Topic 1 - Lifestyle and Risk Flashcards
What do animals require to survive?
Essential substances like oxygen and carbon dioxide
What method do small organisms use to transport substances?
Diffusion
What happens to the surface area to volume ratio as the size of the organism increases?
It decreases
What increases as the size of the organism grows?
Diffusion distance and metabolic rate
What becomes insufficient for larger organisms, necessitating a different transport system?
Diffusion
What is a mass transport system in larger organisms composed of?
Heart and circulation
What are the four features of a mass transport system?
- A network to move through (e.g., vessels)
- A medium for movement (e.g., blood)
- Controlled direction
- Maintenance of speed
What is the role of valves in a mass transport system?
To control the direction of flow
What is the significance of hydrogen bonding in water?
Creates cohesion and adhesion for effective transport
What type of molecule is water, and why?
Polar molecule due to uneven distribution of charge
What is the result of water’s high heat specific capacity?
Minimizes temperature fluctuations in living organisms
Fill in the blank: Water is a _______ solvent.
polar
True or False: The contraction of the heart helps maintain the speed of blood flow.
True
What is the effect of hydrogen bonding on water’s temperature stability/specific heat capacity?
Requires a lot of energy to change temperature
What do arteries carry to the body tissues?
Oxygenated blood
Other than the pulmonary artery
What is the lumen size of arteries and why is it significant?
Small lumen
Maintains high blood pressure
What type of lining do arteries have and why?
Smooth inner endothelial lining
Reduces resistance to blood flow
What components allow arteries to control their diameter?
Thick layer of smooth muscle and elastic fibres
Contract and relax to dilate and constrict blood vessels
What provides strength and support to arteries?
Collagen fibres
Lots of collagen fibres are present
What do veins carry to the lungs?
Deoxygenated blood
Except the pulmonary vein
What is the lumen size of veins and its significance?
Large lumen
Minimises resistance to flow
What features characterize the structure of veins?
Thinner layer of muscle, reduced elastic fibres, and valves
Valves prevent backflow
What are capillaries and their key characteristics?
Very small blood vessels
Fit between cells with a narrow lumen and thin endothelium
What is the structure of the heart?
Four chambers
Right and left atria, right and left ventricles
Name the four main blood vessels associated with the heart.
- Pulmonary vein
- Aorta
- Vena cava
- Pulmonary artery
What are atrioventricular valves and their types?
Valves separating atria from ventricles
Mitral or tricuspid/bicuspid valves
What are semilunar valves and their function?
Valves separating arteries from ventricles
Include pulmonary and aortic valves
What prevents atrioventricular valves from turning inside out?
Tendinous chords/valve tendons
Prevent valve inversion due to pressure
What is the function of the septum in the heart?
Prevents mixing of oxygenated and deoxygenated blood
Composed of muscle and connective tissue
What are coronary arteries?
Wrapped around the heart to supply blood to cardiac muscle
Coronary arteries are essential for delivering oxygen and nutrients to the heart tissue.
Why is cardiac muscle thicker on the left-hand side?
Higher pressure is needed to pump blood further
The left ventricle pumps blood to the entire body, requiring more muscle mass.
What are the three stages of the cardiac cycle?
1) Atrial systole 2) Ventricular systole 3) Cardiac diastole
Each stage plays a crucial role in the proper functioning of the heart.
What happens during atrial systole?
The atria contract, forcing the atrioventricular valves open and blood flows into the ventricles
This stage initiates the filling of the ventricles with blood.
What occurs during ventricular systole?
Contraction of the ventricles causes atrioventricular valves to close and semilunar valves to open
This allows blood to exit the heart through the aorta and pulmonary artery.
Describe cardiac diastole.
Atria and ventricles relax, causing semilunar valves to close and preventing backflow of blood
This phase allows the heart to fill with blood again.
What is atherosclerosis?
Hardening of arteries caused by the build-up of fibrous plaque called an atheroma
Atherosclerosis is a key factor in many cardiovascular diseases.
What initiates atheroma formation?
Damage to the endothelium caused by high cholesterol levels, smoking, or high blood pressure
Endothelial damage is the first step in the development of atherosclerosis.
What build up causes plaque formation in arteries?
White blood cells, cholesterol, calcium salts, and fibres build up and harden
This accumulation leads to the formation of an atheroma.
