Cardiovascular system 2: blood vessels and the heart Flashcards
1
Q
Name the two types of circulation in the body
A
- Systemic circulation - blood pumped from the heart around the body, and back again.
- Pulmonary circulation - blood pumped from the heart to the lungs, and back again.
2
Q
Name the 3 main types of blood vessels…
A
- Arteries
- Veins
- Capillaries
3
Q
Which blood vessel specialises in the exchange of substances between blood and cell/tissues?
A
The capillaries
4
Q
Which blood vessels carry blood away from the heart?
A
Arteries and arterioles
arterioles are smaller arteries
5
Q
Which blood vessels carry blood toward the heart?
A
Veins and venules
6
Q
Except the pulmonary and umbilical blood vessels describe the blood content and pressure of both Arteries/arterioles and Veins/venules
A
Arteries and arterioles are oxygenated with high pressure
Veins and venules are Deoxygenated with low pressure
7
Q
Most blood vessels are formed of three layers. Name the three layers and their positions.
A
- Tunica Externa - outermost layer made of collagen and elastic fibres.
- Tunica Media - middle layer of smooth muscle, controls diameter of blood vessel and therefore blood pressure.
- Tunica Intima - innermost layer made of endothelium. This layer is in direct contact with the blood and is well positioned to respond to changes.
8
Q
The thickness (and presence) of each layer depends on the type of blood vessel. Give a structural characteristic for each type; 1. Arteries and arterioles, 2. Veins and Venules, 3. Capillaries
A
- Arteries and arterioles have a THICKER Tunica MEDIA, and are hence more MUSCULAR
- Veins and venules generally have THIN WALLS. The Tunica EXTERNA is their THICKEST layer.
- Capillaries contain ONLY an ENDOTHELIUM.
9
Q
Fill in the missing words.
Arteries contain large portions of 1.______ tissue. 2._______nerve fibres innervate 3._____ muscle and cause 4._________, which increases blood pressure.
If reduced sympathetic activity, 5._____ _____ is released which causes vasodilation.
A
- elastic
- sympathetic
- smooth
- vasoconstriction
- Nitric dioxide
10
Q
Why are arterioles vital for maintaining blood pressure?
A
Because there are a large volume of arterioles which constrict or dilate depending on the sympathetic nerve activity. (the smooth muscle constricts)
11
Q
Veins have a low blood pressure, name 3 ‘actions’ which aid the return of venous blood to the heart.
A
- Skeletal muscle contraction
- Pumping action of the heart
- Respiratory pump - (the diaphragm when breathing)
*(Veins also contain valves which prevent back flow of deoxygenated blood)
12
Q
How many layers do Capillaries have (name them)
A
Capillaries only have ONE layer of cells - endothelium
13
Q
Fill in the missing words…
Capillaries function in the 1._____ of substances between 2.____and 3.____. Found near every cell in the body. Tissues with a high 4._______ demand have 5._____ capillary networks.
A
- exchange
- blood
- cells
- metabolic
- extensive
14
Q
The key function of the cardiovascular system is to keep blood flowing through capillaries to allow the exchange of …. name 3 and their forms of transport (osmosis etc)
A
- Water - by osmosis
- Nutrients - by facilitated diffusion and active transport
- Gases - carbon dioxide and oxygen by diffusion down the gradient
15
Q
Where is your blood? Give an approximate percentage for each vessel. 1. Veins/Venules
2. Arteries/arterioles 3. Pulmonary vessels 4. Capillaries 5. the heart
A
- 64% in systemic veins/venules
- 13% in systemic arteries/arterioles
- 9% in pulmonary vessels
- 7% in capillaries
- 7% in the heart
16
Q
All blood vessels have smooth muscles (except capillaries) which are influenced by the autonomic nervous system. Name the two systems and their cause.
A
- SYMPATHETIC nervous system stimulation causes vasoconstriction (increasing the blood pressure)
- PARASYMPATHETIC nervous system has little influence. Vasodilation reduces blood pressure.
17
Q
How big is the heart and how many times a day does it beat?
