P+P Part A's 7

Extracellular K+ ion concentration is (mM)

Typical intracellular Na+ ion concentration is (mM)

Extracellular HCO3- concentration is

Extracellular Cl-

Intracellular ionised Ca2+ concentration is

An example of a primary active ion-transporter is

An example of a secondary active ion transporter is

The Na+/K+ ATPase is directly inhibited by the drug

Na+/K+ ATPase inhibition causes the following two effects

The typical equilibrium potential for K+ ions (EK) across the plasmalemma of a resting nerve cell (measured inside relative to outside; in mV) is

The typical equilibrium potential for Na+ ions (ENa) across the plasmalemma of a resting nerve cell (measured inside relative to outside; in mV) is

Raising the extracellular K+ concentration bathing a nerve cell would

Reducing the extracellular concentration of Na+ ions would

In a nerve cell membrane, transmembrane K+ current during repolarisation of the action potential is 2 nanoAmperes. Assuming each individual K+ channel carries a net current of 1 picoAmpere, and has a statistical probability of opening of 0.5, calculate the number of functional K+ channels.

What is the approximate conduction velocity of an unmyelinated nerve of at least 5µm diameter?

What is the approximate conduction velocity of a myelinated nerve of at least 5µm diameter?

What is the typical duration of a nerve action potential at 37°C?

The velocity of propagation of an action potential in nerve fibres is increased by

A rapidly acting, reversible inhibitor of nerve conduction is

The principal autonomic neurotransmitter released at sympathetic ganglia is

The principal post-synaptic receptor sub-type in parasympathetic ganglia is

Chemical transmission at the skeletal neuromuscular junction is blocked by

Acetylcholine applied to the heart

Noradrenaline released at a noradrenergic synapse is removed from the cleft by

A person with a steady cardiac output consumed 400mL of oxygen every minute. An arterial blood sample contained 190 mL of O2 per litre of blood, while a sample from the pulmonary artery contained 140 mL of O2 per litre of blood.

Is a cardiac output of 8L/min higher, lower or the same as the typical value for an adult 70 kg man at rest?

Stimulation of the sympathetic outflow to the cardiovascular system would initially

Administration of an α1 adrenoceptor antagonist (eg. Prazosin) would

An increase in Vagal activity

Cardiac glycosides may act to increase the force of contraction of cardiac muscle by opening voltage gated Na+ channels

Cardiac glycosides may act to increase the force of contraction of cardiac muscle by increasing cytoplasmic free Ca2+ concentration

Cardiac glycosides may act to increase the force of contraction of cardiac muscle by reducing Ca2+ extrusion on sarcolemmal Na+-Ca2+ exchange

Cardiac glycosides may act to increase the force of contraction of cardiac muscle by inhibiting Na+/K+ ATPase activity - True

Cardiac glycosides may act to increase the force of contraction of cardiac muscle by inhibiting sarcoplasmic reticular Ca2+ pump activity

Arterial PO2 is normally

A fall of arterial PO2 can stimulate

A fall of pulmonary arterial and alveolar PO2

PaCO2 in a healthy resting individual is typically (mm Hg)

A rise of arterial PCO2 can initially reduce arterial pH by

inulin appearing in the urine 450 mg/min

Individual nephrons can control their own glomerular filtration rate (autoregulation) through a process called tubulo-glomerular feedback. The cells that sense the composition of the tubular feedback are

Identify a mechanism or drug that would increase glomerular filtration

Hypoproteinemia will cause glomerular filtration rate to

This change (hypoproteinemia) in glomerular filtration rate is because of

The U-shaped arrangement of the vasa recta blood vessels in the medulla of the kidneys

Renin secretion by juxta-glomerular cells in the kidney

Anti-diuretic hormone is secreted by

Na+-HCO3- co-transporters are expressed

NaHCO3 reabsorption by the kidney

In a practical class, a healthy student drank a litre of water in five minutes. Over the next thirty minutes the student produced 150 ml of urine, with a urea concentration of 96 mmol/litre. A blood sample gave a plasma urea concentration of 6 mmol/litre.

In a practical class, a healthy student drank a litre of water in five minutes. Over the next thirty minutes the student produced 150 ml of urine, with a urea concentration of 96 mmol/litre. A blood sample gave a plasma urea concentration of 6 mmol/litre.

Is a urea clearance 80ml/min larger, the same or smaller than the glomerular filtration rate?

Name an example of an accurate marker of glomerular filtration rate.

Accurate markers for glomerular filtration rate must be ... by the glomerulus.

A main function of the colon is the net absorption of

Glucose absorption from the lumen of the intestine is via

Protein digestion is catalysed by proteases secreted from

Salivary secretion contains

The major anion secreted by pancreatic duct cells is

Bile is used for

Bile from the liver can be stored in the

Bile stored in the gall bladder can be released by the hormone

Cholecystokinin is released from the

Cholecystokinin is released in response to

Acetazolamide

Omeprazole

Spironolactone

Dobutamine

Suxamethonium

Which of the following drugs is a Ca2+ channel antagonist that may be used for treatment of cardiac arrhythmias?

Verapamil has the effect of slowing conduction through the atrioventricular node

Drugs which block open or inactivated voltage-gated Na+ channels can

A typical example of such a drug is

A drug that shows 'use-dependent block' of ion-channels is

10 mg of a dye (neglect its volume) was injected into the vein of a healthy adult. After equilibration a blood sample was taken and the dye concentration was found to be 3.33 µg/ml. Calculate plasma volume (rounded to the nearest litre)

State one assumption you need to make about the dye in order to calculate plasma volume

If the dye also passively equilibrated at equal concentration across cell walls, and within the interstitial fluid, what would its plasma concentration most closely match from the drop-down list (µg/ml)?

What would its concentration most closely resemble if it equilibrated equally throughout all compartments in the body (µg/ml)?

Assuming the haematocrit is 45%, what would be the blood volume in litres (rounded to the nearest litre) that corresponds to typical plasma volume?

Give three important factors which govern fluid exchange across the endothelial wall of muscle capillaries and the surrounding interstitial space.

The net hydrostatic force (Pcap) is most subject to short-term physiological control.

Some 20% of the interstitial fluid formed returns to the circulation via the lymphatic system.