. The actions of heroin mostly arise from it being metabolised to codeine = False - Codeine is converted to morphine in the body by the cytochrome P450 enzyme 2D6. It is thought that the analgesic effect of codeine is due primarily to its conversion to morphine.
124
Which one of the following is the most common pathway for the initial dissemination of carcinoma?
A. Direct seeding into body cavities
B. Haematogenous spread via veins
C. Haematogenous spread via arteries
D. Lymphatic spread
E. Direct implantation e.g. during surgery or in a needle tract
Which one of the following is the most common pathway for the initial dissemination of carcinoma?
A. Direct seeding into body cavities
B. Haematogenous spread via veins
C. Haematogenous spread via arteries
**D. Lymphatic spread**
E. Direct implantation e.g. during surgery or in a needle tract
125
A 28-year-old man is brought in by an ambulance to the Emergency Department after being found unconscious at home by his family. An empty container of pills was found with the label missing. Which one of the following clinical features is most suggestive of opioid overdose?
A. Reduced level of consciousness
B. Jaundice
C. ECG abnormality
D. Pupil constriction
E. LFT abnormality
D. Pupil constriction
126
Drug Z has a steady-state plasma concentration of 800mg/l and follows first-order elimination kinetics. What additional information is required to determine the plasma concentration 4 hours after therapy is discontinued?
A. Absorption half-life
B. Bioavailability
C. Elimination half-life
D. Volume of distribution
E. Dose administered
**C. Elimination half-life** = the time it takes for the concentration of the drug to be reduced by 50%.
* steady-state = With first order kinetics if a patient takes a drug regularly there comes a time when the amount of drug taken by the patient in each dose is equal to the amount of drug eliminated.
* first-order elimination kinetics = The rate of elimination is proportional to the drug concentration
127
A 50-year-old man underwent gastroscopy after presenting with a history of long standing symptoms of reflux. Biopsies were taken of an erythematous area of the lower esophogeal mucosa 3cm above the gastroesophageal junction. The histopathologist reported the presence of columnar epithelium with goblet cells, showing no evidence of dysplasia. The histological findings represent which one of the following?
A. hypertrophy
B. hyperplasia
C. carcinoma
D. ischaemia
E. metaplasia
Normal Esophagus = Stratified Squamous Epithelium so if columnar with goblet cells (stomach) =
## Footnote
A. hypertrophy = cells get bigger
B. hyperplasia = An increase in the **number** of cells
C. carcinoma = cancer of the epithelium
D. ischaemia = lack of blood supply
**E. metaplasia =** One adult cell type is replaced by another normal adult cell type (Reversible change)
128
The anti-inflammatory effect of NSAIDs is mainly due to:
A. inhibition of histamine release
B. block of prostaglandin receptors
C. inhibition of the COX-2 enzyme
D. activation of opioid receptors
E. block of bradykinin receptors
The anti-inflammatory effect of NSAIDs is mainly due to:
A. inhibition of histamine release
B. block of prostaglandin receptors = false - Block the production of prostaglandins by inhibiting the enzyme cyclooxygenase (COX)
**C. inhibition of the COX-2 enzyme**
D. activation of opioid receptors
E. block of bradykinin receptors
129
For a lesion to be classified a neoplasm (rather than a reactive inflammatory process) it typically displays:
## Footnote
A. Rapid increase in size
B. Fast necrosis
C. Uncontrolled autonomous growth
D. Sensitivity to chemotherapy
E. Recurrence following excision
For a lesion to be classified a neoplasm (rather than a reactive inflammatory process) it typically displays:
## Footnote
A. Rapid increase in size
B. Fast necrosis
**C. Uncontrolled autonomous growth**
D. Sensitivity to chemotherapy
E. Recurrence following excision
130
The synthesis of purine and pyrimidine nucleotides differ in that:
## Footnote
A. ATP is required in the synthesis of purines but not in the synthesis of pyrimidines.
B. Purine biosynthesis starts with the formation of PRPP, whereas pyrimidines incorporate the PRPP near the end of the pathway.
C. Purine formation requires a THF derivative, whereas pyrimidine formation does not.
D. Pyrimidine biosynthesis is tightly regulated in the cell, whereas purine biosynthesis is not.
E. Pyrimidines go through many steps, adding a single carbon or nitrogen each time, whereas the basic skeleton for purines is formed by two main precursors.
A. ATP is required in the synthesis of purines but not in the synthesis of pyrimidines.
131
Which one of the following statements concerning the enzyme cyclooxygenase (COX) is correct?
## Footnote
A. Aspirin reversibly inhibits COX-1
B. Paracetamol is an irreversible inhibitor of both COX 1 and COX-2
C. Ibuprofen is a selective inhibitor of COX-2
D. Celecoxib selectively inhibits COX-1
E. COX-2 is a constitutive enzyme in the kidney
Which one of the following statements concerning the enzyme cyclooxygenase (COX) is correct?
## Footnote
A. Aspirin reversibly inhibits COX-1 = false - it ***irreversibly*** inhibits COX 1
B. Paracetamol is an irreversible inhibitor of both COX 1 and COX-2 - MOA not well understood, Does not block COX1 or COX2 in peripheral tissues
C. Ibuprofen is a selective inhibitor of COX-2 = not selective
D. Celecoxib selectively inhibits COX-1 = COX-2 inhibitor
**E. COX-2 is a constitutive enzyme in the kidney**
132
A 78-year-old man presents with a long history of having to get up at night to pass urine. On average he would go 3-4 times a night to pass urine. He also finds it difficult to start urination, and when he does start the urine flows weakly. The urine dribbles at the end and often he ends up wetting his underwear. On examination he has soft abdomen. Rectal examination shows an enlarged prostate gland which is smooth with no irregularities or tenderness. Urine analysis is normal.
