Topic 1 - Lifestyle, Health and Risk Flashcards
What is an atheroma?
An atheroma is a fatty deposit or fatty plaque that builds up in the walls of arteries, contributing to atherosclerosis.
What are the key stages in the cascade of events that lead to atherosclerosis?
Damage to the endothelium due to high blood pressure, toxins, high cholesterol, or high blood sugar.
Inflammatory response where white blood cells accumulate in the artery wall, forming an atheroma.
Plaque formation as calcium salts and fibrous tissue build up.
Increased blood pressure as the artery narrows, making it harder for the heart to pump blood.
What are the consequences of atherosclerosis?
Atherosclerosis can lead to:
Coronary heart disease (CHD) and myocardial infarction (heart attack).
Stroke due to restricted or stopped blood flow to the brain.
Gangrene due to tissue decay.
What is an aneurysm, and how is it related to atherosclerosis?
An aneurysm is the abnormal bulging of an artery wall caused by pressure from blood buildup behind a blockage. If an aneurysm bursts, it can lead to rapid blood loss, often fatal.
What is the role of an angiogram in diagnosing atherosclerosis?
An angiogram involves injecting dye into the bloodstream to visualize blood flow through arteries using X-ray footage, helping to detect blockages or abnormalities.
Define the following terms related to atherosclerosis:
Thrombosis
Sclerosis
Myocardial infarction
Thrombosis: A blood clot.
Sclerosis: Hardening of tissues.
Myocardial infarction (MI): A heart attack caused by blocked blood flow to the heart muscle.
Why is blood clotting essential for the body?
Blood clotting is crucial for repairing damaged tissue, preventing blood loss, and protecting against pathogens.
What are some causes of fatal blood clots?
Causes include:
Lack of movement (e.g., prolonged immobility, pregnancy, surgery, obesity).
Atherosclerosis (narrowed arteries).
Snake venoms.
What is the first step in the cascade of blood clotting?
The first step is when platelets come into contact with the damaged endothelium (lining of the blood vessel).
How is thrombin formed during blood clotting?
Thromboplastin, released by activated platelets, along with calcium ions and vitamin K, activates an enzyme that converts prothrombin into thrombin.
What is the role of fibrin in blood clotting?
Thrombin catalyzes the conversion of fibrinogen (soluble protein) into insoluble fibrin, which forms a mesh that traps platelets and red blood cells to create the blood clot.
What is a sphygmomanometer used for?
A sphygmomanometer is used to measure blood pressure.
What is the difference between systolic and diastolic blood pressure?
Systolic pressure is the highest pressure during ventricular systole (when the heart contracts).
Diastolic pressure is the lowest pressure when the heart is relaxed.
What is oedema and how is it related to hypertension?
Oedema is swelling caused by excess fluid in the tissues. Hypertension increases blood pressure, causing more fluid to leak from the capillaries into tissues, leading to oedema.
What are carbohydrates made of, and what is their general formula?
Carbohydrates are made of carbon, hydrogen, and oxygen. Their general formula is C(H₂O)n.
How are disaccharides formed, and what type of bond is involved?
Disaccharides are formed by a glycosidic bond between two monosaccharides through a condensation reaction, which produces water.
Give examples of disaccharides and the monosaccharides that make them up.
Sucrose: Glucose + Fructose (in plants)
Maltose: Glucose + Glucose
Lactose: Glucose + Galactose (found in milk)
What are polysaccharides, and what are their two main functions?
Polysaccharides are long chains of monosaccharides. They function as storage molecules (e.g., starch, glycogen) and as structural compounds (e.g., cellulose in plant cell walls).
What is the structure of amylose, and how is it beneficial for glucose storage?
Amylose is a helical molecule formed by 1-4 glycosidic bonds. Its compact structure allows for the storage of more glucose.
How is amylopectin different from amylose, and why is this important?
Amylopectin has branches formed by 1-6 glycosidic bonds, which makes it easier to break down compared to amylose. This facilitates faster hydrolysis for glucose release.
What is the role of glycogen in animals, and how is its structure adapted for its function?
