Topic 1 - Lifestyle, Health & Risk Flashcards
What is the Heart and Circulations Job in the Body?
To transport substances around the body
How are Substances Transported Through the Body in Small Organisms?
Diffusion
How are Substances Transported Through the Body in Larger Organisms?
Mass transport system
What is an Open Circulatory System?
- Blood circulates in open spaces
- Heart pumps blood into cavities surrounding organs
- When the heart relaxes blood is drawn back to heart through valves
What is a Closed Circulatory System?
- Blood is enclosed in blood vessels
- Blood travels faster and at high pressure
- Blood flows through arterioles to capillaries
- Blood returns to heart via the veins
What Animals Have a Single or Double Circulatory System?
Those with a closed circulatory system
How are Substances Transported in a Single Circulatory System?
- Deoxygenated blood pumped to gills
- Gaseous exchange happens in gills (CO2 in Blood diffuses to water and oxygen from water diffuses into gills)
- Blood flows round whole body before retiring to the heart
Give an Example of an Organism with a Single Circulatory System?
Fish
How are Substances Transported Through a Double Circulatory System?
- Right ventricle pumps deoxygenated blood to lungs
- Oxygenated blood returns to heart by left ventricle and is pumped round the body
- The blood is given a boost to flow quickly
- High metabolic rate as Substances delivered quicker
Give an Example of an Organism with a Double Circulatory System?
Birds or mammals
Why is it Called a Double Circulatory System?
Because blood flows through the body twice for every complete circuit
Give Examples of Water Properties.
- Polar molecule
- Hydrogen end=positive
- Oxygen end=negative
- Dipole molecule
What is a Polar Molecule?
A molecule with an unevenly distributed charge (also known as a dipole molecule)
Why Do Chemicals Disolve Easily in Water?
- Because it’s dipole nature allows reactions to occur in cells
- Ionic compounds mean that positive part is attracted to negative end of water etc.
How Are Hydrophobic Substances Transported?
They bind with proteins (e.g lipids bind with proteins to become lipoproteins)
What are the Thermal Properties of Water?
- Requires large amount of energy to raise temperature by a small amount
- Large amount of energy needed to break hydrogen bonds
- Warms/cools slowly
- Useful for organisms as it is easier to maintain body temperature
Describe the Structure of an Artery.
- Narrow lumen
- Thick layer of muscle/elastic tissue
- More collagen
- No valves
Describe the Structure of a Vein.
- Wide lumen
- Less muscle/elastic tissue
- Less collagen
- Valves ensure blood flows one way
Describe the Structure of a Capillary?
- One cell thick
- Thin walls for quick diffusion
What are Coronary Arteries?
Arteries that supply blood to the heart
What Does the Right Atrium Do?
Draws in deoxygenated blood from vena cava and into the lungs
What Does The Left Atrium Do?
Draws in oxygenated blood from pulmonary veins and pumps around the body
Why Are The Walls of the Left Atrium More Muscular Than The Right Atrium?
Because it needs to pump blood around the whole body
What Do Ventricles Do?
Push blood out of the heart
Why Are Ventricle Walls More Muscular Than The Atria?
Because they need to pump blood out of the heart
What Are Atrioventricular Valves?
Valves in between the atria and ventricles to stop blood flowing back into the atria when the heart contracts
What Are Semi-Lunar Valves?
Valves in between the ventricles and the pulmonary arteries/aorta to stop blood flowing back when the heart contracts
What Is Diastole?
- Relaxation of the heart
- Low blood pressure
- Blood at higher pressures is drawn back to ventricles
- This closes the SL valve
What is Atriole Systole?
- Atria contract
- Blood flows in from the vena cava and pulmonary veins
- Increased pressure forces open atrioventricular valves
- Blood enters ventricles
What Is Ventricular Systole?
- Ventricles contract
- Continuation of high blood pressure
- Forces open SL valve and blood flows up pulmonary arteries and aorta
What Is a Monosaccharide?
A single sugar unit that makes up a carbohydrate
What Is a Disaccharide?
A double sugar unit, combined in a condensation reaction by a glycosidic bond
What Is a Polysaccharide?
A chain of sub-units or monomers, connected by glycosidic bonds to form a carbohydrate
What Is a Condensation Reaction?
Occurs in the linkage of two molecules, releasing H2O
What Is Hydrolysis?
The separation of molecules by adding water
What Is the General Formula For a Monosaccharide?
CH2On (n being the number of carbons)
What Are the Properties of a Monosaccharide?
- 3-7 Carbon backbone
- Each Carbon is attached to 1 Hydrogen and 1 OH (apart from 1 which is double bonded to Oxygen)
How Is a Glycosidic Bond Formed?
