Overview of Cardiovascular System Flashcards
What does the circulatory system transport?
oxygen, carbon dioxide, nutrients, waste, hormones
What is a subsystem associated with the circulatory system and what does it carry?
lymphatic system -carry excess lymph from tissues to bloodstream
What are the two types of circulation and what is the difference between both?
Pulmonary - carries deoxygenated blood from heart to lungs where it is oxygenated and sent to heart again
Systemic - carries oxygenated blood to the body from the heart and carries deoxygenated blood from body to the heart
What is the mediastinum?
The mediastinum is an area found in the midline of the thoracic cavity. It has superior and interior regions
Describe the regions of the mediastinum
Superior mediastinum
-Upper portion: T1 posteriorly, 1st rib
-Lower portion: T4 posteriorly, sternal angle
Inferior mediastinum (larger)
-Anterior (fat and thymus)
-Middle (heart)
-Posterior (aorta, oesophagus)
In which region of the mediastinum does the heart lie?
Inferior Middle T4-T9
What are the two layers of pericardium?
fibrous, serous
What is fibrous pericardium and what does it do?
tough outer connective tissue that anchors heart to diaphragm
it prevents rapid over filling of the heart
What is pericardial effusion and what can it lead to?
Pericardial effusion is an accumulation of fluid in-between the layers of pericardium in the pericardial space.
When it happens quickly or involves a large amount of fluid, the excess fluid can take up too much space in the pericardium, compressing your heart and causing a life-threatening condition known as cardiac tamponade.
What is serous pericardium and what does it do?
two layers:
the outer parietal layer that lines the internal surface of the fibrous pericardium
the internal visceral layer that forms the outer layer of the heart.
Each layer is made up of a single sheet of epithelial cells, known as mesothelium.
Where is the pericardial cavity and what is it’s role?
between the outer and inner serous layers is the pericardial cavity, which contains a small amount of lubricating serous fluid. The serous fluid serves to minimize the friction generated by the heart as it contracts.
What arteries supply the heart and where do they come from?
coronary arteries from the ascending aorta
What vessels branch from the arch of the aorta?
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery
What do the branches from the aorta supply?
brachiocephalic - head and neck (right common carotid artery)
left common carotid artery - head and neck
left subclavian artery - upper limbs
What is the endocardium composed of?
loose connective tissue
simple squamous epithelial tissue
What does the ductus venous vessel in fatal circulation allow and what does it become after birth?
allows blood to bypass liver (30% of maternal blood) to the inferior vena cava. At birth this closes and becomes the ligamentum venosum.
What does the foramen ovale do?
creates a passage between the right atrium and the left atrium so oxygenated blood from the placenta can move to the left atrium. This allows for the oxygenated blood to pass through the left ventricle and into the ascending aorta, oxygenating the brain.
What does the ductus arteriosus do?
allow the fusion of the primitive pulmonary artery to the aorta, therefore allowing blood to pass straight from the right ventricle into the aorta and bypass the inactive lungs.
becomes the ligamentum arteriosus
What do the umbilical arteries transport?
The umbilical arteries are used to transport deoxygenated blood away from the fetal tissue and back towards the placenta for re-oxygenation.
What is the difference between right/left ventricles?
the left ventricle is 3x thicker as it has to pump blood to the entire body whereas the right only has to pump to the lungs
What is the solid muscular wall that separates the atria?
interatrial septum
What is the depression in the wall of the right atria?
the fossa ovalis. This is the remnant of the foramen ovale in the fetal heart, which allows right to left shunting of blood to bypass the lungs. It closes once the newborn takes its first breath.
What are the series of irregular muscular elevations that give ventricles ‘sponge-like’ appearance, and can be grouped into three main types called?
trabeculae carnae
What are the three main types of trabeculae carnae called?
papillary muscle (has chordae tedinase)
bridges
ridges
What is a septal defect?
when there is a hole in the inter ventricular or interatrial septal wall. (cause mixing of blood, increases blood flow)
What valves are more anterior?
the aortic and pulmonary
How many leaflets do the atrioventricular valves have?
bicuspid (mitral) =two
tricuspid =three
What are chordae tedinase and what do they do?
heart strings that connect to the papillary muscles and prevent the mitral and tricuspid vales flipping back into the atria during ventricular contraction
Do semilunar valves have chordae tedinase?
no
What vein does the heart mostly drain to?
coronary sinus
What are branches of the coronary sinus?
great cardiac vein
small cardiac vein
middle cardiac vein
anterior cardiac veins
What is CAD?
coronary artery disease - reduced blood flow to myocardium
What is ischaemia?
reduced blood flow and oxygen to heart muscle
What do the left and right coronary arteries branch into?
LCA -anterior interventricular artery, left marginal artery, left circumflex artery
RCA -posterior interventricular artery, right marginal artery
What artery does infarction happen most in?
anterior interventricular artery
What is angina pectoris?
chest pain related to CAD
What can block arteries?
cholesterol
What can ischaemia cause?
collateral circulation (new blood vessels forming to pass around reduced area)
What embryological germ does the heart develop from?
mesoderm
