This is a draft cheat sheet. It is a work in progress and is not finished yet.
Blood Vessels
Types |
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Arteries: Away from heart, oxygenated (except pulmonary artery) |
Veins: Towards heart, deoxygenated (except pulmonary vein) |
Capillaries: Tiny, exchanges gases |
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Basic Structure |
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Arteries & Veins |
Tunica intima |
Tunica media |
Tunica externa |
Endothelial cells |
Basement membrane |
Collagen fibres |
Veins also have valves |
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Capillaries |
1 cell thick endothelial layer |
Vasodilation Vs Vasoconstriction
Vasodilation |
Vasoconstriction |
Widening → blood flow increase |
Narrowing → blood flow decrease |
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Both Aim To... |
Maintain blood flow |
Move blood |
Control temperature |
Transport WBCs & platelets |
Blood Flow Through The Heart
Deoxygenated Side |
1. Superior & inferior vena cava |
2. Right atrium |
3. Tricuspid valve |
4. Right ventricle |
5. Pulmonary/semi-lunar valve |
6. Pulmonary artery |
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Oxygenated Side |
7. Pulmonary vein |
8. Left atrium |
9. Bicuspid valve |
10. Left ventricle |
11. Aortic/left semi-lunar valve |
12. Aorta |
Venous Return Methods
Skeletal Muscle Action |
Skeletal muscle squeezes veins while walking |
Valves prevent back flow |
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Respiratory Movement |
Breathing in causes diaphragm to move down: |
⬆️ pressure abdominal cavity |
⬇️ pressure thoracic cavity |
Blood moves upwards to heart from abdomen to thoracic cavity |
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Venoconstriction |
Wave-like motion of veins propels blood |
Age-Related Changes
Includes... |
Stiffer & less elastic arteries |
Loss of blood pressure control |
Increased likelihood of hypertension & hypotension |
Increased risk of lifestyle diseases |
Pulse & Blood Pressure Indications
As part of vital signs |
To establish a baseline of normal vital signs |
To monitor/check health status |
To determine blood flow |
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Red & White Blood Cells
Red Blood Cells |
Formation via erythropoiesis |
No organelles |
O₂ binds to Hb's Haem group |
Eliminated in spleen or liver |
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White Blood Cells |
Forms in red blood marrow |
Destroys infections |
Only in blood for 10-12 hours before moving into tissues |
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Granulocytes: |
Agranulocytes |
Basophils |
Lymphocytes |
Eosinophils |
Monocytes |
Neutrophils |
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Never Let Monkeys Eat Bananas said GRANdpa BEN |
Haemostasis
The process of stopping/controlling blood flow |
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1. Vasoconstriction |
2. Platelet Plug Formation |
3. Coagulation |
4. Fibrinolysis |
Cardiac Conduction System
Heart beat via electrical impulses |
Heart is auto-arrhythmic, though can be influenced by brain |
Heart has neuromuscular cells |
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Heart Rate: Cardiac impulse made by SA node. 60-100 times/min |
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Process |
1. Sinoatrial (SA) Node/Pacemaker |
2. Atrial Conducting Fibres & Atrioventricular (AV) Node |
3. Bundle Of His |
4. Purkinje Fibres |
Cardio-Vascular Related Conditions
Heart Attack/Myocardial Infarction (MI) |
Blocked blood supply kills myocardial tissue, preventing contraction |
Can be caused by atherosclerosis |
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Cardiac Arrest |
SA Node stops firing |
Caused by: haemorrhage, MI or SA Node problem |
Major Pulse Sites
Common |
Carotid |
Radial |
Brachial |
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Less Common |
Temporal |
Apical |
Femoral |
Popliteal |
Pedal |
Blood Pressure
The pressure that blood flow puts on an artery wall |
Occurs during heart contraction & relaxation |
Unit mmHg |
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Pressure Types |
Systolic (^) |
Diastolic (v) |
Pressure during contraction |
Pressure during relaxation |
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Blood Pressure When It's... |
Normal (At Rest) |
Abnormal |
Systolic: 100-120 mmHg |
Hypertension: High BP |
Diastolic: 60-80 mmHg |
Hypotension: Low BP |
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Blood
Components |
Erythrocytes |
Leukocytes |
Thrombocytes |
Plasma |
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Functions |
To transport |
To protect |
To regulate electrolyte & fluid balance |
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pH Of Blood |
7.35-7.45 pH |
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pH Buffer |
To maintain blood pH |
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H₂CO₃ ⇌ HCO₃ + H⁺ |
H₂CO₃ formation increases alkalinity |
HCO₃ formation increases acidity |
Heart
One way circulatory system |
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Layers |
Pericardium |
Myocardium |
Endocardium |
Coronary Arteries
Main |
Left Anterior Descending (LAD) Coronary Artery |
Circumflex Coronary Artery |
Right Coronary Artery |
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Diastole: Coronary arteries filling when heart is relaxing |
Cardiac Output
Total blood amount pumped through heart in 1 minute |
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Total Blood Volume... |
On average: ≃ 5 L |
In men: 5-6 L |
In women: 4-5 L |
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Cardiac Output Formula |
Cardiac Output = Heart Rate x Stroke Volume |
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Heart Rate: Amount of beats per minute |
Stroke Volume: Amount of blood pushed out of ventricles |
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Factors Affecting... |
Heart Rate: Exercise, drugs, hormones, stress, individual's size |
Stroke Volume: Ventricle strength |
Pulse
Rate |
No. of bpm |
| |
Normal (At Rest) |
Abnormal |
Adults: 60-100 bpm |
Tachycardia: Above normal |
Children: 90-120 bpm |
Bradycardia: Below normal |
Infants: 120-140 bpm |
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Rhythm |
Pulse regularity |
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Normal (At Rest) |
Abnormal |
Sinus Rhythm: 'Regular'/even spaces between beats |
Arrhythmia: 'Irregular'/uneven spaces between beats |
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Volume |
Strength of beat |
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Strong |
Normal |
Weak |
'Full & bounding' |
'Normal' strength |
'Weak & thready' |
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