Heart & vessels Flashcards
Pulmonary circuit
Pumping blood from the heart to the lungs and back to the heart
Systemic circuit
Pumping blood from the heart to the rest of the body and back to the heart
Visceral pericardium
aka epicardium
Is the layer against the heart muscle
Considered outer most layer of the heart
Parietal pericardium
Is the layer outside the Visceral pericardium and touching the surrounding organs
Pericardial sac
Made by the Visceral and Parietal pericardium
Filled with pericardial fluid
Epicardium
External layer of the wall of the heart
AKA Visceral pericardium
Myocardium
Middle layer of the wall of the heart
Cardiac muscle cells = cardiocytes
Endocardium
Internal layer of the wall of the heart
This tissue is in contact with the blood
Autorhythmicity
Does not need the CNS to stimulate the heart muscle to contract
Is able to generate its own rhythm
Auricles
Flap like structures that expand so that blood can fill the atria
Cardiocytes
Found in Myocardium layer
Extensive circulatory supply
Able to contract without info from CNS
connected by intercalated discs
Functional syncytium
The cardiocytes all contract at the same time as one unit
Right atrium
Receives deoxygenated blood from superior & inferior vena cava, coronary sinus
Contains fossa ovalis
Right ventricle
Receives deoxygenated blood from R atrium through the tricuspid valve
Valve is connected to papillary muscles via chordae tendineae
Sends blood out the pulmonary valve thru the pulmonary circuit
Left atrium
Receives oxygenated blood from lungs via L & R pulmonary veins
Blood is pushed through mitral valve
Left ventricle
has thickest walls
Revises blood from left atrium thru mitral valve
on contraction blood is pushed thru aortic valve into systemic circuit
Main Coronary blood vessels
Right coronary artery (RCA)
Left coronary artery (LCA)
Cardiac veins
Left coronary artery splits into:
Splits into:
Circumflex - goes around left atrium
Anterior interventricular - goes down interventricular sulcus
Main cardiac veins
Great cardiac vein - is just before coronary sinus
Coronary sinus - drains into right atrium
Cardiac cycle
AKA heart rate
Is the alternate periods of contraction and relaxation of the heart
Diastole - relaxation
Systole - Contraction
Internal conduction system of the heart
SA node
AV node
Bundle of his
Purkinje fibers
SA node
Cardiac pacemaker
Located in wall of right atrium
Determines rate of heart contractions
Impulse travels to AV node
AV node
Sits on floor of right atrium
Impulse travels from AV node to bundle of his along purkinje fibers to ventricular myocardium
P wave
SA node is stimulated which causes the P wave and the atria to contract
QRS complex
Contraction of the ventricles forms QRS complex
T wave
The ventricles recovering from the contraction
Disorders of blood vessels
Hypertension
Atherosclerosis (plaque/thrombus-not moving, embolus-moves)
Stroke
Heart attack
Aneurysm (ballooning/bursting blood vessel)
Tunica intima
Innermost layer of blood vessels
Is in contact with the blood
On veins this layer is smooth
On arteries this layer is a bit thicker and wavy
Tunica media
Middle layer of blood vessels
Is thicker on arteries vs veins
This layer causes vasoconstriction and vasodilation
Cannot shut off blood flow completely
Tunica externa
Outermost layer of blood vessels
Has connective tissue to anchor the vessel in place
Vasa vasorum
The blood supply to the blood vessels themselves
Arteries
Carry blood away from the heart
Vessel walls are thicker
Vessels retain shape when cut
Veins
Return blood to the heart
Vessel walls are thinner
Vessels collapse when cut
Lumen of vein & artery
The walls of the vessels
Tunica intima
Tunica media
Tunica externa
Capillaries
Smallest portion of the vessels
Walls thin enough to permit exchange of gases between blood and cells
Fenestrated capillaries
Are capillaries that contain window/openings/pores that make for easier gas exchange
Capillary beds
Where the arterioles and venules connect where defusion happens
Precapillary sphincters
Regulate blood flow through capillaries
They are able to shut down blood flow to some/most of the capillary beds but not all
Matarteriole & Thoroughfare
Channel in capillaries that must stay open so blood can stay in constant motion
Venous valves
Valves only in the lower legs to ensure one way blood flow
They also help the blood go against gravity
Varicose veins
squiggly line veins just under the skin
Blood volume
About 5 liters of blood in the body
Arteries and capillaries contain 30-35% of the volume
Veins contain 65-70% of the volume
All the arteries
Elastic artery
Muscular artery
Arteriole
Capillary
All the veins
Capillary
Venule
Medium-sized vein
Large vein
