The Cardiovascular System Flashcards
How much does the heart weigh?
8-10 ounces
Where is the heart located?
In the mediastium area on top of the diaphragm
What is the tip/ bottom of the heart called?
Apex
What is the pericardium?
A membrane that surrounds and protects the heart
What are the 2 layers of the pericardium?
Fibrous pericardium and serous pericardium
What is the serous pericardium divided into?
Parietal and visceral layer
What is the fibrous pericardium?
A tough non elastic dense irregular CT layer of the heart that attaches to the diaphragm
What is the function of the fibrous pericardium?
Prevent over stretching of the heart, protects it, and anchors heart in its cavity
What is the parietal layer fused to?
The fibrous pericardium
What is the visceral layer connected to?
The heart
What is the pericardial cavity filled with?
Pericardial fluid (serous fluid)
What is the function of the pericardial cavity?
Reduce friction as the heart moves
What are the 3 walls of the heart?
Epicardium, myocardium, and endocardium
What layer is the epicardium?
External (visceral) layer
What layer is the myocardium?
The middle layer
What layer is the endocardium?
The internal layer
How big is the heart?
About the size of the human fist… 5.5 in. Long, 3.5 in. Wide, and 2.5 in. Thick
What is the epicardium made of?
Adipose and fibroelastic tissue
What does the epicardium contain?
Blood vessels, lymphatic vessels, and coronary arteries
What makes up 95% of the heart wall?
The myocardium
What is the myocardium made of?
Cardiac muscle (pumping action)
What is the endocardium made of?
A thin layer of endothelium and a thin layer of CT
What does the endocardium do?
Provide a smooth lining of chambers and it covers valves
What 2 chambers receive receive blood?
The right and left atria
What 2 chambers pump blood to parts of the body?
The right and left ventricles
What type of blood does the right side of the heart deal with?
Deoxygenated blood
What type of blood does the left side of the heart deal with?
Oxygenated blood
What are the 2 main heart valves?
Atrioventricular valves and semilunar valves
What does the atrioventricular valve separate?
Atrium from ventricles
What are the 2 parts of the atrioventricular valves?
The tricuspid valve (right side) and bicuspid/ mitral valve (left side)
What is the function of the atrioventricular valves?
Withstand high pressure from contracting ventricles
What do the semilunar valves separate?
Ventricle from major artery
What are the parts of the semilunar valves?
Pulmonary valve (right side) and aortic valve (left side)
What do the semilunar valves deal with?
Deal with smaller volumes of blood and lower BP exerted on valves
What are arteries?
Blood vessels that carry blood away from the heart
What are veins?
Blood vessels that carry blood towards the heart
What supplies blood to the heart?
Coronary arteries from the aorta
Where is blood drained from the heart?
Drained through the coronary sinus into the right atrium
What are the 3 chamber walls?
Atrial walls, left ventricle wall, and right ventricle wall
What do the atrial walls look like?
They are thin walled
What does the left ventricular wall look like?
It is very thick
How thick is the right ventricular wall?
It is thicker than the atria and thinner than the left ventricle wall
What is the function of the atrial walls?
Collect and pump blood a short distance
What is the function of the left ventricle wall?
Pump blood throughout the entire body
What is the function of the right ventricle wall?
Pump blood to lungs
What happens when the atria contracts?
Higher pressure within forces AV valves to open
What happens when the ventricles contract?
Pressure of blood increases which forces the SL valves to open
What is coronary circulation?
The myocardiums own network of blood vessels
What do the myocardium blood vessels do?
Supply oxygen and nutrients to the heart muscle wall
What kind of blood to coronary arteries carry?
Oxygen rich blood
What kind of blood do coronary veins carry?
Oxygen poor blood
What is the function of coronary arteries?
Deliver blood to heart muscle from the aorta when the heart relaxes
What is the function of coronary veins?
Receive blood from heart muscle and drain into coronary sinus
What is the left coronary artery also called and what is its function?
Also called the widow maker and it supplies oxygen to anterior ventricle walls and left atrium
What is the function of the right coronary artery?
Supply oxygen to right atrium wall and right ventricle wall
What are the two types of coronary artery obstruction?
Partial obstruction and total obstruction
What is partial obstruction called and what is it?
Myocardium ischemia (angina pectoris) and it is severe chest pain
What is total obstruction called and what is it?
Myocardial infarction (heart attack) and it is when the tissue dies and is replaced by scar tissue
What is the cardiac cycle?
All the events that occur during one heartbeat (contraction of atria followed by contraction of ventricles)
What is the average person heart bpm?
70 bpm or 0.85 beats/ minute
What are autorhythmic fibers and what do they do?
They are special cardiac muscle fibers that allow the heart to beat
Name 3 characteristics of cardiac muscle fibers
Self excitable, repeatedly generate action potentials, form cardiac conduction system
What percent of cardiac muscle cells form the electrical conduction system of the heart?
1%
What is an electricocardiogram?
A record of electrical charges accompanying a heartbeat
Where are electrodes placed during an electrocardiogram?
2 on the arms, 2 on the legs, and 4 to 6 around the heart
How many different tracings of activity can and electrocardiogram see?
12
What does an electrocardiogram determine?
A normal conduction pathway, enlarged heart, damaged heart regions, cause of chest pain
What is a systole?
Contraction part during a heartbeat
What is the diastole of a heartbeat?
