Unit 2.2 The Circulatory System Flashcards
1
Q
What is the circulatory system?
A
The circulatory system (also referred to as the cardiovascular system) is the transport system of the body by which food, oxygen, water and other essential nutrients are carried to the cells and waste products such as urea and carbon dioxide are carried away.
2
Q
What are the 3 essential parts of the circulatory system?
A
1) The blood - a liquid containing suspended cells which carries substances around the body.
2) The heart - a muscular pump which provides the force needed to move the blood to the lungs and pick up oxygen and around the body.
3) The blood vessels - the tubes through which the blood travels to, through and from the tissues.
3
Q
What is the blood?
A
Blood as both liquid and solid components and is actually a complex tissue in which living blood cells are suspended in non-living fluid matriculates called plasma.
4
Q
How much blood does an average adult have in their body?
A
Between 3 - 5 litres.
5
Q
What are the main constituents of blood?
A
The plasma which makes up about 55% of blood volume.
The RBCs which make up about 44% of the volume
The remaining 1% consists of WBCs inc leukocytes and lymphocytes and platelets.
6
Q
Where does the red colour of blood come from?
A
The red colour comes from the pigment haemoglobin found in the red blood cells.
7
Q
Why does circulating blood appear bright red in the arteries?
A
Circulating blood appears bright red in the arteries because in the arterial system the haemoglobin is fully oxygenated and oxyhemoglobin is bright red.
8
Q
What happens to oxyhemoglobin during its passage through the body?
A
During its passage through the body, oxyhemoglobin gives up this oxygen to the tissues leaving more purplish red blood in the veins of the body.
9
Q
What is plasma?
A
Plasma is the fluid portion of the blood and is a clear, straw coloured watery fluid similar to the liquid you see in a blister.
10
Q
What components is the plasma made from?
A
- Water
- Proteins
- Salts
- Urea
- Glucose
Other substances inc. vitamins, enzymes, antibodies, and antitoxins are also carried around the body in the plasma.
11
Q
What does the water component of the plasma do?
A
Many of the substances carried in plasma are dissolved in water. It replenishes the intercellular fluid which bathes all the body cells and renders the intracellular fluid (fluid within cells) Up to 90% of the plasma is water.
12
Q
Where are many of the plasma proteins made?
A
In the liver.
13
Q
What are the plasma proteins albumin and globulin responsible for?
A
For maintaining the osmotic press of blood, preventing excess fluid loss into the tissues
14
Q
What is the plasma proteins responsible for blood clots called and what is the plasma called without this protein?
A
Figrinogen is essential for when the blood clots. Plasma with the fibrinogen removed is called serum - the is the clearest fluid that leads out when a clot is formed.
15
Q
What are the salts found primarily in the plasma?
A
Chlorides, sulphates and phosphates of sodium, potassium and calcium.
16
Q
What do the salts do?
A
They help to maintain the pH of the body, neutralising acids or alkalis taken into or formed within the body, thus keeping the blood and body tissues at a slightly alkaline pH of about 7.4
17
Q
What is Urea?
A
Urea is a waste product of protein metabolism in the liver, where amino acid are broken down (metabolised). It is transported along with other waste products to be removed from the body (excreted) by the kidneys.
18
Q
What is glucose?
A
Glucose is a simple sugar, a product of carbohydrate digestion and is used in cellular respiration in all cells. it is transported along with other digested food products such as amino acids from the gastro-intestinal tracts to all parts of the body.
19
Q
How many types of blood cells are there?
A
There are essentially 3 types of blood cells.
20
Q
What are Red Blood Cell also called?
A
Erythrocytes or red corpuscles
21
Q
What are RBCs?
A
They are bi-concave discs which do not have a nucleus - packed full of haemoglobin
22
Q
How many RBCs are there per mm cubed of blood?
A
5,000,000
23
Q
How do RBCs develop?
A
The RBCs develop in the bone marrow, they are formed from stem cells and then under the influence of B12, vit C, cobalt, copper and folic acid they mature so they can be released into the bloodstream. During this process they build up haemoglobin and lose their nucleus and other organelles
24
Q
What is haemoglobin? what does it do?
