Transport System (Core) Ms. Fargo

Assessment StatementsObj Draw and label a diagram of the heart showing the four chambers, associated blood vessels, valves and the route of blood through the heart State that the coronary arteries supply heart muscle with oxygen and nutrients Explain the action of the heart in terms of collection of blood, pumping blood and opening and closing of valves Outline control of the heartbeat in terms of myogenic muscle contraction, the role of the pacemaker, nerves, the medulla of the brain and epinephrine (adrenaline) Explain the relationship between the structure and function of arteries, capillaries and veins State that blood is composed of plasma, erythrocytes, leucocytes (phagocytes and lymphocytes) and platelets State that the following are transported by the blood: nutrients, oxygen, carbon dioxide, hormones, antibodies, urea, heat. 1 Assessment statements from: Online IB Biology Subject GuideOnline IB Biology Subject GuideCommand terms:

Hands-only CPR. Your blood has oxygen in it – but it is not getting to the brain and other organs. Hands-only CPR keeps the blood flowing until help arrives with the Automatic External Difibrilator (AED). The electrical signal is needed to re-start the heart, and we’ll learn why this is in a little while. Call for help. Push hard and fast to the beat of Stayin’ Alive. Don’t stop until help arrives. Learn more here:

Data practice: CPR survival rates. Get started early to save a life! These data compare compression-only CPR with conventional CPR: neurologically favourable one-month survival. Population: bystander-assisted patients, transferred to hospital by ambulance. Japan – Compression-only n=20,707 Conventional CPR n= 19,328 1.Compare survival rates of compression-only CPR with conventional CPR in all cases (top graph). 1.Describe the effect of increasing time to start CPR on survival of patients in cases of cardiac origin. 2.Calculate the difference in survival between hands- only CPR and conventional CPR in cases of non- cardiac origin after 7-8 minutes. 3.Compare survival rates between cases of cardiac and non-cardiac origin. Suggest a reason for the differences. Data from:

Stephen Taylor

Stephen Taylor

Stephen Taylor

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.

Stephen Taylor

Stephen Taylor

6.2.2 State that the coronary arteries supply heart muscle with oxygen and nutrients. The coronary arteries supply heart muscle with oxygen and nutrients.

Stephen Taylor

6.2.3 Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing of valves. The right atrium collects blood from the superior and inferior vena cava and the left atrium collects blood from the pulmonary veins. This blood then flows into the right and left ventricle which pump the blood into the arteries. The direction of the blood flow is controlled by the atrioventricular valves and semilunar valves. When the atria contract the blood flows through the atrioventricular valves which are open, into the ventricle. At this stage the semilunar valves are closed so the ventricle fills with blood. The ventricles then contract which causes a rise in pressure. This rise in pressure first causes the atrioventricular valves to close preventing back flow of blood into the atria. Then the semilunar valves open allowing the expulsion of blood into the arteries. As this happens, the atria start to fill with blood again. The ventricles stop contracting leading to a fall in pressure which causes the semilunar valves to close, preventing back flow of blood from the arteries. When the ventricular pressure drops below the atrial pressure the atrioventricular valves open again and the cycle repeats. Summary: Atria collect blood from veins. Atria contract, atrioventricular valves open. Blood is pumped into ventricles. Ventricle contracts, atrioventricular valves close and semilunar valves open. Blood is pumped into arteries, semilunar valves close. Cycle repeats.

6.2.3Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing of valves. Diastole – Heart muscle is relaxed, this is called diastole – No pressure in heart chambers – Blood tries to flow back into the heart but closes the semi- lunar valves – Both atria fill with blood returning to the heart in the veins – Right atria fills with blood returning in the vena cava from the body tissues (deoxygenated) – The atrio-ventricular valves are still closed and the atria fills up – When the pressure in the atria is greater than the pressure in the ventricles, the atrioventricular valves will open

6.2.3Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing of valves Atrial systole – Both the atria contract together – The muscles of the atria contract – Volume of the atria reduces – Pressure of blood increases – Blood flows into the ventricle, filling this chamber and causing the ventricle wall to stretch

6.2.3Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing of valves Ventricular systole – The ventricle contracts (systole—think sieze=systole) – The pressure increases in the ventricle – The atrio-ventricular valve closes – The pressure rises further – Pressure in the ventricle is greater than the artery, semi-lunar valve opens – Blood pulses into the arteries

Stephen Taylor

Stephen Taylor

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). The heart muscle can contract by itself, without the stimulation of a nerve. This is called myogenic muscle contraction. The region that initiates each contraction is found in the wall of the right atrium and is called the pacemaker (Sinoatrial Node). Every time the pacemaker sends out a signal, a heartbeat results. The pacemaker is under the influence of nerves and adrenaline. One nerve (Cranial Nerve) carries messages from the medulla of the brain to the pacemaker and speeds up the beating of the heart. Another nerve (Vagus Nerve) carries messages from the medulla of the brain to the pacemaker and slows down the beating of the heart. Finally, adrenaline (epinephrine) is carried by the blood and once it reaches the pacemaker it signals it to increase the beating of the heart. Summary: Heart muscle can contract by itself (myogenic muscle contraction). Pacemaker (Sinoatrial Node). initiates contractions. One nerve (Cranial Nerve) carries messages from the brain to the pacemaker to speed up the beating of the heart. One nerve (Vagus Nerve) carries messages from the brain to the pacemaker to slow down the beating of the heart. Adrenaline signals the pacemaker to increase the beating of the heart.

