Blood vessels, blood pressure, heart disease Flashcards
Artery
A blood vessel that carries blood away from the heart
Vein
A blood vessel that carreis blood back to the heart
Capillary
A tiny blood vessel where substances are exchanged between the blood and the body cells
Cardiovascular system
The system made up of the heart and the blood vessels
Method for measuring blood pressure
- sit patient with left arm uncovered resting on table
- fit cuff around this arm
- inflate cuff until blood flow stops
- deflate the cuff
- record the systolic and diastolic values and analyse taking into consideration the time of the day
Cuff problems that can give incorrect blood pressure readings
- Incorrectly sized cuff used
- Position of patient’s arm on which cuff is placed
Make sure patient has not done that following in order to avoid false high blood pressure readings
Within 30 mins before reading:
- drinking coffee
- smoking tobacco
- exercising
Minimum cuff pressure needed to completely stop blood flow will match…
Systolic blood pressure
When cuff relaxes, the first pressure at which pulsing (throbbing) of the artety are no longer detected matches the…
Diastolic blood pressure
Systolic pressure
Defines as maximum arterial pressure during contraction of the left ventricle of the heart
Diastolic pressure
Defined as minimum arterial pressure during relaxation of the ventricles of the heart
Hypertension
Abnormally high blood pressure
Hypetension does not produce symtoms as such…
But can increase a person’s chances of having a stroke or heart attack
Stroke
When blood stops flowing to a part of the brain, due to a clot or rupture in a blood vessel
Atherosclerosis
Condition in which fatty deposits called plaque build up on he inner walls of the arteries
How atherosclerosis can lead to cardiac arrest
- Plaque in the coronary artery bursts
- This causes a blood clot to form
- Plaque / blood clot restricts blood flow into the heart muscle
- Heart muscle starved of (blood and) oxygen
How to reduce the risk of coronary heart disease
- Eat a low fat diet / low salt diet
- Do more physical activity
- Maintain a healthy weight / lose weight
- Give up smoking
- Reduce alcohol consumption
- Control blood pressure / diabetes
- Take prescribed medication
Ways that increase the risk of coronary heart disease
- Eat a high fat diet/ high salt diet
- Do less physical activity
- Don’t maintain a healthy weight / gain weight
- Smoking
- Increase alcohol consumption
- High blood pressure / diabetics
- Not taking prescribed medication
Blood in aorta…
Is at highest pressure
Left ventricle of heart exerts hgiher pressure on blood…
Due to msucle layer being thicker
As blood travels in the artery…
The pressure drops
Rise and fall in pressure corresponds with…
Contraction and relaxation of ventricles in the heart
Fluctuations in blood pressure across cardiac cycle reduced…
Due to stretch and recoilof artery walls
Arterioles have lower pressure…
Due to teh large total cross-sectional area of the network
Low capillary blood pressure means that…
Blood flows slowly in the capillaries, which gives more time for gas exchange
Pressure in the veins is low…
Due to the return of the blood flow being non-pulsatile
Venous blood pressure can be increased by…
The massaging effect of muscles
Valves in veins…
Ensure the one-way flow of blood back to the heart
Glycerol plus 3 fatty acids
Triglyceride
Bond that attaches a fatty acid to glycerol
Ester
Describes fatty aids with only single C-C bonds
Saturated
Describes fatty acids with at least one C=C double bond
Unsaturated
Described fatty acids with two or more C=C bonds
Polyunsaturated
Phospholipids
A lipid consisting of a glycerol bound to two fatty acids and a phosphate group
A phosphate group is…
Hydrophilic
Triglycerides do not dissolve in water so are…
Hydrophobic
Phospholipids make up…
Cell membranes
Steroids are…
Four-ring lipids
Example of steroid hormones include…
Hormones such as oestrogen and testosterone
Steroid that reduces and regulates the fluidity of cell membranes
Cholesterol
3 main roles of lipids
Energy storage thermal insulation, protection of internal organs
Saturated fat in the diet is of particular concern because…
The liver readily converts it into LDL cholesterol
Tunica intima / endothelium
Smooth to reduce friction with blood, innermost layer of blood vessel
Lumen
Space within blood vessel to allow blood to flow through
Tunica media
The middle and thickest layer of tissue of a blood vessel wall
Purpose of muscle middle layer
Contracts to constrict the lumen, allowing blood flow to be regulated
Purpose of elastic fibres in middle layer
Stretches due to high blood pressure when ventricle contracts then recoils when ventricle relaxes, this recoil helps to maintain blood pressure and smooth blood flow
Purpose of tunica externa
Tough outer layer to withstand high blood pressure and stop bursting
Wall of a vein is much thinner than the wall of an artery…
Because the blood pressure is much lower in a vein
Capillaries lack…
Tunica media, and tunica externa
LDL cholesterol
Form in which cholesterol is deposited into artery walls leading to plaque formation
Peripheral vascular disease
Diseases (most commonly atherosclerosis) of blood vessels in places other than the heart or brain
Deep vein thrombosis
Blood clot forms in a large vein, usually in a leg
Pulmonary embolism
Blocking of a pulmonary artery due to a blood clot (e.g. a clot from DVT in a leg breaks off and lodges in the lungs)
Carotid artery
If this is blocked by plaque, blood flow to the brain, neck and face will be reduced, leading to a stroke
Method used to image blockages in peripheral arteries
Doppler ultrasound scan uses reflected ultrasound waves to show disruption to blood flow
Anke-brachial pressure index (ABPI)
- Comparison of ankle versus arm systolic blood pressure (whilst patient lying down)
- Divide ankle pressure by arm pressure
- Lower results indicate more blockage in leg artery
A blockage in a leg artery…
Means you will expect ankle systolic pressure to be significantly lower than arm systolic pressure (more blockage = bigger difference)
Hydrolysis
Breaking a bond by adding water
Condensation reaction
A chemical reaction in which two or more molecules combine releasing water in the process
Type of reaction that will break down a triglyceride
Hydrolysis
Type of reaction that will add a fatty acid to glycerol
Condensation
Angina
A condition of intermittent episodes of sever chest pain due to inadequate blood flow to cardiac muscle
Heart attack (myocardial infarction)
Damage or death of cardiac muscle tissue resulting from blockage of one or more coronary arteries
Cardiac arrest
Complete stopping of heart activity
Arteriole
Small artery-like blood vessel. Muscle layer is especially important here for regulating blood flow via vasoconstriction
Venule
The smallest kind of vein
In a phospholipid bilayer, hydrophilic heads point toward the cytoplasm…
As this is an aqueous environment
In a phospholipid bilayer, hydrophobic tails point away from the cytoplasm…
To avoid the aqueous environment
Blood pressure measurement should be repeated three times…
So a mean can be calculated and any outliers identified
How atherosclerosis could lead to cardiac arrest
- Plaque in coronary artery
- This causes a blood clot to form
- Plaque and clot restrict blood flow into heart muscle
- Heart muscle starved of blood, and therefore oxygen