A
Haemoglobin is an iron-containing protein that transports most of the oxygen that is contained within the blood. Haemoglobin absorbs oxygen from the lungs and releases it to tissues.
25
What does losing the nucleus of RBCs means for the cells?
Losing the nucleus makes more space in the RBCs for oxygen carrying haemoglobin but it means the cells have a limited life span of up to about 120 days in the circulation and they cannot divide to make new cells.
26
What are White blood cells also known as?
Leukocytes or white corpuscles.
27
What makes them different to other cells in the blood?
They are the only complete cells in the blood containing nuclei and organelles.
28
How many WBCs per mm cubed of blood?
Between 6,000 - 10,000
29
Where are WBCs made and matured?
WBCs are made in the bone marrow but some of them mature in the lymphatic system
30
What are the 2 main types of leukocyte in the blood?
Granulocytes (also known as polymorphonuclear leukocytes) and agranulocytes.
31
What are the types of granulocytes?
Neutrophils, Eosinophils and basophils.
32
What percentage of WBCs do Neutrophils, eosinophils and basophils make up?
Neutrophils make up 40-70% of WBCs
Eosinophilss make up 1-4% of WBCs
Basophils make up 0-1% of WBCs, the rarest WBC.
33
What do neutrophils do?
Neutrophils are active phagocytes, they move about independently and engulf and digest other cells or cell fragments. They protect the body from bacterial invasion as well as removing cell debris.
34
What do eosinophils do?
They kill parasitic worms.
35
What do Basophils do?
They contain histamine and are involved in inflammation and allergic reactions.
36
What are the types of agranulocytes?
Lymphocytes, monocytes and macrophages.
37
What percentage of WBCs do lymphocytes make up?
25-30%
38
What do the lymphocytes do, where are they produced?
Lymphocytes are active phagocytes. They are produced in the bone marrow then enter the circulation and lymph nodes, Primarily involved in defence against disease by producing antibodies and antitoxins.
39
Where are the monocytes made and what do they do?
Monocytes are made in the red bone marrow and lymphatic tissue. They are the largest of the blood cells, they remove foreign particles by phagocytosis.
40
What are the macrophages?
Macrophages are cells derived from a monocyte that acts as a phagocyte in the non-specific responses. They form an antigen-presenting cell in the specific immune response.
41
What are platelets? Where are platelet (also known as thrombocytes) made and what are they essential for?
Platelets are small cytoplasmic fragments of large cells in the bone marrow. They are made in the bone marrow and are essential for blood clotting (coagulation) approx a third of a RBC.
42
Do platelets have a nucleus?
In humans they do not have a nucleus.
43
How many platelets are there per mm cubed of blood?
250,000 per mm cubed.
44
When you cut yourself the blood needs to form a solid clot. What happens when the blood clots?
The clotting of your blood involved a series of enzyme controlled reactions which produce a net of fibres made of a protein called fibrin formed from the fibrinogen in blood plasma. the fibrin fibres then trap many red blood cells and more platelets and form a jelly lie clot that dried to form a scab, the skin heals under the scab
45
What are the 9 blood functions?
1. To carry oxygen to the tissues using the haemoglobin in RBCs.
2. to carry dissolved, digested food such as glucose of amino acids to the tissues.
3. To remove waste product such as CO2 or urea from the tissues and transport them to the appropriate organ for excretion.
4. To carry water to the tissues and cells. Excess water is removed mainly through the kidneys but water los can also occur through lungs, skin and bowels.
5. To defend the body against the entry of pathogens and so protect against disease, using the WBCs to engulf pathogens and other foreign material and to produce antibodies and antitoxins.
6. To provide the materials from which glands make their secretions.
7. To carry hormones around the body.
8. To distribute heat evenly around the body and help to regulate body temp.
9. To stop bleeding and blood loss from cuts through clotting.
46
What are antigens?
Antigens are cell surface proteins. The combination of antigens on your cells is unique, they are different from others unless you are an identical twin. Therefore antigens on microorganisms that get into your body are also different from the ones on your own cells.
