Systems: Circulatory Flashcards
What are the functions of the circulatory system?
Transports oxygen and nutrients to the cells, removes CO2 and waste from cells, relays chemical messages around the body (hormones), maintains fluid levels in the body, supports the immune system by carrying immune cells
What are the major components of the circulatory system?
Heart, blood vessels, blood
What is the muscular pump used for moving blood?
Heart
What are blood vessels?
System of tubes through which blood moves
What is the fluid used for transporting materials such as nutrients and oxygen throughout the body?
Blood
What are the types of circulatory systems?
Open and closed circulatory system
Describe an open circulatory system
Blood flows freely within the body cavity. No distinction between blood and other body fluids. Blood moves at a low pressure
What is an indistinguishable mixture of blood and body fluids in a circulatory system called?
Hemolymph
What type of circulatory system do invertebrates like insects and crustaceans have?
Open circulatory system
Describe a closed circulatory system
Blood is contained within vessels such as veins and arteries and kept separate from interstitial fluid
What type of circulatory system do vertebrates such as humans have?
Closed circulatory system
In a closed circulatory system, what is the fluid from which blood is kept separate called?
Interstitial fluid
What is the approximate size and weight of the heart?
Size of the fist. About 300g
What is the fluid-filled sac inside the chest cavity called?
Pericardium
What is the function of the pericardium?
To prevent friction between the heart and the chest cavity
What is the wall that vertically separates the heart called?
Septum
Which side of the heart receives deoxygenated blood from the body and pumps it to the lungs?
Right
Which side of the heart receives oxygenated blood from the lungs and pumps it to the body?
Left
How many chambers does each side of the heart have?
Two
Which chamber of the heart is on top?
Atrium
Which chamber of the heart is on the bottom?
Ventricle
Which chamber of the heart receives blood and which chamber pumps it out?
Atria receive blood while ventricles pump it out
Which system are the blood vessels connecting the heart and lungs a part of?
Pulmonary circulatory system
Which system are the blood vessels connecting the heart to the body a part of?
Systemic circulatory system
Which chamber of the heart receives deoxygenated blood?
Right atrium
Via which vein does deoxygenated blood return from the body to the heart?
Vena cava
Which part of the heart allows deoxygenated blood to flow from the right atrium to the right ventricle?
Tricuspid valve
Which vessel pumps blood from the right ventricle to the lungs?
Pulmonary artery
Which is the only artery in the body that carries deoxygenated blood?
Pulmonary artery
Where is blood oxygenated?
The lungs
To which chamber does oxygenated blood go from the lungs via the pulmonary vein?
Left atrium
Which is the only vein in the body to carry oxygenated blood?
Pulmonary vein
What is another name for the bicuspid valve?
Mitral valve
On which side of the heart is the bicuspid valve?
Left
On which side of the heart is the tricuspid valve?
Right
What is the biggest artery in the body?
Aorta
Which part of the body allows blood to flow down into the left ventricle where it is pumped out to the body via the aorta?
Bicuspid valve
What are the valves between the atria and ventricles called?
Atrioventricular valves (AV valves)
What is the function of the atrioventricular valves?
To ensure there is no backflow of blood
What valves, shaped like half-moons, are present in the heart?
Semilunar valves
What are the coronary arteries?
Branches of the aorta that directly feed the muscles of the heart with freshly oxygenated blood
Describe the pulmonary circuit flow of blood up to their oxygenation in the lungs
Deoxygenated blood enters the heart via the superior vena cava and the inferior vena cava into the right atrium. The blood moves through the tricuspid valve into the right ventricle. Then, it passes through the pulmonary valve and into the left pulmonary artery. From here, two pulmonary arteries pump the deoxygenated blood to the lungs. Once in the lungs, the blood moves into tiny beds of capillaries where waste is released and oxygen is absorbed
Describe the systemic circuit flow of blood from its oxygenation in the lungs
Oxygenated blood moves back to the heart via the pulmonary veins in the left atrium. Then blood moves through the bicuspid valve into the left ventricle. Then blood leaves the left ventricle via the aortic valve, moves through the aorta and is pumped through the rest of the body
Which ventricle is more muscular and why?
