11.2 The Heart (Cambridge (CIE) O Level Biology): Flashcards
Exam code: 5090
1/580Still learning
Know0
- FrontThe Mammalian Heart
Define septum.
Was this flashcard helpful?
Cards in this collection (58)
Define septum.
The muscle wall that separates the two sides of the heart and prevents the mixing of oxygenated and deoxygenated blood.
Which side of the heart receives deoxygenated blood, and where does it pump it?
The right side receives deoxygenated blood from the body and pumps it to the lungs.
Which side of the heart receives oxygenated blood, and where does it pump it?
The left side receives oxygenated blood from the lungs and pumps it to the rest of the body.
Blood is pumped away from the heart in and into the heart in veins.
Blood is pumped away from the heart in arteries and into the heart in veins.
Why does the left ventricle have a thicker muscle wall than the right ventricle?
It pumps blood at high pressure around the whole body, whereas the right ventricle pumps at lower pressure to the lungs.
Why do the ventricles have thicker walls than the atria?
They pump blood out of the heart and so must generate a higher pressure.
Define atrioventricular valves.
Valves that separate the atria from the ventricles and prevent blood flowing back into the atria.
Define semi-lunar valves.
Valves in the arteries leaving the heart that prevent blood flowing back into the ventricles.
What is the basic function of all heart valves?
To prevent blood from flowing backwards.
The two sides of the heart are separated by a muscle wall called the .
The two sides of the heart are separated by a muscle wall called the septum.
True or False?
The left ventricle has a thicker muscle wall than the right ventricle.
True.
The left ventricle pumps blood at high pressure around the whole body, so it needs a thicker wall.
True or False?
The heart muscle is supplied with blood by the coronary arteries.
True.
The coronary arteries deliver oxygen and nutrients to the heart muscle itself.
Through which vessel does deoxygenated blood enter the right atrium?
Through the vena cava.
Deoxygenated blood from the body flows into the via the vena cava.
Deoxygenated blood from the body flows into the right atrium via the vena cava.
How does blood pass from the right atrium into the right ventricle?
Through the atrioventricular valve when the atrium contracts.
Which vessel carries blood from the right ventricle to the lungs?
The pulmonary artery.
Why is blood pumped at low pressure from the right side of the heart to the lungs?
The blood goes directly to the capillaries around the alveoli, which would burst under high pressure.
Which vessel returns oxygen-rich blood to the left atrium?
The pulmonary vein.
Oxygenated blood leaves the left ventricle through the to travel around the body.
Oxygenated blood leaves the left ventricle through the aorta to travel around the body.
What is the function of the semilunar valve in the aorta?
It prevents blood from flowing backwards into the heart.
Define atrioventricular valve.
A valve between an atrium and a ventricle that prevents the backflow of blood.
True or False?
The pulmonary artery carries blood from the right ventricle to the lungs.
True.
The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
True or False?
Oxygenated blood enters the heart through the vena cava.
False.
Deoxygenated blood enters via the vena cava; oxygenated blood returns via the pulmonary vein.
The thick muscular wall of the ventricle contracts to force blood into the aorta.
The thick muscular wall of the left ventricle contracts to force blood into the aorta.
Name three ways the activity of the heart can be monitored.
Heart activity can be monitored by:
using an ECG
measuring pulse rate
listening to the valves closing with a stethoscope
Heart rate is measured in per minute (bpm).
Heart rate is measured in beats per minute (bpm).
Where on the body can a pulse be detected?
Where an artery passes over a bone, such as the radial artery (wrist) and the carotid artery (neck).
What instrument is used to listen to the sounds of the heart valves closing?
A stethoscope.
Define ECG.
A recording of the electrical activity of the heart, used to monitor its activity.
How can you investigate the effect of exercise on heart rate using pulse rate?
Record the resting pulse rate for a minute, then record the pulse rate every minute after exercise until it returns to the resting rate.
After exercise, heart rate may take several to return to normal.
After exercise, heart rate may take several minutes to return to normal.
True or False?
Heart rate is measured in beats per minute.
True.
Heart rate and pulse rate are both measured in beats per minute (bpm).
True or False?
A stethoscope measures the electrical activity of the heart.
False.
A stethoscope is used to listen to the valves closing; an ECG records electrical activity.
What wearable device can record pulse rate?
A wearable device such as a fitness watch (heart rate monitor).
What happens to heart rate and breathing rate during increased physical activity?
Both the heart rate and breathing rate increase.
During exercise, heart rate increases so that sufficient blood reaches the working .
During exercise, heart rate increases so that sufficient blood reaches the working muscles.
Why does heart rate increase during exercise?
To deliver more oxygen and nutrients to the working muscles for increased respiration and to remove waste products faster.
Why does heart rate stay high for a period after exercise stops?
To remove excess waste products and repay the oxygen debt built up during anaerobic respiration.
Define oxygen debt.
The extra oxygen needed after exercise to break down the lactic acid built up during anaerobic respiration.
What is the extra oxygen taken in after exercise used for?
To break down the lactic acid built up in cells during anaerobic respiration.
Muscle cells respiring during exercise build up an oxygen debt.
Muscle cells respiring anaerobically during exercise build up an oxygen debt.
How can breathing rate be measured in a classroom investigation?
By counting the number of breaths per minute (1 inhalation + 1 exhalation = 1 breath).
Why must the measuring time be kept the same and the person rest between activities?
To make it a fair test and to allow full recovery before the next activity.
True or False?
After exercise, heart rate returns to the resting rate immediately.
False.
Heart rate stays high for a period and returns to the resting rate gradually.
True or False?
Lactic acid builds up in muscles during anaerobic respiration.
True.
Anaerobic respiration in muscle cells produces lactic acid, creating an oxygen debt.
Heart rate can be measured by taking a .
Heart rate can be measured by taking a pulse.
Define coronary arteries.
The arteries that supply the heart muscle with oxygen, glucose and nutrients.
What causes coronary heart disease?
A coronary artery becomes partially or completely blocked by fatty deposits (plaques) made mainly from saturated fat and cholesterol.
Define angina.
The severe chest pain caused by partial blockage of a coronary artery, which restricts blood flow to the heart muscle.
What happens when a coronary artery becomes completely blocked?
The heart muscle cells cannot respire and stop contracting, causing a heart attack.
Fatty plaques in the coronary arteries are mainly formed from saturated fat and .
Fatty plaques in the coronary arteries are mainly formed from saturated fat and cholesterol.
Name three risk factors for coronary heart disease.
Risk factors include:
poor diet
smoking
stress
How does smoking increase the risk of coronary heart disease?
Nicotine narrows the blood vessels, increasing blood pressure and the buildup of fatty deposits.
How does a poor diet increase the risk of coronary heart disease?
Eating more saturated fat raises cholesterol levels, increasing the buildup of fatty plaques.
How can a person reduce their risk of developing coronary heart disease?
By:
quitting smoking
reducing animal fats and eating more fruit and vegetables
exercising regularly
Regular helps lower blood pressure, cholesterol and stress, reducing the risk of CHD.
Regular exercise helps lower blood pressure, cholesterol and stress, reducing the risk of CHD.
True or False?
Angina is caused by complete blockage of a coronary artery.
False.
Angina is caused by partial blockage; complete blockage causes a heart attack.
True or False?
Males are more likely to develop coronary heart disease than females.
True.
Gender is a risk factor: males are more likely to develop CHD than females.
Sign up to unlock flashcards
or