47
What recognises foreign antigens?
Your immune system (WBCs and lymphatic tissue) recognise different antigens. Lymphocytes make antibodies which attach to the antigens and either destroy the cell carrying the antigen or let neutrophils or monocytes engulf and digest them.
48
What results in different human blood groups?
The different antigens found on the surface of RBCs.
49
What is the best known blood grouping system? H ow many blood groups in this?
ABO system. with the 4 blood groups A, B, AB and O.
50
In this system what possible antigens and antibodies are there on the RBCs and in the plasma?
In this system there are 2 possible antigens on the RBCs, antigen A and B. There are 2 possible antibodies in the plasma, Antibody Anti-A or Anti-B. These antibodies are there all the time and not made in response to any particular antigen.
51
For each Blood group, A, B, AB and O what antigen is on the RBC and what antibody is in the plasma?
```
A = A antigen and Anti-B antibody.
B = B antigen and Anti-A antibody.
AB = A and B antigen and No antibody.
O = No antigen and Anti-A and Anti-B antibody.
```
52
What happens if blood from different groups is mixed?
If blood from different groups is mixed there may be a reactions between the antigen and the complementary antibody which causes the blood to agglutinate for example antigen A and antibody A. This means they do not work properly and clog up capillaries or even larger vessels. This can be fatal if someone needs a blood transfusion.
53
Why is blood group O useful?
The cells have no antigens so it does not react to any blood antibodies. It is the universal donor and can be given to anyone.
54
What blood groups can be mixed safely?
A blood group can receive A or O
B blood group can receive B or O
AB blood group can receive A, B, AB or O
O blood group can receive O
55
What is the rhesus factor?
The rhesus factor is a protein which acts as an antigen found on the red cells of around 85% of the population. Those with are Rh+ and those without are Rh-. Rhesus compatibly also have to be taken into account in blood transfusions. Incompatibility can cause problem in pregnancy is baby and mom are different.
56
2.2.2 The Heart:
| Where is the heart positioned? what is it?
The heart is a hallow muscular organ lying between the lungs and behind the sternum, it is positioned at an angle so the main pumping chambers lie mainly to the left of the sternum.
57
The heart is a double pump, what does this mean?
One half pumps deoxygenated blood to the lungs to pick up oxygen and the other side pumps oxygenated blood all around the body. It dives both the pulmonary and systemic circulations.
58
How many times does the heart beat per minute?
About 70 times per minute.
59
What is the heart made from?
The heart is made of specialised muscle tissue called cardiac muscle or myocardium which has its own intrinsic rhythm.
60
What does cardiac muscle not get, like striated muscle responsible or skeletal movement and maintaining posture?
Fatigued.
61
What does the external health muscle suppled with oxygen by and what does this mean for the heart?
The external heart muscle is supplied with oxygen by the coronary arteries so the heart muscle does not use oxygen from blood inside the heart?
62
How is the heart divided?
The heart is divided from base to apex by a muscular septum into two distinct halves, the left heart and the right heart.
63
In the normal heart there is no communication between the left side and the right side, when is there an exception?
Before a baby is born there is a hole in the septum which allows blood to pass between the two halves this normally closes after birth.
64
What is the heart contained in?
The heart is contained in a fibrous sac called the pericardium.
65
What is the smooth membrane lining of the chambers of the heart called?
Endocardium.
66
What are the small upper chambers and larger lower chambers called? what do they do?
The small upper chambers of the heart are called the atria and they receive blood from the body or the lungs. The large lower chambers are the pumping chambers and they are called the ventricles.
67
How does the heart prevent blood flowing in the wrong direction?
By 4 main heart valves: the bicupsid valve, tricuspid valve, the aortic valve and the pulmonary value.
68
Where is the bicuspid valve?
The bicuspid value has 2 flaps - it is found between the left atrium and the left ventricle. Sometimes called the mitral valve or left trio-ventricular or left heart valve.
69
Where is the tricuspid valve?
The tricuspid valve has 3 flaps - it is found between the right atrium and the right ventricle and is sometimes called the right trio ventricular or right heart valve.
70
The aortic valve is called a semilunar valve, where is it found?
