STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE CARDIOVASCULAR SYSTEM Flashcards
Where is the heart located?
in the thoracic cavity between the two lungs.
The heart is surrounded by the _______, which protects and holds the heart in place.
pericardium
What are the two parts of the pericardium?
Fibrous pericardium
Serous pericardium
What part of the pericardium is the:
Tough, inelastic and outer connective tissue.
Fibrous pericardium
What part of the pericardium is the:
Thinner, delicate and forms double layer around heart
Serous pericardium:
What functions to protect the heart buy anchoring it in place(to the diaphragm) and prevents it from overstretching
Pericardium
What functions to protect the heart buy anchoring it in place(to the diaphragm) and prevents it from overstretching
Pericardium
What are the two layers of the serious pericardium?
Parietal layer Visceral layer (epicardium):
What layer of the serious pericardium Adheres tightly to the heart?
Visceral layer
What layer of the serious pericardium is Fused to the fibrous pericardium?
Parietal layer
What is between the parietal and visceral layers of the pericardium?
What is its function?
The pericardial cavity filled with lubricating fluid that prevents friction between membranes
The Heart wall is made of what layers?
Epicardium
Myocardium
Endocardium
What layer of the heart wall lines the inside and covers valves?
Endocardium
What layer of the heart wall consists of cardiac muscle, forms two separate networks via gap junctions and intercalated disks: Atrial and ventricular.
Myocardium
visceral layer of the serous pericardium is also known as what?
Epicardium
What are the 4 chambers of the heart
R and L Atria
R and L Ventricles
What separates the Ventricles?
interventricular septum
what separates the Two atria
Interatrial septum
Atria are the thinnest chambers why?
They only have to empty their contents into the ventricles
Why are ventricles are thicker than Atria
they have to move blood out of the heart to the lungs (R ventricle) or to the rest of the body (L ventricle)
What is the thicker ventricle and why?
The left ventricle
Pumps blood to the rest of the body
What are the two Atrioventricular valves and what side are they on?
Tricuspid Valve (R) Bicuspid (mitral) Valve (L)
What on the ventricular side connects the papillary muscles to the Atrioventricular valves?
And what do they do?
Chordae Tendineae
Prevent valve cusps from pushing up into the atria when ventricles contract
What are the two semilunar valves?
What is there function?
Aortic Valve
Pulmonary Valve
-Prevent blood from flowing back into the heart
What are the Vessels that bring Deoxygenated blood into the heart?
What chamber do they drain into
- Superior Vena cava
- Inferior Vena cava
- Coronary Sinus
The right Atrium
What drains deoxygenated blood from the coronary veins into the right atrium?
Coronary Sinus
What carries oxygenated blood from the lungs and transports it to the left atrium?
Pulmonary veins
What carries oxygenated blood to the entire body from the left ventricle
Aorta
What is coronary circulation
Blood flow through the myocardium
What are two principal coronary vessels?
(a) Right coronary artery
(b) Left coronary artery
When reviewing an ECG what does the P wave represent?
atrial depolarization
When reviewing an ECG recording what does the QRS complex represent?
ventricular depolarization
When reviewing an ECG what does the T wave represent?
ventricular repolarization
Can you see atrial REpolarization on a ECG?
No, its masked by the QRS Complex
A cardiac cycle represents everything associated with one heartbeat, typically
lasting how long?
0.8 seconds
Cardiac excitation normally begins in what node?
Sinoatrial node SA
What does the action potential travel through from the SA node to the AV node?
The atria (via Bachmann’s bundle) this causes contraction of the atria
After the AV node gets the signal where does the action potential go?
The atrioventricular (AV) bundle or Bundle of his
The atrioventricular (AV) bundle or Bundle of his sends the action potential to what?
R and L bundle branches
From the R and L bundle branches where does the action potential go?
Purkinje fibers
Where in the conduction system of the heart causes the Ventricles to contract
Purkinje Fibers
What Color covers Atrial Contraction?
Blue
What Color covers Ventricular Contraction?
Yellow
What are the three phases of the cardiac cycle?
