Chapter 13 - Cardiovascular System Flashcards
What is the main function of the cardiovascular system?
Propel and transport blood
Gas exchange in tissues and lungs
What two systems is the circulatory system comprised of?
- Cardiovascular system
- Lymphatic vascular system
What does the cardiovascular system consist of? (3)
Heart
Blood
Blood Vessels
What does the lymphatic system consist of?
Lymph
Lymphatic vessels
What does the lymphatic system do?
Receive excess tissue fluid from capillaries, take it to the lymph nodes, and eventually bring it back to the heart
What are the two size classifications of blood vessels?
- Macrovasscular
- Microvascular
What are the 4 types of macrovascular vessels?
- Elastic Artery
- Muscular Artery
- Large Vein
- Medium-sized vein
What are two examples of elastic arteries?
- Aorta
- Pulmonary artery
What type of muscle surrounds muscular arteries?
Smooth muscle
Veins have thinner walls than arteries - why?
Blood is under lower pressure
Which has a larger lumen? Arteries or veins
Veins - they move a greater volume
What are the three tu[es of microvasculature?
Arterioles
Venules
Capillaries
Two-directional exchange of fluid occurs between ____ and ______ within the capillaries
Blood and Tissues
What are the two fates of fluid after leaving the capillaries?
- re-enters at the venous end of capillaries
- remaining fluid enters lymphatic vessels
What characteristics of microvasculature allow for gas exchange?
Smaller lumen
Smaller walls and muscular arteries
Narrow arterioles
What two things makeup lymph?
Excess Interstitial Fluid
Larger particles
What is pulmonary circulation?
Blood from heart > lungs > heart
What is systemic circulation?
Blood from heart > tissues > heart
What is the path of blood from super/inferior vena cava to the aorta?
Deoxygenated blood > superior/inferior vena cave > right atrium > right ventricle > pulmonary artery > lungs (gas exchange) > pulmonary veins > left atrium > left ventricle > aorta
What is the only artery that carries deoxygenated blood?
Pulmonary Artery
What is the only vein that carries oxygenated blood?
Pulmonary vein
The heart is a __ chambered organ composed of 2 ___ and 2 _____
4
atria, ventricles
What prevents backflow of blood between chambers?
Valves
What separates the right and left atria?
Inner Atrial Septum
What separates the right and left ventricles?
Inner Ventricular Septum
Which is thicker the inner atrial septum or inner ventricular septum? Why?
The Inner Ventricular Septum
There is a decreased abundance of cardiac muscle in the atria walls because you don’t need as much force, the blood is under less pressure
How does cardiac muscle function?
Contracts to propel blood
What are the two functions of the fibrous skeleton?
- Attachment point for cardiac muscle, cuspid valves, and semilunar valves
- Electrical insulator between atria and ventricles
What pieces make up the coronary vasculature?
Two coronary arteries and cardiac veins
What tissue type composes the fibrous skeleton?
DICT
What creates the core of cuspid and semilunar valves?
Fibrous Skeleton
What tissue type makes up the septa?
DCT
What allows for the isolated contraction of atria and ventricles?
Septa made of DCT
What function does coronary vasculature provide?
The heart tissue itself needs nutrients
What are the two overarching valve types?
Atrioventricular valves - separate atria and ventricles
Semilunar valves - separate vasculature and ventricles
What are the two atrioventricular valves?
- Tricuspid Valve (separates right atria and ventricle)
- Mitrial / bicuspid valve (separates left atria and ventricle)
What are the two semilunar valves?
- Pulmonary valve (separate right ventricle and pulmonary artery(vein??))
- Aortic valve (separate left ventricle and aorta)
Cardiac muscle contraction occurs _______
Spontaneously
Does cardiac muscle contract via nervous system stimulus?
No
How does the autonomic nervous system affect the heart?
Changes heart rate
What are the two parts of the autonomic nervous system? In what way do they affect the heart rate?
- Sympathetic > increase BPM
- Parasympathetic > decrease BPM
Where does the electrical impulse in the heart begin? What is the rest of the pathway?
SA node in right atrium > inner atrial septa > AV node > fibrous skeleton on inner ventricular septum = bundle of his > right and left bundle branches > Purkinje fibers
What two characteristics set the cardiac cells of the SA and AV nodes apart from the others?
- Smaller cardiac muscle cells
- Lack intercalated discs
How are the AV bundle, bundle branches, Purkinje fibers cardiac cells different than the others?
They are larger than ventricular muscle cells
What are the two layers of the pericardium?
- External fibrous layer
- Inner serous layer
What tissue type is external fibrous layer?
DCT (and a little adipose)
What is the function of the external fibrous layer of the pericardium? (3)
It serves as a protective sac
Affix the heart to surrounding structures
Contains adipose tissue which acts as insulation and cushioning
What are the two layers of the inner serous layer of the pericardium?
- Parietal layer: inner fibrous surface
- Visceral layer: part of the epicardium
What tissue type is the mesothelium made of?
Simple Squamous Epithelium
What function does the mesothelium/inner serous layer provide the heart?
Creates a slick surface so there is less friction
Where is the pericardial cavity located? What is it filled with?
In between 2 layers of serous pericardium
Filled with pericardial fluid
What function does the pericardial cavity serve?
Shock absorber
What can happen to the pericardial cavity after a trauma or illness?
Trauma/illness > excess pericardial fluid > heart can’t contract properly
What are the three layers of the epicardium? And what tissue type is found in that layer?
- Inner layer of mesothelium = visceral layer of pericardium
- Middle layer of fibroelastic CT
- Deep layer of adipose tissue
Myocardium makes up the ____ of the heart
Bulk
What is the myocardium mostly made of?
Bundles of cardiac muscle
What are the three layers of the endocardium and what does each contain?
Inner layer of endothelium and subendothelial CT
Middle layer of DCT containing smooth muscle
Deep subendocardial layer made of DCT containing Purkinje fibers
Which layer of the heart is in contact with the lumen of the heart?
Endocardium
What type of tissue is endothelium made of?
Simple squamous epithelium
What are Purkinje fibers?
Specialized cardiac conducting cells
Larger than myocardium cells
How to tell the difference between CMF and Purkinje fibers
PF are lighter because they have increased glycogen compared to muscle fibers > decrease actin and myosin which give it the eosinophilic stain
What are the three things each valve is composed of?
- Fibrosa
- Spongiosa
- Ventricularis
What is the main function of heart valves?
Stop the regurgitation of blood from
- atria (atrioventricular)
- arteries (semilunar)
How are valves attached to the heart?
Attached via DCT fibrous
What is a heart valve?
CT core with overlaying endocardial layer
What is the orientation of each layer of the heart valve?
Blood Vessel/atrial side = spongiosa
Core = fibrosa
Ventricular Side = ventricularis
What tissue type is the spongiosa layer of the heart valve made of? What function does this serve?
LCT with collagen and elastic fibers
High proteoglycans > increased water > provides shock absorption for when the valves close
What tissue type is the ventricular layer of the heart valves made of?
Endothelium and DCT with elastic fibers
What are chordae tendinea? What do is their function?
Extensions of DCT
Attach heart valve to papillary muscle
What constitutes the conducting system of the heart? (5)
SA node
AV nod
bundle of HIs
right and left bundle branches
Purkinje fibers
The SA node is known as the
anatomical pacemaker
What is the path that leads to atrial and ventricular contraction?
SA node > atrial contraction > AV > bundle of His > Purkinje > ventricles contract