It is found between the left ventricle and the aorta
71
The pulmonary valve is another semilunar valve, where is it found?
It is found between the right ventricle and the pulmonary artery.
72
What makes the lub-dub sound of the heart?
It is made from the back flow of blood hitting the heart valves when they close. the first heart sound comes from the closing of the bicuspid and tricuspid valves and the second sound comes from the closing of the aortic and pulmonary valves.
73
Where is deoxygenated blood from all parts of the body collected?
it is collected through the superior and inferior vena cava which then empty into the right atrium and as this fills up the tricuspid valve opens and blood struts to fill the right ventricle.
74
When happens when the right ventricle is full?
The tricuspid valve prevents a back flow of blood. once the ventricle is full it in turn contracts and forces blood through the pulmonary valve into the pulmonary artery. - the pulmonary valve prevents back flow.
75
What happens to the blood in the pulmonary artery?
The pulmonary artery transports the deoxygenated blood to the lungs where it loses waste CO2 and picks up oxygen from the air in the lungs becoming oxygenated again.
76
How does the oxygenated blood return to the heart?
The pulmonary veins return the oxygenated blood to the left atrium which then contracts and forces the blood through the bicuspid (mitral) valve into the left ventricle.
77
What happens when the left ventricle is full?
Once the left ventricle is full it contracts and forces the oxygenated blood through the aortic valve into the larger artery in the body, the aorta.
78
What happens at the same time in the heart?
The two atria contract at the same time so blood flow into the left and right ventricles at the same time,When the two ventricles contract blood leaves the heart.
79
When the aorta leaves the heart what happens?
The aorta separates into various smaller arteries which distribute the blood to all parts of the body supplying tissues with oxygen, water and food. Various veins then carry the blood away from these organs.
80
What is diastole?
Diastole is when the heart muscles relax and blood fills the heart. Ventricular diastole is when the ventricles are relaxed whilst atrial diastole is when the ratio are relaxed.
81
What is the blood pressure like when diastole?
The blood pressure in your arteries is at its lowest.
82
What is Systole?
Systole is when the heart muscles contract and force the blood out into the blood vessels.
83
What is Atrial Systole?
Atrial systole is the contraction of the heart muscle of the left and right atria. Normally at the same time.
84
What is ventricular systole?
Ventricular systole is the contraction of the muscles of the left and right ventricles. it is at this time when blood is being forced out of the heart, when the blood pressure in your arteries is at its highest.
85
Cardiac muscle has the intrinsic ability to beat rhythmically without any chemical of electrical stimulus - this process is governed by a special area of cardiac muscle called what? Where is it found?
The sinoatrial node (SAN) also known as the pacemaker region of the heart because it is the starting point of a heartbeat. The SAN is found close to where the superior vena cava enters the heart.
86
What happens after a contraction impulse starting in the SAN?
A contraction impulse starting in the SAN spread rapidly to the walls of the atria so they contract and initiate the heartbeat
87
What does the wave of excitation triggers?
The wave of excitation triggers a response in a second region called the atrioventricular node which after a brief pause traits the impulse to the walls of the ventricles through special fibres called Purkinje fibres - this short pause creates a delay between ventricular and atrial contractions
88
What is the basic rhythm given by a natural pacemaker region?
60 beats per minute - but other factors in the body affect the resting rate and they way the hear responds to exercise.
89
What happens if the electrical pacemaker mechanism of the heart stops working?
An artificial pacemaker unit is needed to regulate the heartbeat.
90
Although the heartbeat is automatic, the rate at which it beats can be speeded up or slowed down by what?
The autonomic nervous system.
91
What slows both the rate and force of contraction?
The parasympathetic nervous system.
92
What increases both the rate and force of contraction?
The sympathetic nervous system.
93
What allows the heart to increase or decrease supply with changing demand?
The balance of the parasympathetic and sympathetic nervous system along with the effect of hormones such as adrenaline.
94
When the blood is forced out of the heart through the aorta (the largest artery in the body) what does it travel through before arriving back at the heart?
