organisational complexity of the human circulation system
TRANSCRIPT
Organisational Complexity of the Human
Circulation System
You need to know……
Lymphatic system ABO blood groups
Composition of blood Rhesus Factor Blood pressure
Pulse
Coronary arteries & veins supplying the heart muscle
Role of muscle and valves in heart and blood vessels
Structure of the heart & path of blood path through it
Pulmonary & systemic circulation and portal systems
Arteries, arterioles, veins, venules and capillaries
The way a closed circulation system is organised
Two types of Circulation System
Heart pumps blood into vessels that are open ended ……eg in Insects
Blood remains in a continuous system of blood vessels…..eg in Humans
Open Circulation Systems
Closed Circulation Systems
Advantages of a Closed Circulation System
1. Blood can be pumped faster
2. Blood flow rate to different organs can be changed
Therefore nutrients can be delivered faster to cells allowing the organism to be more active
For example blood flow can be increased to the leg mucles when running
Main parts of Human Circulation System
1. Heart
2 Blood Vessels
Arteries
3. Blood
Veins
Capillaries
Arterioles
Venules
Main Blood VesselsArteries
Veins
Carry blood away from the heart
Carry blood under high pressure
Thick elastic wall
Narrow lumen
Carry blood towards the heart
Carry blood under low pressure
Have valves to prevent backflow
Thin wall
Wide lumen
Smaller Blood vessels
Arterioles
Venules
Arterioles connect arteries and capillaries
venules connect capillaries to the veins
Capillaries
The thin wall allows easy exchange of materials with cells
Tiny blood vessels linking arterioles and venules
Blood vessels under the microscope
Thick Wall
Arteries Veins
Narrow lumen
Thin Wall
Wide lumen
Have valves to prevent backflow
Collagen
Muscle andElastic fibres
Endothelium
Lumen
1 Give three differences between arteries and veins
2 What is the function of valves in veins
3 Name the blood vessels that connect capillaries and veins
4 Give one advantage of a closed circulation system
Muscle expand to allow increased blood flow through the vessel
Elastic fibres bring the blood vessel back to shape
Valves prevent backflow
Location Between the lungs, slightly to the left side of the thorax, above the diaphragm
Function To pump blood around the body
StructureA hollow structure made of cardiac muscle, surrounded by a double membrane
Role of Heart Muscle
1. The heart wall is made of Cardiac Muscle
2. Contraction of the cardiac muscle drives blood around the body
3. Cardiac Muscle does not fatigue
Human Two-Circuit Circulation
Pulmonary Circuit
Systemic Circuit
Pumps to the head, trunk and limbs and back to the heart
Pumps to the lungs and back to the heart
Advantages of a Double Circulation System
1. Separation of oxygen rich and oxygen poor blood
2. Blood pressure can be kept high
Pathway of blood Around Body
Portal systems
Hepatic Portal System
A blood pathway that begins and ends in capillaries
Connects the stomach and intestines with the liver
1 Name the blood vessel that connects the digestive system with the liver
2 Distinguish between the systemic the pulmonary blood circuits
3 Give one advantage of a double circulation system
Vena Cava
Right Atrium
Tricuspid Valve
Right ventricle
Left Ventricle
Left Atrium
Pulmonary Vein
Aorta
Pulmonary Artery
Bicuspid Valve
Septum
Cardiac muscle
Semi Lunar Valves
Blood pathway through heart
Right Atrium
Tricuspid valve
Right ventricle
Left atrium
Bicuspid valve
Left ventricle
Vena Cava
Pulmonary arteryAorta
Pulmonary vein
Role of Valves
Semi Lunar valves
Tricuspid valve
Bicuspid Valve
Prevent backflow into heart
Prevents backflow into left atrium
Prevents backflow into right atrium
Blood supply to the heart wall
Coronary arteries
Cardiac muscle is supplied with blood by the coronary arteries. These branch from the aorta just above the semi lunar valves ot the aorta
Coronary veins
Drain blood from heart wall into the right atrium
1 Where does blood go immediately after leaving the right ventricle ?
2 Name the blood vessel that enters the right atrium
3 What is the function of the coronary arteries ?
4 State the exact location of the opening into the coronary arteries
2 Name the valve between the left atrium and left ventricle
( Higher level material on heartbeat control in section 3.2.4 )
The heart beat consists of alternate contraction and relaxation of the cardiac muscle
The heart beat is controlled by the pacemaker in the right atrium. This sends an electrical signal to the cardiac muscle
The heart beat sound is caused by the closing of the heart valves
Pulse
A wave of expansion passes down the walls of arteries following a contraction of the left ventricle. The elastic fibres in the artery walls then bring about a contraction of the artery wall.
Average pulse rate is 72 beats per minute
The alternate expansion and contraction of arteries is called a pulse
Blood Pressure
As blood passes from arteries to veins pressure drops
Blood pressure is measured with an instrument that records the pressure it takes to stop the blood flow in an artery of the upper arm
Pressure in the due the to contraction of the ventricles which forces blood into the arteries
Effect of smoking on the circulation system
2. CO2 reduces the amount of O2 carried by the blood
1. Nicotine increases the heart rate and blood pressure
These puts a bigger workload on the heart
This reduces energy levels
3. Other chemicals in tobacco
Increase the chance of clots
Effect of Diet on the circulation system
High salt intake
High intake of fat causes a build up of cholesterol
Cholesterol may block arterioles and lead to stroke or heart attack
Raises blood pressure which can cause heart attack
Effect of Exercise on the circulation system
Exercise increases our ability to transport oxygen
Exersise strengthens the heart
This improves circulation
This gives increased energy levels
1 What causes the blood to be under pressure in the arteries ?
2 Explain the term Pulse
3 What controls the rate of heartbeat
4 Give two harmful effects of cigarette smoke on the circulation system
5 Explain why salt can have a negative effect on the circulation system
Lymphatic System
A secondary transport system consisting of one way system of vessels that collects and returns excess tissue fluid to blood system
1. Lymph vessels
2. Lymph Nodes
3. Lymph
Structure
Lymphatic System Functions
1. Collect tissue fluid and return it to the blood system
2. Fight Infection by
3. Transport digested fat away from intestine
(a) Filtering out microorganisms in the lymph nodes
(b) Destroying microorganisms by antibody production
(c) Mature and store lymphocytes
Plasma Liquid part of the blood
Red Blood Cells
White Blood Cells
Platelets
Composed of mainly water which acts as a transport medium for the cells and dissolved substances
Plasma
Red Blood Cells
White Blood Cells
Platelets
Carry Oxygen
Fight Infection
Clotting
Higher level
material in sec 3.2.3
Composed of mainly water which as a transport medium for the cells and dissolved substances
Digestion products ….Glucose, amno acids, Fatty acids, glycerol, minerals and vitamins
Waste….Carbon dioxide, urea
Hormones….eg Insulin
Antibodies
It is essential to know a persons blood group for safe blood transfusions
A
B
AB
O
Group
Another blood grouping system
Involvs antigen called factor D on the red cells
If you have factor D you are Rhesus positive or Rh+
If you haven’t you are Rhesus negative or Rh-
Rhesus factor is important in pregnancy as problems may arise in second and further pregancies if the mother is
Rh - and the baby is Rh +
1 Name the three main parts of the Lymphatic System
2 Name three substances dissolved in plasma
3 Name a blood grouping system other than the ABO System
4 What is the function of white blood cells
5 Give two functions of the Lymphatic System
See PowerPoint in section 3.2.3 for for higher level material on blood cells
See PowerPoint in section 3.2.4 for higher level material on heartbeat control