UNIT 9 Circulatory Systems Flashcards
Where is blood pumped
blood is pumped away from the heart in arteries
and returns to the heart in veins
Describe how blood is transported from the vena cava to the lungs. [4]
(blood) enters heart at right atrium;
then atrium contracts ;
[correct ref to atrioventricular valve ;]
then to right ventricle ;
then ventricle contracts ;
[correct ref to semi-lunar valves ;]
then pulmonary artery to lungs ;
How may the activity of the heart be monitored?
ECG - electrocardiogram, can measure the electrical signal from the heart to see if it is contracting in a healthy rhythm,
pulse rate - measuring beats per minute or blood pressure,
and listening to
sounds of valves closing - using a stethoscope you can listen for if the valves are opening and closing correctly
Where do veins transport blood?
Veins transport blood TOWARDS the heart
Where do arteries transport blood?
Remember A-A
Which blood vessel has a high carbon dioxide concentration, a low oxygen concentration and a
high blood pressure?
Arteries transport blood AWAY from the heart
Pulmonary artery
What do coronary arteries/veins do?
Supply oxygen, nutrients & remove carbon dioxide from the heart
Whats the largest vein in the body?
blood vessel w/ the largest lumen
Vena cava
Largest artery in the body?
& What is the circulatory system? Separated by? What does that do?
Aorta
: a system of blood vessels with a pump and valves to ensure
one-way flow of blood
The two sides of the heart are separated by a muscle wall called the septum,
septum separates the two sides of the heart and so prevents mixing of oxygenated and deoxygenated blood
When labelling, your left is the heart’s ___?
Right
What are the atria? Receive ___ from the ____?
Upper chambers of the heart
Reveive blood from veins
What are ventricles?
What do they do?
Do they have thicker muscle walls than atria? Why?
Ventricles = lower chambers of the heart
Push blood out towards arteries
ventricles have thicker muscle walls than the atria as they are pumping blood out of the heart and so need to generate a higher pressure
basic function of all valves?
Valves prevent blood from flowing backwards
How many sets of valves in the heart?
Called?
Separate the ____ from the ____?
Name of valve on right? On left?
Two sets of valves in the heart:
The atrioventricular valves separate the atria from the ventricles
The valve on the right side of the heart is called the TRICUSPID and the valve on the left side is called the BICUSPID
Valves pushed open when?
When ventricles contract, they are … to …?
These valves are pushed open when the atria contract
but when the ventricles contract they are pushed shut to prevent blood from flowing back into the atria
Semilunar valves found in … that…?
The semilunar valves are found in the two blood arteries that come out of the top of the heart
Unusual in that - how many arteries contain valves?
only two arteries in the body that contain valves
When do the valves open? Shut to…?
These valves open when the ventricles contract so blood squeezes past them out of the heart, but then shut to avoid blood flowing back into the heart
Muscle walls of ___ thicker than ___?
Muscle walls of VENTRICLES (!!) thicker than ventricles
Which ventricle wall is thicker?
Why?
LEFT ventricle’s wall thicker
; has to pump blood at high pressure around the entire body, whereas the right ventricle is pumping blood at lower pressure to the lungs
Thicker walls do what?
Can push blood further
What does our circulatory system allow us to do?
Allows us to transport nutrients, waste products and gases (mainly focus on transport of gases)
PULMONARY circulation
Where is deoxygenated blood pumped? What happens to it?
What side of the heart receives deoxygenated blood?
Deoxygenated blood is pumped to the lungs [from the right side of the heart] where it is oxygenated and carbon dioxide is removed
right side of the heart receives deoxygenated blood from the body, pumps it to the lungs
SYSTEMIC circulation
Where does oxygenated blood flow back to? Where is oxygenated blood pumped?
Side of the heart? From? To?
Oxygenated blood flows back to the heart [left side, from the lungs] and is pumped to body cells
Respectively, where does oxygen & carbon dioxide diffuse into?
When then does the blood do?
Oxygen diffuses into body cells and carbon dioxide diffuses into the blood. The blood then flows back to the heart to repeat the cycle.
Known as…
Because?
double circulatory system as there are TWO circuits
[The coronary arteries]
The heart is made of…. that need…. to…?