A
The heart is a fist-sized muscular organ that beats approx 100,000 times a day.
18
Q
How many miles of blood vessels does the heart pump blood through within the human body.
A
60,000 miles of blood vessels
19
Q
What is the approximate size of the average heart?
And what is the average mass in grams of the female and male heart?
A
12cm long, 9cm wide.
Average mass: 250g in females, 300g in males.
20
Q
Where is the heart situated? (use correct terminology)
A
The heart rests on the diaphragm near the midline of the thoracic cavity, pointing left.
21
Q
Where is the apex of the heart and what forms it?
A
The Apex of the heart is formed by the left ventricle and lies in the fifth intercostal space.
22
Q
Name the three layers of the heart…
A
- Pericardium
- Myocardium
- Endocardium
23
Q
Where is the pericardium layer of the heart, describe its characteristics and main function.
A
- Pericardium is the outer layer of the heart.
- Thin, double layered membrane. Contains a fibrous pericardium that attaches to the diaphragm and an inner serous pericardium that consists of a visceral and parietal layer.
- Functions to keep the heart in position within the thorax and allow free movement during contractions
24
Q
Where is the myocardium layer of the heart, describe its characteristics and main function
A
- middle layer
- Consists of cardiac muscle and makes up 95% of the heart
- functions to pump blood out of the heart
25
Where is the Endocardium layer of the heart, describe its characteristics and main function
- Innermost layer
- Thin layer of endothelium overlaying a thin layer of connective tissue
- Provides a smooth lining for the heart chambers (also covers heart valves)
26
Fill in the missing words...
The thickest layer of the heart is the 1.______ making up 95% of the heart. The myocardium is formed of 2._______ _______, this is striated and 3.________.
1. Myocardium
2. Cardiac Muscle
3. Involuntary
27
Name the FOUR heart chambers in order of blood flow...
1. Right Atrium
2. Right Ventricle
3. Left Atrium
4. Left Ventricle
28
How thick is the right Atrium, where and what type of blood does it receive and where does it pump blood?
The right atrium is:
- 3mm thick.
- Receives deoxygenated blood from superior and inferior vena cava.
- Pumps blood into the right ventricle through the tricuspid valve
29
How thick is the right Ventricle, where and what type of blood does it receive and where does it pump blood?
The right ventricle is:
- 5mm thick
- receives deoxygenated blood from the right Atrium
- Pumps blood to the lungs through the pulmonary valve into the pulmonary trunk which divides into the left and right pulmonary arteries.
30
How thick is the left Atrium, where and what type of blood does it receive and where does it pump blood?
The left atrium is:
- 3mm thick
- receives oxygenated blood from the lungs via the pulmonary vein
- pumps blood to the left ventricle through the mitral/bicuspid valve
31
How thick is the left Ventricle, where and what type of blood does it receive and where does it pump blood?
The left ventricle is:
- 10 to 15mm thick
- receives oxygenated blood from the left atrium
- pumps blood through the aortic valve into the ascending aorta, which is then pumped around the body (Some of the blood in the aorta flows into the coronary arteries which carry blood to the heart wall).
32
The myocardium performs periodic contractions through a network of cardiac fibres that are self excitable (auto rhythmic) Name the two nervous systems that increase and decrease rate and strength of contraction.
1. Sympathetic nervous system
| 2. Parasympathetic nervous system
33
What is the Sinoatrial node? (SA node) and where is it located?
The SA node is the pacemaker of the heart, that sets rate and rhythm of contraction.
It initiates cardiac conduction, and is located in the right arterial wall.
34
Name the five parts of the conduction system of the heart...
1. Sinoatrial Node (SA node)
2. Atrioventricular Node (AV node)
3. Atrioventricular Bundle (bundle of His)
4. Right and left bundle branches
5. Purkinje fibres
35
What is the Atrioventricular Node and where is it located?
A relay station - conducts impulses once the atria has finished contracting. It is located in the bottom right of the interatrial septum (the wall of tissues that seperates the right and left atria of the heart)
36
What is the Atrioventricular Bundle?
