Cardiovascular system part 1 Flashcards
The Cardiovascular Anatomy includes:
Heart, Blood vessels, coronary blood supply (blood supply to heart), blood supply to head and neck, venipuncture sites (where to start IV), the conduction system
Heart Anatomy: The heart is divided into __ and __ halves. Each half is divided into an __ and __ chamber. Chambers are like rooms. __ chambers are called Atrium, plural is atria. __ chambers are called ventricles.
The heart is divided into left and right halves. Each half is divided into an upper and lower chamber. Chambers are like rooms. Upper chambers are called Atrium, plural is atria. Lower chambers are called ventricles.
Atria description
-Thin walled, low pressure chambers. Reservoirs of blood. 70% passive flow in systole (contraction phase). Right- systemic return via vena cava (large veins) and receives deoxygenated blood. Left- pulmonary return via pulmonary veins and receives newly oxygenated blood.
Ventricles description:
-Major pumping mechanism of heart.
-Thick walled
-Right- receives deoxygenated blood to lungs via pulmonary artery
-Left- receives newly oxygenated blood to systemic circulation (the rest of the body) via aorta
The heart valves prevent what?
backflow of blood
In between chambers of the heart and between chambers and major blood vessels are
valves
Where is the tricuspid valve
In between the right atria and right ventricle is tricuspid valve
Where is the mitral (bi-cuspid) valve
In between the left atria and left ventricle is mitral (bicuspid) valve
Where is the aortic valve
Aortic valve at base of aorta from left ventricle
Where is pulmonic valve
pulmonic valve lies at the entrance to the pulmonic artery from the right ventricle
Each __ is connected to a small muscle called __ muscle by stringy tendons called __ tendineae
Each valve is connected to a small muscle called papillary muscle by stringy tendons called chordae tendineae
Oxygen poor blood ( __ blood) returns to the __ side of the heart after __ __ __ __. The __ side collects and pumps blood to __ through the __ arteries. The __ refresh the blood with a new supply of __ making it turn __.
Oxygen poor blood (blue blood) returns to the right side of the heart after circulating through your body. The right side collects and pumps blood to lungs through the pulmonary arteries. The lung refresh the blood with a new supply of oxygen making it turn red.
Oxygen rich blood, (__ blood) then enters the __ side of the __ and is pumped through the __ to the __ to supply __ with __.
Oxygen rich blood, (red blood) then enters the left side of the heart and is pumped through the aorta to the body to supply tissues with oxygen.
4 valves keep heart moving the right way
Tricuspid valve, Mitral valve, pulmonary valve, aortic valve
A contraction is called
systole
Relaxing is called
diastole
systole:
muscle contracts forcing blood into lungs and body
diastole:
ventricles relaxed and is filled with blood from atria
The valves open only one way and only when pushed on. They open once per heart beat or once per second. A beating heart contracts and relaxes. The heart cycle consists of systole and diastole. Example:
When viewed from inside the right ventricle we can see the underside of the tricuspid valve is connected to a papillary muscle via the chordinae tendineae. Which when the muscle contracts will pull the valve open.
Summarize if we were to trace a drop of blood through the heart what the pathway would look like:
the superior vena cava collects venous blood from the upper body while the inferior vena cava collects venous blood from the lower body. These two blood vessels dump their blood into the right atria. The blood then flows past the tricuspid valve into the right ventricle. It then passes through the pulmonic valve into the pulmonary artery. From here the blood flows to the lungs where it picks up oxygen it then flows back to the heart through the pulmonic vein and dumps into the left ventricle from here the blood is pumped through the aortic valve into the aorta and to the rest of the body.
__ and __ vena cava to the __ atrium through the __ valve into the __ ventricle through the __ valve into the __ artery to the __ to pick up __ back from the __ via the __ vein into the __ atrium through the __ valve into the __ ventricle through the __ valve into the __ to the rest of the __.
superior and inferior vena cava to the right atrium through the tricuspid valve into the right ventricle through the pulmonic valve into the pulmonary artery to the lungs to pick up oxygen back from the lungs via the pulmonic vein into the left atrium through the mitral valve into the left ventricle through the aortic valve into the aorta to the rest of the body.
How does blood get from arteries to veins?
Arterial blood flows in arteries that divide into smaller vessels called arterioles. These arterioles have progressively divide into smaller and smaller vessels until they get into very tiny thin walled vessels called capillaries. These capillaries have walls that are so thin oxygen can freely migrate through the wall so when the blood gets to its final destination it will give up oxygen. The remaining blood is now deoxygenated. It will flow through progressively larger vessels from capillaries to venules and then to veins and finally to the vena cava. In the same way the capillaries surround small air sacs in the lungs called alveoli, oxygen is passed from alveoli to the blood and carbon dioxide is passed from the blood to the alveoli to be exhaled.
cardiac output
the amount of blood pumped out of the heart in one minute (usually about 5 QT)
Right heart circulation
-receives venous blood from the body
-deoxygenated blood (blue)
-low pressure
-sends blood through the pulmonary circulation to replenish oxygen
-Note: Exception to the rule: the pulmonary artery carries deoxygenated blood to the lungs.
-The rule: Usually when we talk about veins we’re talking about deoxygenated blood.
-Generally veins carry blood to the heart while arteries carry away from the heart. -Newly oxygenated blood is carried from the lungs back to the left atrium by the pulmonic vein- same exception to the rule.
