(Applied Anatomy & Physiology) Cardio-Respiratory System Flashcards
What are some functions of the cardiovascular system?
- controlling temperature
- blood clotting
- transport
Why is blood clotting important?
It helps open wounds to heal and prevents them from becoming infected.
What are arteries?
Arteries are a type of blood vessel.
What characteristics do arteries have which help it do its job?
Arteries are elastic at we and thick. This lets them cope with the high pressures at which blood is pumped away from the thick, muscular ventricles of the heart.
They also have the thickest walls and largest external diameter of all blood vessels. They have a slightly smaller lumen (internal diameter)
Think of the walls of arteries like elastic bands. They can stretch to cope with the high pressure from the heart but then return to their original shape and size m. This prevents them from bursting.
What is the job of the veins?
Veins carry blood towards the heart (mostly deoxygenated blood)
How are veins structured?
They have a large internal diameter (lumen) but think walls as the pressure inside them is low. Veins have valves to prevent the back flow of blood, which is a possibility due to the lower pressures. This means they do not have a pulse.
What are capillaries?
Capillaries are a tiny network of blood vessels that link the arteries and veins.
What is the structure of the capillaries?
They are very small and can only let 1 red blood cell through at a time.
They are only 1 cell thick.
What is the function of the Capillaries?
They make diffusion easier (shorter distance for oxygen or carbon dioxide to travel)
What does vasoconstriction cause?
Causes space in blood vessels to get smaller, letting less blood through. During exercise, blood vessels leading to the stomach will construct (get narrower) to reduce blood bf low to ‘non-essential’ organs.
What does vasodilation cause?
Causes the space in blood vessels to get larger, letting more blood flow through. During exercise, blood vessels in the working muscles dilate (get wider) to allow more blood in.
What is the vena cava?
A vein that returns deoxygenated blood back to the right atrium
What does the Pulmonary artery do?
Carries deoxygenated blood from the right ventricle to the lungs.
What does the Pulmonary vein do?
Carries oxygenated blood from lungs back to the left atrium.
What is the Aorta?
The largest artery that carries oxygenated blood from the left ventricle to the rest of the body.
Why is the atria small?
They are small because the body only needs them to pump blood into the next change of the heart (ventricle).
What is the function of the right atrium?
It receives deoxygenated blood from the rest of the body through the superior vena cava.
What is the function of the of the left atrium?
It received oxygenated blood from the lungs through the pulmonary vein.
What is the structure of the right ventricle?
It has thinner walls and is less muscular. This is because less pressure is needed to pump the deoxygenated blood into the lungs via the pulmonary vein.
What is the structure of the left ventricle?
It has a thick, strong wall. This is because it needs to pump oxygenated blood to the entire body at a high pressure to make sure it gets there.
What is the name of the wall that separates the right and left ventricles?
The septum
How does deoxygenated blood travel during the cardiac cycle?
°Deoxygenated blood enters the right atrium from the vena cava (from the body)
°The atrium contracts and blood is pushed through a valve (to prevent backflow) into the right ventricle.
°The right ventricle then contracts and pumps blood through the pulmonary artery.
°The pulmonary artery carries the deoxygenated blood to the lungs where gaseous exchange takes place.
How does oxygen blood travel in gaseous exchange?
Gaseous exchange in the lungs causes the blood to become oxygenated.
°Having been oxygenated in the lungs, blood then travels along the pulmonary vein back to the heart.
°Oxygenated blood enters the left atrium from the pulmonary vein.
°The atrium then contracts and pushes the oxygenated blood through another valve (to prevent backflow) and into the left ventricle.
°The left ventricle then contracts to pump blood into the aorta at a high pressure.
What is the pathway of air?
- Air is taken in through the mouth or nose
- The air flows through the trachea (windpipe)
- When the trachea reached the lungs, it divides into 2 branches called the bronchi. Each bronchi enters a lung.
- In the lungs, the bronchi divide further into many bronchioles. These bronchioles are less than 1mm in diameter m.
- At the end of the bronchioles are a cluster of alveoli. These are tiny air sacs where gaseous exchange takes place.
What adaptations do the lungs to make sure efficient gaseous exchange takes place?
Contain alveoli
° There are millions of alveoli (air sacs) in each lung.
°The alveoli have the following adaptations for gaseous exchange:
- They are only 1 cell thick, meaning that there’s a short distance for the oxygen to travel
- They are moist.
- Good blood supply
- Large surface area
Why does oxygen travel from the alveoli into the blood?
°There is a high concentration of oxygen in the alveoli
°There is a low concentration of oxygen in the blood
Why does carbon dioxide travels from the blood into the alveoli?
°There is a high concentration of carbon dioxide in the blood
°There is a low concentration of carbon dioxide in the alveoli
What is haemoglobin?
Red blood cross carry haemoglobin, which transports gases around the body. It carries carbon dioxide from the body to the alveoli in the lungs. Oxygen binds with haemoglobin to make oxyhaemoglobin. This is transported through the blood to the tissues around the body.
What happens to the intercostal muscles and diaphragm when we inhale?
They contract, causing the rib cage to rise up and outwards. The diaphragm also contracts and flattens out.
What is inhaling?
The process of breathing air in by increasing the volume of the chest cavity.
What is exhaling?
The process of breathing out by reducing the volume of the chest cavity. Exhalation is passive because the muscles just relax.
What happens to the intercostal muscles and diaphragm when we exhale?
When we exhale, the intercostal muscles relax. This causes the rib cage to fall and decrease the volume of the chest cavity. When we exhale,the diaphragm relaxes.
What is the Inspiratory reserve volume?
The amount of air that can be forced into the lungs after 1 normal inhalation (after tidal volume)
What is residual volume?
The volume of air that is left in the lungs after an exhalation. There is always some air left in the lungs (about 1500ml)
What is tidal volume?
The volume of air that is breathed in it out while at rest. The amount of air that enters the lungs is the same amount that leaves the lungs.
What is expiratory reserve volume?
The additional air that can be forced out of the lungs after 1 normal exhalation (after tidal volume)
What is vital capacity?
The most air you can breathe in after breathing out as far as possible
What is the equation for cardiac output?
Q = SV X HR
