The Cardiovascular System Flashcards
What is the function of the cardiovascular system?
Transporting oxygen, nutrients, hormones, and cellular waste products throughout the body.
Pumping blood around the body to get oxygen to organs, muscles and tissue in need of oxygen for energy (ATP).
What is the cardiovascular system?
The cardiovascular system consists of the heart, blood vessels, and the approximately 5 liters of blood that the blood vessels transport.
What does the cardiac cycle involve?
It involves the heart filling with blood and then pumping this to the rest of the body via the arterial system.
How long does it take to complete a heart beat?
Just under one second
What are the stages of the cardiac cycle?
Stage 1- atrial diastole
Stage 2- ventricular diastole
Stage 3- atrial systole
Stage 4- ventricular systole
What happens in stage 1 of the cardiac cycle?
The atria fill with blood returning from two key areas: the body and the lungs.
The valves remain shut.
What happens in stage 2 of the cardiac cycle?
The bicuspid and tricuspid valves open because of the pressure build-up in the atria; blood flows into the ventricles and the valves shut again.
What happens in stage 3 of the cardiac cycle?
The atria contract and blood is forced into the ventricles and pressure increases to become greater than that in the aorta and pulmonary artery.
What happens in stage 4 of the cardiac cycle?
The semilunar valves (pulmonary valve and aortic valve at the top of the heart) open and the ventricles contract, forcing blood into the aorta to move to the rest of the body or into the pulmonary artery to go to the lungs.
What is stroke volume
How much blood is squeezed out of the heart into the aorta each time it beats.
What is heart rate?
How many times your heart beats per minute.
What is cardiac output?
It is the amount of blood pumped out of the heart per minute.
What is the equation to work out cardiac output?
Cardiac output= stroke volume x heart rate
Q= SV x HR
What happens to our CO, SV and HR during exercise?
As we begin to exercise our HR goes up and so does our SV – therefore our CO increases.
Comparing trained and untrained individuals
As we train our HR does not increase as much as our ability to pump blood around our body is better (our SV is better).
Untrained= beats more! but pushes less blood out Trained= beats less because it pushes out more blood.
How much blood is in your body?
5-6 Litres for males
4-5 Litres for females
What happens when water is lost from the body?
When water is lost form the body (sweat), it is lost from the blood (plasma), the blood then becomes more viscous which then it is therefore harder to pump around the body.
Explain the redirection of blood flow.
When we exercise our body redirects blood flow to where it needs to go, so to our working muscles. This also means it is redirected away from our intestinal tract and non essential organs.
What is blood composed of?
•Red blood are produced in bone marrow and contain hemoglobin, which
carries oxygen to body tissues and muscles.
•White blood cells fight infection. They are produced in bone marrow,
lymph tissue and the spleen.
•Platelets are cells that help form blood clots to stop bleeding.
They are produced in bone marrow.
•Blood plasma carries nutrients and also removes waste products.
•Plasma is 90% water and contains fibrinogen, which assists platelets in blood clotting.
What are the functions of blood?
- Transportation of gases, fuels, and minerals
- Protection against infection and dehydration
- Maintaining the body’s state of equilibrium (homeostasis) via enzyme and hormone regulation
Measuring blood pressure and HR.
We measure blood pressure by measuring the force that is exerted by the blood against the blood vessel walls.
As blood is pumped by the heart the pressure in the arteries increases and decreases.
When blood is pumped into the aorta (ready to go around the body) it is the greatest pressure – systole.
It is the lowest pressure during ventricular diastole – when the heart relaxes and fills with blood.
Blood pressure typically is 120/80.
With 120= systole and 80= diastole
What are blood vessels?
Blood vessels make up the vascular network through which all blood flows to all parts of the body.
What is the function of the respiratory system?
The respiratory system provides oxygen to the body’s cells whilst removing carbon dioxide.
What do the airways consist of?
The airways includes, the nose, mouth, pharynx, larynx, trachea, bronchi, and bronchioles which carries air between the lungs and the body’s exterior.
The lungs
The lungs consist of the alveoli, where the gaseous exchange takes place (pulmonary diffusion).
The body has more than 500 million alveoli.
The surface of each alveoli has a rich blood supply to help with gaseous exchange.
The respiratory muscles include?
The diaphragm and the intercostal muscles.
What are the intercostal muscles?
They are the muscles situated between each rib that contract and relax to assist breathing.
Breathing in
Breathing in = Inspiration
Active
• Intercostals and diaphragm both contract
• Ribs move upwards & outwards
• Diaphragm moves downwards
• Lung space increases causing decreased lung pressure
• Air moves into the lungs
Breathing out
Breathing out = Expiration
Passive
• Intercostals and diaphragm relax
• Ribs drop and diaphragm return to dome-like relaxed state
• Lung space decreases causing increased lung pressure
• Air moves out of the lungs
What is intrapulmonary pressure?
It is the pressure within the lungs.
What is tidal volume?