In a condensation reaction, between 2 carbons (e.g. 1, 4 glycosidic bond)
What Are the Properties of a Polysaccharide?
- Must be digested into a Monosaccharide before being absorbed
- There are 3 main types: starch, cellulose and glycogen
What Are the Roles of Starch and Glycogen?
Energy storage (their insolubility doesn’t affect the water concentration or movement in the cytoplasm)
What Is Starch Made Up Of?
Amylose and amylopectin
Where Is Glycogen Found In Humans?
In the liver and muscles
What Is Cellulose?
A dietary fibre and non-Stacy polysaccharide
What Is Cellulose Thought To Prevent?
Coronary heart disease and diabetes
What Happens In Atherosclorosis?
- Endothelium damaged by high pressure
- Inflammatory response (white blood cells accumulate chemicals to form an atheroma)
- Calcium salts/fibrous tissue build up a plaque on the artery wall (loses elasticity)
- Lumen shrinks and positive feedback occurs
What Happens In The Clotting Cascade?
- Platelets stick to damaged area and release thromboplastin
- Thromboplastin catalyses prothrombin to thrombin
- Thrombin catalyses fibrinogen to fibrin
- Fibrin mesh traps platelets and blood cells to form a clot
What Is Oedema?
The build up of fluid in the tissues surrounding the capillaries
What Are The Contributing Factors Of Oedema?
- High blood pressure
- Liver disease
- Kidney disease
Where and Why Does The Tissue Fluid Form?
At the arteriole end due to high pressure and forcing out plasma (with nutrients and oxygen)
What Causes The Swelling?
The tissue cells surrounding the capillary absorb the nutrients and oxygen from the tissue fluid and then transfer it back to the capillary through osmosis
Where Does The Remaining Tissue Fluid Go?
20% is drained into lymph capillaries and lymph vessels returns lymph fluid to blood and into the vena cava
What Is LDL?
- Low-density lipoprotein
- Formed by triglycerides bonding with cholesterol and protein
What Are Some Of The Properties Of LDLs?
- Circulate in blood stream
- Excess LDLs increase blood pressure (atheromas form)
- It’s cholesterol is involved in cell membrane synthesis
What Is HDL?
- High density lipoprotein
- Transports cholesterol from tissue to liver to be broken down
What Are The Properties Of Saturated Fats?
- Increase LDL and HDL (LDL increase is greater)
- Maximum no. of hydrogens
- Strong intermolecular forces so solid at room temperature
What Are The Properties Of Unsaturated Fats?
- Decreases LDL and HDL
- X1 double bond between carbons
- Double bond causes a kink to prevent them closely packing together
- Weak intermolecular forces so oily at room temperature
How Can An Unsaturated Fat Be Solidified at Room Temperature?
By adding hydrogen
What Are Free Radicals?
Molecules with an unpaired electron that result in bodily reactions
Why Are Free Radicals Harmful?
They are highly reactive and damage cell components, resulting in cancer, heart disease and premature ageing
Why Are Free Radicals a Repetitive Process?
They look for other electrons to steal, resulting in positive feedback
What Are Anti-Oxidants?
They prevent free radical behaviour by providing hydrogen to pair with its unpaired electron
What Is an Apolipoprotein?
- The protein component of lipoproteins
- Formed in the liver and intestines
What Is The Apolipoprotein Gene Cluster Associated With The Cause Of?
Coronary heart disease and Alzheimers
some of its alleles reduce risk and others increase it
What Is Apolipoprotein A?
- Major HDL protein
- Mutations cause reduced HDL
What Is Apolipoprotein B?
- Major LDL protein
- Mutations increase LDL
What Is Apolipoporotein E?
- Major component of HDLs and VLDLs (involved in cholesterol removal)
- 3 common alleles: E2, E3 and E4
- E4 slows cholesterol removal
What Are ACE Inhibiting Drugs?
- Antihypertensive drugs that reduce angiotensin II
- Causes vasoconstriction of vessels to control blood pressure
What Are The Side Effects of ACE Inhibitors?
Dry cough, dizziness and reduced kidney function
What Are Calcium Channel Blockers?
- Antihypertensive drugs that block calcium channels Ain muscle cells, lining arteries
- Failure of calcium entering stops muscle contraction and vessel constricting, lowering blood pressure
What Are The Side Effects of Calcium Channel Blockers?
Headaches, nausea and swollen ankles
What Are Diuretics?
- Increase urine volume to rid the body of excess fluids and salts
- Decreases blood plasma and blood pressure
What Are The Side Effects of Diuretics?
Dizziness, nausea and muscle cramps
What Are Non-Medical Methods of Reducing the Risk of CVD?
- More polyunsaturated fat
- Less saturated fat
- No smoking
- Exercise
- Low alcohol intake
