Lifestyle and Influence Flashcards
Why is water a polar molecule?
Water is a polar molecule because it has an unevenly distributed electric charge.
What charges do the atoms in a water molecule have and why?
The hydrogen end of the molecule becomes slightly positive whilst the oxygen end of the molecule becomes slightly negative, this is because the electrons in the molecule are more concentrated at that end.
How are water molecules joined?
The slightly positive charged end of the water molecule is attracted to the slightly negative end of the surrounding water molecules. Hydrogen bonds hold the water molecules together and this results in many of waters properties such as being a liquid at room temperature.
what type of molecules dissolve in water and why?
Polar molecules because they’re hydrophilic (water loving)
What type of molecules don’t dissolve in water and why?
Non-polar molecules dont dissolve in water because they’re hydrophobic (water-repelling)
Give an example of a non-polar molecule
Lipids are non-polar molecules because they don’t dissolve in water (fatty acid tails are hydrophobic) therefore they need to combine with proteins to form lipoproteins.
Why does it take a lot of energy to raise waters temperature?
It requires a lot of energy to increase waters temperature by 1 degrees because it takes a high quantity of energy to break the hydrogen bonds between each individual water molecule. Therefore a large input in energy only causes a small input in temperature.
Why does water have a high boiling point?
Water has a high boiling point because there are a vast array of hydrogen bonds and these all have to be broken to make the water boil (high amount of energy required)
Why does blood remain a liquid at room temperature?
TBC
Why is blood solvent for polar and ionic substances?
TBC
Why does blood have a high specific heat capacity?
TBC
Describe the vessels/chambers that oxygenated blood from the lungs flows through in order to get back to the blood (deoxygenated)
TBC
Describe the structure of an artery
- Thick walls made up of lots of collagen and elastic fibres, the walls have to be thick enough to be able to withstand the high pressure of blood forced against them during systole.
- Due to the thick walls of the arteries, the lumen is very narrow, this means that the pressure of the blood in them is very high
- The arteries contain a layer of smooth muscle
- There are no valves in the arteries
Describe the structure of a vein
- thinner walls still made up of collagen and elastic fibres but much less of them compared an artery.
- The lumen of a vein is much wider than that of an artery, this helps in this assist of blood flow return to the heart because more blood can be accommodated.
- Veins contain a layer of smooth muscle
Describe the structure of a capillary
Capillaries contain a lumen surrounded by a layer of endothelium cells, the flow of blood in the capillaries is very steady and quite slow due to the friction caused by the blood moving against the walls. This friction causes the flow of blood to slow down which in turn maximises the chance of materials to be exchanged between the blood and surrounding cells.
Describe the flow of blood in an artery
Blood in an artery flows at very high pressure and the flow of blood in the arteries is assisted by the heart contracting during systole (constant contractions).
The elastic recoil of the artery wall behind the blood helps to push the blood forward through the artery, hence the need for no valves.
Describe the flow of blood in a vein
The flow of blood in a vein is under relatively low pressure and more continuous, the hearts contractions doesn’t have a direct effect on the flow of blood.
The flow of blood in veins is assisted by the contraction of the skeletal muscles during movement of limbs and breathing - the skeletal muscles contract and push blood forwards, its the valves that prevent the backward flow of blood by closing shut.
What muscle divides the heart?
The septum
Why is the left ventricle wall thicker than the right ventricle
The left ventricle wall is 3x as thick as the right side because it has to pump blood with enough force for the blood to travel around the entire body whereas the right hand side of the heart only has to pump blood to the lungs.
What do valves do?
Valves prevent the back flow of blood
What are the blood cycles of the heart?
Atrial systole
Ventricular systole
Cardiac diastole
Describe the process of Atrial Systole
Blood returns back to the heart as a result of the action f skeletal muscles during breathing and movement of limbs. Blood under low pressure flows into the atria from the great veins, as the atria continue to fill, the pressure of blood against the atrioventricular valves forces them to open and blood then flows into the ventricles. The atria then simultaneously contract which forces any remaining blood into the ventricles.
Describe the process of Ventricular Systole
After a slight delay atrial systole is followed by ventricular systole. The ventricles contract form the base of the heart upwards which increases the pressure in the ventricles, the pressure forces open the semi lunar valves and pushes blood up and out through the aorta and pulmonary artery. The pressure of blood against the atrioventricular valves forces them to close which creates the ‘lub’ sound.
Describe the process of Cardiac diastole
During cardiac diastole the atria and ventricles relax. The elastic recoil of the relaxing heart walls lowers the pressure in the atria and ventricles, the opposite pressure forces attracts high pressure blood from the aorta and pulmonary artery back towards the verticals which causes the semi lunar valves to close ‘dub’ sound. The low pressure in the atria helps to draw blood into the heart from the veins.
What is an atheroma?
TBC
Describe the process of blood clotting
Blood clots are a resulting factor of a tear/damage to the endothelBlood clots are a resulting factor of a tear/damage to the endotheliuiuf larger cells) come into contact with the damaged vessel they change from their flattened disc shape into spheres with projections which makes them stick together (sticky). This causes them to stick together and to the damaged vessel causing a temporary plug. The platelets and damaged vessels release a protein called THROMBOPLASTIN. The thromboplastin reacts with the calcium and vitamin k found in the plasma of the blood to catalyse the conversion of the protein PROTHROMBIN into the enzyme THROMBIN. Thrombin then catalyses the conversion of the soluble plasma protein FIBRINOGEN into the insoluble protein fibrin. A fibrin mesh forms, this traps more platelets and red blood cells to form a clot. Once the damaged has been healed the clot is dissolved by the blood.
Describe the process of atherosclerosis
Atherosclerosis starts off with damage being caused to the endothelium. The endothelium damage can result from high blood pressure which puts extra strain on the layer of cells. Once the inner lining of the artery is breached, there is an INFLAMMATORY RESPONSE - WBC leave the blood vessel and move into the artery wall. These cells accumulate chemicals from the blood such as CHOLESTEROL - and a fatty acid builds up (ATHEROMA). Calcium salts and fibrous tissue also build up at the site resulting in a hard swelling called plaque on the inner wall of the artery. The build up of fibrous tissue means that the wall loses some of its elasticity (hardens). Plaques cause the lumen of the artery to become narrower - more difficult for the heart to pump blood around the body and this can lead to raised blood pressure (DANGEROUS POSITIVE FEEDBACK). The raised blood pressure makes it more likely that other plaques will form as damage to endothelial tissue in other areas becomes more likely.
What are the chemicals/hormones used in blood clotting and if they combine with anything, what do they combine with?
TBC
What is risk?
The probability of an unwanted outcome or event
What is probability?
Probability has a precise mathematical meaning and can be given a numerical value or percentage
What do we need to remember when calculating risk?
The exposure to the hazard
People may over estimate the risk of something happening if the risk is …..
Unfamiliar Dreaded Involuntary Not Natural Unfair Very small
There are many different risks which contribute to health risks, such as …….
Age Hereditary Physical environment Lifestyle and behaviour choices Social environment
What is correlation?
When a change in one variable is accompanied by a change in another
What is causation?
Causation is when one variable is responsible for a change in another variable
What is a null hypothesis?
They assume that for the sake of an argument that there will be no difference between an experimental group and a control group, and then rest this hypothesis using statistical analysis
What do scientists do to identify risk factors associated with a particular disease?
Scientists look for correlations between potential risk factors and the occurrence of the disease
Who identifies risk factors for CVD?
Epidemiologists are scientists who study a specific pattern in the occurrence of a disease, they look for correlations between a disease and the specific risk factors.
