The Cardiovascular System Flashcards
Describe the location of the heart within the thorax
The MEDIASTINUM is where the heart is located.
The mediastinum consists of a posterior, anteiror, superior and inferior.
Summarise the major functions of the cardiovascular system
The cardiovascular main function is to circulate oxygen around the body and remove carbon dioxide, provides cells with nutrients, removes the waste products of metoblaism to the excretory organs and protect the body from infections and bacteria .
Name the different classes of blood vessels and describe theirstructural and functional relationship
Arteries: carry blood away from the heart. have high pressure always as they are connected to the ventricles of the heart. as a means of high pressure, arteries have more elastic tissues than smooth muscle.
Arterioles: these are smaller vessels with more smooth muscle than elastic tissue and are part of the autonomic nervous system. It’s the ANS that influences the shape and diameter of the arterioles.
Capillaries: composed of a single endothelial layer. The exchange of nutrients are done via diffusion.
Venules: these are the smallest of the veins are receive blood from cappileries.
Veins: Blood flows from the Venules to the veins. Veins are single layer, low pressure, more smooth muscle than elastic and take blood back to the heart. The reason for low pressure is because preassjre overcomes resistance.
Describe the nature of blood flow and the factors that influence bloodflow.
Factors that affect the flow of blood is : Pressure, viscosity so blood thickness, cardiac output so the amount of blood flow from the heart through the ventricles and Elasticity of vessel walls.
So how does blood flow work in simple terms ?
Let’s start if with the deoxygenated side:
- The superior vena cava (2nd largest vein) receives deoxygenated blood from the upper part of the body. And the inferior vena cava (1st Largest vein) receives deoxygenated blood from the lower part of the body. The blood is then brought into the right atria. The right atria then pushes the blood to the right ventricle via the tricuspid valve. The heart then contracts aka systole and the blood pushes into the pulmonary trunk via the pulmonary valve. The blood then goes into the right or left arteries.
So to recap deoxygenated blood has 4 steps:
1) Recieves deoxygenated blood via the inferior and superior vena cava.
2) blood is then in the right Atria.
3) blood is pushed into the right ventricle via tricuspid valve.
4) heart contracts aka systole and blood pushed into pulmonary trunk via pulmonary valve.
Now oxygenated blood:
1) the blood returns back to the heart with oxygenated blood from the lungs via the right and left pulmonary veins.
2) the blood is then collected into the left atrium. When the heart relaxes aka diastole the blood is pushed into the left ventricle via the bicuspid valve
3) when the heart is then contracted aka systole the left ventricle pushes the blood into the aorta via the aortic valve. From here we have a systematic circuit of blood flow.
So to recap oxygenated blood:
1) oxygenated Blood is received via the left and right pulmonary arteries
2) blood is then collected into the left atrium
3) on diastole the blood is pushed into the left ventricle via the bicuspid valve.
4) on systole the blood is pushed into the aorta via the aortic valve.
Explain the term ‘tissue perfusion’ and describe ischaemia
Tissue perfusion is the amount of oxygenated blood reaching organs and vessels.
Now ischaemia js the lack of blood flowing to the brain this is why a stroke occurs the brain doesn’t receive enough oxygen. A cardiac ischaemia is when there’s something blocking the heart from pumping the blood around the body.
Outline the regulation of the vascular system
The nervous system helps with the cardiovascular system in terms of chemoreceptors which monitor oxygen levels in cells
Identify the major structures of the heart
Major structures of the heart include the:
-left atrium
Right atrium
Left ventricle
Right ventricle
Bicuspid valve (mitral)
Tricuspid valve
Aortic valve
Pulmonary valve.
What is the location and function of the hilum in the lungs
The location of the hilum is the midpoint of the two lungs. The function is that it’s is a passageway of where structures enter and exit the lung like pulmonary vessels
How many lobes does the left lung have,
and what distinguishes it from the right
lung?
The left lung has 2 lobes:
Superior (upper)
Inferior (lower)
What distinguishes it from the right lung is that the right lung has 3 lobes. The left lung has a cardiac notch for where the heart sits. There is only 1 oblique fissure in the left lung. The right lung has 2 a horizontal and oblique one.
How is the left lung different from the right
lung?
The left lung has 2 lobes
The right lung had 3 lobes
The left lung has 1 oblqiue fissure
The right lung has 2 fissures horizontal and oblique
The left lung has a cardiac notch for the heart to sit
The right lung is shorter than the left lung due to liver siting beneath it.
Left lung is longer and narrower
Describe the layers of the pleural
membranes
There are two layers called the visceral (inner layer of lung) and parietal (outer layer of lung)
What is the function of the pleural cavity?
Function of Pleaural cavity is to allow easy movement when we breathe and the pleural fluid acts as a lubrication from the lung tissue causing friction with the ribs.
Describe the typical structure of a blood
vessel, mentioning the three tunics.
Tunica Adventitia = outer layer
Tunica media = middle layer
Tunica intima = inner layer
Remember only CAPILLERIES have a tunica intima nothing else
Explain the distribution of the aorta into
thoracic and abdominal sections. What are
the components of each section?
The aorta is the main artery of the human body. It arises from the left ventricle of the heart and travels superiorly to form the ascending aorta. It then loops inferiorly to form the arch of the aorta and through the thorax to form the thoracic aorta. After crossing the diaphragm into the abdomen, the aptly-named abdominal aorta eventually bifurcates into the common iliac arteries in the lower abdomen. Along the way, the aorta gives rise to the arterial branches that are responsible for transmitting oxygenated blood to all the tissues of the body.
What role do arteries play in the circulatory system
Arteries take blood away from the heart to supply it to the rest of the body.
