Circulation Flashcards
Adaptations of Red Blood Cells
Contain haemoglobin - binds with oxygen to form oxyhaemoglobin which transports oxygen to respiring cells
No nucleus - more haemoglobin can be packed into each cell so more oxygen can be transported
Biconcave discs - Increase surface area to volume ratio. Decreases distance to centre of cell. Increases rate of diffusion of oxygen.
What side of the heart does oxygenated blood enter?
Left side
What side of the heart does deoxygenated blood enter?
Right side
What type of blood vessel pumps blood towards the heart?
VeIN. IN to the heart
Which blood vessel pumps blood away from the heart?
Artery. Away from the heart.
What are the purpose of valves?
To prevent backflow of blood that is travelling at a low pressure.
Describe the structure of veins
Thin outer wall, thin elastic and muscle tissue.
Blood travels at low pressure.
Contains valves (semi-lunar) to prevent backflow of blood.
Large lumen.
Usually carries deoxygenated blood into the heart.
Which ventricle wall is thicker and why? Left or right?
Left because it needs to pump the blood around the body at a higher pressure and it needs to pump the blood further around the body.
What does the right side of the heart do?
Pumps deoxygenated blood to the lungs
What does the left side of the heart do?
Pumps oxygenated blood to the body.
What is the left and right side of the heart separated by?
The septum.
What is the function of the circulatory system?
To transport substances around the body.
Name of valve between right atrium and right ventricle
Tricuspid valve
Name of valve between left atrium and left ventricle
Bicuspid valve
Name of valve between right ventricle and pulmonary artery
Semi-lunar valve
Name of valve between left ventricle and aorta
Semi-lunar valve
What are the names of the artery(s) and vein(s) involving the liver?
Hepatic vein, hepatic artery and hepatic portal vein (leads to stomach and intestines)
What are the names of the artery(s) and vein(s) involving the kidneys?
Renal vein and renal artery
Generally, what type of blood do veins carry and what is the exception?
Deoxygenated blood (they are blue) except the pulmonary vein which carries oxygenated blood from the lungs to the heart. Carries blood into the heart.
Generally what type of blood do arteries carry and what is the exception?
Oxygenated blood (they are red) except the pulmonary artery which carries deoxygenated blood from the heart to the lungs. Arteries carry blood away from the heart.
What are phagocytes?
Larger cells with a multi-lobed nucleus that engulf and digest pathogens using enzymes. A type of white blood cell.
What are lymphocytes
Cells with a very large nucleus that make and release antibodies, which bind to and destroy specific pathogens.
What are platelets?
Cell fragments that help clot blood and form scabs.
What is plasma?
Straw coloured liquids that transports blood cells and many other substances including:
dissolved nutrients (glucose, amino acids…) dissolved waste products (CO2 and Urea) and hormones, heat energy and proteins.
What are red blood cells?
Small red cells that carry oxygen around the body and contain haemoglobin (oxygen binds to hameoglobin).
Describe the structure of arteries
Thick outer wall
Thick layer of muscle and elastic tissue
Blood flows at a high pressure
Small lumen
Usually carries oxygenated blood away from heart.
Describe the structure of capillaries
Walls are once cell thick.
How does the structure of a vein link to its function?
Valves prevent blood flowing backwards.
Blood travels at a low pressure so thick walls aren’t needed.
Layer of muscle and elastic tissue means that wall can contract to keep blood flowing.
How does the structure of an artery link to its function?
Thick layer of elastic tissue - artery wall can stretch and recoil to keep blood flowing at a high pressure.
Thick layer of muscular tissues - can control flow of blood by dilatating and constricting.
Small lumen and thick outer wall means that blood travels at a high pressure to travel all around the body.
How does the structure of a capillary link to its function?
Wall is one cell thick so short distance for diffusion of substances from blood into tissues.
Factors that increase the risk of coronary heart disease
Obesity - increases blood pressure
Smoking - increases blood pressure and risk of fatty deposits forming
High blood pressure - increases risk of fatty deposits forming and damages artery lining
Lack of exercise - High blood pressure
Diet - High consumption of saturated fats leads to fatty deposits as it increases cholesterol.
What blood vessel goes from the heart to the lungs?
Pulmonary artery
What blood vessel goes from the lungs to the heart?
Pulmonary vein
What blood vessel goes from the heart to the rest of the body
Aorta
What blood vessel goes from heart to liver?
Hepatic artery
What blood vessel goes from liver to heart?
Hepatic vein
What blood vessel goes from heart to kidney?
Renal artery
What blood vessel goes from kidney to heart?
Renal vein
What blood vessel goes from body into heart?
Vena Cava
Describe how the heart pumps blood
Two sides of the heart relax and contract at the same time. Atria contract, emptying blood into the ventricles. The ventricles then contract, pushing blood into the arteries. Valves close to to ensure blood flows in the correct direction.
What is the natural resting heart rate controlled by?
A group of cells called the pacemaker, in the right atrium
Why does heart rate increase during exercise and remain high after exercise?
Muscles cells (aerobically) respire faster to release more energy.
Increased respiration means more oxygen, glucose and waste removal (of CO2) is needed
Heart rate increases to deliver oxygen and glucose more frequently
Volume of blood pumped increases to supply larger amounts of glucose and oxygen.
Heart rate remains high to supply more oxygen to the muscles to break down the lactic acid made during anaerobic respiration.
How does heart rate increase during exercise?
Muscles produce CO2 during aerobic respiration
Sensors in the aorta detect this increase
Nerve impulses sent to the medulla Medulla responds by sending nerve impulses along accelerator nerve
Accelerator nerve increases heart rate
More blood supplied to muscles to supply more oxygen and glucose to meet demands of aerobic respiration of contracting muscles cells.
Describe how adrenaline leads to higher heart rate
Heart rate increases to deliver oxygen and glucose more frequently to respiring muscle cells.
Glucose and oxygen are needed for aerobic respiration.
Volume of blood pumped around body also increases to supply larger amounts of glucose and oxygen
Describe what coronary heart disease is
Fatty deposits build up in artery walls. Narrows lumen of artery. Restricts blood flow to the heart muscle cells.
Causes heart muscle cells to receive less oxygen and glucose for aerobic respiration. Aerobic respiration decreases and anaerobic respiration increases in heart muscle cells. Lactic acid builds up due to increase in anaerobic respiration, poisoning the heart muscle cells and leading to heart attacks.
What is the coronary artery?
Supplies the heart muscle cells with blood. This provides the glucose and oxygen needed for aerobic respiration and removes CO2 produced by aerobic respiration.
How do vaccines create immunity?
Antigens enter bloodstream
Lymphocytes recognise the antigens in the bloodstream
The lymphocytes produce antibodies specific to the antigen encountered
Memory cells are produced from the lymphocytes
Memory cells and antibodies subsequently remain circulating in the blood stream
Future infection by the same pathogen will trigger a response that is much faster and much larger compared to the initial response
Due to the rapid nature of the response, the pathogen is unable to cause disease and the individual is said to be immune
