Ch. 13 Cardiovascular System Flashcards
The cardiovascular system is..
A closed circuit that consists of the heart and blood vessels (arteries, capillaries, and veins), and blood
A functional cardiovascular system is vital for supplying..
Oxygen and nutrients to tissues and removing wastes (CO2, metabolic waste) from them
Oxygen-poor blood is carried by the pulmonary circuit to the..
Lungs, where it picks up oxygen and drops of carbon dioxide
- [Pulmo:Lung] - Pulmonary system: From the heart to the lungs (Inhale) , then from the lungs to the heart (Exhale)
The systemic circuit sends oxygen-rich blood to..
All body cells, where it drops of oxygen and picks up carbon dioxide
What are the anatomic structures of the cardiovascular system?
1.Heart
2. Blood Vessels
- Arteries
- Capillaries
- Veins
3. Blood
Structure of the heart..
- Muscular, cone-shaped organ the size of a fist
- A muscular pump within the mediastinum in the thoracic cavity
- [Mediastinum: Space between the lungs, Houses the heart, trachea, esophagus, aorta, superior, and inferior vena cava)
Location of the heart..
- Anterior to the vertebral column, posterior to the sternum (breastbone), and between the lungs
- Base: (Superior) Lies beneath the second rib (clavicle)
- Apex: (Inferior) Extends to the fifth intercostal space
- [Inter: In between]
- [Costal: Cartilage]
Function of the heart..
Pumping action circulates blood throughout the body
Blood vessels are..
Tube-like structures that carry blood throughout the body
The blood vessels form a closed circuit that carries blood away from the heart, to the cells, and back again
- Blood vessels:
- Arteries— Carry blood away from the heart
- Arterioles— Connects an artery to a capillary (Smallest arteries)
- Capillaries— Materials are passed between blood and tissues through capillary walls (Diffusion takes place)
- [Diffusion: Movement from high to low concentration]
- Venules— Connects a capillary to a vein
- Veins— Carry blood towards the heart
The blood vessels include..
- (1) Arteries
- Function: Carry blood away from the heart
- (2) Capillaries
- (Very thin blood vessels that run between arteries and veins)
- Microscopic blood vessels
- Function: Materials are passed between blood and tissues through capillary walls
- (3) Veins
- Function: Carry blood towards the heart
Arteries.. (Function)
Are blood vessels that carry blood away from the heart
Transports blood under relatively high pressure from heart to arterioles
Capillaries.. (Structure and function)
(Very thin blood vessels that run between arteries and veins)
- Microscopic blood vessels - Function: Materials are passed between blood and tissues through capillary walls (Allows nutrients, gases, and wastes to be exchanged betweem blood and tissue fluid; connects an arteriole to a venule)
Veins.. (Structure and function)
Blood vessels that carry blood towards the heart
[Thinner wall, larger than artery, have valves (especially on lower extemities) to prevent backflow]
Blood..
- Fluid circulated through heart, arteries, capillaries, and veins
- Composed of plasma and formed elements (Erythrocytes, leukocytes, platelets/thrombocytes)
The pericardium is..
A membranous sac that encloses the heart
The pericardium consist of 2 portions:
- (1) Fibrous pericardium— Outer, tough, connective tissue layer
- (2) Serous pericardium— The inner, more delicate, double-layered (which consists of):
- Parietal pericardium— Lines the inner surface of the fibrous pericardium
- Visceral pericardium (Epicardium)— Inner layer of serous membrane, covers the heart
- Pericardial cavity— The space between the visceral and parietal layers, contains serous fluid to reduce friction between layers
Fibrous pericardium—
Outer, tough, connective tissue layer
Serous pericardium—
- The inner, more delicate, double-layered (which consists of):
- Parietal pericardium— Lines the inner surface of the fibrous pericardium
- Visceral pericardium (Epicardium)— Inner layer of serous membrane, covers the heart
- Pericardial cavity— The space between the visceral and parietal layers, contains serous fluid to reduce friction between layers
Parietal pericardium—
Lines the inner surface of the fibrous pericardium
[Fibrous pericardium— Outer, tough, connective tissue layer]
Visceral pericardium —
(Epicardium) Inner layer of serous membrane, covers the heart
Pericardial cavity—
The space between the visceral and parietal layers, contains serous fluid to reduce friction between layers
The wall of the heart is composed of 3 layers:
- (1) Epicardium (Visceral pericardium)— The outermost layer; a serous membrane made up of connective tissue and epithelial; decreases friction in the heart
- [Epi: Above] - (2) Myocardium— The middle layer; consist of cardiac muscle, the thickest layer of the heart wall; pumps blood out of the heart chambers
- [Myo: Muscle]
- [Cardiac: Heart] - (3) Endocardium— The inner layer; made up of connective tissue and epithelium; continuous with the endothelium of major vessels joining the heart; contains the Purkinje fibers (part of the cardiac conduction system)
- [Endo: Within]
- [Cardiac: Heart]
Epicardium —
(Visceral pericardium) The outermost layer; a serous membrane made up of connective tissue and epithelial; decreases friction in the heart
