2019 Past Exam

Question 1

Which of the following is NOT an example of diffusion?
A) transport of glucose through a carrier from high concentration to low concentration
B) osmosis
C) the sodium-potassium pump
D) facilitated diffusion
E) transport of Na+ ions through a Na+ channel

Answer 1

C (sodium-potassium pump)?

Question 2

Tonicity is
A) the concentration of solutes in a cell
B) the effect of a solution on cell shape
C) the concentration of solutes in a solution
D) diffusion across the membrane
E) the permeability of a cell membrane

Answer 2

B (the effect of a solution on cell shape)

Question 3

A motor unit refers to
A) a sheet of smooth muscle cells connected by gap junctions
B) all of the motor neurons supplying a single muscle
C) a single motor neuron plus all of the muscle fibres it innervates
D) a pair of antagonistic muscles
E) a single muscle fibre plus all the motor neurons that innervate it

Answer 3

C (a single motor neuron plus all of the muscle fibres it innervates)

Question 4

Meissner’s corpuscles respond and 
A) rapidly adapt to light touch
B) slowly adapt to pressure stimuli
C) rapidly adapt to pressure stimuli
D) slowly adapt to cold temperature
E) slowly adapt to light touch

Answer 4

A (rapidly adapt to light touch)

Question 5

Which of the following comparisons between the nervous system and endocrine system is INCORRECT? Cellular communication
A) has a longer duration of action in the nervous system than the endocrine system
B) involves neurotransmitters in the nervous system and hormones in the endocrine system
C) requires receptors in both the endocrine and nervous systems
D) occurs faster in the nervous system than the endocrine system
E) involves long distance travel of chemical messengers in the endocrine system and short distance travel in the nervous system

Answer 5

A (has a longer duration of action in the nervous system than the endocrine system)

Question 6

Capillary hydrostatic pressure is
A) a type of osmotic force
B) higher at the venular end of a capillary than the arteriolar end
C) a force that pushes fluid out of the capillaries during bulk flow
D) the same at both the venular and arteriolar end of a capillary
E) a force resulting from the presence of plasma proteins inside the capillary

Answer 6

C (a force that pushes fluid out of the capillaries during bulk flow)

Question 7

During the cardiac cycle, an increase in ventricular pressure above aortic pressure is associated with
A) isovolumetic ventricular contraction
B) closing of the aortic valve
C) the second heart sound
D) the first heart sound
E) a decrease in ventricular blood volume

Answer 7

E (a decrease in ventricular blood volume)

Question 8

The baroreceptor reflex response to a DECREASE in blood pressure involves
A) a decrease in heart rate
B) increased contractile strength of the ventricle
C) activation of the parasympathetic nervous system
D) a decrease in venous return
E) vasodilation of arterioles

Answer 8

B (increased contractile strength of the ventricle)

Question 9

Which of the following statements about the flow of blood through the cardiovascular system is INCORRECT?
A) Increasing the pressure gradient along the vessels will increase blood flow
B) Vasoconstriction of the blood vessels will decrease cardiovascular resistance
C) Increasing the cardiovascular resistance will decrease blood flow
D) The pressure is lowest in vessels returning blood to the heart
E) Vasodilation of the arterioles will increase blood flow

Answer 9

B (Vasoconstriction of the blood vessels will decrease cardiovascular resistance)

Question 10

During exercise, O2 is consumed by cells and CO2 is produced. A decrease in O2 will cause
A) arterioles to dilate, resulting in an increase in mean arterial blood pressure
B) arterioles to dilate, resulting in an increase in peripheral resistance
C) metarterioles to open, resulting in an increase in blood flow to the tissues
D) precapillary sphincters to open, resulting in an increase in capillary blood flow
E) arterioles to constrict, resulting in a decrease in capillary blood flow

Answer 10

B

Question 11

Which of the following factors will impair inspiration?
A) increased alveolar surface tension
B) decreased airway resistance
C) increased lung compliance
D) increased alveolar surfactant concentration
E) decreased elastic recoil

Answer 11

A (increased alveolar surface tension)

Question 12

Ventilation will increase when central chemoreceptors are stimulated by
A) an increase in CO2 in the arterial blood
B) an increase in O2 in the arterial blood
C) an increase in H+ in the arterial blood
D) a decrease in CO2 in the arterial blood
E) a decrease in H+ in the arterial blood

Answer 12

A (an increase in CO2 in the arterial blood)

Question 13

Oxygen dissociation from haemoglobin in the tissues is encouraged by 
A) high PO2
B) higher acidity
C) high HCO3-
D) low PCO2
E) a cooler temperature