The only site where action potential can conduct from the atria to the ventricles.
37
What are the right and left bundle branches in regards to the conduction system of the heart?
The left bundle branch conducts impulses to the left ventricle, and the right bundle branch conducts impulses to the right ventricle.
They are offshoots of the 'bundle of His' in the heart's ventricle. They play an integral role in the electrical conduction system of the heart by transmitting cardiac action potentials from the bundle of His to the Purkinje fibers.
38
What do Purkinje fibres do?
The Purkinje fibres rapidly conduct the action potential beginning at the apex of the heart, up the remainder of the ventricular myocardium causing ventricular contraction.
39
What type of organ is the cardiac muscle?
Aerobic organ
40
What percentage of body weight does the heart account for, and what percentage of total body oxygen does it consume?
1% of body weight
| 10% of total body oxygen consumption
41
What are the predominant fuel in cardiac muscle (50-70%)
| And which fuel is used 30% of the time
Predominant fuel are Fatty acids
| Followed by glucose
42
During exercise the heart can use what, to produce ATP.
Lactic acid
43
What does ECG stand for and what does it do?
Electrocardiography
An ECG amplifies the electrical currents generated by the action potentials in the heart that can be detected on the surface of the body.
44
ECG - What does the P wave represent?
P wave represents atrial depolarisation (from the SA (sinoatrial) node over the atria)
45
ECG - What does the QRS wave represent?
The QRS wave represents rapid ventricular depolarisation (hence the sharp curve)
46
ECG - What does the T wave represent?
The T wave represents ventricular re-polarisation (when the heart is resting and refilling)
47
The pulse rate is a blood pressure wave originating from the heart. What is the average pulse for an adult?
70 - 90 bpm
48
What is meant by cardiac output?
The volume of blood being pumped out by the heart per minute.
49
How is cardiac output measured and whats the average?
Cardiac output = Stoke volume x heart rate
(Stroke volume = volume ejected per beat from both ventricles)
Average cardiac output is 5 litres per minute (5L/min)
50
What does Systole mean?
The force that drives blood out of the heart - contraction
51
What does Diastole mean?
Period of relaxation when the heart fills with blood
52
What is Tachycardia?
Rapid heartbeat - Resting heart rate over 100bpm
53
What is Bradycardia?
Slow heart rate - Resting heart rate under 60bpm (although this may be normal for athletes)
54
Blood pressure constitutes one of the principal vital signs. What are the normal (NHS) ranges?
90/60 - 140/90
The higher number represents systolic contraction and the lower number, Diastolic relaxation.
55
Cholesterol is a vital compound for cell structure and function. It is found in every body cell. Name 3 of the key functions of cholesterol...
1. Cell membrane integrity (vital in the brain)
2. Vitamin D and Calcium metabolism
3. Sex hormones - oestrogen, testosterone
56
Which organ creates cholesterol? (if not consumed within the diet) and how much can it produce daily
Acquired from liver cells - hepatocytes
| Can produce 1000mg daily
57
Cholesterol is vital, but in excess can cause what to form?
Is thought to be part of the pathogenesis of arterial plaque formation. (Clot)
58
How is cholesterol transported around the body?
Cholesterol is hydrophobic therefore needs to be transported by lipoproteins around the body.
59
Lipoproteins transport cholesterol and fatty acids throughout the body. There are four major classes of lipoproteins name the two talked about in the lecture.
1. Low density lipoproteins - LDL
| 2. High density lipoproteins - HDL
60
Describe Low density lipoproteins - LDL.
- Carry 75% of total cholesterol in the blood, carrying it from the liver to cells of the body.
- When present in excess LDL's can deposit cholesterol in the arteries
61
Describe High density lipoproteins - HDL
- Remove excess cholesterol from body cells and blood and transport it to the liver
- Prevent accumulation of cholesterol in blood
62
What are the NHS guidelines for cholesterol levels?
Should be 5 mmol/L or less for healthy adults and
| 4 mmol/L or less for those at high risk.
63
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the SKIN ....
