circulatory system Flashcards
name the colours of blood vessels
veins - blue
arteries - red
lymphatic system - green
what is the role of the circulatory system?
allows cells to exchange substances with eachother and the environment e.g. nutrients, gases, hormones, waste produce
list some functions of the circulatory system
- regulates blood pressure and blood flow
- produces immune cells - lymphatic system
- distributes drugs throughout the body
what do venule do?
carry the deoxygenated blood back to the lungs
why do we need to maintain sufficient pressure?
to force the blood around the body
what are the determinants of blood pressure?
Blood volume - the higher the volume the more the strain on the heart and blood vessels so the higher the blood pressure
- Overall compliance - expansion/ and retraction of vessels which regulates blood flow
- Cardiac output (blood pumped out per time) - increase in cardiac output gives higher arterial blood pressure.
- peripheral resistance - Peripheral resistance is the resistance of the arteries to blood flow. the higher the resistance the higher the arterial blood pressure.
what does the vascular network consist of?
arteries, veins, , capillaries join and widen into venules which merge to become veins
what do valves do?
prevent blood from flowing backwards
is blood flow equal to all organs?
no, bc different volumes to different tissues, also different function so theres a different need for oxygen.
differential distribution of drugs in highly and poorable perfused organs
name some highly perfused organs:
lungs, kidneys, liver, brain
name some poorly perfused organs:
adipose, skin
what does the distribution of blood depend on?
the need, exercise, eating
how does vasoconstriction and vasodilation regulate blood flow?
Vasoconstriction- the diameter of the vessel decreases, so more blood is available for other sites, would restrict blood flow to a particular organ
Vasodilation - diameter of vessel increases, so less blood is avaible for other argons, also there is a decrease in the vascular resistance and therefore blood pressure
what is RAAS?
The renin–angiotensin–aldosterone system (RAAS) plays a key role in the pathology of cardiovascular disease, hypertension, diabetic kidney disease and heart failure.[12] Under normal conditions, stimulation of the RAAS occurs in response to threats that compromise blood pressure stability, such as hypotension, blood loss and excessive loss of sodium and water. Blood pressure depends on total peripheral resistance and cardiac output.
what does the right hand side of the heart do?
collects deoxygenated blood from the body and pumps it into the lungs via the right ventricle.
what does the left hand side of the heart do?
collects oxygenated blood from the lungs into the left atrium to the left ventricle to the rest of the body (via the aorta)
the heart function in 6 steps
- collection of venous bloodvia the vena cava
- moves from right atrium to right ventricle
- exits right ventricle through pulmonary valve to pulmonary artery
- Blood rich in O2 leaves lungs via pulmonary vein to left atrium
- enters left ventricle
- pumped out of left ventricle to main aorta and all around the body
what does systolic and diastolic mean?
systolic means contraction and diastolic means relaxation
what activates the muscle tissue in the heart?
depolarization, therefore it can contract and relax very fast compared to other muscles.
what is a arrhythmias?
a problem with the rate or rhythm of the heartbeat
what is the most common type of arrhythmias?
atrial fibrilliation
what is atrial fibrillation caused by?
abnormal electrical impulses giving irregular pulse
what is the treatment for atrial fibrillation?
reduce stroke risk, control heart rate by beta blockers (digoxin).
pacemaker, catheter ablation, cardioversion (electric shock)
what factors affect cardiac output?
age, body surface area
what is the role of the blood?
to transport oxygen, nutrients e.g. glucose, hormones
removal of waste products - CO2, lactic acid, urea
- regulates pH and temperature
- defence function - contains immune cells
- distributes drugs
what is the main component of the blood volume?
the plasma, 55% of blood
functions of plasma
dissolves substances
- contains proteins - maintains oncotic pressure
- it is a transport medium
what is oncotic pressure?
osmotic pressure exerted by proteins
what is the most important protein in human plasma?
albumin
which drugs bind to albumin?
acidic and neutral drugs. acidic - warfarin
neutral - cyclosporine
what must a drug be to be able to bind to albumin?
acidic or neutral
when does dependancy on albumin increase?
there is a higher dependency on albumin as age goes up
where are white blood cells (leukocytes) produced?
in the bone marro
what are the cell types of white blood cells (leukocytes)?
neutrophils, monocytes/macrophages, and lymphocyts
what is the most abundant type of white blood cells?
neutrophils, they account for 50 - 70% of leukocytes
what is the function of neutrophils?
phagocytosis and destruction of bacteria, first responders to infection.
what is the life san of neutrophils in the blood?
about 5.4 days
what is the function of monocytes / macrophages?
phagocytosis
what is the function of lymphocytes?
immune response
what is neutropenia?
it is a common side effect of many chemotherapeutic drugs, resulting in a low neutrophil count
what is thrombocytopenia?
condition where you have a low number of platelets or thrombocytes, resulting in excessive bleeding
what is thrombocytosis?
when you have a v high number of platelets or thrombocytes - resulting in increased formation of blood clots, this can lead to stroke an myocardial infarction
what is the lymphatic system?
a network of lymph nodes, ducts and vessels that produce and transport lymph.
does the lymphatic system have a central pump?
no, and its not a closed system
what is the function of the lymphatic system?
it returns excess fluid to the blood circulation.
lymph tissues are a filter of bacteria.
- also produces immune cells (lymphocytes, monocytes)
- can absorb monocolonal antibodies
what is the movement of the lymphatic system like?
it’s slow, under low pressure
what factors can increase the risk of developing hypertension?
smoking, high alcohol consumption, lack of exercise and diet
what is the function of HDL?
carries cholesterol to liver for metabolism or excretion.. it is the good type
what is the function of LDL?
Carries cholesterol to cells where build up can occur in artery walls “bad”
what is Hypercholesterolemia?
an excess of cholesterol in the bloodstream
what are the causes of Hypercholesterolemia?
genetic factors, environmental factors like obesity alcohol disease etc, secondary causes like diabetes
what are the consequences of Hypercholesterolemia?
Increased risk for heart attack, stroke, transient ischaemic attack (TIA), peripheral arterial disease (PAD)
what is the treatment for Hypercholesterolemia?
mainly statins, and then lifestyle changed
what are the 2 top selling drugs used for cardiovascular diseases?
atorvstating and CLOPIDOGREL
how does atorvstatin work?
lowers blood cholesterol by inhibiting enzyme responsible for synthesis of cholesterol
how doe clopidogrel work?
antiplatelet drug, inhibits blood clots in coronary artery disease and cerebrovascular disease
what can pharmacists do to reduce Hypercholesterolemia?
provide regular monitoring of blood pressure and give advice on preventive measures.