Answer 13

B (higher acidity)

Question 14

Emphysema causes
A) inflammation of the airways, which makes inspiration difficult
B) decreased airway resistance, which makes expiration difficult
C) the breakdown of elastic fibres, which makes inspiration difficult
D) decreased elastic recoil, which makes expiration difficult
E) increased surface tension, which makes expiration difficult

Answer 14

D (decreased elastic recoil, which makes expiration difficult)

Question 15

(see exam for background information)
Refer to the table showing respiratory values for patient A and patient B. Which of the following statements is CORRECT?
A) Patient A has more air available for gas exchange per minute compared to patient B
B) Patient A and patient B both have the same volume of air available for gas exchange per minute
C) Patients A and B have the same pulmonary ventilation because they have the same dead space
D) Patient B has reduced alveolar ventilation compared to patient A because the tidal volume is not available for gas exchange
E) Patient A is taking faster, shallower breaths than patient B

Answer 15

A (Patient A has more air available for gas exchange per minute compared to patient B) ??

Question 16

Which definition describes a competitive antagonist correctly? A competitive antagonist has
A) affinity for the receptor and at least some efficacy
B) affinity for the receptor and higher potency than the physiological ligand
C) affinity for the receptor but no efficacy
D) no affinity for the receptor and no potency
E) no affinity for the receptor but high efficacy

Answer 16

C ?? (affinity for the receptor but no efficacy)

Question 17

When discussing potency, efficacy and antagonism, which of the following statements is CORRECT?
A) Pharmacological antagonists bind to receptors and produce a cellular response opposing that of the agonist
B) If a drug is potent, it must be very efficacious
C) Agonists and antagonists have both potency and efficacy
D) All drugs binding to one receptor type have differing potencies and similar efficacies
E) Physiological antagonists bind to receptors and produce a cellular response, which opposes that of the agonist

Answer 17

E??

Question 18

The hormone, adrenaline, causes an increase in heart rate by stimulating β-adrenoceptors, resulting in stimulation of adenylate cyclase. Isoprenaline mimics this action of adrenaline. Propranolol is an antagonist at the cardiac β-adrenoceptors. Based on this information, which of the following statements is INCORRECT?
A) Propranolol, adrenaline and isoprenaline all have affinities for the cardiac β-adrenoceptors
B) Propranolol reduces the effects of adrenaline and isoprenaline on heart rate
C) The binding of isoprenaline, but not propranolol, to the cardiac β-adrenoceptors causes stimulation of adenylate cyclase
D) Propranolol, administered in the absence of adrenaline or isoprenaline to an isolated heart preparation, causes a decrease in heart rate
E) Transduction following binding of isoprenaline to β-adrenoceptors is mediated by a G-protein

Answer 18

i have no clue- too many big words

Question 19

Drug X and Drug Y are both substrates of, and metabolised by, the cytochrome P450 3A4 enzyme. You should not allow a patient to be prescribed both of these drugs, because
A) only one of the drugs inhibits the P450 3A4 enzyme, causing excess circulating levels of the other drug
B) the metabolic degradation of both Drug X and Drug Y will be greatly elevated, leading to their rapid clearance
C) higher than normal levels of each drug will occur since they compete for the same metabolic enzyme
D) changes in liver blood flow caused by one drug will affect the distribution of the other drug
E) induction of the P450 3A4 enzyme by one of these drugs will cause elevated metabolism of the other drug

Answer 19

C? (google docs)

Question 20

When two different drugs elicit two opposing outcomes via different receptors and second messenger pathways, this is defined as
A) functional antagonism
B) non-competitive antagonism by blocked pathway
C) competitive antagonism
D) reversible, non-surmountable antagonism
E) pharmacokinetic antagonism

Answer 20

A? (google docs)

Question 21

Calcium channel blockers are used in the treatment of hypertension because they
A) cause vasodilation
B) block adrenoceptors in the heart
C) increase heart rate
D) increase intracellular calcium ion concentrations
E) cause diuresis

Answer 21

A (cause vasodilation)

Question 22

The pain felt during angina is due to
A) an increase in pressure in the pulmonary circulation and pulmonary oedema
B) bronchoconstriction
C) cardiac oxygen demand exceeding coronary oxygen supply
D) a decrease in pressure in the pulmonary circulation and pulmonary oedema
E) relaxation of the oesophageal sphincter, allowing stomach acid into the oesophagus