Left heart and arterial system
-receives oxygenated blood (red) from the lungs
-pumps oxygenated blood into the systemic circulation (rest of body)
-high pressure
-another exception to the rule: pulmonary vein carries oxygenated blood back to the heart
-the rule: usually when talking about veins we’re talking about deoxygenated blood. Generally veins carry blood to the heart while arteries carry away from the heart.
The right heart and venous system: How blood goes from arteries to veins:
Arteries to arterioles to capillaries to venules to veins
Your heart is nourished by blood too. __ __ extend over the surface of your heart and branch into smaller __. This is the network of blood vessels that feed your heart oxygen rich blood.
The coronary arteries: Your heart is nourished by blood too. Coronary arteries extend over the surface of your heart and branch into smaller capillaries. This is the network of blood vessels that feed your heart oxygen rich blood.
Where are the coronary arteries, what are they?
The coronary arteries come right off the aorta and give oxygen to the heart itself. It divides into a right coronary artery, and is further divided into the right marginal artery. The left coronary artery has a branch called the circumflex artery and another branch called the left anterior descending artery (LAD).
Clinical correlation/Diseases of the coronary arteries
-atherosclerotic cardiovascular disease (ASCVD) or coronary artery disease (CAD)
-angina pectoris (not enough blood flow to heart muscle results in chest pain)
-myocardial infarction (MI)- heart attack
How the body remains adequate pressure in the circulatory system
controlled in variations in blood pressure, heart rate and heart rhythm
Physiologic control of blood pressure
CV system obeys same laws of physics as pumps pipes and hoses. Heart as pump, blood vessels as hoses. If diameter of hose get bigger, pressure of water in hose goes down- so if blood vessels dilate the blood pressure will go down. If diameter of hose gets smaller, pressure of water in hose increases- so if vessels constrict then blood pressure will go up.
-Three major factors which control blood pressure are:
-These three factors are regulated by the:
-the force and rate of the contraction of the heart
-the construction and dilation of the blood vessels
-the volume of fluid in the system.
-these three factors are regulated by the autonomic nervous system (ANS) and the endocrine system.
The autonomic (involuntary) nervous system
-The autonomic nervous system is divided into the parasympathetic division and the sympathetic division.
-parasympathetic (couch potato): constricts pupil, saliva production, slows heart, stimulates stomach pancreas intestines (digestion)
-sympathetic (getting scared-fight or flight syndrome): heart rate would race, blood pressure would go up, and your mouth would go dry, bronchi in lungs relaxed, adrenaline increased
Sympathetic system
-chemical produced is a form of adrenaline called norepinephrine
-the sympathetic system is divided into alpha and beta
-the alpha system controls arteries and veins so stimulation will cause vessels to constrict
-the beta part of the system controls the big organs - heart and lungs. beta 1 controls the heart- stimulation of beta 1 will increase the blood pressure and the heart rate. beta 2 controls the lungs- stimulation of beta 2 will dilate the bronchioles therefor many asthma meds are specific beta 2 stimulators called beta 2 agonists. (beta 1- you have one heart and beta 2- you have two lungs)
parasympathetic
-chemical released is acetylcholine
-salivary glands are stimulated
-medications that dry salivary secretions block the parasympathetic system like atropine or robinol
-regulates heart rate
-balance between sympathetic and parasumpathetic efforts on heart (accelerates vs brakes)
-the main parasympathetic nerve that controls the heart rate is called the vagus nerve
-stimulation of the vagus nerve will slow the heart rate down
-ones resting heart rate is largely controlled by the parasympathetic innervation.
-atropine interrupts the parasympathetic nerve supply thereby taking the foot off the breaks which increases the heart rate
-clinically medication are directed to either stimulating or blocking different components of the autonomic nervous system to control dysrhythmias (tachycardia bradycardia asystole etc) and blood pressure problems as well as asthma
-Components of the conduction system
-Pathway of conduction system
-Autonomic input
-Sinoatrial (SA) Node- the pacemaker
-Internodal pathways and atria
-Atrioventricular (AV) node
-AV bundle (Bundle of His)
-Right and Left Bundle branches
-purkinje fibers
-SA node to AV node to Bundle of His to R/L branches to purkinje fibers
The conduction system of the heart
-partial control from the central nervous system (CNS)
-where sympathetic stimulation will speed up the heart and parasympathetic stimulation will slow heart
-special cells can conduct electricity and they’re arranged in pathway in heart and send signal sequentially through heart
-the signal then stimulates heart muscle which causes contraction
-the pathway is marked by clusters of cells called nodes
-it starts in the right atrium at a cluster of cells called the sinoatrial node (SA node) this is the pacemaker. there are pathways inside the atria that lead to atrioventricular node (AV node). from here the signal travels approximately to the septum that divides the right and left ventricles, called the bundle of his. the signal travels down the septum to divide into right and left bundle branches that encircle bottom of ventricle. these branches terminate into purkinje fibers.
Risk factors of cardiovascular disease
-smoking
-hypercholesterolemia
-family hx of premature heart disease
-obesity
-sedentary lifestyle
-hypertension
-increasing age
-history of MI (heart attack)
-congestive heart failure (CHF)
-heart valve malfunctions
-irregular heartbeat (dysrythmias)