Skin:
- Blood delivers clotting factors and white blood cells to aid REPAIR when skin is injured.
- Changes in blood flow to the skin is used to adjust body TEMPERATURE
64
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the SKELETAL SYSTEM ....
Blood delivers bone minerals and hormones to control bone remodelling and RBC production (erythropoietin) to the bones
65
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the MUSCULAR SYSTEM ....
Blood transports heat and lactic acid from the muscles
66
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the ENDOCRINE SYSTEM ....
Blood delivers hormones to their target tissues
67
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the LYMPHATIC / IMMUNE SYSTEM ....
Blood distributes immune cells around the body
68
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the RESPIRATORY SYSTEM ....
Blood transports substances such as oxygen and carbon dioxide
69
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the DIGESTIVE SYSTEM ....
Blood carries absorbed nutrients to the liver and distributes hormones that aid digestion
70
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the URINARY SYSTEM ....
20% of cardiac output goes to the kidneys for filtering
71
The heart and blood vessels service the whole body. How does the cardiovascular system help with homeostasis of the REPRODUCTIVE SYSTEM....
Blood distributes reproductive hormones
72
What does hypercholesterolaemia mean?
elevated blood cholesterol
hyper - elevated
cholesterol
aemia - blood
73
What does a defect on chromosome 9 cause
| hypercholesterolaemia
Causes an inability to remove LDL from the blood.
| LDL = Low density lipoproteins
74
Name 5 of 9 causes / risk factors of hypercholesterolaemia...
1. Familial (defect on chromosome 9)
2. Age-related
3. Hypertension
4. Diabetes mellitus (and insulin resistance)
5. Obesity
6. Smoking
7. Sedentary lifestyle
8. Diet (high trans fats, table salt, refined sugars)
9. Excessive alcohol
75
What do statins do?
| hypercholesterolaemia
Statins interfere with the enzyme that produces cholesterol in the liver. Statins are used to treat high cholesterol levels in the blood but do come with many side affects also inducing deficiency of CoQ10 - which will create fatigue.
76
Name two signs of hypercholesterolaemia...
1. Xanthelasma (yellowish deposit of cholesterol under the skin, usually occurring around the eyelids)
2. Corneal Arcus (ring/arc around the eye)
77
What is arteriosclerosis?
Thickening and loss of elasticity of arterial walls.
78
Atherosclerosis is a kind of arteriosclerosis. List the pathophysiology process ... (5)
1. Damage to of the vascular endothelium occurs, creating inflammation.
2. LDL's deposit in the damaged tunica intima and are oxidised, subsequently attracting phagocytes.
3. Macrophages surround the fatty material in an attempt to destroy it and create foam cells.
4. There is proliferation of vascular smooth muscle cells.
5. A cap is formed over the atherosclerotic plaque. Increases blood clot formation and affects arterial wall.
79
Name 2 causes / risks of atherosclerosis…
1. Hereditary, male, age (male 45+, female 55+) ethnicity (south Asian and African or Caribbean background)
2. Hypercholesterolemia
3. Hypertension
4. Diabetes
Obesity, smoking, stress, sedentary lifestyle, excessive alcohol.
80
Atherosclerosis presents clinically as… name 3
1. Angina pectoris
2. Myocardium infarction
3. Ischaemic heart pain
4. Stroke
5. Transient ischaemic attack
81
Name two complications of Atherosclerosis
1. Aneurysm and subsequent haemorrhage
| 2. Embolism - a mobile blood clot which travels through the blood and caused blockage
82
What does ischaemic mean?
Inadequate blood supply to organ or tissue
83
What is Angina pectoris and name the two types..
Ischaemic heart disease due to obstruction or spasm of the coronary arteries.
1. Stable: pain is precipitated by physical exercise
2. Unstable: occurs randomly
84
Name 2 signs and symptoms of angina pectoris
1. Heavy, constricting chest pain, radiating to the neck, left shoulder and jaw. Eases on rest
2. Dyspnoea (difficult or laboured breathing)
85
Name the main allopathic treatment for Angina pectoris (acute relief)
GTN (glyceryl trinitrate) sublingual (applied on/under the tongue)
This is converted in the blood to nitric oxide which causes vasodilation
86
What is another name for a stroke?
