The Heart: Anatomy & Physiology
Name for the circuit that transports blood to and from the lungs
Pulmonary Circulation
Name for the circuit that transports blood to and from the body
Systemic Circulation
Arteries that come off the Aorta right behind aortic valve and it's function
Right Coronary - gives blood to the right ventricle
Left Coronary - gives blood to the left ventricle
Since the left ventricle is so much bigger, the Left main coronary artery divides into:
Circumflex - does the back of the left ventricle
Anterior descending (LAD) - does the anterior and lateral portion of left ventricle
Double lined connective tissue bag containing the heart
Pericardium
Pericardium is made up of what 2 layers that are separated by a space
Parietal layer and Visceral layer
Outside layer of the pericardium
(pericardial space is in between, filled with pericardial fluid)
Parietal layer
Inner most layer of pericardium that is on heart
(also called the epicardium)
Visceral layer
3 layers of the heart muscle wall
Epicardium - outer layer
Myocardium - thick middle layer
Endocardium - inner layer
Systole is the _____________ phase.
Contracting phase
Diastole is the ___________ phase.
Non contracting phase, filling
Names given to the wall that is shared by the two pumps
Intertribal Septum - between Right and Left atrium
Interventricular septum - between Right and Left
ventricles
Right atrium flows into the right ventricle through the
Tricuspid Valve
Right ventricle flows into the Pulmonary Artery through the
Pulmonic Valve
Left atrium flows into the left ventricle through the
Mitral Valve
Left ventricle flows into the Aorta through the
Aortic Valve
The blood is returned to the heart via
Large veins
The blood is taken away from the heart via
Large arteries
Brings blood back from the body to the right atrium
Inferior and Superior vena cava
Brings blood back to the left atrium
Pulmonary veins
Takes blood away from the right ventricle
Pulmonary Artery
Takes blood away from the left ventricle
Aorta
3 factors that regulate stroke volumn
Preload
Contractility
Afterload
The amount of blood in pumping chamber before it contracts
(also called End diastolic volumn)
Preload
How hard ventricle is trying to pump the blood
(effected by ANS, disease, medications)
Contractility
The resistance to blood being pumped out of the chamber
Afterload
The circulation is divided into 2 parts:
(named for the location the blood is pumped)
Pulmonary and Systemic Circulations
The heart is located in the
Mediastinum
Membrane that surrounds and protects the heart
Pericardium
Right and left ventricals seperated internally by the
Interventricular septum
Right and left atriums seperated internally by the
Interatrial septum
Of the four chambers, which has the highest workload and thickest wall
Left ventricle
Dense connective tissue that surrounds the valves of the heart
Fibrous skeleton of the heart
Amount of blood ejected by a ventricle during each systole
Stroke volumn (SV)
Difference between a person's maximum cardiac output and his cardiac output at rest
Cardiac reserve
Heart rate is effected by
Nervous system and hormones in the body
Cardiac muscle is very similar to skeletal muscle in that is has
Sarcomeres
Cardiac muscle is different in that it has
Gap junctions on cell membrane on intercalated discs
(allows action potential to be passed directly from cell to cell)
The fastest areas in the heart are called
Pacemakers
Passes the action potential throughout the heart
Electrical conduction system
This wave is due to the depolarization of the atrium
P wave
This wave is due to the depolarization of the ventricle
QRS complex
This is the time period between the beginning of the P wave and the beginning of the QRS.
-time when atria contracts
PR interval
Time period from end of QRS until beginning of the T wave
-time when ventricle contacts
ST segment
This is where a portion of the atria other than the SA node triggers a wave
-comes early, P wave looks different from the normal P wave seen in other beats, QRS will look the same
PAC Premature Atrial contraction
This is where a portion of the ventricle triggers a full wave
-QRS will be big and odd looking and appear different from all other EKG beats
PVC Premature Ventricular contraction
Here the PR interval is longer than normal
-about 4 boxes
-all P waves have a QRS after them
1st Degree heart block
There are 2 types of 2nd degree heart block:
-some P waves will not have a QRS after them
Mobitz and Wenckebach
2nd degree heart block where the PR interval is consistant
Mobitz
2nd degree heart block where the PR interval is changing
Wenkebach
What constitutes 3rd degree heart block
-aka complete heart block
there is no relationship between the P waves and the QRS
The functions of the blood:
Transportation
Regulation
Protection
Coagulation
Temperature of the blood:
38C or 100.4F (higher than cells)
The pH of the blood: L
7.35 - 7.45 (slightly alkaline)
The normal blood volume for an adult is about:
5L
The blood is generally divided into 2 parts:
Plasma Component 55%
Formed elements 45%
The Plasma Component is made up of what?
-(know the %)
Water 91.5%
Proteins 7.0%
Others 1.5%
The Formed elements are made up of what?
RBC
WBC
Platelets
These cells fight infection, stress, and inflammation:
-know the 2 types
White Blood cells (WBC)
-Wander
-Fixed
The term that describes how WBC can be attracted
Chemotaxes
Fragments of megakaryocytes
-small, no nucleus
-plug holes, stop damage to pipes
Platelets
3 Granular leukocytes
Eosinophils
Basophils
Neutrophils
2 Agranular leukocytes
Lymphocyte
Monocyte
The body has a 3 phase response to a hole in a blood vessel
1. Vascular spasm
2. Platelet plug
3. Clotting
Damage to blood vessel wall causes the smooth muscle of the vessel to contract,
decreases blood flow thru vessel,
lasts minutes to hour
Vascular Spasm
acts as an enzyme and splits Prothrombin into Thrombin
Prothrominase
Thrombin acts as an enzyme to split
Fibrogen
stabilizes the platelet plug
Fibrin
activates tissue factors outside the blood
Extrinsic pathway
activates from plasma factors inside the blood
Intrinsic pathways
Synthesis blood cells occurs in Red bone marrow
Hemopoiesis
Shows response of the body to anemia
RBC - Reticulocyte
Band is precursor, body being overwhelmed by infection
WBC: Neutrophil
Natural antithrombin, prevent Thrombin from clotting
Heparin
3 types of blood vessels
Arteries
Capillaries
Veins
Arteries start off ______ and as they move away from the heart get ______.
start large and get smaller
Veins start off _______ and get ______ larger as they get closer to the heart
tiny and grow larger
Which are the thickest of the walls of the blood vessel?
Arteries, Cappillaries, or veins
Arteries, due to pressure from pumping action of heart
Lack of perfusion due to lack of pumping
Cardiogenic Shock
Which ion is important in the clotting process
Calcium
Blood is returned to the heart from the veins via 2 mechanisms
1. Skeletal muscles contract, squeezing blood through vein
2. Respiratory pump, as pressure in chest goes down on inspiration, blood is drawn into chest through the veins
Endothelium changes in different typs of Capillaries
Continuous- only opening is intercellular cleft
Fenestrated- pores (small holes)
Sinusoids- wider, more winding (big holes)
2 ways capillary sphincter controls flow into capillary, sphincter muscles relax or contract, open or close
1. local chemical help dictate vasomotion
2. NS controls vasomotor (brain can order open or close)