Stephen Taylor Outline the control of the heartbeat in terms of myogenic muslces contraction, the role of the pacemaker, nerves, the medulla of the brain and epinephrin (adrenaline)

Stephen Taylor

Stephen Taylor (Answer on next slide)

Answer! The right ventricle has less muscle than the left ventricle because the pressure on the right side is 25% less. With less pressure, the heart needs less muscle to pump the same amount of blood. The left ventricle is thicker that the right ventricle because it pumps blood to most of the body whiles the right ventricle only pumps blood to the lungs. Pressure of blood in the aorta is high so the left ventricle has to generate more pressure while in the right ventricle the pressure of the pulmonary artery is not as high.

6.2.5 Explain the relationship between the structure and function of arteries, capillaries and veins. Arteries – Arteries have a thick outer layer of longitudinal collagen and elastic fibers to avoid leaks and bulges. They have a thick wall which is essential to withstand the high pressures. They also have thick layers of circular elastic fibres and muscle fibres to help pump the blood through after each contraction of the heart. In addition the narrow lumen maintains the high pressure inside the arteries.

6.2.5 Explain the relationship between the structure and function of arteries, capillaries and veins. Veins – Veins are made up of thin layers with a few circular elastic fibres and muscle fibres. This is because blood does not flow in pulses and so the vein walls cannot help pump the blood on. Veins also have thin walls which allows the near by muscles to press against them so that they become flat. This helps the blood to be pushed forwards towards the heart. There is only a thin outer layer of longitudinal collagen and elastic fibres as there is low pressure inside the vein and so little chance of bursting. Finally, a wide lumen is needed to accommodate the slow flowing blood due to the low pressure.

6.2.5 Explain the relationship between the structure and function of arteries, capillaries and veins Capillaries – Capillaries are made up of a wall that is only one cell layer thick and results in the distance for diffusion in and out of the capillary being very small so that diffusion can occur rapidly. They also contain pores within the their wall which allow some plasma to leak out and form tissue fluid. Phagocytes can also pass through these pores to help fight infections. In addition, the lumen of the capillaries is very narrow. This means that many capillaries can fit in a small space, increasing the surface area for diffusion.

Stephen Taylor Explain the relationship between the structure and function of arteries, capillaries, and veins

6.2.5 Explain the relationship between the structure and function of arteries, capillaries and veins. Summary: – Arteries: Thick outer layer of longitudinal collagen and elastic fibres prevents leaks and bulges. Thick wall withstands high pressure. – Thick layers of circular elastic fibres and muscle fibres to pump blood. Narrow lumen to maintain high pressure. – Veins: Thin layer with few circular elastic fibres and muscle fibres as blood does not flow in pulses. Thin walls so that nearby muscles can help push blood towards the heart. Thin outer layer of longitudinal collagen and elastic fibers as pressure is low. Wide lumen to accomodate the slow flowing blood. – Capillaries: Wall is one cell layer thick so distance for diffusion is small. Pores allow plasma to leak out and form tissue fluid. Phagocytes can also pass through pores. Very narrow lumen so that many can fit in a small space.

Fargo! Keep it simple! ArteryCapillaryVein Thick wallWall is 1 cell thickThin walled No exchangesAll exchanges occur hereNo exchanges No internal valves Have internal valves High internal pressureLow internal pressure Narrow lumen Wide lumen Moves blood away from heart Moves blood from arteries and transports blood to veins Takes blood back to heart

6.2.6 State that blood is composed of plasma, erythrocytes, leucocytes (phagocytes and lymphocytes) and platelets. ErythrocyteRed blood cell, transports oxygen Leukocyte White blood cells, or leukocytes (also spelled "leucocytes") are cells of the immune system involved in defending the body against both infectious disease and foreign materials. --Lymphocyte Type of white blood cell in the vertebrate immune system. Under the microscope, lymphocytes can be divided into large lymphocytes and small lymphocytes. Large granular lymphocytes include natural killer cells (NK cells). Small lymphocytes consist of T cells and B cells. Both are lymphocytes, a subclass of white blood cell. The t cells are mainly used in identifying antigens and releasing chemicals which attack macrophages (big immune cells which 'eat' antigens), to destroy the antigen. b cells are used in the production of antibodies. when they encounter a new antigen, plasma cells and memory cells are formed from the division of a b cell. the memory cell remembers the antigen and which antibody to use, while the plasma cell makes the antibodies to fight a particular antigen or class of antigens --Phagocyte Cells that protect the body by ingesting (phagocytosing) harmful foreign particles, bacteria, and dead or dying cells. Platelets Platelets, or thrombocytes are small, disk shaped clear cell fragments (i.e. cells that do not have a nucleus), 2– 3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days. Platelets are a natural source of growth factors. They circulate in the blood of mammals and are involved in hemostasis, leading to the formation of blood clots. Plasma pale-yellow liquid component of blood that normally holds the blood cells in whole blood in suspension. It makes up about 55% of total blood volume.

Fargo…keep it simple ComponentDescription PlasmaLiquid portion of blood ErythrocytesRed blood cells (carry oxygen and carbon dioxide) LeucocytesWhite blood cells (Phagocytes and lymphocytes) T cells are necessary for identifying antigens B-cells are used in the production of antibodies (proteins) **Antigen—a substance that invokes an immune response. PlateletsCell fragments (assist in blood clotting)

6.2.7 State that the following are transported by the blood: What is transportedWhat it is or does NutrientsGlucose, amino acids, etc. OxygenReactant needed for aerobic cell respiration Carbon dioxideCO 2 and Water are products of aerobic cell respiration. CO 2 is a waste product HormonesTransported from gland to target cells AntibodiesProtein molecules involved in immunity UreaNitrogenous waste (Filtered out of the blood by kidneys) HeatSkin arterioles (smallest artery) can change diameter in order to gain or lose heat.