Blood is forced out of the heart through the aorta, it then travels through other arteries, arterioles, capillaries, venues and veins before arriving back at the heart - these blood vessels are linked together in a continuous network in the body.
95
What do the arteries carry?
Arteries carry blood away from the heart to the organs of the body. The usually carry bright red oxygenated blood except the pulmonary artery which takes purple red deoxygenated blood to the lungs.
96
When blood is forced through an artery what happens?
The arteries stretch when blood is forced through them and go back into shape afterwards.
97
What is the structure of an artery?
Arteries have this walls containing muscle and elastic fibres which a tough outer layer, a smooth lining of endothelial cells and a relatively small lumen.
- fibrous outer layer
- elastic fibres and smooth muscle
- inner layer of epithelial cells
- relatively narrow lumen.
98
Why is it dangerous to cut an artery?
The blood in the arteries is under pressure and blood spurts out rapidly every time the heart beats.
99
What are arterioles?
Arterioles are smaller than arteries and have less fibrous tissue - they have a lot of smooth muscle and they contract and relax to control blood flow between the artery and the capillaries in the tissues.
100
What do the capillaries form?
The capillaries form a huge network of tiny vessels lining the arterioles and the venues.
101
What does the structure of capillaries allow them to do?
Capillaries are narrow with walls which are only one cell thick. This enables substances such as oxygen and glucose to easily diffuse out of the blood into the cells. The substances produced by your cells such as CO2 pass easily into the blood through the walls of the capillaries.
- single layer of epithelial cells
102
What are venules?
Venules are small veins which link the capillaries and larger veins.
103
What do the veins do?
Veins carry blood back towards the heart and do not have a pulse.
104
What is the blood like in the veins?
Blood in veins is usually low in oxygen and so is a deep purplish colour.
105
What is the structure of the veins like?
Veins have much thinner calls than arteries with a greatly reduced layer of muscle and elastic fibre - as a result they have a much larger lumen and much lower blood pressure. Veins often have valves to prevent back flow of blood as it moves back to the heart.
- tough collagen rich outer layer
- thin layer of elastic fibres and smooth muscle
- inner layer of epithelial cells
- large lumen.
106
What does double circulation mean in humans?
Humans have a double circulation, which means there are 2 completely separate circulation systems in the body.
107
What does the pulmonary circulation do?
The pulmonary circulation takes deoxygenated blood from the heart to the lungs where it is oxygenated and travels back to the heart. It involves the movement of purplish deoxygenated blood from the right side of the heart to the lungs via the pulmonary artery.
108
What does the systemic circulation do?
The systemic circulation carries oxygenated blood from the heart around the body and brings the deoxygenated blood back from the tissues to the heart.
It involves the pumping of bright red oxygenated blood to every organ, tissue and cell of the body. the blood is returned to the right atrium in the veins. In most cases oxygenated blood travels to the organ, material are exchanged in the capillaries and deoxygenated blood returns to the heart.
109
When happens to the deoxygenated blood when it reaches the lungs via the pulmonary artery?
In the lungs the CO2 is released from the blood plasma to the air in the alveoli to be breathed out and inhaled oxygen is absorbed from the air by the red blood cells - the newly oxygenated blood then returns to the left atrium of the heart via the pulmonary vein.
110
How does the liver receive oxygenated blood?
from the hepatic artery as normal but it also received blood from the stomach, intestines, spleen and pancreas via the hepatic portal vein.
111
What is the state of the blood coming from the hepatic portal vein?
This is blood that has already supplied the gut with oxygen so it is relatively deoxygenated but loaded with the products of digestion so the liver processes many of these products.
112
What does the blood leave the liver via?
All the blood leaves the liver through the hepatic vein.
113
The circulation maintains a constant blood supply to the vital organs and is responsible for diverting blood in time of need, what are examples of these times?
During physical exercise the amount of blood flowing to the digestive system is reduced so that more blood can be supplied to the large skeletal muscles, conversely in times of inactivity blood can be directed from the skeletal muscles to the gut to help digest a large meal.
114
What is the lymphatic system made up of?
The lymphatic system is made up of a network of capillaries, vessels, ducts and nodes which carry out a number of functions.