- [Epi: Above]
Myocardium—
The middle layer; consist of cardiac muscle, the thickest layer of the heart wall; pumps blood out of the heart chambers
- [Myo: Muscle] - [Cardiac: Heart]
Endocardium—
The inner layer; made up of connective tissue and epithelium; continuous with the endothelium of major vessels joining the heart; contains the Purkinje fibers (part of the cardiac conduction system)
- [Endo: Within] - [Cardiac: Heart]
The heart contains 4 chambers:
- 2 Upper chambers: Atria— Receiving chambers (Receive blood)
- Receive blood returning to the heart
- Have thin walls and ear-like auricles projecting from their exterior
- 2 Lower chambers: Ventricles— Pumping chambers (Pump blood)
- Thick-muscled ventricles that pump blood out of the heart
2 Upper chambers:
Atria
2 Lower chambers:
Ventricles
Atria—
Receiving chambers (Receive blood)
- Receive blood returning to the heart - Have thin walls and ear-like auricles projecting from their exterior
Ventricles—
Pumping chambers (Pump blood)
- Thick-muscled ventricles pump blood out of the heart
Septum:
Separates the atrium and ventricle on the right from those on the left
Two parts of the septum include:
- Interatrial septum— The wall that separates the two atriums
- [Inter: In between]
- Interventricular septum— The wall that separates the two ventricles
[Septum: Separates the atrium and ventricle on the right from those on the left]
Interatrial septum—
The wall that separates the two atriums
- [Inter: In between]
Interventricle septum—
The wall that separates the two ventricles
Atrioventricular (AV):
Door between the atrium and ventricles valve to ensure one-way flow of blood from atria to ventricle
The right AV (Tricuspid) valve and left AV (Bicuspid or mitral) valve have cusps to which..
Chordae tendineae attach (Attached to the wall by the tendon and muscles)
Chordae tendineae are attached to (1)__________ ; These muscles contract during (2)_________.
- (1) Papillary muscles in the inner wall of the heart
- (2) Ventriculae contraction to prevent backflow of blood through the AV valves
Superior and inferior vena cavae bring blood
Back from the systemic circuit to the right atrium
- [Vena: Big vein]
Coronary sinus drains blood from the
Myocardium (coronary circulation) into the right atrium
Right ventricle has a thinner wall than the left ventricle, because..
it must pump blood only as far as the lungs, compared to the left ventricle pumping blood to the entire body
Each side of the heart has a semilunar valve between the ventricle and the blood vessel into which blood is pumped:
- (1) Pulmonary semilunar valve
- (2) Aortic semilunar valve
Right ventricle pumps blood to the lungs through the pulmonary trunk/artery; at the base of the pulmonary trunk/artery is the..
Pulmonary semilunar valve, which prevents backflow of the blood into the right ventricle
Left ventricle pumps blood to the systemic circuit through the aorta; at the base of the aorta is the aortic semilunar valve, which..
Prevents backflow of blood into the left ventricle
Tricuspid valve is located at the..
Opening between right atrium and right ventricle
The tricuspid valve.. (Function)
Prevents blood from moving from the right ventricle back into the right atrium during ventricular contraction
The pulmonary semilunar valve is located at the..
Entrance to pulmonary trunk, between the pulmonary trunk and right ventricle
The pulmonary semilunar valve.. (Function)
Prevents blood from moving from the pulmonary trunk, back into the right ventricle during ventricular relaxation
The mitral (bicuspid) valve is located at..
The opening between left atrium and left ventricle
The mitral (bicuspid) valve.. (Function)
Prevents blood from moving from the left ventricle into the left atrium during ventricular contraction
The aortic semilunar valve is located at..
The entrance to aorta, between aorta and left ventricle
The aortic semilunar valve.. (Function)
Prevents blood from moving from the aorta into the left ventricle during ventricular relaxation
The Systemic and Pulmonary Circuits
- 1) Pulmonary circulation— Flow between heart and lungs
- (2) Systemic circulation— Flow between heart and body tissues
- Pulmonary circuit
- Deoxygenated blood from the upper body and lower returns to the right atrium via the superior and inferior vena cava and coronary sinus of the myocardium
- The right atrium contracts, forcing blood through the tricuspid value into the right ventricle
- The right ventricle contracts, closing the tricuspid value, and forcing blood through the pulmonary semilunar value into the pulmonary trunk/arteries
- The pulmonary arteries carry blood to the lungs, where it enters alveolar capillaries, the site of gas exchange with the alveoli of the lungs,; here the blood drops of CO2 and picks up O2
- Systemic circuit
- Oxygenated blood flows back into the left atrium via pulmonary veins
- The left atrium pumps blood through the mitral (bicuspid) valve into the left ventricle
- The left ventricle contracts, closing the mitral valve, opening the aortic semilunar valve, and pumping blood into the aorta for distribution to the systemic circulation of the body
Blood flow proceeds in a continuous..
