The document discusses the structure and function of the cardiovascular system. It describes the heart as a four-chambered pump made of cardiac muscle that circulates blood through the body. Blood travels through the heart chambers and vessels, passing through the lungs to collect oxygen and release carbon dioxide. The document also outlines the composition of blood and its role in transporting materials throughout the body.

1. 6.2 The Transport System
Topic 6 Human Health and Physiology

2. 6.2.1 Draw and label a diagram of the heart showing the four
chambers, associated blood vessels, valves and the route of blood
through the heart.
(Care should be taken to show the relative wall thickness of the
four chambers. Neither the coronary vessels nor the conductive
system are required)
6.2.2 State that the coronary arteries supply heart muscle with
oxygen and nutrients.
6.2.3 Explain the action of the heart in terms of collecting blood,
pumping blood, and opening and closing of valves.
(A basic understanding is required, limited to the collection of blood
by the atria, which is then pumped out by the ventricles into the
arteries. The direction of flow is controlled by atrio-ventricular
and semilunar valves)

3. 6.2.4 Outline the control of the heartbeat in terms of myogenic
muscle contraction, the role of the pacemaker, nerves, the medulla
of the brain and epinephrine (adrenaline).
(Histology of the heart muscle, names of nerves or transmitter
substances are not required)
Aim 7: Simulation and data logging involving heart rate monitors,
or data logging involving an EKG sensor to measure electrical
signals produced during muscle contractions, can be used.
6.2.5 Explain the relationship between the structure and function of
arteries, capillaries and veins.

4. 6.2.6 State that blood is composed of plasma, erythrocytes, leucocytes
(phagocytes and lymphocytes) and platelets.
6.2.7 State that the following are transported by the blood: nutrients,
oxygen, carbon dioxide, hormones, antibodies, urea and heat.
(No chemical details are required)

5. The Heart
 The mammalian heart is a muscular pump.
 The mammalian heart is a closed system.
 It has a double circulation system (passes through the heart
twice).
 The mammalian heart has two sides separated by a
muscular septum.
 The mammalian heart has 4 chambers:
 Left and right atria (singular - atrium)
 Left and right ventricles

6. The Heart
Handout: The Heart

7. The Heart
 The walls of the atria are thinner than the walls of the
ventricles
 Coronary arteries around the heart supply the heart with
blood.
 The heart consist of cardiac muscle which can contract
without nervous or hormonal impulses.

8. Path of blood through the heart
 The path blood follows through the heart is:
 Blood returns to the heart via the vena cava (superior and inferior)
 Blood enters the right atrium and then passes through the
atrioventricular (tricuspid) valve to the right ventricle.
 Blood is then pumped out of the heart through the semi-lunar
valves to the lungs via the pulmonary arteries.
 Oxygenated blood returns to the heart from the lungs via the
pulmonary veins and enters the left atrium.
 Blood then passes through the atrioventricular (bicuspid) valve to
the left ventricle.
 Blood is then pumped out of the heart and to the body via the
largest artery in the body, the aorta.

9. The Heart Beat
 The heart beat is myogenic, meaning that the contraction originates in
the heart itself.
 There is no need for nervous impulses from the brain.
 Contraction of the heart is known as systole and relaxation is known as
diastole.
 The heart beat starts in the sinoatrial node, a small patch of tissue
sometimes called the pacemaker and passes to the atrioventricular
node.
 The heart beat rate can be altered by nervous messages from the brain
or from hormones eg: adrenaline
 Handout: The Heart Beat

10. Blood Vessels
 There are 3 main types of blood vessels;
 Arteries
 Veins
 Capillaries
 Arteries carry blood away from the heart and generally carry
oxygenated blood. Arteries are thicker to handle the higher pressure of
the blood travelling through them.
 Veins carry blood back to the heart and generally carry deoxygenated
blood. Veins have valves (semi-lunar valves) to prevent back flow of
blood.
 Capillaries connect arteries and veins and are a network of tiny blood
vessels, with walls that are one cell thick. No cell in the body is very
far from a capillary.

11. Blood Vessels
Handout: Blood Vessels

12. Blood Blood is composed of:
 Plasma (55%)
 Plasma is mainly water
 Carries absorbed nutrients, hormones ,antibodies, urea and carbon
dioxide .
 Erythrocytes (red blood cells)
 Carry respiratory gases; oxygen and a little carbon dioxide
 Produced in the red bone marrow and destroyed in the liver and
spleen.
 Leucocytes (white blood cells)
 Larger than erythrocytes
 Responsible for fighting infection
 Numerous types; phagocytes(neutrophils, macrophages),
lymphocytes (B cells and T cells)
 Platelets
 Cause blood clotting, smaller than erthrocytes

13. 6.2.1 Draw and label a diagram of the heart showing the four
chambers, associated blood vessels, valves and the route of blood
through the heart.
(Care should be taken to show the relative wall thickness of the
four chambers. Neither the coronary vessels nor the conductive
system are required)
6.2.2 State that the coronary arteries supply heart muscle with
oxygen and nutrients.
6.2.3 Explain the action of the heart in terms of collecting blood,
pumping blood, and opening and closing of valves.
(A basic understanding is required, limited to the collection of blood
by the atria, which is then pumped out by the ventricles into the
arteries. The direction of flow is controlled by atrio-ventricular
and semilunar valves)

14. 6.2.4 Outline the control of the heartbeat in terms of myogenic
muscle contraction, the role of the pacemaker, nerves, the medulla
of the brain and epinephrine (adrenaline).
(Histology of the heart muscle, names of nerves or transmitter
substances are not required)
Aim 7: Simulation and data logging involving heart rate monitors,
or data logging involving an EKG sensor to measure electrical
signals produced during muscle contractions, can be used.
6.2.5 Explain the relationship between the structure and function of
arteries, capillaries and veins.

15. 6.2.6 State that blood is composed of plasma, erythrocytes, leucocytes
(phagocytes and lymphocytes) and platelets.
6.2.7 State that the following are transported by the blood: nutrients,
oxygen, carbon dioxide, hormones, antibodies, urea and heat.
(No chemical details are required)