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What is the main purpose of the heart and the circulatory system?
Primarily used for exchange of oxygen and carbon dioxide between air we breathe and blood
To move substances around the body
To collect carbon dioxide waste materials and fluids for return to the veins.
Diffusion is the movement of ions or molecules across a cell membrane in the direction that is, from an area of lower concentration to one of higher concentration.
When it comes to movement of substances around the body, what is the problem for humans and mammals?
They are smaller and so cannot have enough space for movement to take place
They only have one cell that is used to function their entire being
They have problems functioning properly
They are too large for diffusion to move substances around their bodies quickly enough
Multicellular organisms deal with their difficulty in moving substances around the body because they usually have blood to carry vital substances around their bodies and a heart to pump it around
Difference between open and closed circulatory systems?
In closed systems: Simple heart pumps blood into the cavities but returns the blood back to the heart, and then to the body In open systems: The heart pumps blood around the body and substances diffuse between the organs and cells
In closed systems: blood is enclosed within tubes. the blood is forced along fairly narrow channels instead of flowing into large cavities In open systems: simple heart pumps blood out into cavities surrounding the animal’s organs. Substances can diffuse between the blood and cells. When the heart muscle relaxes, blood is drawn from the cavity back into the heart, through small valved openings along its length.
In closed systems: The blood flows in the body organs which uses enclosed tubes to send it back to the heart In open systems: The heart pumps the blood in cavaties and then blood is drawn from cavity back into the heart
Closed circulatory systems are much slower because they are larger and need less pressure to move substances
In a human the blood flows through the heart once for each complete circuit of the body.
Why do mammals and birds have higher metabolic rates?
The oxygen and food substances required for metabolic processes can be delivered more rapidly to cells in mammals and birds
There are extremely large numbers of capillaries which ensure oxygen is exchanged quicker
Longer time for the blood to circulate around their body
Organs diffuse substances quicker to the body , then the heart accepts quicker and then pump blood around.
That is a diagram of a human circulatory system...
The transport medium in animals is usually blood
The blood leaves the heart under pressure and flows along venules to capillaries.
What is the function of a valve?
To prevent the blood from flowing in the arteries
To prevent the entrance of waste in the blood
To ensure that blood flows only in one direction
To ensure that the heomoglobin in the blood has enough oxygen
What plays a vital role in regulation of body temperature, transferring energy around the body.
Water
Blood
Lymph
Saliva
Urine
The reason water has an unevenly distributed electrical charge is because it is heavily ionised
Many biochemical reactions occur in the cytoplasm of cells due to the solvent properties of water
Polar molecules are said to be...
Hydrophobic
Hydrophilic
None of the above
Why is it difficult for lipids to be transported by transport mediums in the body?
Lipids have no ionic properties
Lipids are hydrophobic
Lipids are very soluble
Lipids have strong covalent bonds
Lipids can be transported around the body by binding with amino acids to form lipoproteins which can then be transported by transport mediums
The specifi c heat capacity of water, the amount of energy in joules required to raise the temperature of 1 cm3 (1 g) of water by 10 ºC, is very high
In the diagram, which labeled structures are atrioventricular valves?
A
B
C
D
E
What makes arteries and vessels strong and durable?
Thick walls
Muscle
Collagen
Fibres
During diastole, blood is forced into arteries and their elastic walls stretch to accommodate the blood.
What occurs when you feel a pulse?
An artery has just passed over a bone close to the skin.
A valve has just closed
The vein that has passed over a bone close to the skin has just returned blood back to the heart
By the time the blood reaches the smaller arteries and capillaries there is a steady flow of blood.
The diagram shows a vein
The heart muscle is supplied with blood through two vessels called the
Circumflex artery
Marginal artery
Mitral artery
Cardiac vein
Coronary artery
One complete sequence of filling and pumping blood is called a
Pulmonary cycle
Heartbeat
Cardiac cycle
Pulse
The cardiac cycle can be simplified into four phases
Blood under low pressure flows into the left and right atria from the
Pulmonary veins and vena cava
Inferior vena cava and Pulmonary artery
Pulmonary vein and right ventricle
Just the vena cava
What phase of the cardiac cycle when the atrioventricular valves are forced open, when the atria fills up with blood
Ventricular systole
Ventricular diastole
Atrial systole
What is the correct order of the phases in the cardiac cycle
Atrial systole, Diastole, Ventricular systole
Ventricular systole, Atrial systole, Ventricular Diastole, Atrial Diastole
Atrial systole, Atrial diastole, Ventricular systole, Ventricular diastole
Atrial systole, Ventricular systole, Diastole
Closing of the bicuspid valves and then the tricuspid valves creates the characteristic sounds of the heart.
Thrombosis is the the disease process that leads to coronary heart disease and strokes
What are some of the causes of when the arteries have been narrowed?
Athletes foot and Heart attack
Gangrene and Tissue death
Swelling and skin redness
Chest pain and Scars
A deposit of cholesterol that builds up is called an atheroma
This picture shows a
A diseased coronary artery
A healthy coronary artery
A platelet
A diseased pulmonary vein
Platelets are a type of blood cell with a nuclues
What happens to platelets when they reach a damaged cell?
They differentiate to form more platelets
The shrink and stick to each other to form a better a shape
They change shape
Release substances that activate to make more platelets
They grow longer in order to be able to reach and stick to the damaged cell
Platets change their cell surfaces causing them to stick to the exposed collagen in the wall
What causes a complex series of chemical changes in the blood?
The direct contact of blood with collagen
Exercise
Eating
All of the above
Prothrombin is insoluble
The first stage of clotting is that thrombrin is converted to prothrombin
Fibronogen is an enzyme that catalyses the conversion of another soluble plasma protein
The reason fibrin can form a tangled mesh with its strands is because of its insolubility
Arteries get atherosclerosis because of the fast flowing blood under preassure causing damage to the walls
Veins and Arteries get atherosclerosis
Thromboplastin is released from fibronogen in order to make it easier to convert to fibrin
In the False-colour scanning electron micrograph, the green coloured substance is the...
Fibrins
Platelets
Cells
Fibronogen
In the False-colour scanning electron micrograph, the yellow coloured substance is the...
Fiibronogens
Angina is chest burn caused by narrowing of the coronary arteries
Why do we feel pain when we have coronary heart disease?
Chemical changes when the muscle respires anaerobically
The burning of the heart muscle after damage to the cells due to high blood pressure in the arteries
Lack of blood supply to the brain
Dead cells occupying areas of heart tissue
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