Supplied by….?
The heart is made of [muscle tissue]/MUSCLE CELLS that need their own supply of blood to deliver oxygen, glucose and other nutrients and remove carbon dioxide and other waste products
The blood is supplied by the coronary arteries
What happens if a coronary artery becomes partially or completely blocked by fatty deposits called ‘plaques’?
If a coronary artery becomes partially or completely blocked by fatty deposits called ‘plaques’ (mainly formed from cholesterol),
the ARTERIES are NOT AS ELASTIC as they should be and so cannot stretch to accommodate the blood which is being forced through them - leading to coronary heart disease
Partial blockage does? Leads to?
Partial blockage of the coronary arteries (bc it’s narrowed) creates a restricted blood flow to the cardiac muscle cells and results in severe chest pains called angina
Complete blockage means? Leads to?
Complete blockage means cells in that area of the heart will not be able to respire and can no longer contract, leading to a heart attack
How can someone’s diet lead to coronary heart disease?
A diet too high in saturated fat + cholesterol
What is plague?
Mainly a build up of cholesterol + white blood cells
6 Risk Factors for CHD
- Poor diet
Eating more saturated fat increases cholesterol levels, increasing the chance of the buildup of fatty plagues
- Stress
When under stress, hormones produced can increase blood pressure, increasing the chance of a blockage in the coronary arteries
- Smoking
Nicotine in cigarettes will cause blood vessels to become narrower, increasing blood pressure which will cause the buildup of fat globules. If this occurs in the coronary artery, this will cause CHD
- Genetic Predisposition
Studies show people w/ a history of CHD in their family are more likely to develop it themselves, suggesting it partly has a genetic basis
- Age
The risk of developing CHD increases as you get older
- Gender
Males are more likely to develop coronary heart disease than females
How can you reduce the risks of developing coronary heart disease?
Think risk factors [typical of cancer for e.g]
- Quit smoking
- Diet - reduce animal fats & eat more fruits and veges - this will reduce cholesterol levels in the blood and help with weight loss if overweight
- Exercise regularly - again, this will help with weight loss, decrease blood pressure and cholesterol levels and help reduce stress
Circulatory systems in Fish - how many chambers & what kind of circulation?
Fish have a two-chambered heart and a single circulation,
meaning for every one circuit of the body, the blood passes through the heart once
Describe what is meant by the term double circulation.
blood flows through heart twice, for one (complete) circuit
Circulatory systems in Mammals - how many chambers & what kind of circulation?
Mammals have a four-chambered heart and a double circulation,
meaning for every one circuit of the body, the blood passes through the heart twice
Advantages of Double Circulation
➡ circulatory system very efficient as oxygenated and deoxygenated blood do not mix, maintains steeper concentration gradient, increasing rate of diffusion
➡ Blood travelling through small capillaries in the lungs loses a lot of PRESSURE given by the pumping of the heart, meaning it CANNOT travel as FAST
By returning blood to the heart after going through lungs, its pressure can be RAISED AGAIN before sending it to the body, meaning cells can be supplied w/ the oxygen and glucose needed for respiration FASTER and more frequently
How to investigate the effects of exercise on heart rate?
Record the pulse rate at rest for a minute
Immediately after they do some exercise, record the pulse rate every minute until it returns to the resting rate
This experiment will show that during exercise the heart rate increases and may take several minutes to return to normal
Investigating Effect of Physical Activity on Heart Rate
Breathing rate measured by? Heart rate?
When?
Results presented how?
Breathing rate can be measured by counting the number of breaths per minute, while heart rate can be measured by taking a pulse (bpm)
Either can be measured before and after an activity is performed and the results plotted on a bar chart
Important to…
important that the time over which breathing rate and pulse rate are measured is consistent, and that individuals fully recover (rest) before starting a new activity
Why?
Increased physical activity results in an increased heart rate and breathing rate
Heart rate remains high for a period of time after physical has stopped, there is a gradual return to resting heart rate
Why does the heart rate increase?