The left because the systemic system propels the blood with enough force for it to travel to all the body parts
What are the three main types of blood vessels?
Arteries, capillaries, veins
What are thick-walled blood vessels that carry blood away from the heart?
Arteries
What are blood vessels smaller than arteries which control blood flow into capillaries?
Arterioles
What are very small blood vessels less than 1mm long and less than 0.01mm in diameter?
Capillaries
What progressively larger vessels do capillaries merge into?
Venules
What larger vessels do venules merge into?
Veins
What are thin-walled blood vessels that carry blood towards the heart?
Veins
Describe arteries
Thick-walled because blood pumps at a high pressure. 3 layers thick. The outer and inner layers are made of connective tissues and the middle layer is muscle fibre with elastic tissue. Very strong and flexible, expanding as blood surges through and snapping back during relaxation of the ventricles
What is vasoconstriction and what is it’s function. Give an example
A nerve impulse that causes the arterioles to become smaller, so as to keep the blood warm and away from the surface when it is cold, such as becoming pale with fear
What nerve impulse is the result of the body cooling blood near the surface when it is hot, such as when blushing?
Vasodilation
What are the smallest blood vessels in the body?
Capillaries
Which two blood vessels do capillaries connect?
Arterioles and venules
What blood vessel is the site of gas exchange between the blood and body cells?
Capillaries
Due to low pressure, which blood vessels have valves to avoid backflow?
Veins
Which blood vessels have wells less thick or elastic than those of arteries?
Veins
Which blood vessels are reservoirs of blood and can hold up to 50% of the body’s blood at once?
Veins
What are varicose veins?
Occurring when people age, the valves get weaker and blood can pool in the legs and feet
What are the four components of blood and their percentages?
55% blood plasma, <1% white blood cells, 44% red blood cells, <1% platelets
Which component of blood is clear, yellowish fluid?
Blood plasma
What are the components of blood plasma and their percentages?
92% water, 7% dissolved blood protein, 1% organic substances and inorganic materials; salts and electrolytes
What are the major blood proteins in blood plasma?
Albumin, globulins, fibrinogen
What is another name for red blood cells?
Erythrocytes
Describe red blood cells
Disk-shaped cells with no nucleus, used for transporting oxygen, each one containing about 280 iron-rich hemoglobin molecules
What role does hemoglobin play in the gas exchange process?
Bonds to oxygen and releases it in the presence of cells that need it. It then takes the carbon dioxide waste back to the lungs
What is another name for white blood cells?
Leukocytes
Describe white blood cells and their function
Colourless cells with a nucleus, made in the bone marrow. They act to fight infection and can double their normal number when doing so
What is another name for platelets?
Thrombocytes
What is the smallest component of blood?
Platelets
Describe platelets and their function
Fragments of broken bone marrow cells that contain no nucleus and last only 7 to 10 days. The smallest component of blood, used for clotting to prevent blood loss after injury
Describe how blood clots
When blood vessels break, they release chemicals that attract platelets. The platelets rupture and combine with chemicals to produce an enzyme. Several reactions occur, producing fibrin, an insoluble protein that creates a mesh over the injury and forms a clot
What is fibrin?
An insoluble protein that creates a mesh over the injury and forms a clot
About how many times does the heart beat in a person’s life?
3 billion
How many major blood groups are there and what are they?
Four. A, B, AB, O
Which blood type is known as the universal donor?
O-
Which blood type is known as the universal recipient?
AB+
What happens if the wrong blood type is given during a transfusion?
Agglutination occurs, causing the blood to clot. This will lead to death
What are the protein markers of A+ blood?
A, +
What are the protein markers of A- blood?
A
What are the protein markers of AB+ blood?
A, B, +
What are the protein markers of AB- blood?