How does atherosclerosis affect blood flow?
It narrows the artery and restricts blood flow, increasing blood pressure
This creates a cycle of damage to the endothelial lining.
What are some modifiable risk factors for atherosclerosis?
Smoking, high cholesterol, high blood sugar, high blood pressure, diet, sedentary lifestyle/no exercise
Modifiable factors can be controlled through lifestyle changes.
What are some non-modifiable risk factors for atherosclerosis?
Genetics, Age, Gender
These factors are inherent and cannot be changed.
True or False: Atherosclerosis is a multi-factorial condition.
True
Atherosclerosis involves multiple risk factors and processes.
What increases the likelihood of formation of plaque in arteries?
High cholesterol levels
High cholesterol can lead to atherosclerosis and cardiovascular diseases.
What effect does nicotine have on arteries?
Narrows arteries
Smoking contributes to cardiovascular disease risk.
What lifestyle factor increases obesity risk?
Physical inactivity
Lack of exercise can lead to weight gain and associated health issues.
What are some ways to reduce the risk of cardiovascular disease (CVD)?
- Stopping smoking
- Regular exercise
- Reducing alcohol consumption
- Dietary changes
- Maintaining healthy body weight
These lifestyle modifications can significantly lower CVD risk.
What cardiovascular diseases can atherosclerosis lead to?
- Angina
- Stroke
- Myocardial infarction
- Aneurysms
Atherosclerosis is a major contributor to these serious health conditions.
What is thrombosis?
Blood clotting
Thrombosis prevents blood loss and protects against infection.
What triggers the conversion of prothrombin into thrombin?
Thromboplastin released from platelets
Calcium ions and vitamin K are necessary for this conversion.
What does thrombin do in the clotting process?
Catalyses the conversion of fibrinogen into fibrin
Fibrin forms a network that traps blood cells to create a clot.
What is energy balance?
Balance of calories consumed vs. calories burned
It determines weight loss or gain based on physical activity levels.
What happens when more calories are burned than consumed?
Leads to weight loss
A caloric deficit is essential for losing weight.
What is the formula for calculating BMI?
BMI = weight in kilograms / (height in meters)^2
BMI is a common measure to assess body weight relative to height.
What does a BMI value below 18 indicate?
Underweight
BMI classifications help identify weight-related health risks.
What does a BMI value above 30 indicate?
Obesity
Higher BMI values are associated with increased health risks.
What can waist-to-hip ratio indicate?
It can determine the likelihood of heart disease based on fat distribution.
A value above 1 suggests a health risk.
What are carbohydrates composed of?
Only carbon, hydrogen, and oxygen.
They are long chains of sugar units called saccharides.
What are the three types of saccharides?
- Monosaccharides
- Disaccharides
- Polysaccharides
Define monosaccharide.
A simple sugar monomer.
Define disaccharide.
Two monosaccharides.
Define polysaccharide.
Many monosaccharides.
How do monosaccharides join to form disaccharides and polysaccharides?
By glycosidic bonds formed in condensation reactions.
What is glucose?
A monosaccharide containing six carbon atoms and the main substrate for respiration.
What are the two main isomers of glucose?
- Beta glucose (most common in plants)
- Alpha glucose (most common in animals)
What is ribose?
A monosaccharide containing five carbon atoms and a component of DNA and RNA.
What is maltose?
A disaccharide formed by condensation of two glucose molecules.
What is sucrose?
A disaccharide formed by condensation of glucose and fructose.
What is lactose?
A disaccharide formed by condensation of glucose and galactose.
What are polysaccharides formed from?
Many glucose units joined together.
What is glycogen?
Energy storage molecule in animals made from alpha glucose molecules.
What type of glycosidic bonds are found in glycogen?
1, 4 and 1, 6 glycosidic bonds.
What feature of glycogen allows for energy hydrolysis?
It has a large number of side branches.
What is the primary function of starch in plants?
Starch stores energy in plants
Starch is a mixture of amylose and amylopectin.
What are the two polysaccharides that make up starch?
- Amylose
- Amylopectin
Describe amylose.
Amylose is an unbranched chain of glucose molecules joined by 1, 4-glycosidic bonds, making it a compact molecule.
What type of bonds are present in amylopectin?