Answer 22

C

Question 23

The main difference between a coronary stent and a coronary bypass is that
A) a coronary bypass surgery is more common in remote regions compared to stent surgery
B) stents are used as a last resort to replace blocked vessels, whereas a bypass is less invasive and thus first line therapy
C) a coronary stent is designed to improve any major vessel in the body, whereas coronary bypass is only for coronary veins
D) a stent involves grafting of blood vessels around the damaged region of the heart, while a bypass physically opens the blocked vessel with a balloon
E) a stent involves an inflatable balloon, whereas bypass is grafting of blood vessels from elsewhere in the body

Answer 23

E? (a stent involves an inflatable balloon, whereas bypass is grafting of blood vessels from elsewhere in the body)

Question 24

List THREE (3) different factors that affect the diffusion rate of a molecule. Explain whether each factor will increase or decrease the diffusion rate.

Answer 24

1) size of the concentration gradient: the greater the gradient, the faster the diffusion
2) membrane surface area: the bigger the surface area, the faster the diffusion
3) size of the molecule: the smaller the molecule, the quicker the diffusion
4) diffusion distance: the smaller the distance, the greater the diffusion rate
5) lipid solubility of the molecule: hydrophobic = faster diffusion rate; hydrophilic = slower diffusion rate

Question 25

Use the Frank-Starling law of the heart to explain the relationship between venous return and stroke volume.

Answer 25

Stroke volume is the volume of the blood pumped out of the ventricle during contraction. It is the difference between EDV (volume of blood in ventricle during relaxation) and ESV (volume of blood in ventricle after systole).
Venous return is the volume of blood returning to the heart each minute. Increasing venous return will increase EDV.
Frank-Starling law of the heart states that the greater the EDV, the greater the force of contraction during systole. Thus, increasing venous return will increase EDV which will increase the stroke volume and force of contraction.

Question 26

Explain the forces that allow air to move into and out of the lungs during quiet breathing. Your answer should include general changes in pressure and muscle activity.

Answer 26

During quiet breathing, airways remain open. The intra-alveolar pressure is greater than the airway pressure, intra-pleural pressure and atmospheric pressure. The airway pressure is greater than the intra-pleural pressure. Thus the resistance to airflow is low.
muscle activity: ?

google doc:
The major inspiratory muscles include the diaphragm and external intercostal muscles, which contract to accomplish inspiration during quiet breathing. When inspiration occurs, contraction of these muscles increase the volume of the thoracic cavity through increasing the vertical dimension by the diaphragm contracting and pulling down and the external intercostals elevate the ribs outwards, which causes the pressure to drop. Before inspiration, the intra-alveolar pressure is equal to atmospheric pressure so there is no air flowing into or out of the lungs. As the inspiratory muscles contract and increase the volume of the thoracic cavity, the lungs also expand to fill the larger thoracic cavity. This causes a slight drop in the intra-alveolar pressure. Therefore, as the intra-alveolar pressure is now less than atmospheric pressure, air flows into the lungs down this pressure gradient. Air continues to enter the lungs until no further gradient exists, which is when the intra-alveolar pressure equals the atmospheric pressure.

Question 27

Briefly discuss why different types of sensation (modalities) are nerve specific, and not receptor specific.

Answer 27

Modalities such as touch, pressure, temperature, light, pain, sound and chemical changes are nerve specific, not receptor specific. This is because of the labeled lined theory. This theory holds that the central nervous system determines the type of stimulus based on receiving input from all sensory cells activated by that stimulus.

Question 28

In Australia about 2 million people suffer from asthma, and about 400 patients die from asthma every year. Discuss the main causes or mechanisms that lead to increased small airway resistance in asthma.

Answer 28

The increased small airway resistance in asthma is due to:

• inflammation - the thickening of airway walls
• increased mucus secretion
• airway hyper-responsiveness- bronchoconstriction

Question 29

In Australia about 2 million people suffer from asthma, and about 400 patients die from asthma every year. Briefly discuss the mechanisms of actions of ONE (1) class EACH of preventer and reliever medications.

i) Preventer medication:
ii) Reliever medication:

Answer 29

i) Preventer medication:
leukotriene receptor antagonists (LTRAs)- taken orally to reduce leukotriene activity. Relaxation of smooth muscle, no effects on inflammation
(other ICS)
ii) Reliever medication:
Short-acting Beta 2 Agonists (SABAs): short term stimulation of Beta 2 receptors on smooth muscle lining the bronchioles. Effective in early phase
(others: LABAs, methylxanthines, muscarinic antagonists)

Question 30

Name FOUR (4) common triggers for an asthma attack in affected individuals.

Answer 30

.allergens, irritants, exercise, viral infections