Biology Topic 9 Flashcards
What is the circulatory system?
A series of blood vessels with a pump and valves to prevent backflow
What type of circulatory system do fish have?
Single circulatory system
Describe a single circulatory system
The blood only passes through the heart once for each full circuit of the body
What type of circulatory system do mammals have?
Double circulatory systems
Describe a double circulatory system
The blood passes through the heart twice per circuit
What is the advantage of a double circulatory system?
Double circulatory systems can maintain a higher blood pressure which increases the speed at which the blood flows so nutrients can be delivered and waste can be removed more quickly
What is the name of the top chambers of the heart?
Atria
What is the name of the bottom two chambers of the heart?
Ventricles
Name the blood vessel that carries blood to the heart from the rest of the body
Vena cava
Name the blood vessel that carries blood to the heart from the lungs
Pulmonary vein
Name the blood vessel that carries blood away from the heart to the rest of the body
Aorta
Name the blood vessel that carries blood away from the heart to the lungs
Pulmonary artery
Which valve prevents baackflow from the ventricle to the atrium?
Atrioventricular valve
Which valve prevents back flow from the arteries to the ventricles?
Semi-lunar valve
What is the name of the wall that separates the right and left sides of the heart?
The septum
What type of muscle is the heart made of?
Cardiac muscle
Why is the wall of the left ventricle thicker than the wall of the right ventricle?
The left ventricle has to pump blood a further distance around the whole body so the blood needs to be under a higher pressure
“Why do the ventricles have thicker walls than the atria?
“
The ventricles need to pump blood at a higher pressure to pump it out and round the body and to the lungs whereas the atria only need to pump the blood into the ventricles (a shorter distance) so do not need to generate as high of a pressure
What is the difference in function between veins, arteries and capillaries?
“Arteries carry blood away from the heart
Veins carry blood towards (into) the heart
Capillaries flow close to tissues for exchange”
Why is the septum important?
It separates the oxygenated blood from the deoxygenated blood
Describe the blood flow through the right side of the heart
“Deoxygenated blood flows into the right atrium from the vena cava
This blood passes through the right AV valve into the right ventricle
The blood is then pumped out of the heart to the lungs through the right SL valve and into the pulmonary artery”
Describe the blood flow through the left side of the heart
“Blood enters into the left atrium from the pulmonary vein
The blood is then pumped through the left AV valve into the left ventricle
The blood is then pumped out through the left SL valve and into the aorta”
Give 3 ways of measuring the activity of the heart
ECG, Pulse rate, Listening to the sounds of the valves
State the effect of physical exercise on heart rate
Physical exercise increases heart rate
Explain the effect of physical exercise on heart rate
“Muscular contraction requires energy from respiration
More respiration requires more oxygen and more carbon dioxide
Heart pumps faster to provide more oxygen to the muscles for respiration and to remove the carbon dioxide quickly”
What is coronary heart disease (CHD)?
When the artery providing the heart tissue with blood (the coronary artery) becomes blocked
Give 6 common risk factors for coronary heart disease
Smoking, Poor diet, Lack of exercise, Stress, Genetic predisposition, Gender
How can coronary heart disease be prevented by altering lifestyle choices?
“Exercise regularly
Control diet: Eat less saturated fats, Eat more fruit and vegetables, Eat less salty foods, Stop smoking/drinking”
Describe the structure of arteries
They have thick walls made of muscle and elastic tissue and a small lumen to transport blood under high pressure
Describe the structure of capillaries
They have thin walls about one cell thick to allow for the easy exchange of substances at the tissues.
Describe the structure of veins
Veins have less muscle and elastic tissue than arteries and they have a larger lumen as the blood is at lower pressure, they also have valves to prevent backflow
Name the main artery that takes blood to the kidneys
The renal artery
Name the main vein that takes blood away from the kidneys
Renal vein
Name 4 components of the blood
Red blood cells, White blood cells, Platelets, Plasma
Name 2 types of white blood cell
Phagocyte, Lymphocyte
What is the function of platelets?
They are used in forming blood clots
What is the purpose of blood clotting?
“Preventing excess blood loss
Preventing the entry of pathogens through wounds”
Describe the process of blood clotting
Fibrogen converted to fibrin (insoluble fibres)
Fibrin tangle together to form mesh to trap platelets + blood cells
Blood clot formed
What is the function of red blood cells?
Transporting oxygen to tissues using haemoglobin
State 2 functions of white blood cells
“Producing specific antibodies
Phagocytosis (engulfing pathogens) “
What is the function of plasma?
Transporting substances like ions, soluble nutrients, hormones and carbon dioxide in the blood
Describe the transfer of nutrients at capillaries
Transporting substances like ions, soluble nutrients, hormones and carbon dioxide in the blood
Name of main blood vessel to liver
Hepatic artery
Hepatic portal vein
Name of main blood vessel from liver
Hepatic vein