115
What does the lymphatic system do?
The network collect leaked plasma fluid and proteins from various body systems like the nervous system, digestive system and skeletal system.
116
What do the glands in the lymphatic system do?
The glands filter and remove bacteria form lymph nodes when you have an infection, which is why they become swollen when you are ill.
117
The walls of the blood capillaries are permeable to everything except what?
Red blood cell and the plasma proteins.
118
What happens to the fluid in blood as it flows through the capillaries under pressure from the arterial system?
The fluid is squeezed out of the vessels and fills the spaces between the cells and is known as tissue fluid intercellular fluid or interstitial fluid.
119
How do substances pass from the blood to the cells and from the cells to the blood?
By diffusion through the tissue fluid.
120
At the venous end of capillaries, how does most of the water from intercellular fluid and waste products and ions return to the blood?
At the venous end of the capillaries, most of the water from the intercellular fluid returns to the blood by osmosis with the waste products and ions returning by diffusion.
121
How much intercellular fluid is returned through the lymphatic system?
About 10%
122
How does intercellular fluid return to the blood through the lymphatic system?
Tissue fluid drains into a series of connected tubes called lymphatic capillaries. Once the fluid is in these it is known as lymph. The lymphatic capillaries join up to form larger vessels and fluid moves through the lymph system by a squeezing effect of muscle as the body moves.
123
How is back flow prevented in the capillaries?
By a series of valves.
124
How is lymph returned to the blood?
The lymph is returned to the blood into large veins in the neck area which feed into the vena cava and ultimately bad into the heart.
125
What does the lymphatic system play an important part in?
The immune response and defence mechanisms of the body.
126
What are enlarged lymph glands a sign of?
A sign the body is dealing with an invading pathogen, this is why doctors often examine the neck, armpits, stomach and groin in patients as these are the main sites of the lymph glands.
127
2.2.4 Common pathologies of the cardiovascular system:
| What is anaemia?
Anaemia is a condition where the blood does not carry enough oxygen
128
What are the most obvious symptoms?
Tiredness, lethargy, feeling faint and breathlessness.
129
There are a number of causes of anaemia, what are these?
- Not enough haemoglobin in the RBCs - a result of a lack of iron, vitamin B12 or folic acid in the diet.
- Abnormal haemoglobin as a result of genetic disorders such as sickle cell disease.
- Reduced numbers of RBSc for example as a result of blood loss (haemorrhage).
- A decrease in the number of RBCs due to the problems in bone marrow as a result of cancer, radiation or one medications known as aplastic anaemia.
130
In healthy blood there are fewer WBCs than RBCs - In leukaemia what happens?
In leukaemia the bone marrow becomes cancerous and rapidly produces vast numbers of WBCs - These new WBCs are immature and do not work properly in the immune system, as a result the body can no longer fight disease causing bacteria and viruses.
131
What is leukopenia, what can it be caused by?
Leukopenia is where you have too few blood cells and can be cause by certain medicines such as corticosteroids and anticancer agents.
132
What is an arrhythmia?
An arrhythmia is an atypical heart rhythm arising from abnormal electrical activity within the heart. The beat of the heart may be irregular, faster or slower than normal. Some may result in a heart attack.
133
What can be arrhythmia be corrected or controlled by?
Some can be corrected using a pacemaker, others can be controlled by drugs.
134
There are many different causes of heart disease, if untreated can lead to what?
Chronic heart failure.
135
What is heart failure?
In heart failure either the left side, the right side of both sides of the heart fail to pump blood properly.
136
What symptoms can heart failure cause?
Chest pain, tiredness, fluid retention and breathlessness.
137
What are some causes of heart failure?
```
High blood pressure
Disease of the heart valves
Certain abnormal heart rhythms
Enlargement of the heart
Some dogs and chemicals such as excessive alcohol or cocaine, and some types of chemotherapeutic (cancer treating) drugs.
```
138
What is angina?
Chest pain.
139
What is myocardial infarction?
A hear attack - whereto coronary arteries become completely blocked by a blood clot of a fatty plaque - a region of the heart muscle may be damaged or destroyed - if the area affected is large enough the hear may stop beating completely causing death.