The relaxation period
What happens during the diastole?
The chambers fill with blood
What happens during the systole?
The chambers contract and empty blood. The atria contract first and then the ventricles
Why does the heartbeat make a noise?
The sound the result from turbulence in blood flow when valves shut
What is the lubb sound of a heartbeat?
A long grueling initial sound resulting from AV valves closing at the end of ventricular systole
What is the dubb sound Of a heartbeat made from?
The SL valves closing at the end of ventricular systole
Why is there a pause after the dubb sound?
It is the relaxation period
What are the three electrocardiogram waves?
P wave, QRS wave, T wave
What happens during the P wave?
The atria contracts (depolarization)
What happens during the QRS wave?
Onset of ventricular contraction (depolarization)
What is the T wave??
Ventricular relaxation (Repolarization)
How do you calculate the cardiac output?
Stroke volume times heart rate
What is cardiac output (CO)?
Volume of blood ejected from the ventricle each minute
What is stroke volume (SV)?
The amount of blood checked it during each ventricle contraction (each beat)
What affects cardiac output?
Either Stroke volume or heart rate
What factors affect stroke volume?
Preload, Force of contraction, and afterload
What is the preload?
Blood pressure at the end of diastole
What is afterload?
Vascular pressure to overcome to push blood out of chamber
What does the heart rate influence?
ANS, hormones, ions, body temperature, age, gender, physical fitness
What are The functions of blood vessels
Transport blood through the body, exchange substances, diffuse oxygen and nutrients
What percent of blood is carried by systemic veins and venules?
64%
What percent of blood is carried by systemic arteries and arterioles?
13%
What percent of blood is carried by pulmonary vessels?
9%
What percent of blood is carried by the heart?
7%
What percent of blood is carried by systemic capillaries?
7%
What are the 3 tunics of arteries surrounded by?
Lumen(hollow tube)
What do smooth muscles in the walls of arteries cause?
Vasoconstriction and vasodilation
What is the function of arterioles?
Regulate blood pressure and blood flow to capillaries
Name two characteristics of arterioles
They are almost microscopic and they branch from small arteries into tissues
What is the function of capillaries?
Exchange nutrients and waste between blood and tissue fluid
What do capillaries contain and what do they do?
They contain sphincters (smooth muscle rings) that control the direction of blood flow
How do capillary blood cells move?
In single file
Name two characteristics of capillaries
They are thin walled and microscopic
Do venules deal with low or high blood pressure?
Low
What is the function of venules?
Carry blood away from capillaries
Can veins expand?
Yes
What is the largest blood reservoir in the body?
Veins
What type of blood vessel contains valves?
Veins
What are the three layers of a vein?
Tunica interna, Tunica media, tunica externa
What where is the tunica interna and what is it made out of?
It is the inner layer and it is made of simple squamous tissue and a basement membrane
What layer is the Tunica media and it what is it made out of?
It is the middle layer and it is made out of smooth muscle
What layer is the tunica externa what does it look like?
Outer layer. It is elastic, tough, stretchy and It is the thickest part of the vein
What is vascular resistance?
Opposition to blood flow
What does vascular resistance depend on?
The lumen diameter, blood viscosity, and total blood vessel length
What is blood viscosity?
Ratio of red blood cells to plasma volume
What is happens in obesity?
Additional blood vessels in adipose tissue
The contraction of what generates blood pressure?
Ventricles
What is blood pressure?
Pressure exerted on walls of arteries
What is blood pressure determined by?
Cardiac output, blood volume, vascular resistance
What is systolic blood pressure?
Highest pressure in arteries during left ventricles systole
What is diastolic blood pressure?
The highest pressure in arteries during ventricular diastole
What is a normal blood pressure for adults?
120/80mmHg
Where is blood pressure measured?
The brachial artery of left arm
What device is used to measure blood pressure?
Sphygmomanometer
What are the sounds heard when taking blood pressure?
Korotkoff sounds
What are you hearing during systolic blood pressure?
The force of blood pressure on arterial walls just after ventricular contraction
What happens during diastolic blood pressure?
The force exerted by blood remaining in arteries during ventricular relaxation
What is a pulse?
Alternate expanding and recoil of arterial walls
Where is the radial artery located at?
Wrist
Where is the carotid artery located at?
Lower neck
Where is the brachial artery located at?
Elbow
Where is the femoral artery located at?
Groin
Where is the popliteal artery located at?
Behind knee
What is a stroke and what does it cause?
A small cranial arteriole burst that causes lack of oxygen in the brain
What is coronary artery disease caused by and what does it reduce?
Caused by accumulation of atherosclerosis plaques inside wall of coronary arteries and reduces blood flow to myocardium
What is a atherosclerosis
A progressive disease from accumulative cholesterol arteries
What is congestive heart failure and what is it caused by?
Loss of pumping efficiency caused by coronary artery disease, heart attacks, and valve disorders
What is an aneurysm?
A thin weak section of an artery or vein wall that boulders outward
What is arrhythmia?
In irregular heartbeat
What is sternosis?
Narrowing of heart valve opening that restricts bloodflow into chambers
What is a heart murmur caused by?
leaky heart valves
What is varicose veins?
Blood back up and pooling in veins do to weak or damaged valves in veins
What does having varicose veins cause?
Swelling and twisting of beans at surface
It is the most deadly fibrillation?
Ventricular fibrillation