Glycogen is an animal storage polysaccharide with more branches than amylopectin, allowing for extremely rapid hydrolysis. This is crucial for animals with a high metabolic rate.
What is cholesterol, and where is it found?
Cholesterol is a short, simple lipid molecule and an example of a steroid. It is insoluble in water and is found in saturated fatty foods like meat, dairy, and eggs. It is also synthesized in the liver.
What is the role of cholesterol in the body?
Cholesterol helps stabilize the fluidity of cell membranes over a broader temperature range, ensuring membrane integrity.
What is the difference between HDL and LDL, and why is the HDL:LDL ratio important?
HDL (High-Density Lipoprotein): Carries cholesterol to the liver to be broken down. It is linked to unsaturated fats (good).
LDL (Low-Density Lipoprotein): Carries cholesterol to body cells. It is linked to saturated fats (bad) and can lead to cholesterol build-up in blood vessels.
You want a high HDL:LDL ratio for heart health.
What is the difference between correlation and causation?
Correlation: When one variable changes, it is associated with a change in another variable. This can be positive (both increase or decrease together) or negative (one increases while the other decreases).
Causation: A change in one variable directly causes a change in another variable.
What is epidemiology?
Epidemiology is the study of diseases in populations, specifically focusing on how, when, and where diseases occur and spread in human or animal populations.
What is a cohort study and what are its pros and cons?
Cohort study (prospective): Follows healthy individuals over time to see if they develop illnesses.
Pros: High reliability, technology and research may improve over time.
Cons: Takes a long time, expensive.
What is a case-control study and what are its pros and cons?
Case-control study (retrospective): Compares individuals with a disease to those without it to find common features.
Pros: Can help identify disease origins and potential prevention methods.
Cons: Can be inaccurate, as the data relies on past reports and recollections.
Why is it important for samples in epidemiological studies to be representative?
A representative sample ensures that the results can be generalized to the wider population, making the study more valid and reliable.
What is metabolism and what does it include?
Metabolism is the sum of all the chemical reactions that occur in the body. It includes processes like breaking down nutrients for energy and building molecules for growth and repair.
What factors influence metabolic rate?
Factors that influence metabolic rate include:
Age
Diet
Genetics
Gender
Activity level
Muscle: fat ratio
Why do vertebrates have a closed circulatory system while invertebrates have an open circulatory system?
Vertebrates are larger and have greater distances for blood to travel, requiring a closed system to maintain high pressure. Invertebrates are smaller and their hemolymph can mix directly with tissues, so they don’t need high pressure.
Why do invertebrates not need a high-pressure circulatory system?
Invertebrates are smaller and have lower activity levels, allowing diffusion to work efficiently without needing a high-pressure, closed circulatory system.
What is the function of the pulmonary artery?
The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation.
What is the function of the pulmonary vein?
The pulmonary vein carries oxygenated blood from the lungs back to the heart.
What does the aorta do in the circulatory system?
The aorta carries oxygenated blood from the heart to the rest of the body.
What is the role of the hepatic portal vein?
The hepatic portal vein carries blood from the digestive system to the liver, containing nutrients and waste products. It is partially oxygenated and deoxygenated.
What is the function of the renal veins and renal arteries?
The renal veins carry deoxygenated blood from the kidneys to the heart, while the renal arteries carry oxygenated blood to the kidneys for filtration.
What is the role of a catalyst in a biochemical reaction?
A catalyst provides an alternative reaction pathway that reduces the activation energy of a reaction, without being used up in the process.
What are glycerides made of?
Glycerides are made up of glycerol and fatty acids.
What is the difference between saturated and unsaturated fats?
Saturated fats have no double bonds between carbon atoms and are solid at room temperature (e.g., found in animals, like meat and butter).
Unsaturated fats have one or more double bonds between carbon atoms and are liquid at room temperature (e.g., found in plants, like olive oil).
How are triglycerides formed?
Triglycerides are formed by a condensation reaction between glycerol and 3 fatty acids, with the formation of ester bonds.
What are the health effects of saturated fats compared to unsaturated fats?
Saturated fats (found in animal products) are a risk factor for cardiovascular disease (CVD).
Unsaturated fats (found in plant oils) are cardioprotective, meaning they help protect the heart.