A, B
What are the protein markers of O+ blood?
+
Why is AB+ the universal recipient?
It has no antibodies to attach to protein markers
Why is O- the universal donor?
It has no protein markers and thus, will not react with any antibodies
What antibodies are present in A+ blood?
Anti-B
What antibodies are present in A- blood?
Anti-B, anti-+
What antibodies are present in AB+ blood?
None
What antibodies are present in AB- blood?
Anti-+
What antibodies are present in O+ blood?
A, B
What antibodies are present in O- blood?
A, B, +
What blood types can A+ blood receive?
A+, A-, O+, O-
What blood types can A- blood receive?
A-, O-
What blood types can AB+ blood receive?
A+, A-, B+, B-, AB+, AB-, O+, O- (all of them)
What types of blood can AB- blood receive?
A-, B-, AB-, O-
What types of blood can O+ blood receive?
O+, O-
What types of blood can O- blood receive?
O-
Where is the sinoatrial node?
Wall of the right atrium
What is the sinoatrial node?
A group of nerves and muscles that sends out an electrical impulse stimulating the muscles of the heart to contract rhythmically at regular intervals
What is known as the pacemaker of the heart?
Sinoatrial node
Describe how the heart beats up to the contraction of the ventricles
The sinoatrial nodes send out an electrical impulse stimulating the muscles of the heart to contract rhythmically at regular intervals. The impulse it sends causes the two atria to contract simultaneously. As they contract, the signal then reaches the atrioventricular node, moves through the bundle of His, and sends the signal to the Purkinje fibres causing the ventricles to contract
What sound does the heart make?
Lub-dub
How does the “lub” sound originate?
Atrioventricular valves close as blood is pumped from the atria to the ventricles (caused by the action of the sinoatrial node)
How does the “dub” sound originate?
Semilunar valves close as blood is pumped from the ventricles to the arteries (caused by the action of the atrioventricular node)
What device does a doctor use to measure heartbeat?
Stethoscope
What is the normal heart rate for people over 10 years old and elite athletes?
60-100bpm, 40-60bpm
What are the unusual sounds of the heartbeat?
Stenosis, heart murmur
What is a non-smooth flow of blood through the heart caused by narrowed valves or arteries?
Stenosis
What is caused by a leaky valve in the heart allowing the backflow of blood?
Heart murmur
How does an electrocardiogram work?
A doctor uses electrodes placed on the chest to measure the electrical pulses the body creates to make the heart beat
What is a more advanced method of monitoring heart activity?
Electrocardiogram
Define blood pressure
The pressure exerted against the walls of the blood vessels as blood passes through it
What are the two readings for blood pressure?
Systolic, diastolic
What is the pressure of blood exerted when the ventricles contract, forcing blood into the arteries?
Systolic blood pressure
Which blood pressure reading is the higher number?
Systolic blood pressure
What is the blood pressure when the ventricles relax and pressure in the arteries drop?
Diastolic blood pressure
What blood pressure reading is the top number and generally higher?
Systolic blood pressure
What is a cuff device used to measure blood pressure?
Sphygmomanometer
What is normal blood pressure?
120/80 mmHg
How does exercise affect blood pressure?
Causes it to rise
What factors affect blood pressure?
Smoking, fitness level, genetics, diet, stress, medication
What determines blood type?
The protein markers (antigens) present on the surface of the red blood cells
What is heart rate?
The number of heart beats per minute
What is stroke volume?
The amount of blood forced out of the heart with each heartbeat
What is cardiac input?
The amount of blood pumped from each ventricle of the heart each minute. The product of heart rate and stroke volume
How does regular cardiovascular exercise affect resting stroke volume?
Increases it because it enlarges the ventricle chamber, increases the distensibility of the ventricles, and strengthens the ventricle walls
Which blood vessel carries blood to the brain?
Carotid artery
Which blood vessel carries blood away from the brain?
Jugular vein
Vasoconstriction and vasodilation are controlled by what?
The brain, chemicals, exercise
