Cardiovascular system Flashcards
Which chamber of the heart delivers blood to the systemic circulation?
The left chamber
What chamber of the heart transports blood to the lungs?
The right chamber
Oxygenated/deoxygenated blood returns to the RHS of the heart
Deoxygenated
Name the upper chamber of the heart
Atrium
Name the lower chamber of the heart
Ventricle
The superior vena cava returns blood from…
Head & neck region, arms & chest
The inferior vena cava returns blood from…
The organs below the heart, legs & feet
What is the role of the pulmonary artery?
It transports deoxygenated blood to the lungs for gas exchange
What is the role of the pulmonary vein?
It brings oxygenated blood back to the left atrium of the heart
Describe the pericardium
A multilayered sac with an outer fibrous covering with an inner secretory lining
The fibrous portion of the pericardium is composed of…
Dense irregular connective tissue
The inner serous/secretory lining of the pericardium is composed of…
Thin connective tissue
What is the inner lining of the ventricles called?
Trabeculae
Describe the microscopic features of myocardial cells
They are multinucleated, branched and elongated cells
What three types of cell junctions exist in intercalated discs?
Fascia adherens, desmosomes/macula adherens & gap junctions
What node initiates an action potential to generate electrical impulses and where is it located?
The sinoatrial (SA) node
Located in the upper right atrium
What is the function of the atrioventricular (AV) node?
It receives the impulse from the SA node and delivers it to the AV bundles/bundles of His
What happens when the Purkinje fibres receive electrical impulses?
The ventricles contract
The endothelium is…
The epithelial lining of blood, lymph vessels and the heart
Which side of the heart has a bicuspid valve?
The LHS
What happens when the atrioventricular (AV) valves close?
Contraction of the ventricles
Baroreceptors detect…
Stretch
How is blood pressure maintained by the parasympathetic nervous system?
Parasympathetic nervous system reduced heart rate & force of atrial contraction
Describe the role of autorhythmic cells in the heart
They are responsible for depolarisation to threshold potential without neural input
Sistole refers to…
The contraction of the ventricles, leading to ejection of blood
Diastole refers to…
Relaxation of the heart - where the ventricles fill with blood
List the three main structural differences between veins and arteries
Veins lack elastic laminae, have valves and have a wider lumen
What is the role of the metaarteriole?
It diverts blood to the dermis by closing blood supply to the capillary bed
How does baroreceptor firing rate change to increase BP?
Baroreceptor firing rate decreases
Name the too blood pressure sensors
Carotid sinus and aortic arch
What happens when the beta 2 receptor is stimulated?
It decreases blood pressure by decreasing TPR
What hormone stimulates beta 1 adrenergic receptors?
Adrenaline
What happens when beta 1 receptors are stimulated?
Heart rate increases.
Vasoconstriction.
What organ is a major blood pressure sensor?
Kidneys
Why is there an action potential delay when it reaches the AV node?
Different structure to SA node.
Allows ventricles to fill with blood from atria.
What is the role of autorhythmic cells?
They depolarise to threshold without neural imput through repeated AP generation
What two ion channels open during the pacemaker potential?
Na funny channels and T-type Ca channels
The intake of what ion causes the restoration of the membrane potential in autorhythmic fibres?
K ions (potassium)
Preload refers to…
The stretch of the heart walls at the end of diastole (heart relaxes)
Afterload refers to…
Ventricular contraction at the end of systole. Pressure in pulmonary trunk is overcome before blood ejection