140
What can cause angina?
If the coronary arteries are narrowed or blocked for example due to atherosclerosis then not enough blood reaches the heart muscles to supply the oxygen it needs and the affected person may get angina.
141
What is blood pressure a result of?
Blood pressure is a result of the pressure that the blood exerts on the artery walls.
142
In a healthy person at rest, what does the maximum pressure come from and what is it equal to? what is this pressure known as?
In a healthy person at rest, the maximum pressure comes from the contraction of the left ventricle and is equal to about 120mm of mercury (mmHg). - This is know as the systolic pressure?
143
When is the minimum blood pressure taken? What is this pressure known as? What should the pressure be at?
At the point when the heart is relaxed and filling with blood. this is known as diastolic pressure and should be around 80mm of mercury.
144
What can hypertension cause?
Hypertension can cause damage to organs such as the heart, brain, kidney and eye if untreated.
145
What is hypertension a risk factor for?
Many diseases from strokes and heart attacks to kidney damage and blindness.
146
What is the cause of high blood pressure?
In many cases the cause of the high blood pressure is unknown although narrowing or stiffening of the artery walls is a common cause, as is stress.
147
What can hypertension cause?
Hypertension can cause thickening of the lining of the blood vessels which narrows the lumens and accelerates the development of atherosclerosis and coronary heart disease - prolonger hypertension in arteries in the brain can lead to strokes.
148
What does hypertension in the heart cause?
In the heart, hypertension forces the ventricles to work harder when they eject blood, as a result the left ventricle enlarges, weakens and dilates causing heart failure.
149
Which is atherosclerosis?
Atherosclerosis is a build up of yellowish fatty deposits on the endothelium of the arteries.
150
What does atherosclerosis cause?
It restricts the flow of blood through the artery or even blocks it completely - it greatly increases the risks of heart attacks and strokes
151
What factors is atherosclerosis linked to?
It is linked to many factors including raised levels of cholesterol in the blood.
152
How is atherosclerosis treated?
It is commonly now treated with a stent, a metal mesh that is placed in the artery - a tiny balloon is inflated to open up the stand and the blood vessels at the same time, and the stand is left in place to hold the blood vessel open - stents are other used instead of or as well as the drugs described below.
153
What are iron supplements used for?
Iron supplements are used to treat simple anaemia.
154
What is iron needed for?
Iron is needed to make haemoglobin so iron supplements make it possible for the body to make more haemoglobin and increase oxygen transport round the body.
155
What are anticoagulants and what are they used for?
Anticoagulants are drugs that reduce the tendency of the blood to clot. They are used to treat patients with a risk of deep vein thrombosis, strokes and clot formation.
156
What are lipid regulators, what are they used for?
Lipid regulators are drugs that lower LDL cholesterol delves in the blood, lowering the risk of atherosclerosis developing in the arteries. Statins are widely used.
157
What do positive inotropic agents do? what are they used to treat?
Positive inotropic agents increase the force of contraction of the heart and are important in treating congestive heart failure.
158
What do anti-arrhythmic drugs help with?
They help to control abnormal rhythms of the heart
159
What do diuretics do? what can they help with?
Diuretics stimulate the output of urine by the kidneys, this reduces oedema and helps people with chronic heart failure by reducing the blood pressure.
160
What do beta-blockers do? what are they used to treat?
Beta-blockers reduce the rate and force of the heartbeat and increase vasodilation in the blood vessels. They are used to treat high blood pressure and some heart arrhythmias such as atrial fibrillation.
161
What do calcium channel blockers do? what can they be used to treat?
Calcium channel blockers widen the arteries and reduce the rate and force of the heartbeat - they can be used to treat angina, hypertension and heart arrhythmias.
162
What do ACE inhibitors/ positive angiotensin receptor blockers do?
Increase vasodilation and reduce the formation of vasoconstrictive angiotensin by the kidneys to treat hypertension.
163
What do nitrates do?
Nitrates cause relaxation of the vascular smooth muscle in both arteries and veins and relieve angina.