So that sufficient blood is taken to the working muscles to provide them with enough nutrients and oxygen for increased respiration
+ allows for waste products to be removed at a faster rate
Following exercise, the heart continues to beat faster for a while - because…?
to ensure that all excess waste products are removed from muscle cells
What else is likely?
also likely that muscle cells have been respiring anaerobically during exercise and so have built up an oxygen debt
needs to be ‘repaid’ following exercise and so the heart continues to beat faster to ensure that extra oxygen is still being delivered to muscle cells
What is extra oxygen used for?
extra oxygen is used to break down the lactic acid that has been built up in cells as a result of anaerobic respiration
Functioning of the heart
Deoxygenated blood ➡ ____ atrium via _______
____ atrium fill w/ blood ➡ heart gives little beat ➡ blood pushed thru _____ valve
INTO the _____ ventricle.
Deoxygenated blood coming from body flows into RIGHT atrium via the VENA CAVA
Once the RIGHT atrium has filled with blood the heart gives a little beat and the blood is pushed through the TRICUSPID (atrioventricular) valve into the RIGHT ventricle
Now, in right ventricle
what happens? Blood pushed to what artery through ____? Preventing?
The walls of the ventricle contract and the blood is pushed into the pulmonary artery through the semilunar valve which prevents blood flowing backwards into the heart
Where does blood travel?
Moves through?
What takes place here?
The blood travels to the lungs and moves through the capillaries past the alveoli where gas exchange takes place
(this is why there has to be LOW pressure on RIGHT side of the heart – blood is going directly to capillaries which would burst under higher pressure)
Oxygenated blood returns where? Via?
Passes through what valve into what ventricle?
Oxygen-rich blood returns to the left atrium via the pulmonary vein
It passes through the bicuspid (atrioventricular) valve into the left ventricle
What do the ventricles do now? Helped by their…? Going…?
The semilunar valve in the aorta does what?
The thicker muscle walls of the ventricle contract strongly to push the blood forcefully into the aorta and all the way around the body
The semilunar valve in the aorta prevents the blood flowing back down into the heart
Blood Vessels - Arteries, Veins & Capillaries
- ARTERIES
⭐ Carry blood at ____ pressure _____ the heart
⭐ Carry _____ blood (except?)
⭐ Have ___ muscular walls containing ____
⭐ Have… lumen
⭐ Speed of flow is _____
⭐ Carry blood at high pressure away from the heart
⭐ Carry oxygenated blood (other than the pulmonary artery)
⭐ Have thick muscular (elastic) walls containing elastic fibres; can stretch, felt as pulse
⭐ Have a narrow/small lumen
⭐ Speed of flow is fast
- VEINS
⭐ Carry blood at ____ pressure _____ the heart
⭐ Carry _____ blood (except?)
⭐ Have ___ walls
⭐ Have… lumen
⭐ Contain ____
⭐ Speed of flow is _____
⭐ Carry blood at low pressure towards the heart (squeezed back towards the heart by the action of the skeletal muscles)
⭐ Carry deoxygenated blood (other than the pulmonary vein)
⭐ Have thin walls bc lower pressure
⭐ Have a large lumen bc lower pressure
⭐ Contain valves (preventing backwards flow of blood)
⭐ Speed of flow is slow
- CAPILLARIES (that form a huge network linking arteries and veins)
⭐ Carry blood at ____ pressure within ____
⭐ Carry …
⭐ Have walls that are…
⭐ Walls are ____
⭐ Speed of flow is _____
⭐ Carry blood at low pressure within tissues
⭐ Carry both oxygenated and deoxygenated blood (allows blood to access every cell in body)
⭐ Have walls that are one cell thick, reducing diffusion distance
⭐ Have ‘leaky’ walls
⭐ Speed of flow is slow
Main Blood Vessels in the Body
Arteries ➡ Arterioles ➡ capillaries ➡ venules ➡ veins
Blood is carried away from the heart and towards organs in arteries
These narrow to arterioles and then capillaries as they pass through the organ
The capillaries widen to venules and finally veins as they move away from the organs
Veins carry blood back toward the heart
ORGANS, TOWARDS, AWAY
- Heart.
