Cardiovascular system and diseases Flashcards
(62 cards)
Components of the circulatory system
- A central pump - the heart
- A distributary system (away) - aorta, arteries, arterioles
- An oxygenation system - pulmonary vessels/lungs
- A system for exchange - the capillaries
- A collecting system (toward) - veins, vena cava
what are the four heart valves and where are they located?
tricuspid - between right atrium and right ventricle
pulmonary - between right ventricle and pulmonary artery
mitral - between left atrium and left ventricle
aortic - between left ventricle and aorta
Myocardium
The cardiac muscle composed primarily of a collection of specialized muscle cells - contract at their own pace
how are ventricular myocytes arranged?
circumferentially in a spiral orientation
coronary arteries
provide a constant supply of oxygenated blood to the heart
what are the Three major epicardial coronary arteries? what do they support?
Left anterior descending (LAD) artery - left ventricle, Left circumflex (LCX) artery - surroundings, Right Coronary artery - right ventricle
where do myocardial infarctions tend to happen? why?
at the LAD artery - causes pump failure meaning oxygenated blood cannot be taken to the rest of the body
when does Most coronary arterial blood flow to the myocardium occur?
during ventricular diastole, - when the microcirculation is not compressed by cardiac contraction
what does the Cardiac conduction system regulate?
heart rate and rhythm
what are the components of cardiac conduction and where are they located?
• The sinoatrial (SA) pacemaker of the heart, the SA node, located
near the junction of the right atrial appendage and the superior
vena cava
• The atrioventricular (AV) node, located in the right atrium along the atrial septum;
• The bundle of His, which courses from the right atrium to the
summit of the ventricular septum; and its major divisions
• The right and left bundle branches, which further arborize in the
respective ventricles through the anterior-superior and posterior-inferior divisions of the left bundle and the Purkinje network
arrhythmias
Conduction defects due to uncoordinated generation of impulses lead to non uniform and inefficient contraction
Ventricular fibrillation
ventricles are not contracted in a coordinated way
The Frank-Starling mechanism
Increased filling volumes dilate the heart and increase functional cross-bridge formation within the sarcomere to increase contractility
Activation of neurohumoral systems for Myocardial adaptation
Noradrenaline release, which increases heart rate and contractility. RAAS activation and atrial natriuretic peptide release to adjust filling volumes and pressures
Common cardiovascular
diseases
- Atherosclerosis
- Hypertension
- Stroke
- Heart Failure
- Arrhythmia
- Heart valve problems
Structure and function of the venous system
smaller diameter blood vessels, lower pressure, less smooth muscles, less contraction
Structure and function of arterial system
larger diameter blood vessels, higher pressure, more smooth muscles, more contraction
what is the ECM composed of?
elastin, collagen, and glycosoaminoglycans
what factors affect blood pressure?
cardiac
output (heart) and peripheral vascular resistance (vessels)
hypotension
(low pressures) results in inadequate organ perfusion and can lead
to dysfunction or tissue death
90/60
Hypertension
(high pressures) can cause vessel and end-organ damage
140/90
normal blood pressure
120/80
how are high BP and atherosclerosis linked?
high BP causes vessel damage, hardening of walls and plaque formation
risk factors of hypertension
age, genetics, BMI, diet (incl, Na intake), stress
