Semester 2: Human Physiology

Carboxyhaemoglobin is formed in blood even when small concentrations of carbon monoxide are present in inspired air.

Haemoglobin has a much higher affinity for CO than for O2.

Tetanic contractions do not occur in cardiac muscle.

The long refractory period of cardiac muscle prevents re-excitation from occurring until the previous contraction has finished.

Glucose is not normally present in the urine

Output of the left ventricle is equal to the output of the right ventricle.

Osmolarity of the fluid entering the top of the loop of Henle is lesser than the osmolarity of the fluid at the base of the loop of Henle.
 
 

Glomerular filtration rate is the same as the renal blood flow.

If there is an increase in the stimulation of sympathetic nerves running to a blood vessel in the skin then there is a increase in the diameter of the blood vessel.

When there is an increase in carbon dioxide tension in tissue (pCO2), there is an increase in the tendency of oxyhaemoglobin to give up O2 to the tissue.
 
 

When there is an increase in atrial natriuretic peptide release there is an increase in glomerular filtration rate.
 

Osmoreceptors are located in the hypothalamus.

Baroreceptors are stimulated by the increase in blood pressure.

Chemoreceptors are stimulated by the decreased oxygen tension (pO2) in arterial blood. 

At rest the stroke volume of the human ventricle is approx 70ml.

Hyperventilation results in the reduction in pCO2.

The basal metabolic rate of a human subject can be estiated from a knowledge of resting heat production.

pH changes in body fluids may effect enzyme activity, potassium excretion and nerve and muscle excitability.

Renin is secreted by juxtaglomerular granular cells.

Arteries and veins line endothelial cells

Neither arteries or veins are sites of gas exchange with surrounding tissue.

Arteries provide the major site of resistance in the circulation.

Veins function as capacitance vessels in the circulation.