Towards organ: vena cava, pulmonary vein
Away from organ: aorta, pulmonary artery
- Lungs
Towards: pulmonary artery
Away: pulmonary vein
- Kidney
Towards: Renal artery
Away: Renal vein
Structure & Function of Blood Vessels
Adaptations -
- Arteries
⭐ Have thick muscular walls containing elastic fibres to withstand the high pressure of blood and maintain the blood pressure as it recoils after the blood has passed through
⭐ Have a narrow lumen to maintain high pressure
- Veins adaptations
⭐ Have a large lumen as blood pressure is low, LOW resistance to blood flow
⭐ Contain valves to prevent the BACKFLOW of blood as it is under low pressure
- Capillaries adaptations
⭐ Have walls that are one cell thick so that substances can easily diffuse in and out of them
⭐ Have ‘leaky’ walls so that blood plasma can leak out and form tissue fluid surrounding cells
Arterioles & venules
Form from…? What are they?
As arteries divide more as they get further away from the heart, they get narrower
The narrow vessels that connect arteries to capillaries are called arterioles
Veins also get narrower the further away they are from the heart
The narrow vessels that connect capillaries to veins are called venules
main blood vessels to and from the liver
The hepatic artery brings oxygenated blood from the heart to the liver
The hepatic vein brings deoxygenated blood from the liver back to the heart
The HEPATIC PORTAL VEIN transports deoxygenated blood from the gut to the liver
Components of Blood
Blood consists of red blood cells, white blood cells, platelets and plasma
Components of blood - structure
- Red blood cells
Biconcave discs containing no nucleus but plenty of the protein haemoglobin
- White blood cells
Large cells containing a big nucleus, different types have slightly different structures & functions
; usually round in shape
- Platelets
Fragments of cells
- Plasma
Straw coloured/pale yellow liquid
Components of Blood: Function
- Red blood cells
transport oxygen around the body from the lungs to cells which require it for aerobic respiration
/ “carry oxygen”
They carry the oxygen in the form of oxyhaemoglobin
- White blood cells
defend the body against infection by pathogens by carrying out phagocytosis and antibody production
/ “identify and destroy foreign material”
- Platelets
involved in helping the blood to clot
- Plasma
important for the transport of carbon dioxide, digested food (nutrients), urea, mineral ions, hormones and heat energy
+ RBCs, WBCs
Blood Clotting -
What are platelets?
fragments of cells which are involved in blood clotting
& forming scabs where the skin has been cut or punctured
What does blood clotting prevent?
Blood clotting prevents [continued/significant] bleeding from wounds or bruising & stop pathogens entering the bloodstream when scab forms
What does scab formation do?
Remains until…?
Scab formation seals the wound with an insoluble patch that prevents entry of microorganisms that could cause infection
It remains in place until new skin has grown underneath it, sealing the skin again
White blood cells are…?
How many types? What?
part of the body’s immune system, defending against infection by pathogenic microorganisms
There are two main types, phagocytes and lymphocytes
phagocytes
Carry out phagocytosis by engulfing foreign material and digesting the pathogens by releasing digestive enzymes to destroy it
How do phagocytes detect pathogens?
Phagocytes have a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells
Phagocytes easily recognised under the microscope by…?
⭐ their multi-lobed nucleus
⭐ & their granular cytoplasm
Lymphocytes
Produce antibodies to destroy pathogenic cells by tagging foreign material/pathogens for destruction,
as well as antitoxins to neutralise toxins released by pathogens
Lymphocytes easily recognised under the microscope by…?
⭐ large round nucleus which takes up nearly the whole cell
⭐ their clear, non-granular cytoplasm
Conversion of Fibrinogen - how blood clots, scab formation
PLATELETS arrive to stop bleeding ➡
REACTIONS in blood plasma:
PLATELETS release chemicals ➡
Soluble fibrinogen proteins convert into insoluble fibrin
Form insoluble mesh across wound ➡
Trapping red blood cells, forming a clot ➡
Clot dries, now scab
Protects wound from bacteria entering!
When skin is broken (i.e. wound), platelets arrive to stop the bleeding
A series of reactions occur within the blood plasma
Platelets release chemicals that cause soluble fibrinogen proteins to convert into insoluble fibrin and form an insoluble mesh across the wound, trapping red blood cells and therefore forming a clot
The clot eventually dries and develops into a scab to protect the wound from bacteria entering
What causes your blood to clot?
