Cardio System Flashcards
Name and define the components of the cardiovascular system.
- Heart: muscular pump that propels blood throughout the body
- Arteries: carry blood away from the heart
- Veins: carry blood to the heart
- Capillaries: exchange nutrients and wastes between blood and other body tissues
- Blood: only fluid tissue in the body and serves as a transport medium
List the functions of the cardiovascular system.
- Oxygen/Carbon Dioxide Exchange:
oxygen picked up by red blood cells in lungs and transported to tissues of the body
CO2 absorbed by blood and carried back to lungs where it’s exhaled
- Nutrient/Waste Exchange:
primarily involving the dig and urinary systems
nutrients are absorbed into blood stream by dig system and then carried throughout body
some wastes are picked up by bloodstream and carried to kidneys
- Hormone Transport
- Acid/Base Balance:
hemoglobin and bicarbonate (HCO3-) help absorb excess hydrogen ions and prevent unmarked changes in pH
- Thermoregulation:
when body temp rises, blood flow is channeled to superficial vessels to help radiate excess heat
when body temp lowers, surfaces blood flow is reduced to lessen heat loss
- Body Defense:
gamma globulins (impart immunity) white blood cells (phagocytic cells) clotting mechanism
Name the major external landmarks of the heart.
Base - superior end
Apex- inferior end
Sternocostal surface - anterior aspect
Diaphragmatic surface - inferior aspect
Pulmonary surface - left side
Right border - right side
Anterior/Posterior Interventricular Grooves - mark interventricular septum that internally separates the left/right ventricles
Coronary groove: fat filled landmark between atria above and ventricles beneath
List and differentiate the layers of the heart.
- Endocardium:
- has c.t. proper and simple squamous epithelium (endothelium)
* endothelium lines the heart and extends into the vessels - Myocardium: c.t. proper and cardiac muscle
* contractile portion of the heart and contains purkinje fibers which conduct impulses (part of electrical system mentioned later) - Epicardium:
thin outer layer of the heart (consists of mesothelium)
*forms the visceral layer of serous pericardium (form the inner part of closed sack)
Other Parts:
Pericardial Cavity - hollow space between parietal and visceral layers
Parietal layer of the serous pericardium: outer layer of sac that doesn’t touch the heart
(think of fist in balloon)
Differentiate the four heart chambers
Right Atrium: collects blood from superior and inferior vena cava as well as coronary sinus (from the rest of the body)
Left Atrium: collects blood from the 4 pulmonary veins (returning from lungs)
Right Ventricle: receives blood from -
- Right Atrium
- Right Atrioventricular Valve (tricuspid)
- Pulmonary Trunk (via pulmonary valve)
Left Ventricle: receives blood from -
- Left Atrium
- Left Atrioventricular Valve (mitral)
- Aorta (via aortic valve)
Differentiate the four heart valves in regard to their names (and aliases), location, general structure, and their open/shut position during the cardiac cycle.
Right Atrioventricular Valve
Alias: Tricuspid Valve
Location: Between right atrium/ventricle
General Structure: 3 cusps anchored by chordae tendineae to papillary mm.
Open/Shut position:
Ventricular Systole (contraction) - closed
Ventricular Diastole (relaxation) - open
Differentiate the four heart valves in regard to their names (and aliases), location, general structure, and their open/shut position during the cardiac cycle.
Pulmonary Valve
Alias: semilunar valve
Location: between right ventricle and pulmonary trunk
General Structure: 3 leaflets that aren’t anchored to papillary mm. or chordae tendineae
Open/shut position:
Ventricular systole: open
Ventricular diastole: closed
Differentiate the four heart valves in regard to their names (and aliases), location, general structure, and their open/shut position during the cardiac cycle.
Left Atrioventricular Valve
Alias: Mitral Valve
Location: between left atrium/ventricle
General Structure: 2 small 2 large cusps which are anchored by chordae tendineae to papillary mm.
Open/Shut position:
Ventricular Systole: closed
Ventricular Diastole: open
Differentiate the four heart valves in regard to their names (and aliases), location, general structure, and their open/shut position during the cardiac cycle.
Aortic Valve
Alias: semilunar valve
Location: between left ventricle and ascending aorta
General Structure: 3 leaflets that aren’t anchored to papillary mm. or chordae tendineae
Open/shut position:
Ventricular systole: open
Ventricular diastole: closed
Discuss the cardiac cycle.
- During diastole AV valves are open due to gravity and blood flowing to ventricles
- Aortic and Pulmonary Valves are closed due to pressure
- @ beginning of systole atria contract right before ventricles to empty and completely fill ventricles with blood
- ventricles begin to contract which closes the AV valves (due to intraventricular pressure) and opens aortic and pulmonary valves (due to pressure)
- blood rushes through aorta and pulmonary trunk
- when ventricle stops contracting aortic and pulmonary valves close and the AV valves open
- Cycle repeats
State the name and causes of normal heart sounds.
“Lub” is caused by the simultaneous closing of left and right AV valves
“Dub” is caused by the simultaneous closure of aortic and pulmonary valves
Period of time between 1st and 2nd heart sound = systole
Period of time between 2nd and next 1st heart sound = diastole
Explain the causes of cardiac murmurs.
Cardiac murmurs are caused by problems with the AV valves and the aortic and pulmonary valves opening/closing.
In other words: the valves don’t open/close properly
Insufficient: means the heart valves don’t close securely to prevent leakage
Valvular stenosis (narrowing): means heart valves fail to open
- can be caused by infectious diseases that cause scarring and fusion of adjacent cusps
- Remember
If it’s up near the sternum (2nd/3rd intercostal space) depending on whether it’s right or left side, it’s murmurs involving Aortic and Pulmonary Valve
If it’s near apex of heart depending on whether it’s right or left side, it’s murmurs involving Tricuspid and Mitral Valve
Discuss the electrical conduction system of the heart.
purkinje fibers - control contraction of heart muscle
- Sinoatrial node (SA node) - initiates impulses that lead to systole
- travel through atria (in purkinje fibers) to AV node
- it’s delayed for a fractional part of a second before being passed onto ventricles
(allows atria to empty before ventricles contract) - impulses continue downward to AV bundle (atrioventricular fasicle)
- they then go to left/right crura
- impulses distributed to myocardium of ventricular walls
Define Arteries and differentiate the three class sizes.
Arteries: vessels which carry blood from heart to the capillaries
- Elastic Arteries
- pulmonary trunk, aorta, some of their branches
- LARGEST
- have significant amount of elastic c.t. in their tunica media - Muscular Arteries
- can be seen with naked eye
- hv. mainly smooth muscle in their tunica media
- this muscle can be involuntarily contracted by ANS to elevate blood pressure or relaxed to lower it - Arterioles
- smallest
- supply capillaries
- in some cases empty directly into veins (arteriovenous anastomoses)
*those connections are mainly found in surface blood vessels for thermoregulation
Remember: arteries are much too thick to allow nutrient/waste exchange
tissues in walls of veins/arteries are nourished by vessels that enter them from external surfaces (vasa vasorum)
Explain why capillaries are the only blood vessels which can exchange nutrients and waste products with surrounding tissues, and list the avascular components of the body.
- capillaries are the smallest vessels and the only ones with walls thin enough to allow diffusion of nutrients and waste products
avascular components:
- mature cartilage
- hair/nails (epithelial derivatives)
- membranous epithelium
- cornea/lens of the eye