The amount of air inhaled and exhaled per breath.
What is respiratory rate?
The amount of breaths taken per minute.
What is minute/pulmonary ventilation?
The volume of air moved into and out of the respiratory tract each minute.
What is the equation for minute ventilation?
Minute Ventilation= respiratory rate x tidal volume
MV= RR x TV
What is steady state?
It is the point during exercise when oxygen supply equals oxygen demand.
What is VO2 maximum? How can it increase?
The maximum volume of oxygen the body can take in, transport and utilise – O2 uptake
This increases with training.
Aerobic more.
Both circulatory and respiratory systems.
What is pulmonary diffusion?
The gaseous exchange that occurs in the lungs
What are the main functions of pulmonary diffusion?
- to provide blood with oxygen before being transported to muscles & other cells
- to remove carbon dioxide from blood returning from the muscles & other cells
Movement of gases at the alveoli is two way:
- oxygen moves from the alveoli into the blood &
* carbon dioxide moves from the blood to the alveoli.
When haemoglobin and oxygen combine they form?
Oxyhaemoglobin:
The explanation and equation for oxyhaemoglobin is?
Most oxygen is transported by the red blood cells combined with hemoglobin (Hb) and when the two combine they form oxyhaemoglobin:
Hemoglobin + Oxygen = Oxyhaemoglobin
Hb + O2= HbO2
What does a-VO2 diff. stand for?
Arteriovenous oxygen difference
What types of blood vessels are there staring from the heart and ending back at the heart?
Arteries Arterioles Capillaries Venules Veins
What is the arteriovenous oxygen difference?
It’s the difference in oxygen concentration between arterial and venous blood
At rest, the AVO2 diff. is approximately 5 mL of oxygen per 100 mL of blood and this reveals the amount of oxygen used by muscles.
Trained and untrained arteriovenous oxygen difference
Untrained= less likely to use all of the oxygen in the muscles. Trained= more likely to use all of the oxygen in the muscles.
When we exercise what happens to our heart rate?
Your heart rate increases when you exercise, because you are working harder.
How much your heart rate increases depends on the intensity of your exercise and how fit you are.
When we exercise what happens to our stroke volume?
Your stroke volume increases when you exercise to increase the circulating blood in your system so your body responds appropriately to exercise.
When we exercise what happens to our tidal volume?
Exercise causes an increase in tidal volume because your requirements for oxygen go up.
When we exercise what happens to our oxygen uptake?
Oxygen uptake increases as it is required to feed your muscles and keep them working. A steady state is reached, although the more exercise, the increased oxygen uptake.
When we exercise what happens to our ventilation?
Ventilation increases to meet the demands of exercise through the following two methods:
- An increase in ‘tidal volume’ which refers to the quantity of air that is inhaled and exhaled with every breath. This is similar to ‘stoke volume’ in the cardiovascular system.
- An increase in the ‘respiration or breathing rate’ which refers to how many times a person completes an inhalation and exhalation every minute. This is similar to ‘heart rate’ in the cardiovascular system.
What is systemic circulation?
The part of blood circulation that carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart.
What is pulmonary circulation?
The part of blood circulation which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated blood back to the heart.
What is gaseous exchange?
The ‘swapping’ of gases between the alveoli air and the blood.
Diffusion occurs when molecules move from an area of high concentration (of that molecule) to an area of low concentration.
This occurs during gaseous exchange as the blood in the capillaries surrounding the alveoli has a lower oxygen concentration of Oxygen than the air in the alveoli which has just been inhaled.
Both alveoli and capillaries have walls which are only one cell thick and allow gases to diffuse across them.
The same happens with Carbon Dioxide (CO2). The blood in the surrounding capillaries has a higher concentration of CO2 than the inspired air due to it being a waste product of energy production. Therefore CO2 diffuses the other way, from the capillaries, into the alveoli where it can then be exhaled.
Systolic
Cuff
Diastolic
End had
What happens to blood flow when we exercise?
As you exercise, the blood vessels in your muscles dilate and the blood flow is greater.
As ATP gets used up in working muscle, the muscle produces several metabolic byproducts (such as adenosine, hydrogen ions and carbon dioxide). These byproducts leave the muscle cells and cause the capillaries (small, thin-walled blood vessels) within the muscle to expand or dilate (vasodilation). The increased blood flow delivers more oxygenated blood to the working muscle.
What happens to the blood when it arrives at the muscles it is needed at?
The oxygen is used at the working muscle and the deoxygenated blood is pumped back to the heart through the superior and inferior vena cava I to the right side of the heart and into the lungs to be re-oxygenated and sent back to the heart to begin again.
How is blood flow controlled through capillaries?
Blood flow through capillaries is controlled by small muscular rings known as pre-capillary sphincters and these can stop blood flowing into capillaries and redirect it to other parts of the body.
What is the respiratory system?
The respiratory system comprises of the mouth, nose, airways and lungs. Most of the system is encased by the ribs, sternum and vertebrate.