1, 4 and 1, 6 glycosidic bonds
How does the structure of amylopectin affect its digestion?
Due to its many side branches, amylopectin is rapidly digested by enzymes.
What are lipids soluble in?
Organic solvents such as alcohols
What distinguishes saturated lipids from unsaturated lipids?
Saturated lipids do not contain any carbon-carbon double bonds.
What type of fats are typically saturated?
Animal fats
What is a characteristic of unsaturated lipids?
Unsaturated lipids contain carbon-carbon double bonds and melt at lower temperatures.
Why do unsaturated lipids have a lower melting point?
The double bonds create a ‘kink’ in the hydrocarbon chain, reducing intermolecular forces.
What state are saturated fats at room temperature?
Solid
What state are unsaturated lipids at room temperature?
Liquid
List two properties of lipids.
- Waterproof
- Very compact
Why are lipids considered better for energy release than carbohydrates or proteins?
They provide better gram-for-gram energy release due to more energy stored in C-O bonds.
Why are lipids non-polar and insoluble in water important for storage?
They don’t interfere with water-based reactions in the cytoplasm.
What is the primary function of lipids in terms of heat?
Lipids conduct heat slowly and provide thermal insulation.
This property is important for maintaining body temperature in organisms.
What are triglycerides composed of?
One molecule of glycerol and three fatty acids joined by ester bonds.
Triglycerides serve as energy reserves in both plant and animal cells.
What type of group replaces one fatty acid in phospholipids?
A phosphate-containing group.
This modification leads to the formation of hydrophilic heads and hydrophobic tails.
What structure do phospholipids form in the cell membrane?
Phospholipid Bilayer
The hydrophilic heads face watery environments while the hydrophobic tails move away from them.
What is cholesterol and how is it transported in the body?
Cholesterol is a soluble lipid transported by proteins in lipoproteins.
Lipoproteins consist of proteins and lipids.
What characterizes high density lipoprotein (HDL)?
HDL is formed from unsaturated fats, protein, and cholesterol.
It transports cholesterol from body tissues to the liver and reduces cholesterol levels.
What is the role of low density lipoprotein (LDL)?
LDL transports cholesterol from the liver to the blood, increasing cholesterol levels.
It is linked to atherosclerosis due to its composition of saturated fats, protein, and cholesterol.
What is the correlation between saturated fats and cholesterol levels?
High levels of saturated fats are correlated with high blood cholesterol.
Saturated fats are components of low density lipoproteins.
True or False: Cholesterol is involved in plaque formation linked to cardiovascular diseases.
True.
This involvement establishes a causal relationship between cholesterol and cardiovascular diseases.
What are anticoagulants and provide an example and risk of use?
Anticoagulants reduce the risk of clot formation; an example is warfarin.
Dosage of anticoagulants must be carefully controlled to prevent uncontrolled bleeding.
What are statins used for, when are they most effective?
To reduce blood cholesterol levels by blocking the enzyme that produces cholesterol in the liver
Statins are most effective when combined with a healthy diet.
What are common side effects of statins?
- Nausea
- Inflammation
- Diarrhoea
- Constipation
Statins can have various side effects that affect patient compliance.
What is the primary function of platelet inhibitors? Example?
To make platelets less sticky, reducing the risk of blood clots and atheroma formation
Aspirin is a common platelet inhibitory drug.
What potential risk is associated with aspirin as a platelet inhibitor?
Stomach bleeding due to irritation of the stomach lining
This side effect is important to consider in patients with gastrointestinal issues.
What do antihypertensives do?
Reduce blood pressure
Antihypertensives are a class of medications used to manage high blood pressure.
What are beta blockers and their effect on the heart? Risk of taking them?
They reduce the frequency and power of heart contractions by blocking the heart’s response to hormones
Beta blockers may increase the risk of diabetes.
What are diuretics and their primary effect? Side effects?
Lowers blood volume and pressure by increasing volume of urine.
Diuretics can lead to side effects such as nausea, muscle cramps, and dizziness.
What is the mechanism of action of ACE inhibitors?
They block the conversion of Angiotensin I to Angiotensin II, which causes arterial constriction
This action leads to reduced blood pressure.
What are common side effects of ACE inhibitors?
- Dizziness
- Cough
- Heart arrhythmia
These side effects can influence patient adherence to the medication.
