The Circulatory System + Heart Disease Flashcards
(24 cards)
What is the function of the Circulatory System?
The function of the Circulatory System is to carry Carbon Dioxide, Oxygen, heat, glucose, waste products, amino acids, fatty acids and glycerol or hormones around the body. It does this via a system of arteries, veins and capillaries.
What do arteries do?
The arteries carry Oxygenated blood away from the heart, to the rest of the body.
How are arteries adapted to their function?
They have thick, muscular walls that can withstand the high pressure of blood being pumped out from the heart- allowing them to efficiently deliver Oxygen and nutrients to tissues and organs. They also have a narrower lumen.
What do veins do?
Veins carry de -oxygenated blood from the body tissues back to the heart. This deoxygenated blood is then pumped from the heart to the lungs to get oxygenated.
How are veins adapted to their function?
Veins carry blood under lower pressure than arteries and so they have a thinner, flaccid and less elastic muscular wall than arteries.
Veins contain one-way valves to prevent the back flow of low-pressure blood.
They also have a wider Lumen.
What do Capillaries do?
Capillaries are tiny thin walled vessels that form a network to take blood through the organs and other body tissues, facilitating the exchange of substances between them.
Oxygen and dissolved foods diffuse into body cells from the blood, and Co2 and other waste products diffuse out of body cells into the blood.
How are Capillaries adapted to their function?
-The dense networks of capillaries present a large surface area, allowing materials to be exchanged between body cells and the blood quicker.
-Their thin walls provide a shorter diffusion distance so substances can move through between the blood and tissues easier.
Why is the Circulatory System known as the double system?
Because blood circulates through the heart twice during one complete circuit of the body.
(Pulmonary Circuit- heart to lungs and back + Systemic Circuit- heart to rest of body + back)
Why does the left ventricle have a thicker muscular wall?
The left ventricle has a thicker muscular wall as it has to pump blood to the entire body, while the right ventricle only needs to pump blood to the nearby lungs. This requires a higher pressure and force to circulate the blood, thus a thicker muscular wall.
What do Coronary arteries do?
Coronary arteries encircle the heart, making sure the muscle tissue gets all the oxygen and nutrients that it needs to keep contracting. They carry Oxygen and Glucose to the heart muscle to provide energy (by respiration) for the muscle to contract.
List two things that could happen if a coronary artery gets blocked?
It could lead to
-Coronary Heart Disease
-Heart attack
What is the Septum?
The central wall of the heart that is a thin layer of muscle.
What is the Sino-atrial Node and where is it located in the heart?
The SAN or Pacemaker is a special cardiac muscle tissue in the heart.
It sets the rhythm at which all other cardiac muscle cells beat, by sending excitation waves (depolarisation) over atrial walls.
It is located in the Right Atrium.
The Left Ventricle is the …..
chamber with the thickest muscle
What do Valves do?
Valves prevent the backflow of blood, when the heart relaxes, making sure it is only travelling in one direction.
Almost half of heart disease deaths are from…
coronary heat disease (CHD)
Name 4 causes of Heart Disease:
-Poor Diet, High in fat
-Lack of Exercise
-Drinking Alcohol
-Smoking
List three ways of helping against Heart Disease:
-Statins
-Stents
-Bypass
Describe Statins, referencing to advantages and disadvantages.
Statins are medication took to reduce cholesteroll.
This must be done as arteries have narrow lumins, so the heart has to work harder if there is alot of cholesteroll.
-They are cheap
-But has side effects of fatigue and muscle pain
Describe Stents, referencing to advantages and disadvantages
Stents are a metal mesh tube that widens a blocked narrow artery through insertion.
-It’s possible to dislodge some of this fat, which may move further along and cause blockages, but the mesh structure lining the blood vessel helps prevent this.
-Quick, so no long hospital stay
-But, it doesn’t always work.
Describe Bypass, referencing to advantages and disadvantages
Bypass’ stops the heart and redirects all blood through a machine, which circulates your blood for you. This is done by cutting the chest and cracking open the sternum to get to the heart.
-Invasive as it’s open heart surgery
-Can only be done with a by-pass machine so may be limitations
-Very Expensive and time consuming
-Rib bones take time to heal
Describe a Bypass in the leg for a blocked Coronary Artery.
The vein would be removed from the leg, then stuck around the blocked Coronary Artery, meanwhile a machine pumps your blood.
-This leads to circulatory issues in the legs, as you grow older so reduced life expectancy but it’s done as the heart is more important than a vein.
-Risk of infection as bacteria can get in
Explain the effect of a partly blocked coronary artery on the human body.
A blocked artery is when the coronary artery that supplies Oxygen and glucose to the heart muscle is blocked with fatty material. So there is
-Reduced blood flow to the heart muscle, so less oxygen + glucose being delivered to the heart muscle
-This means less Aerobic respiration in the heart
-SO more Anaerobic respiration
-SO less energy released
-So less muscle contraction
-Less blood containing O2 + Glucose being able to be pumped around the body
-So less Co2 being removed from the body
-Resulting in breathlessness + tiredness
-+ the Anaerobic respiration causes the production of Lactic Acid
-And this buildup of Lactic Acid causes muscle pain and fatigue