Cerebrovascular accident
| Cerebro- = cerebrum/brain
87
What is a stroke? And list two causes
A disruption of blood supply to the brain. Caused by thrombus/embolus (80%) = ischaemic stroke, or a haemorrhage stroke - blood vessel damage (bleed)
88
What is a transient ischaemic stroke?
(Mini stroke)
| Temporary inadequacy of circulation to part of the brain. Lasts no longer than 24 hours
89
What does F.A.S.T stand for in regards to identifying a stroke?
F - facial changes
A - inability to raise arms
S - speech (slurring/difficulty speaking)
T - time - call an ambulance
90
What would you call an abnormal local dilation of arteries due to weakness of the vessel wall?
An aneurysm
91
Name two common examples of aneurysm …
1. Abdominal Aortic Aneurysm (AAA)
| 2. Berry Aneurysm
92
What’s the difference between an abdominal aortic aneurysm and a Berry aneurysm?
Abdominal aortic are 80% fatal and are asymptomatic until it bursts, whereas a Berry aneurysm occurs in the centre of the cerebrum (anterior part of the brain) causing haemorrhage, presents as a very severe headache.
93
What does polycythaemia stand for?
```
Poly = many
Cyt = cell
Aemia = blood
```
Abnormally increased concentration of haemoglobin in the blood
94
What is heparin
A blood thinner
95
What does DVT stand for?
Deep vein thrombosis
96
If a clot from DVT dislodges it may cause a ….
Pulmonary embolism
| A mobile clot that moves and lodges in the lungs
97
Name three risk factors for DVT…
1. Reduced blood flow from immobility, pressure on the vein, shock or long haul flights
2. Changes in blood - dehydration, polycythaemia, sticky platelets, oral contraceptive pill
3. Damage to blood vessel wall
98
What is Transient Ischaemic Stroke and how low do they last?
A temporary inadequacy of circulation to the brain (mini stroke) Lasts no longer than 24 hours.
99
What is the medical term given to the abnormal local dilations of arteries due to weakness of vessel walls?
Aneurysm
100
Name the two common Aneurysms ...
1. Abdominal Aortic Aneurysm (AAA)
| 2. Berry Aneurysm - occurs in the centre of the cerebrum (brain)
101
What does DVT stand for
Deep Vein Thrombosis
102
Give three risk factors for DVT...
1. Reduced blood flow through immobility eg long haul flight, pressure on vein by a tumour, shock.
2. Changes in blood - Dehydration, polycythemia, sticky platelets
3. Damage to blood vessel wall.
103
Break down the word Polycythemia
poly = many
cyte = cell
aemia = blood
Abnormally increased concentration of haemoglobin in the blood
104
One of the tests for DVT is the Positive Homans Sign, what is this?
Forcing foot into a dorsi flexion - if it causes pain behind the knee it could be a sign of deep vein thrombosis - keeping in mind any inflexibility or pro injuries in the leg.
105
Name three signs / symptoms of DVT
1. Limb pain
2. Calf swelling
3. Tenderness along the vein
4. distention of superficial veins
5. increased skin temperature and local redness
106
What is the name given to the incompetent valves which cause pooling of the venous blood and chronically dilated veins.
Varicose Veins
107
Name one of each - sign/symptom, Diagnosis, Treatment - for Varicos Veins
- Aching and fatigue of legs (swollen blue veins)
- Doppler ultrasound
- Compression, hydrotherapy, leg elevation.
108
Give another name for Haemorrhoids
Piles
109
What are haemorrhoids
Enlarged and often inflamed veins in the anal canal.
| Some prolapse, other types do on straining and can be permanent
110
Name three causes of Haemorrhoids
1. Chronic constipation
2. Hypertension
3. Obesity
111
Give two signs/symptoms of haemorrhoids
1. bright red blood on faeces/toilet paper
| 2. Protruding piles causing pain and itching
