LO1: Cardiovascular System Flashcards
(13 cards)
What is double circulation?
System where blood passes through heart twice for every complete circuit.
- Systemic circulation: Blood leaves left side to body tissues and returns on right side.
- Pulmonary circulation: Blood leaves on right side to lungs and returns back to heart on left side
What is the structure of the blood
- Plasma
- Red Blood Cells
- Platelets
- White blood cells
Structure and Function of Red Blood Cells
Erythrocyte (RBC)
- Lots of haemoglobin
- Flexible to fit through narrow vessels
-Biconcave shape provide large S.A.
Structure and Function of White Blood Cells (Leucocytes)
- B lymphocytes: Produce antibodies that bind to antigens and form memory B cells.
- T lymphocytes: Can form cytotoxic T cells that produce chemicals that destroy pathogen-infected cells.
- Monocytes: Largest
Describe the 5 functions of Blood
- Transport oxygen, nutrients (vitamins, sugars fats, proteins), hormones and waste products
- Exchange of substances between tissue and capillaries i.e. C02, urea, glucose and oxygen
- Maintain body temp: vasoconstriction (narrow when cold) and vasodilation (wide when hot)
- Preventing infection through phagocytosis/antibody production
- Blood clotting: When cut blood vessel wall breaks, platelets activate and become spiky, attach to blood vessel where fibrin threads stick together over platelets = blood clot.
Describe the structure of the heart including where it is located and briefly what it does.
- atria: Receives blood
- ventricles: Thicker cardiac muscle
- vena cava: Carries deoxygenated blood from body to heart
- pulmonary arteries (deox. blood from heart to lungs) and veins (oxy. blood from lungs to heart)
- aorta: main artery
- tricuspid (bottom right) and bicuspid valves (left atrium to left ventricle)
- SL Valves: pulmonary (top middle, blood out of heart) aortic (between tricuspid and bicuspid valve from left ventricle to aorta
- coronary arteries : delivers oxygen and nutrients to cardiac muscle
Describe the cardiac cycle.
- Atria diastole (atria relax as blood fills)
- Pressure increases, AV valves open, atrial systole
- Blood rushes into ventricles, ventricular diastole and blood fills ventricles
- Pressure increases closing AV valves
-Ventricular systole opening semi-lunar valves, blood enters aorta. - Pressure increases (aorta) = SL valves close blood rushes out of aorta.
What is the sinoatrial node and the atrioventricular node and the purkyne fibres ?
- SAN: In the upper wall of right atrium of and responsible for setting the
rhythm of the body’s heart rate / pulse (known as the pacemaker). - AVN: In the bottom of right atrium and responsible for delaying
transmission of electrical impulses received from the SA node so blood can empty out of the atria
into the ventricles. - Purkyne fibres: In walls of ventricles, middle. Send out electrical impulse to ventricles
What is an ECG trace?
Show electrical activity in heart. Sensor attached to skin which detect electrical signals produced every heart beat. Signals can be analysed to identify irregular, fast or slow heartbeat.
- P wave: atrial contraction
- QRS wave: ventricular contraction
-T wave: ventricular relaxation.
Compare and contrast the structure and function of blood vessels
Artery: Blood away from heart, large, thick and lots of elastic tissue and muscular walls = withstand high pressure, stretch and recoil and contract for high pressure
Veins: Carry blood to organs at low pressure, larger lumen to prevent resistance caused by pressure, thin wall, little muscle & elastic tissue, has valves to prevent backflow
Capillaries: Carry blood through organs, thin permeable walls, one cell thick = for exchange of gases and for short diffusion pathway
How is tissue fluid formed?
- Water and dissolved substance in blood plasma in capillaries is forced out leaky capillary walls by hydrostatic pressure (contraction of heart) at arteriole end
- Tissue fluid carries nutrients, oxygen and small molecules to cells of tissues
- Fluid returns to circulatory system to prevent oedema and rest drains into lymph vessels and re-joins blood system into veins
What is hypertension, causes, risk factors, monitoring methods, treatment, lifestyle changes, impacts, care?
High blood pressure
- Caused by strain put on heart due to high salt/fat diet, lack of sleep, excessive alcohol consumption, smoking
- BP monitor.
Treatment: ACE inhibitors relax veins and lower BP.
Calcium Channel Blockers: prevent calcium entering, relaxing blood vessels.
Can have side effects.
- Lifestyle Changes: eat healthy, regularly exercise, avoid drinking too much, stop smoke
Positive impact: - Easy to change diet, not expensive
- stopping smoking reduces risk of other conditions
-monitoring & treatment is easy to access both at home or from GP.
Negative impact:
- hard to exercise regularly
- social influence from peers makes reducing alcohol and stopping smoking
- may forget to take medication.
Care: monitor cholesterol or BP.
Summarise the malfunction Coronary Heart Disease
Issues involving coronary arteries
Symptoms: Angina, feeling faint, shortness of breath, nausea.
CAUSE: Atheroma (artery’s endothelium is damaged and fatty deposits build up in wall of artery that are trapped with WBC that attacked them) = angina (less oxygen to heart cells) & heart attack if clot forms
RF: high bp/cholesterol levels, diabetes, obese, age, family history
Monitoring: ECG, Blood test to determine high cholesterol, Angiogram (medical imaging to visualise inside blood vessel using a dye to identify blockages
Treatment: Statins reduce LDL cholesterol, Beta blockers to slow down heart rate, Anticoagulants to break up clot to allow blood to flow.
- Angioplasty : Insert wire mesh tube (stent) to widen artery
- Coronary Bypass: Diverts blood flow around clogged parts to improve blood flow.
CARE: Visits from medical team to inform of condition, procedures, rehabilitation
IMPACTS:
Positive - easy to change diet, lifestyle changes can reduce risk of further deteriorating
Negative - medication could have side effects and recovery after surgery may be debilitating.
