Ch 5 - The Cardiovascular System Flashcards
What makes up the circulatory system
The heart
Blood vessels:
The arteries
The Veins
The capillaries
Blood transports:
Carbon dioxide Oxygen Glucose and other Nutrients Hormones White blood cells Haemoglobin Platelets Plasma
What blood vessels do when experiencing cold conditions and warm conditions
Vasoconstriction - The vessels constrict and move inwards towards the warmth
Vasodilation - Move outwards towards the skin and dilate to lose heat
Circulatory Systems
Pulmonary:
Heart to the lungs (de-o2) and then to the heart (o2)
Systemic:
Heart (o2) to the body where exchange happens at the cells, then back to the heart (de-o2)
Arteries
Carry o2
Red in diagrams (usually)
Move blood away from the heart
Work under much higher pressure than the veins
Veins
Transport de-o2 blood
Usually blue in diagrams
Carries de-o2 blood to the heart
Have valves in them to prevent back flow
Capillaries
1 cell thick
Permeable for gas exchange (Ficks Law of Diffusion)
How the Blood vessels interact
Arteries (transport o2) -> Capillaries (gas exchange occurs) -> Veins (carry de-o2 blood back to the heart)
Composition of Blood - RBC
Red Blood Cells
Produced in the bone marrow Transport: Haemoglobin - Body decides how much it needs (people and height and athletes have a higher amount usually) - Also made in bone marrow - A type of protein - Replaced every 108 - 140 Days
The Composition of Blood - WBC
White Blood Cells
- Made in bone marrow
- Fight infections/bacterias (part of the immune system)
Composition of Blood - Plasma
A salty liquid in our blood that has no cells in it
- Where you would find the carbonic acid mix
Composition of Blood - Platelets
Responsible for the coagulation of our blood (clump our blood together)
- Forms blood clots
- Rush to the surface when we cut ourselves to form a scab
Blood Flow Through The Heart
All De-Oxygenated:
1 - Vena Cava
2 - Right Atrium - Stores blood (weak pump)
3 - Right Ventricle - Main pumping force (strong thick muscle)
4 - Pulmonary Arteries (only arteries to carry de-o2)
5 - Lungs (where the blood exchanges CO2 for O2 and becomes oxygenated)
All Oxygenated: 1 - Pulmonary Veins (transport newly o2ated blood to heart -Only veins to carry 02ated blood) 2 - Left Atrium (storage) 3 - Left Ventricle - Major pump 4 - Aorta 5 - Systemic System
Blood Supply to the Heart
The heart is a big muscle and requires fuel (o2 and glucose) through internal respiration
Wrapped in its own arteries and veins
- Coronary artery delivers o2 and nutrients
- Coronary Veins remove waste products:
- Carbon dioxide
- Water (Which forms carbonic acid)
Pulse Rate
Average of 72bpm in an average healthy adult
Controlled by: (autonomous NS / Vegetative)
- Glucose levels
- Exercise
- Adrenaline
- CO2
Effected by: - Eating
- Caffeine / drugs
- Age (pulse increases as you get older)
- Gender (females have a slightly higher pulse)
Stroke Volume
The amount of blood pumped by the left ventricle in 1 contraction
- Roughly 70ml on average
Cardiac Output
The volume of blood pumped by the heart in 1 minutes
CO = HR x SV
Average is roughly 5-5.5 Litres per minute
Coronary Heart Disease
Coronary arteries block over time - Plaque builds up
- The heart then no longer can function properly as it doesn’t receive the nutrients and energy it needs
- Clots can form and also block the arteries and veins
When veins block, the waste products can no longer be removed :
- Leads to pain in the heart (angina)
Factors that can increase the risk of Angina
Age
Stress
CHD
Heart Attack (Myocardial Infarction)
CHD can lead to a heart attack (where an area of the heart receives such little o2, it actually dies)
Symptoms of a Heart Attack
Pain in the left side of the body and heart Breathing rate increases Chest becomes tight Feelings of Nausea - Vomiting Sweating Pallor
80% of victims admitted to hospital survive
Most common cause of deaths to males over 40
Factors making you most prone to a myocardial infarction
