Test 4a Flashcards
What constitutes the cardiovascular system?
Heart and all blood vessels
4 things that the cardiovascular system transports to main homeostasis
Oxygen, carbon dioxide, hormones, nutrients
Where is the heart located?
Mediastinum in the middle of the chest cavity
The more pointed end of the heart
Apex
Where does the apex point?
Diagonally down to the left
The upper posterior portion
Base
Outer protective layer formed of fibrous tissue
Pericardium
What does the pericardium do?
Helps to keep heart anchored to surrounding structures
What does the pericardium anchor to?
Sternum and diagphragm
Protective layer surrounding the heart that is deep to fibrous pericardium
Serous pericardium
The two layers of the serous pericardium
Parietal layer, visceral layer
Outer most layer in contact with the fibrous pericardium
Parietal layer
Inner most layer that is actually apart of the heart wall
Visceral layer
What is between the parietal and visceral layer?
Serous fluid
What produces serous fluid?
Pericardial membranes
3 layers of the heart wall
Epicardium, myocardium, endocardium
Outer layer that is also the same as the visceral layer of membrane covering the heart
Epicardium
Thick cardiac muscle bundles that are arranged in a twisted, ring-like manner
Myocardium
Thin endothelium that lines the four heart chambers
Endocardium
Which layer of the heart wall contracts?
Myocardium
4 chambers of the heart
2 atria, 2 ventricles
What are atria and ventricles lined with to assist with smooth blood flow?
Endocardium
Top chambers of the heart that receive blood from periphery
Atria
Lower chambers of the heart that disperse blood back to circulate to the body
Ventricle
Wall that divides the heart longitudinally into left and right
Septum
Two septums of the heart
Interventricular septum, interatrial septum
Right side heart function
Pumps blood to lungs for exchange of gases
Left side heart function
Pumps blood to periphery to distribute needed substances to cells and pick up waste products
Carries oxygen poor blood from upper body to right atria
Superior venae
cavae
Carries oxygen poor blood from lower body to right atria
Inferior venae cavae
How does right atria receive blood?
Through valve in right ventricle
From right ventricle where does blood go?
Through valve into pulmonary trunk
From pulmonary trunk where does blood go?
Divides in right and left pulmonary arteries
From pulmonary arteries where does blood go?
Lungs
What occurs in the lungs?
Gas exchange in capillaries
From lungs, where does blood go?
Returns to heart via pulmonary veins
From pulmonary veins where does blood go?
Left atria
From left atria where does blood go?
Through valve to left ventricle
From left ventricle where does blood go?
Through valve to aorta
Technical term for circulation through right side of the heart, to the lungs, and back to the heart
Pulmonary circulation
Technical term for circulation through left side of the heart and out into the periphery
Systemic circulation
What is the purpose of the 4 heart valves?
Prevent back flow of blood as it travels through the four chambers of the heart
How many flaps/cusps does the right AV valve have?
3 (tricuspid)
How many flaps/cusps does the left AV valve have?
2 (bicuspid)
What is the left AV valve also known as?
Mitral valve
Tiny cords that anchor the valves cusps to the walls of the ventricles
Chordae tendinae
Projections of cardiac muscle that terminate in the chordae tendineae
Papillary muscle
Where are the relaxed valves during filling time?
Hanging down into ventricles
Located between the ventricles and the large vessels exiting the ventricles
Semilunar valves
How many cusps/leaflets do semilunar valves have?
3
Valve located at the base of pulmonary trunk
Pulmonary semilunar valve
Valve located at the base of the aorta
Aortic semilunar valve
____ valves open during heart relaxation and close during ventricular contraction; ____ valves closed during heart relaxation and open during ventricular contraction
AV, semilunar
“Lub”
Closing AV valves
“Dub”
Closing of semi-lunar valves
Our blood volume
6 liters
How many times a day does heart pump out 6 liters a day?
1000
What is heart activated regulated by?
Autonomic nervous system and intrinsic conduction (nodal system)
Special tissue that is a combination of nervous and muscle tissue that causes depolarization in 1 direction
Nodal system
Where does the intrinsic electrical conduction system begin?
Sinoatrial node (pacemaker)
Rapid heart rate
Tachycardia
Slow heart rate
Bradycardia
Systole
Contraction
Diastole
Relaxation
Measure of blood pressure
Systolic pressure / Diastolic pressure
3 components of heart cycle
Mid-to-late diastole, Ventricular systole, Early diastole
During mid-to-late diastole, what is the pressure like?
Low
Where is blood during mid-to-late diastole
Into atria, through atria, and into ventricles from both right and left sides
What are the valves doing during mid-to-late diastole?
Semilunar valves closed, AV valves open
What happens to ventricular pressure once ventricular contraction begins?
Increases, closing the AV valves
What happens when ventricular pressure continues to increase?
Semilunar valves forced open
What happens when semilunar valves open?
Blood rushes out of ventricles
During early diastole, what happens to ventricles?
Relax
During early diastole, what happens to semilunar valves?
Close
What is the pressure in ventricles during early diastole?
Lower
What does lower pressure in ventricles cause?
AV valves opening
What oxygenates heart tissue?
Right and left coronary arteries
Where are the right and left coronary arteries?
Branch off aorta and encircle the heart at junction of atria and ventricles
What does left coronary artery branch into?
Circumflex artery and left anterior descending (LAD)
Chest pain caused when the myocardium is deprived of oxygen?
Angina
Prolonged deprivation of oxygen where cells may die
Infarct
Death of heart tissue (aka heart attack)
Myocardial infarction
How are heart attacks detected?
EKG changes and cardiac enzyme changes
What are blood vessels also known as?
Vascular system
General schematic of blood flow:
Blood leaves heart in arteries -> arterioles -> capillaries -> venules -> veins -> re-enter heart
3 layers of blood vessel walls
Tunica intima, Tunica media, Tunica externa
Inner most layer of blood vessel walls
Tunica intima
What is tunica intima composed of?
Thin endothelium layer
2 functions of tunica intima
Provides slick surface, decreases friction of blood flow
Middle layer of blood vessel walls
Tunica media
What is tunica media composed of?
Smooth muscle and elastic fibers
What is tunica media’s smooth muscles controlled by?
Sympathetic nervous system that changes diameter of vessel
Most external layer of blood vessel walls
Tunica externa
What is tunica externa made of?
Fibrous connective tissue
Function of tunica externa
Supports vessels walls