What is the purpose of antihypertensive drugs, and what are some examples?
Antihypertensives reduce blood pressure, which lowers the risk of damage to the endothelium and prevents atherosclerosis.
Examples: calcium channel blockers, ACE inhibitors.
Side effects: nausea, dizziness.
How do cholesterol-lowering drugs work and what are some examples?
Cholesterol-lowering drugs inhibit the production of LDL cholesterol by the liver, reducing the risk of atheroma formation and preventing atherosclerosis.
Example: Statins.
Side effects: nausea, liver damage, muscle cramps.
What is the function of anti-coagulant and platelet-inhibitor drugs and what are some examples?
Anti-coagulant and platelet-inhibitor drugs reduce the risk of blood clot formation, which can lead to blockages in arteries, heart attacks, and strokes.
Examples: Aspirin, Warfarin.
Side effects: nausea, uncontrolled bleeding, internal bleeding, stomach ulcers.
What is risk?
Risk – the probability of occurrence of some unwanted event or outcome.
What are the main components of blood and their approximate percentages?
Erythrocytes (Red blood cells): 45% of blood
Lymphocytes and phagocytes (White blood cells): <1%
Platelets: <1%
Plasma: 55% of blood (mostly water, carries nutrients, glucose, hormones, etc.)
Why is water an effective solvent in the body?
Water is a dipole molecule, meaning it has a positive charge on one end and a negative charge on the other. This property allows it to form hydrogen bonds with other molecules, making it a good solvent for substances like salts.
What are the properties of water due to its hydrogen bonding?
The hydrogen bonding in water gives it the following properties:
Good solvent
Cohesion and adhesion
High surface tension
High specific heat capacity
Liquid over a large temperature range
What is specific heat capacity and why is it important for regulating body temperature?
Specific heat capacity is the amount of heat energy required to raise the temperature of 1 kg of a substance by 1 degree Kelvin (or Celsius). Water has a high specific heat capacity, making it effective at regulating body temperature, as it resists temperature changes.
What factors determine if an organism needs a circulatory system?
Size of the organism
Surface area to volume ratio
Activity levels
How does the surface area to volume ratio affect an organism’s need for a circulatory system?
As the size of a cube increases, its surface area to volume ratio decreases, making diffusion less effective over longer distances. Larger organisms require a circulatory system to transport molecules effectively.
What are the benefits of the human double circulatory system?
Branching vessels: Direct blood flow to specific organs
Unidirectional flow: Prevents mixing of deoxygenated and oxygenated blood, maintaining higher pressure
Pressure gradient: Enables efficient gas exchange
Fluid medium: Blood can flow more easily and is kept at an ideal temperature
Isolation of blood: Ensures higher pressure and efficient circulation
How do grasshoppers and fish differ in their circulatory systems?
Grasshoppers: Open, single circulatory system with blood bathing organs in the body cavity
Fish: Closed, single circulatory system where blood passes through the heart once, circulating through the body in vessels
What are the key characteristics of arteries?
Thick muscular walls
Small lumen
High pressure
Carry oxygenated blood (except pulmonary arteries)
Endothelium reduces blood flow restriction
Elastic fibres for recoil to maintain smooth blood flow and prevent damage
What are the main features of veins?
Thin elastic walls
Large lumen
Low pressure
Carry deoxygenated blood (except pulmonary veins)
Contain valves to prevent backflow
High proportion of collagen to muscle fibres to prevent overstretching
What are the functions and features of capillaries?
1 cell thick for efficient exchange
Form a network to deliver blood to specific places
Allow exchange of substances with body cells
No muscle or elastic fibres
Spaces between cells enable white blood cells to escape
What is the role of arterioles in the circulatory system?
Thinner than arteries
Carry blood from arteries to capillaries
What are venules and their function?
Thinner than veins
Carry blood from capillaries to veins
How does Vitamin C (ascorbic acid) help prevent tissue damage and atherosclerosis?
Vitamin C is an antioxidant that prevents free radicals from taking electrons from other molecules.
Free radicals (with unpaired electrons) can damage tissues, including the endothelium, leading to atherosclerosis.