Hereditary (most contributing factor) Smoking High blood pressure (hypertension) Lack of exercise (20/30 mins 3x a week) Diabetes (bought upon by obesity)
Anaemia
A low red blood cell count leading to:
- Decreased amounts of haemoglobin
- Decreased amounts of iron (found in broccoli, chocolate, red meat, wheetabix)
Symptoms:
- Pallor (pale)
- Lethargic (tired, weak, fatigue)
Carbon Monoxide Poisoning
Caused by the incomplete combustion of carbon
(Piston engine aircraft more likely than jets)
CO is more easily absorbed into haemoglobin than o2 (210-250% more easily than o2)
Body does not react to it and doesn’t know it is happening
- Odourless
- Colourless (cant detect it)
Highly toxic and will kill you
Symptoms of Cardbon Monoxide poisoning (CO)
Headache Quite red (flushed - cherry red skin (RUDDY)) Dizziness and impaired vision Nausea Lethargic (sleepy and weak) Joint Pain Impaired memory Unconsciousness -> Death
Can be caused by cockpit heaters but there are detectors
If carbon monoxide is present in the cabin and factors that affect the severity
Put on o2 mask and breath 100%
Turn off cabin heater
In light aircraft you can open the windows or Verny
Land ASAP
Can be several days recovery - See you AME
Factors affecting the severity:
- Altitude
- Smoking
- Lung disease or infection
- Age
- Obesity
Smoking
Cigarettes contain:
- Carbon monoxide - reduce the amount of saturated O2
- Nicotine
- Tar (substance used to tar roads)
- Arsenic and Cyanide (Highly Poisonous)
Affect:
- Time of useful consciousness is reduced by 50% in the case of hypoxia
- Night vision decreases
- Reduced G tolerance
- Increase the risk of CHD and heart attacks
- Carboxyhemoglobin levels increase by 7% if smoking 20 a day
Blood Pressure
Depends on:
- HR (xSV=CO)
- Elasticity of arterial walls and thickness
- Peripheral resistance (plaque)
- Viscosity of the blood
- Age plays a big part. BP increases as you get older as arterial walls thicken and elasticity decreases
Systolic/Diastolic (mmHg)
Systolic Pressure
When the ventricles contract.
Is the pressure in the arteries as the ventricles contract.
Measured on the upper arm as the blood pressure is going to be roughy the same as the heart as it is on the same level of the heart.
Diastolic Pressure
When the ventricles are relaxed, in between beats
Hypertension definition causes and effects
High BP. 140/90mmHg
Causes: Age Obesity Stress Hereditary Gender Pregnancy Smoking
Effects: Can lead to strokes Heart attack Angina Nose bleeds Heart palpitations Complete kidney failure (stagnation of waste products -> toxins)
Treating Hypertension
Decrease amount of salt in the diet (decrease cholesterol) Exercise Reduce stress Drugs (thin the blood) Stop smoking
Hypotension causes and effect
Low blood pressure
Causes: Haemorrhage - accidents /disease Low glucose levels Giving blood - bad response which is emotional (shock) Emotions Genetics / Hereditary
Effects: Death Pallor and clammy Dizziness -> pass out Nausea Reduced concentration levels Stagnation of blood (pooling in the lower extremities which can lead to death of areas in contact with) Lethargy
Treatment of Hypotension
Clog bleeding asap
Drugs to increases platelet count
Eat surgery items
Pressoreceptors
Located in the carotid artery, up stream of the heart but before the brain
They help regulate BP and Heart rate
Part of the autonomous NS regulation.
Hypertensive - pressorecptors decrease HR and atrial walls relax
Hypotensive -> Increase HR and tighten arterial walls
Blood Donation
The reaction to blood donation is emotional (shock) which leads to a decrease BP and then fainting (syncope)
Increased susceptibility to hypoxia due to the decreased levels of haemoglobin (cant usually give blood within 3/4 months)
- Shouldn’t give blood 24 hours before duty
If you give blood, you can reduce the effects:
- Drink plenty of fluids
- Lying flat (supine) for 15 - 30 minutes
- Seek advice from AME before you do it