Why is this important?
Platelets cause your blood to clot
Inportant to stop bleeding or bruising & stop pathogens entering the bloodstream
Blood clotting involves the conversion of the protein fibrinogen to fibrin to form a mesh. Explain why this is required for blood clotting.
Fibrinogen is soluble in blood. It is converted by an enzyme to fibrin when wounded. Fibrin is insoluble in blood, forcing it out of solution and forming a clot.
correct sequence for blood being pumped from the heart to the lungs?
right atrium → right ventricle → pulmonary artery
example where all three blood vessels carry oxygenated blood?
aorta,
pulmonary vein,
renal artery
Blood from vena cava to…?
Pulmonary artery
Which heart valves are open and which are closed when blood passes OUT of the RIGHT ventricle towards the lungs?
tricuspid valve closed, semi-lunar valve open
Arteries oxygenated except…
pulmonary artery
Veins deoxygenated except…
pulmonary vein
sequence of organs through which urea passes as it travels from where it is
produced to where it is removed from the blood?
liver → heart → lungs → heart → kidneys
What describes the aortic (semi-lunar) and bicuspid (mitral) heart valves when the left ventricle is
relaxing?
Semi-lunar (aortic) valve => CLOSED
Bicuspid (mitral) => OPEN
structure that prevents backflow of blood
from pulmonary artery to right ventricle
semilunar valve
Explain the change in pulse rate between 2 minutes and 3 minutes after the recordings
started.
adrenaline stimulates increase in, heart/pulse, rate ;
increase in blood, carbon dioxide (concentration)/acidity, detected ;
nerves stimulate heart to beat faster ;
muscles require more energy/muscles are doing more work ;
(rate of aerobic) respiration increases ;
blood vessel that carries
oxygenated blood away from the heart
aorta
Sometimes surgery is required to treat coronary heart disease.
Describe one named example of surgery that can treat coronary heart disease.
stent ;
small mesh tube inserted in artery ;
opens / supports, (narrow/weak) artery ;
Explain why blood pressure must decrease in the arterioles before entering the
capillaries. [2]
high pressure would, burst/ damage, capillaries /AW ;
capillaries / capillary walls, are, thin/ fragile/weak / delicate/ narrow ;
wall/ lining, (of capillary) is one cell thick ;
Explain how blood returns to the heart in the femoral vein against the pull of gravity. [3]
contraction of muscles (in the legs)/ movement of legs ;
pushing/ squeezing, blood ;
(semi-lunar) valves, ensure blood flows towards heart/ prevents backflow ;
explain how the structure of an artery is related to its function.
thick wall ;
withstands (blood) pressure ;
elastic (tissue) ;
stretches to allow blood surge
State what could cause the lactic acid concentration in the blood to increase to
200 mg dm–3
anaerobic respiration ;
oxygen debt;
State two effects that a concentration of adrenaline of 100 ng dm–3 might have on the
body.
increase in, blood pressure or heart rate/ pulse/ stroke volume;
increase in breathing rate;
Describe the role of the liver in regulating the concentration of glucose in the body. [3]
(liver cells respond) to insulin if blood glucose is high ;
(enzymes / liver cells) conversion of glucose to glycogen ;
glycogen is stored (in the liver) ;
Describe the role of phagocytes in defence against disease
engulf/ ingest/AW, bacteria/ pathogens / dead cells ; A phagocytosis
into vacuole ;
use enzymes ;
to digest bacteria / pathogens ;
Describe the roles of white blood cells in tissue rejection [3]
recognition tissue is foreign ;
lymphocytes release antibodies ;
phagocytes / lymphocytes, cause tissue destruction ;
Amino acids are processed by the liver.
Describe this process. [3]
deamination ;
(part of excess) amino acids converted to urea ;
(part of) amino acid converted to ammonia ;
ammonia converted to urea ;
(rest of) amino acid molecule, releases energy ;
Outline how antibodies protect the body
attach to, bacteria / viruses / pathogens ;
cause them to, aggregate / stick together / AW ;
stop them spreading ;
Suggest how the activity of thrombin was determined.
time taken for fibrinogen to disappear ;