Relaxation period atrial systole (contraction) Ventricular systole (contraction)
Which phase of the cardiac cycle?
both atria depolarize (noted as the P wave). After depolarization the last 25% of blood is ejected from the atria to the ventricles.
atrial systole
Which phase of the cardiac cycle?
Indicated by the QRS complex. The ventricles depolarize then contract ejecting the blood into either the pulmonary trunk (right ventricle) or the aorta (left ventricle).
Ventricular systole
Which phase of the cardiac cycle?
Indicated by the QRS complex. The ventricles depolarize then contract ejecting the blood into either the pulmonary trunk (right ventricle) or the aorta (left ventricle).
Ventricular systole
Approximately how much blood is ejected into systemic circulation per ventricular contraction?
70 ml
Which phase of the cardiac cycle?
-the ventricles start to relax and repolarize
-all four chambers of the heart, including
the atria enter into a period of diastole
Relaxation period
during diastole, the ventricles
are filled to what percentage?
75%
What is the amount of blood ejected from the left ventricle into the aorta per minute?
Cardiac output
CO formula = stroke volume x heart rate
What is the output for a pt with a HR of 75
= 70 ml/beat x 75 beats/min
= 5250 ml/min or 5.25 L/min
True/False
The right ventricle ejects less blood than the Left ventricle
False
The right ventricle ejects the same amount as the left
What are the five main types of blood vessels?
Arteries Arterioles Capillaries Venules Veins
What type of blood vessel?
Thick, triple layered vessels that carry blood away from the heart.
Arteries
What type of blood vessel?
Thin vessels formed by arteries branching down in size
Arterioles
What type of blood vessel?
Hair-like microscopic vessels found throughout the body, connects arterioles to venules.
also known as exchange vessels……
Capillaries
What type of blood vessel?
Very thin vessels formed when capillaries reunite
Venules
What type of blood vessel?
Designated vessels that return deoxygenated blood to the heart to be oxygenated.
Veins
What is the ability of local tissues to adjust blood flow (constrict or dilate) into the area according to metabolic demands via vasodilators and vasoconstrictors.
Autoregulation
Slowest rate of blood flow takes place within what and why?
the capillaries
allows time for exchange through walls
Blood pressure is defined as………
Pressure exerted on the walls of the vessels as the ventricles contract.
Where is blood pressure the highest?
aorta and the large systemic arteries
Normally the blood volume of the cardiovascular system?
5 liters or 5.3 quarts.
Volume or blood loss more than ___% is potentially life threatening
10%
Anything that increases blood volume, i.e. water retention will do what to blood pressure?
Increase
Vascular resistance is what?
Opposition to flow (lumen size)
Vascular resistance which depends on what?
- Smaller lumen (with vasoconstriction)
- Greater vessel length (weight gain)
- Higher viscosity (as with high hematocrit)
Vascular resistance: Smaller lumen(with vasoconstriction) results in what?
results in greater resistance…
Vascular resistance:
Greater vessel length (weight gain) results in what?
results in greater resistance…
Vascular resistance: Higher viscosity (as with high hematocrit) results in?
greater resistance……………/……
Blood Flow to the body is regulated by what part of the brain?
medulla oblongata
The medulla oblongata is controlled by neural and hormonal feedback from what 3 receptors?
Proprioceptors
Baroreceptors
Chemoreceptors
What type of receptor is this?
Monitor movements of joints and muscles
Proprioceptors
What type of receptor is this?
Pressure receptors in the aorta and carotid arteries
Baroreceptors
What type of receptor is this?
Located in the arch of the aorta and carotid bodies that stimulate sympathetic and parasympathetic response to chemical changes in the body
Chemoreceptors
What is Systemic circulation?
Arteries and arterioles that carry oxygen and nutrient rich blood THROUGHOUT THE BODY, veins and venules that carry carbon dioxide and waste to the right atrium.
All systemic arteries branch off what blood vessel?
Aorta
All systemic veins empty into what blood vessels?
superior vena cava, inferior vena cava or the coronary sinus.
What is Pulmonary circulation?
Blood pumped by the right ventricle to the lungs, picks up oxygen and returns via pulmonary veins to the left atria.
Where does gas exchange take place to RE-oxygenate the blood
Pulmonary capillaries