University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

119

Pages:

4
Author:

Mariam A. A.

Great vessels **Colours in the diagram are not indicative of artery/vein, shows oxygenated (red) and deoxygenated blood (blue)** Venous blood ● Venous blood enters the right atrium through the superior vena cava and inferior vena cava (deoxygenated blood from the body systems) ● Right atrium fills and the gravity opens the valve and blood flows into the right ventricle ● Contraction pushes blood out of the pulmonary trunk (will branch) [artery] ● Branches into the L and R pulmonary artery, taking deoxygenated blood to the lungs through the hilum ● Pulmonary artery is superior and anterior ● Blood undergoes gaseous exchange in the lungs ● Oxygenated blood goes back to the heart - Pulmonary veins (L and R) brings the blood to the heart (after its been to the lungs) Both go to the left atrium (left and right pulmonary veins both go to the LA) Artery has two openings because it has split into its lobar branches early (before entering the hilum of the lung) Arterial blood ● LA fills with blood ● Gravity pushes on the valve so the blood can go to the LV ● Contraction occurs and the blood goes against gravity into the aorta [artery] via the aortic valve ● Then distributes it to the rest of the body Muscles in the ventricular walls ● R pump blood just to the lungs and the lungs are right next to it ● ● Target organ is very close Circulatory system ● ● ● ● L pumps blood to the aorta and then to all of the body systems Greater force of contraction Blood has to travel further Needs more muscle fibres to do that *Muscles are connected to the tendinous cords and papillary muscles Arteries that nourish the myocardium and the veins that drain it ● The heart is a muscle and needs its own blood supply to keep it alive ● Arteries are always posterior to the vein ● Arteries ○ Heart takes blood from the first branches of the aorta (L and R coronary arteries) ○ R coronary artery supplies the R atrium, R ventricle and pacemaker ○ L coronary artery supplies the L atrium, L ventricle, septum and anterior interventricular artery ○ Blockages in the L coronary artery is mostly associated with heart attacks because ventricle cannot pump and get oxygen to the rest of the body, part of the heart not getting oxygen will die (cell and muscle death) ● Veins ○ All of the smaller veins empty their deoxygenated blood into the coronary sinus before going to the R atrium ■ Great cardiac vein ○ ○ ■ Middle cardiac vein ■ Small cardiac vein R atrium gets deoxygenated blood from: superior vena cava, inferior vena cava and coronary sinus Note: All other veins have the term cardiac not 'coronary', the term coronary is normally associated with the arteries