Topics I need work on Flashcards
What type of circulatory system is the heart.
Double circulatory system
Where is blood pumped away in the heart?
Aorta
Why does blood slow down at the capillaries?
Capillaries are much smaller then the arteries.
Slower movement allows for gas exchange.
How does the vein prevent blood backflow?
Has valves
What is the problem of a single circulatory system?
Blood loses a lot of pressure meaning that blood travels to organs very slowly so it cant deliver a lot of oxygen.
What is the benefit of a double circulatory system?
Because it pumps through the heart twice, blood travels faster meaning it can deliver oxygen needed to cells.
What are the heart’s 4 chambers?
Right atrium
Left Atrium
Right ventricle
Left ventricle
How is blood transferred around the body?
The vena cava brings in deoxygenated blood from the body.
The blood passes from the heart to the lungs in the pulmonary artery.
In the lungs the blood collects oxygen.
Oxygenated blood passes from the lungs to the heart in the pulmonary vein.
Oxygenated blood is pumped from the heart to the body in the aorta.
What are the veins that branch out from the aorta and spread to the heart muscle?
Coronary artery
What is the purpose of the coronary arteries?
To provide oxygen to the muscle cells of the heart.
The oxygen is used in respiration to provide the energy for contraction
What controls the resting heart rate?
The pacemaker
What controls the resting heart rate?
The pacemaker
What is the use of a artificial pacemaker?
An artificial pacemaker is a small electrical device and it corrects irregularities in the heart rate.
Describe 3 ways mitosis occurs.
Growth
Replacing cells
Repairing tissues
Explain 3 stages of the cell cycle?
Stage 1 - The cell grows, DNA is made into copies and more organelles are made.
Stage 2 - Mitosis in which the nucleus divides inside the cell
Stage 3 - The cell splits into two identical daughter cells
What are the functions of meristems in plants?
It can differentiate to any type of plant.
Some athletes train at high altitude.
Training at high altitude increases the number of red blood cells per cm3 of blood.
Explain why having more red blood cells per cm3 of blood is an advantage to an athlete
More haemoglobin. (1)
(therefore) more oxygen can be carried / transported. (1)
(for) more (aerobic) respiration of muscle (cells).
Accept more energy released for muscle (cells).
The data was collected over 15 years and 400 patients were involved.
Use information from the table above and your own knowledge to answer the following question.
A patient decides to have a mechanical valve replacement rather than a pig tissue valve replacement.
Suggest reasons for and against choosing a mechanical valve.
Reasons for: any two of the following
* Less likely to die (44% cf. 59%)
* Lower risk of death from having a second operation
* Lower risk of heart infections
* Less chance of the valve stopping working
* Longer lasting
* Doesn’t cause rejection
* Avoids religious issues of using organs from a pig or no
* Ethical issue from using part of a living organism.
Reasons against: any two of the following
* Chance of death by bleeding is increased
* Offers no advantage against clots or equal risk of blood clots
* have to take anti-clotting drugs for life
* can be noisy.
Which two blood vessels carry deoxygenated blood?
Vena cava
Compare the structure of an artery with the structure of a vein.
Arteries have a thicker layer of muscle (tissue) or veins have a thinner
layer of muscle (tissue). (1)
Arteries have a thicker layer of elastic tissue or veins have a thinner
layer of elastic tissue. (1)
Arteries have a narrower lumen or veins have a wider lumen.
Allow descriptions of ‘lumen’. (1)
Arteries do not have valves and veins have valves.
Allow only veins have valves
A patient may be fitted with an artificial pacemaker.
What condition may be treated using an artificial pacemaker?
An irregular heartbeat.
The circulatory system transports substances such as glucose and oxygen around
the body.
a. Name three other substances that the circulatory system transports around the body.
Any three from:
Carbon dioxide / CO2 (1)
Urea (1)
Protein (1)
Water / H2O (1)
Hormones / insulin
Blood is a tissue. Blood contains red blood cells and white blood cells.
Name two other components of blood.
Platelets
Plasma
A comparison is made between blood taken from an artery in the leg and blood taken from a vein in the leg.
Give two differences in the composition of the blood.
Any two from:
(artery has) more oxygen (1)
(artery has) more glucose (1)
(artery has) less carbon dioxide (1)
(artery has) less lactic acid
