The amount of blood coming from the artery will be higher than the one from the vein. It is because the blood pressure in the arteries is higher than in the veins.

P96/Q4

High blood pressure → increased hydrostatic pressure → more fluid forced out of capillary.

Fall in the amount of plasma protein → higher WP of plasma → smaller difference/gradient between WP of plasma & WP of tissue fluid → less water reabsorbed from tissue fluid.

P97/Q5

Muscle and epithelium.

P98/Q6

Hepatic portal vein.

Hepatic vein.

P99/Q7

No mitochondria.

No nucleus/DNA.

P106/Q8

(liver) → hepatic vein → vena cava → (heart) → pulmonary artery → (lungs) → pulmonary vein → (heart) → aorta → renal artery → (kidney).

P103/Q9

Pulse in the pulmonary artery beats at the same rate as pulse in the wrist.

P104/Q10

A: "lub"

C: "dup"

P105/Q11

The delay allows atria to complete contractions before ventricles start to contract. Hence there is some time for the blood from atria to fill up ventricles before ventricular contractions begin.

This ensures that the ventricles contract from the base upwards, squeezing blood into the arteries.

P105/Q12

(5500cm�) / (70) = 78.6 cm�/beat

P107/Q13

During exercise muscles respire faster → fall in O₂ concentration in blood → diameter of veins increases
→ more blood enters the heart → walls of the heart are stretched more than usual → response of the heart: beating faster with greater strength.

Assignment

P109/Q1		P wave: Every time the muscle cells in the SAN beat, they sent out a wave of electrical activity which spreads over the surface of the atria, causing the muscles in the atrial wall to contract. A ring of fibrous tissue between the atria and the ventricles prevents the spread of the excitation wave directly to the ventricles. The excitation wave can only pass through one region - AVN. After a short delay here the wave passes down specialised conducting fibre in the septum/wall separating the ventricles. These fibres (bundle of His) conduct the excitation wave to the base of the ventricles. QRS complex: The excitation wave then spreads upwards through the muscle in the wall of the ventricle. The ventricles contract from the base upward. T wave: Walls of the atria and ventricles relax.
P110/Q2		Taking an ECG involves attaching a number of pairs of electrodes to the surface of the chest. Each pair records electrical activity at different parts of the heart, hence a number of traces.
P110/Q3	a) b)	A different position of the heart during pregnancy is caused by the pressure exerted by an increased size of uterus, in which foetus grows. Different position of the heart → different pathways of electrical activity/impulses.
P110/Q4	a) b)	1 sec. 60 beats/min.
P110/Q5		This is the time when there is a short delay in the transmission of the excitation wave through the AVN.
P110/Q6	a) b)	There is an additional wave between T and P waves. No diastole will take place → atria and ventricles will not be filled with blood → circulation of blood will stop.
P111/Q7	a) b)	Graph Heart rate increases at the "expense" of the filling time, which gets shorter. The emptying time stays the same even if heart rates change.

Examinations

P111/Q1	a)	Blood pressure at the arterial end of capillary (4.6 kPa) is larger than osmotic pressure of blood plasma at the same end (3.3 kPa). As a result fluid leaves a capillary at the arterial end. At the venous end of capillary osmotic pressure of blood plasma (3.3) is larger than the blood pressure at the same end (1.3). As a result fluid returns to the capillary.
	b)	More fluid is forced out of the capillaries than is reabsorbed back into them. This accumulated tissue fluid is returned to the blood by the lymphatic system. Excess tissue fluid drains into small, blind-ending tubes called lymphatic capillaries. These lead into larger lymph vessels, which finally empty the lymph into the blood in the veins in the neck. Lymph vessels possess valves that ensure flow in one direction.
P111/Q2	a) b) c)	Heart rate = 60 / 0.8 = 75 beats/min (i) Pressure of blood in the ventricle is higher than the blood pressure in the aorta → the valve opens. (ii) The valve between the left atrium and the left ventricle is closed during ventricular systole which occurs between 0.13 - 0.40, hence the answer: 0.27 sec. During this period ventricles contract → blood pressure increases → atrio-ventricular valve is closed. (i) Pressure in the right ventricle is lower than the pressure in the left ventricle. (ii) The circuit heart - lungs - heart (h-l-h) is shorter than the circuit heart-body-heart (h-b-h). Less pressure is needed to pump blood round the shorter circuit than the longer one, hence stronger/thicker walls of the left ventricle.
P112/Q3	a) b) c)	Endothelium is a 1-cell thick layer of cells, both in arteries & veins. Vessel A is an artery, because of: Thick layer of smooth muscle Thick layer of elastic fibre Valves in the veins open when blood flows towards the heart and close when back-flow of blood is about to occur.