Cardi Phys Flashcards
Which side of the heart is responsible for Pulmonary circulation
Pumps blood through the lungs back the heart
under lower pressure
Right side
Which side of the heart is responsible for Systemic circulation
Pumps blood through the entire body
Under greater pressure b/c it has more structures and a further distance to push blood
Left side
What is the name of the cavity where the heart sits in thorax
Mediastinal
Describe the layers of the heart wall (3)
1) Double wall Pericardium:
Parietal Layer (outer most fibrous layer)
Pericardial cavity and fluid
Visceral layer (hugs the heart) aka epicardium
2) Myocardium (the cardiac muscle)
3) Endocardium (lines the internal chambers of the heart and the valves extend off of it)
what are the 2 Atrioventricular valves (separate the atria from ventricles)
Tricuspid valve- right
Mitral (bicuspid) valve- left, under greater pressure to prevent blood flowing back into the left atrium
What position should the AV valves be in for systole/ diastole?
AV valves should be closed during systole to prevent back flow in the atrium.
Open during diastole to allow for blood to pass into ventricles.
what are the 2 Semilunar valves
Pulmonic semilunar valve
Aortic semilunar valve
What position should the semilunar valves be in for systole/ diastole?
Semilunar valves should be open during systole to allow blood to move out into the body tissues.
Closed during diastole to allow for filling and to prevent blood flowing in from the ventricles
Right coronary artery: function and the 3 branches
branch off of the aorta and supplies the heart with fuel
Conus
Right marginal branch
Posterior descending branch
Left coronary artery: function and the 2 branches
Left anterior descending artery (LAD feeds the majority of the Lft. heart muscle, can lead to widow-maker, MI)
Circumflex artery
Coronary Arteries function
Feed the heart muscle cells
Coronary veins function
drain blood to the right atrium
3 Coronary veins
Coronary sinus: sits at the back of the heart and drains back into right atrium
Great cardiac vein
Posterior vein of the left ventricle
What are the 4 The Great Vessels
1) Superior venae cavae and inferior venae cavae
2) Pulmonary artery
3) Pulmonary veins
4) Aorta
Superior/ inferior venae cavae function
Superior: drains the head, neck and arms.
Inferior: drains trunk and legs.
Both brings blood back to RA.
Pulmonary artery function
Right and left pulmonary arteries (right and left lung)
Arteries that carry de-oxygenated blood to lungs
Pulmonary veins function
carry oxygenated blood to the heart
Aorta function
sends oxygenated blood to the systemic system
Which ventricle is under great pressure, right or left? Why?
The Lft. ventricle generates about 5X the pressure that the Rt. ventricle does. This is due to the difference in distance blood has to be pumped from the Lft. (systemic) compared to the Rt. (lungs)
List the pathway of nodes/ fibers of the Conduction system? (5)
Sinoatrial node (SA) Upper Rt. Atrium
Atrioventricular node (AV)
Bundle of His (AV bundle)
Right and left bundle branches
Purkinje fibers
Sinoatrial node (SA) Upper Rt. Atrium function
pacemaker cells, can generate and initiate their own action potential. Wave of depolarization across top (atrium) and down the heart (contraction)
Atrioventricular node (AV) function
slow down the impulse to allow atrium to fully contract before ventricles contract. This allows verticals to fully fill
Bundle of His (AV bundle) function
speed up impulse
Purkinje fibers function
Talk to individual ventricles to contract from the bottom up. Forcing blood out of the aorta and into the pulmonary trunk
Cardiac innervation: what neurotransmitter is used for the Sympathetic nerves/ Parasympathetic nerves? What is the result?
Sympathetic: turning up HR via eip/norepi
Parasympathetic: turning down HR, ACH
Order for vessels of blood flow (7) from the heart to the lung and back:
ARTERIAL
Arteries
Arterioles
Capillaries at the lung
VENOUS
Venules
Veins
Layers of Vascular Anatomy
Lumen
Tunica intima: inner most layer (endothelium)
Tunica media: smooth muscle (larger in arteries b/c under great pressure and can change vasodilation)
Tunica externa: outer layer (adventitia)
Factors affecting blood flow (2)
Pressure (BP) and resistance
Resistance from vessels:
how it is created
diameter change and its relation to BP
the equal and opposite force against the hydrostatic pressure (Opposition to force)
Diameter and length of the blood vessels contribute to resistance
Change in diameter via vasodialation (decrease resistance), vasoconstriction (increase resistance). Direct relationship on BP.
Factors affecting blood flow (3)
Velocity: changes in diameter
Laminar vs. turbulent flow
Vascular compliance- stretch in vessel walls
BP = CO x PR
BP: force forward and against the vessel wall
CO: amount of blood ejected per min
PR: peripheral resistance- the overall amount of RESISTANCE in the body (vasodilation/ vasoconstriction)
CO = HR x SV
Cardiac Output: (L/min) Volume of blood flowing through either the systemic or pulmonary circuit in liters per minute
HR: beat/ min
SV: stroke volume (L/beat) amount of blood ejected out of the heart per beat
Preload:
The blood in the ventricle when it fills.
Left ventricular end-diastolic volume.
another way to say it: how much blood is in the LV (stretch and filling) at the end of diastole
Afterload:
Determined by the preload, BP.
Load the heart muscle must move after it starts to contract to get the blood out.
Another way to sat it: mount of force the heart has to put forward to get blood out
More preload, more force the heart has too use to eject the blood
What factors regulate homeostatic BP (3)
- vasodilation and constriction of vessels
- changes in the heart: CO, HR, SV
- change in blood volume
Hormones that effect changes in blood volume (3):
- ADH: increase water reabsorption= increase blood vol. increasing BP
- ANH: decrees Na and H2O reabsorption= decrease blood vol. and decrease BP
- RAAS (aldosterone): Increase Na and H2O reabsorption= increase blood vol. increasing BP
Heart rate regulation is controlled by (4)
Cardiovascular control center (excitatory and inhibitory centers)
Neural reflexes
Atrial receptors
Hormones
Stroke volume
Myocardial contractility = squeezing of the cardiac muscle
2 functions of
Lymphatic system
1) fluid balance/ return (obligatory load of 10%). Returns Lymphatic fluid to subclavian vein
2) Clean and filter and carry out any needed immune response (macrophages, T and B cells found in lymph nodes)
Lymphatic vessels (2) What ares do they cover?
Right lymphatic duct: RIGHT side of face, arm and upper trunk.
Thoracic duct: LEFT side of face, arm and chest; lower quadrants of the abdomen, and legs
If MAP is too low
If MAP is too high
- some tissue will not receive enough blood leading to hypoxia etc.
- it can cause damage to vessel walls and the tissues that the blood is going to
Mean arterial pressure (MAP)
What does it effect (4)
- cardiac output
- total peripheral resistance
- hyperemia (excessive blood volume)
- hormones (AHD, aldosterone, ANH)
Regulation of arterial pressure (MAP):
why is it required
what is the needed range
-need enough MAP to perfuse all the tissue in the body.
An MAP of about 60 is necessary to perfuse coronary arteries, brain, kidneys. >110 may cause damage to tissue