Circle
Two circuits, or subdivisions , for blood flow with respect to gas exchange:
- (1) Pulmonary circulation— Flow between heart and lungs
- (2) Systemic circulation— Flow between heart and body tissues
Describe the blood flow through the heart (With image):
- Deoxygenated blood returns to the right atrium via the vena cavae and coronary sinus
- The right atrium contracts, forcing blood through the tricuspid valve into the right ventricle
- The right ventricle contracts, closing the tricuspid valve, and forcing blood through the pulmonary semilunar valve into the pulmonary trunk/arteries
- The pulmonary arteries carry blood to the lungs, where it enters alveolar capillaries, the site of gas exchange with the alveoli of the lungs; here the blood drops off CO2 and picks up O2
- Oxygenated blood flows back to the left atrium of the heart via pulmonary veins
- The left atrium pumps blood through the mitral (bicuspid) valve into the left ventricle
- The left ventricle contracts, closing the mitral valve, opening the aortic semilunar valve, and pumping blood into the aorta for distribution to the systemic circuit of the body
Right and left coronary arteries:
First branches off the aorta, which carry oxygenated blood to the heart
Blood flow increases during relaxation of the ventricles, because..
Myocardial vessels are not compressed at this time
Due to the constant pumping of the heart, cardiac muscles cells..
Require a continuous supply of oxygen
Branches of the coronary arteries feed..
Many capillaries of the myocardium
Branches of the coronary arteries have connections called anastomoses, which..
These provide alternate pathways for blood, in case a pathway becomes blocked
- Anastomoses: Joining
Cardiac veins drain blood from the heart muscle, and carry it to the coronary sinus, which is
A large vein that empties into the right atrium
Systole:
- Contraction
- Peak pressure
- 120 mm of Hg (Mercury)
Diastole:
- Relaxation
- Lowest pressure
- 80 mm of Hg (Mercury)
The cardiac cycle consist of the following events:
[Cycle: Repeat]
(1) First, the atria contract (called atrial systole), while ventricles relax (called ventricular diastole)
(2) Then, the ventricles contract (called ventricular systole), while the atria relax (called atrial diastole)
(3) Then the entire heart relaxed for a brief moment
Atria contract is called..
Atrial systole
Ventricles relax is called
Ventricular diastole
Ventricles contract is called..
Ventricular systole
Atria relax is called..
Atrial diastole
Cardiac conduction system:
- Specialized cardiac muscle tissue conducts impulses throughout the myocardium
- These cells do not contract, but initiate and distribute impulses in the heart, coordinating the cardiac cycle
Components of the cardiac conduction system:
- Sinoatrial (SA) node— A self-exciting mass of specialized cardiac muscle, serves as the pacemaker; located in the posterior right atrium; generates the impulses for the heart beat
- Atrial syncytium— From the SA node, causes atrial contraction to occur
- Junctional fibers— Lead to the next major component, the AV nose
- Atrioventricular (AV) node— Passes impulses to the AV bundle (Bundle of his), delaying the signal until atria have finished contracting; located in the interatrial septum
- AV Bundle (Bundle of his)— From the AV node, impulses pass to the AV bundle and travel down the interventricular septum
- Bundle branches—AV bundle divides into left and right bundle branches under the endocardium
- Purkinje fibers— Bundle branches give off the purkinje fibers, which spread impulses to the ventricular wall and papillary muscles
Sinoatrial (SA) node—
A self-exciting mass of specialized cardiac muscle, serves as the pacemaker; located in the posterior right atrium; generates the impulses for the heart beat
Atrial syncytium—
From the SA node, causes atrial contraction to occur
Junctional fibers—
Lead to the next major component, the AV node
Atrioventricular (AV) node—
Passes impulses to the AV bundle (Bundle of his), delaying the signal until atria have finished contracting; located in the interatrial septum
AV Bundle (Bundle of his)—
From the AV node, impulses pass to the AV bundle and travel down the interventricular septum
Bundle branches—
AV bundle (Bundle of his) divides into left and right bundle branches under the endocardium
Purkinje fibers—
Bundle branches give off the purkinje fibers, which spread impulses to the ventricular wall and papillary muscles
The action of the purkinje fibers stimulates..
Contraction of the papillary muscles, and cause the ventricles to contract in a twisting, upward motion
Electrocardiography..
- “EKG”
- A recording of the electrical changes that occur during a cardiac cycle
- Recording results from the summed action potentials of many cardiac muscle cells, which can be detected through electrical currents in the body fluids
Components of the ECG:
- P wave— Atrial contraction
- QRS complex— Ventricular contraction
- T wave— Ventricular relaxation
P wave—
Atrial contraction
QRS complex—
Ventricular contraction
T wave—
Ventricular relaxation
Heart sounds are due to..
Vibrations in heart tissues as the valves close
Heart sounds can be described as a..
“lubb dupp” sound
The first heart sound (lubb) occurs as..
Ventricles contract and AV valves are closing
The second heart sound (dupp) occurs as..
Ventricles relax and aortic and pulmonary valves are closing
An abnormal heart sound is called a..
Murmur; it is due to valve damage
Average adult resting heart rate:
70 - 75 bpm, with normal range of 60 to 100 bpm
Tachycardia—
Resting heart rate > 100 bpm