What is the most likely diagnosis?
Benign prostatic hyperplasia (BPH).
133
List 4 common symptoms of Benign prostatic hyperplasia (BPH).
**Common Symptoms of BPH**
1. Hesitancy (difficult initiation)
2. Urgency
3. Poor stream/decrease flow, stream
4. Frequency/nocturia
5. Incomplete emptying
6. Terminal dribbling of urine
7. Stranguary
8. Pis-en-deux (double voiding)
9. Overflow incontinence
134
Briefly outline the pathophysiological mechanism for Benign prostatic hyperplasia (BPH).
**Pathophysiology of BPH**
* Prostate is an endocrine dependent tissue
* Responds to dihydro-testosterone by hyperplasia
* Estrogen at physiological male levels potentates hyperplasia by inducing androgen receptors
* Tissue growth causes obstruction of urethra
135
List 3 other common causes of the patient’s symptoms.
**Common causes of BPH like symptoms**
1. Prostatic carcinoma (cancer)
2. Urethral strictures
3. Bladder Stones
136
Define and describe apoptosis
Apoptosis, or programmed cell death, is the orderly biochemical process of cell death required in developmental processes and to maintain cell homeostasis in the whole organism. It is characterised by cell shrinking, DNA fragmentation and membrane blebbing.
137
Name one family of enzymes critical to both the signaling and execution phases of apoptosis.
Caspases (Cytoplasmic protease enzymes)
138
Below is a picture of a normal blood film. Please label the cell types
A. Erythrocyte
B. Neutrophil/leucocytes
C. Platelets
A. **Erythrocyte** - Anucleate, circular, biconcave discs
B. **Neutrophil**/**Leucocytes** - Larger than RBC, Segmented nucleus (up to 5 lobes), Lilac granules in cytoplasm
C. **Platelets** - Small fragments derived from megakaryocytes in bone marrow, Numerous cytoplasmic granules
139
Describe the biochemical effects of radiation on cellular DNA and the consequences for such cells.
**Biochemical Effects**
* Causes DNA strand breaks and adduct formation
* Causes Mutations
* DNA repair is capable of reversing much of this damage
* Increases free radical damage to lipids and proteins
* Turnover and replacement of damaged proteins and lipids reversed most of this damage
**Consequences**
* Cell death – apoptosis / necrosis
* Increased DNA repair - mutations
140
Discuss the mechanism of action of the following antimetabolite drug:
Methotrexate
**Antimetabolite drugs** = Group of drugs used for treatment of cancer --\> compete in metabolic pathways with the correct/natural substrate
**Methotrexate** = Competitive inhibition of the enzyme dihydrofolate reductase. It depletes the cellular pool of reduced folates (used for purine synthesis and conversion of dUMP to dTMP).
* Folates act as coenzymes for the synthesis of factors such as purine nucleotides which are essential for DNA synthesis and cell division
* In order to act as coenzymes folates must be reduced to tetrahydrofolate (FH4) by the enzyme dihydrofolate reductase
* Methotrexate is an antimetabolite which inhibits the enzyme dihydrofolate reductase
* Methotrexate inhibits DNA synthesis and cell division
* Methotrexate can also exert effects on normal cells
141
Discuss the mechanism of action of the following antimetabolite drug:
Cytosine arabinoside
**Cytosine arabinoside - MOA:**
Competitive inhibition of RNA and DNA synthesis since it replaces deoxycytosine
142
Discuss the mechanism of action of the following antimetabolite drugs:
5-fluorouracil
**5-fluorouracil - MOA:**
Working as an antimetabolite to prevent cell proliferation, it primarily inhibits the enzyme thymidylate synthase blocking the thymidine formation required for DNA synthesis.
143
Describe the role of platelets in haemostasis
**Role of Platelets in Haemostasis**
* In primary haemostasis, platelets form a plug at the site of vascular injury to close the defect.
* In the secondary phase of haemostasis, platelets provide the phospholipid surface required for the reactions involved in the formation of thrombin from activated coagulation factors.
144
In the table, summarise the different features of benign versus malignant tumours
145
Define sensitivity and specificity.
**Sensitivity** - the probability of testing positive if the disease is truly present. Or the ability of the test to detect disease when it is present.
**Specificity** - the probability of testing negative if the disease is truly absent. Or the ability of the test to correctly identify the absence of disease.
146
Differentiate between a carcinogen & a mutagen.
**Carcinogen**
* an agent directly involved in the promotion of cancer.
* may be due to genetic instability or the disruption of cellular metabolic processes
* carcinogens damage/ alter DNA (eg. inhaled tobacco smoke or asbestos)
**Mutagen**
* a physical or chemical agent that changes the genetic information(usually DNA) & the frequency of mutation above the natural background level
* as many mutations cause cancer, mutagens may also be carcinogens
* not all mutations are caused by mutagens
* can have “spontaneous mutation” occurring due to errors in DNA replication, repair & recombination of DNA sequences.
147
List 4 primary tumours that commonly metastasise to bone
**Primary tumours that commonly metastasis to bone**
1. Prostate
2. Breast
3. Lung
4. Kidney
5. Melanoma
6. Thyroid
