Topic 9 Flashcards
The circulatory system
A system of blood vessels with a pump and valves to ensure one-wat flow circulation
Single circulation of fish
Blood passes through the heart ONCE per full cycle
The double circulation of mamals
Blood passes through the heart TWICE each full circuit
What does the circulatory system consist of
A pump (heart)
Blood vessels
Valves -> allows ONE directional flow of blood
Which are the three types of vessels
Capillaries
Veins
Arteries
Advantages of double circulatory system
- Blood travels at a higher pressure
- Blood pumped much fastee -> delivers more oxygen to cells
-> this is important a mammals use a lot of oxygen in mantaining body temperatures
How is blood plumped through blood vessels
In mammals, blood is plumped away from the heart arteries and returns to the heart in veins
Three ways of monitoring the heart rate
- Listening to the valves opening and closing
- ECG
- Measuring the pulse rate
Listening to the valves opening and closing
The opening and closing of heart valves makes a ‘lub dub’ sound
-> A stethoscope can be used to listen to heart sounds
ECG
The hearts activity is controlled by electrical impulsed
-> sensors are attatched to persons sskin that detect these electrical impulses
-> these are recorded by a machine
Measuring pulse rate
This gives an idea of how quickly the heart is beating conpared to what is expected
Why are the walls of the ventricles thicker than the walls of the atria
Because they are plumping blood to a further distance. To the lubgs or the rest of the body
Why are the walls of the left ventricle thicker than the walls of the right ventricle
Because blood is pumped at a higher pressure and more force to travel further to the whole body
What are the roles of valves
One way structure that helps seperate the chambers and prevent backflow of blood
Why does heart rate increase when you exercise?
Because muscles need more energy to sutain muscle contraction
-> therefore respiration increases so the heart has to pump more blood as more oxygen is needed for the body (muscles) for aerobic respiration
What is Coronary heart disease
A disease that affects the heart. It occurs when the coronary arteries become blocked with fatty depositis (plaques)
Risk factors for coronary heart disease (7)
Smoking
Diet
Lack of exercise
Age
Genetics
Biological sex
Stress
How cam coronary heart diseas be prevented
- a change in diet -> reduce saturated fats and salt
- no smoking
- less stressful environment
- exercising frequently
Coronary arteries
These supply the heart with blood (O2 for respiration) -> energy for muscle contraction
What happens when the coronoary arteries are blocked by plaques
Less blood reaches the heart
-> therefore there is less oxygen
-> less respiration
-> heart can’t contract efficiently
-> can lead to a heart attack
Prevention of coronary heart disease: diet
High blood pressure and high LDL cholesterol causes fatty deposits in the arteries
- Reducing salt -> reducing blood pressure
- Reducing saturated fate -> reduces cholesterol levels
- Eating lots of fruit and vegetables -> helps protect against CHD
Prevention of coronary heart disease: exercise
Regular exercise lowers blood pressure
Capillaries: function, valves, pressure of blood, lumen
Function: gas exhange aswell as nutrients and waste
Lumen: very small
Valves: NO
Pressure of blood: very low
Arteries: function, valves, pressure of blood, lumen, exceptions
Function: carry oxygenated blood away from the heart
Blood pressure: high
Lumen: small
Valves: NO
Exceptions: pulmonary arteries -> deoxygenated blood
Veins: function, valves, pressure of blood, lumen, exceptions
Function: carry deoxygenated blood back to the heart
Blood pressure: very low
Lumen: large
Valves: YES
Exceptions: pulmonary veins -> oxygenated blood
Heart: main blood vessels to.. and from..
Vena cava -> aorta
Pulmonary vein -> pulmonary artery
Lungs: main blood vessels to.. and from…
Pulmonary artery -> pulmonary vein
Kidney: main blood vessels to.. and from..
Renal artey -> renal vein
Liver: main blood vessels to.. and from..
Hepatic artery
Hepatic portal vein -> BOTH hepatic artery
Blood
Blood is a tissue that transports dissolved substabces from digestion
Blood’s 4 main components
1) blood plasma
2) red blood cells
3) white blood cells
4) platelets
Function of red blood cells
To transport oxygen around the body
- Contains heamoglobin
Role of heamoglobin in blood
It binds to oxygen in the lungs and releases oxygen at tissues
Adaptations of red blood cells
- Biconcave shape (larger surface area)
- no nucleus
White blood cells: function
Destroy/fights pathogens/diseas
Consist of Phagocytes and Lymphocytes
Phagocytes
Carry out phagocytosis -> engulf pathogens
Lymphocytes
Produce antibodies -> proteins that attatch to antigens on pathogens to destroy them
Platelets and clotting
- Small fragements of cells
Clotting:
1) blood contains fibrinogen
2) when you damage a blood vessel, it triggers fibrinogen to convert into fibrin
3) these tangle together and form a mash where RBCs and platelets become trapped
4) the blood clotting creates a barrier to pathogens and stops bleeding
+ lack of platelets can cause bruisng and excesive bleeding
What is fibrinogen
Soluble protein
What is fibrin
Insoulble fibres
Function of plasma
Pale straw with couloured liquid which carries substances in the blood
What does plasma contain? (6)
RBCs, WBCs, platelets
Soluble nutrients (eg glucose and amino acids)
Carbon dioxide
Ions
Hormones
Urea (excretion)
Role of blood clotting
Prevents blood loss and the entry of pathogens
Left ventricle
Thicker wall -> needs more muscle to pum blood around the whole body at high pressure
Right ventricles
Thinner wall -> only has to pump blood to the lungs
Ventricle walls
Are thicker than atria walls -> as atria walls only has to pump blood to ventricles
Coronary arteries
Arteries surrounding heart that supply blood
Septum
Sepertaes deoxygenated from oxygenated blood
Pulse
contractions in ventricle creates surge of blood in arteries
Haemaglobin
iron-containing protein, where the red colouring of blood comes from
The structure of arteries related to blood pressure
Small lumen - more pressure
Structure of veins realted to blood pressure
Large lumen -> lowers the pressure
How is the structure of capillaries related to their function
Capillaries have a very thin wall -> small diffusion distance
Investigating the effect of physical activity on pulse rate:
- Put 2 fingers on wrist/neck and count number of pulses in 1 min
- Take your 1 min pukse after doing physical activities
- Plot results
- Repeat 3 times for mor accuracy and caclculate average
Conclusion: pulse will increase the more intense the physical activity
