Lecture 1: Overview And Anatomy STUDY GUIDE FOR QUIZ Flashcards
- What are the major functions of the cardiovascular system?
- Transport essential substances to tissues
- Remove by-products of metabolism
- Regulation of body temperature
- Humoral communication throughout body
- Adjustments of oxygen and nutrient supply in different physiologic states
- Why is the heart considered two pumps?
- The RV = pulmonary circulation
- The LV = systemic circulation
- What parts of the heart cause unidirectional flow in the cardiovascular system?
Valves
- What part of the circulation distributes blood to the tissues?
LV = systemic circulation
- What part of the circulation contains the majority of the total blood volume?
-The venules, veins, and vena cava = 70% of total blood volume
- The greatest resistance to blood flow occurs in what part of the circulation?
The arterioles.
- What is the function of the capillaries?
Gas exchange
- Is blood flow pulsatile or non-pulsatile in the capillaries?
Non-pulsatile
- As the cross-sectional area of a vascular bed increases, the velocity of blood flow increases or decreases?
Decreases.
- What contributes to optimal conditions for capillary function?
Blood flow velocity is very slow
- What is the control of blood flow related to in the majority of the tissue beds in the body?
The blood flow to each tissue of the body is almost always precisely controlled in relation to tissue needs
- Describe the boundaries of the mediastinum.
- Superior = above plane between sternal angle and inferior border of T4 vertebral body
- Inferior = anterior, middle, posterior
- In what part of the mediastinum is the heart located?
-In the inferior middle mediastinum
- Name the different layers of the pericardium.
- Fibrous
- Serous–parietal layer, visceral layer
- What nerves travel across the pericardium to the diaphragm? From which nerve roots do these nerves originate?
- Phrenic nerves
- Originate from C3, C4, C5
- What is the sympathetic innervation to the heart?
- T1-T4 = “cardiac accelerators”
- Stellate ganglia (cervicothoracic ganglia) and middle cervical ganglia
- Distributed throughout the heart
- What is the parasympathetic innervation to the heart?
- Originate in the medulla oblongata
- Vagus nerves
- Much innervation to SA and AV nodes
- Little innervation to ventricles
- What are the different parts of the conduction system?
- SA node–interatrial pathway = SA to LA; internodal pathway = SA to AV
- AV node
- Bundle of His (AV bundle)
- Bundle branches–right and left bundle branches (left has left anterior division and left posterior division)
- Purkinje fibers
- What structures are part of the right atrium?
- Vena Cavae
- Crista terminalis
- Coronary sinus
- Fossa ovalis
- Tricuspid valve
Vena Cavae
- Superior
- Inferior–Eustachian valve
What does the Crista terminalis do?
- Divides the right atrium
- Right atrial appendage (right auricle); trabeculated
- Smooth portion of atrium around vena Cavae
- What is the coronary sinus?
- It is a venous channel that receives blood from the coronary veins and empties into the right atrium of the heart
- Responsible for venous drainage of the heart
Fossa ovalis
-Remnant of foramen ovale
- Describe the tricuspid valve apparatus. How many leaflets does the valve have?
-3 leaflets
- The tricuspid valve separates which cardiac chambers?
-The right atrium and right ventricle
- Describe the shape of the right ventricle in cross-section.
- Crescent-shaped
- Coarsely trabeculated inlet
- Smooth outlet (right ventricular outflow tract, RVOT)
- Describe the thickness of the walls of the RV in comparison to those of the LV.
-The right ventricle is thin-walled as compared to LV.
- Which portion of the ventricle is common to both the RV and LV?
The inter ventricular septum
- Describe the shape of the left ventricle in cross-section.
Circular in cross-section.
- How many pulmonary veins are normally present? What cardiac chamber do they drain into?
- 4
- Drain into the left atrium
- Is pulmonary vein blood oxygenated or deoxygenated?
Oxygenated
- In what left atrial structure may blood clots (thrombi) develop in the setting of atrial fibrillation?
Left atrial appendage
- What is the function of the papillary muscles?
To prevent the back flow of blood from the ventricles into the atria during ventricular systole.
- What cardiac valves have associated papillary muscles?
- Tricuspid valve (right)
- Mitral valve (left)
- How many leaflets are found in a normal aortic valve?
-3 (trileaflet)
- Where are the origins of the coronary arteries in relationship to the aortic valve?
-Right and left main coronary arteries originate from the sinuses of valsalva–Dilatations of the ascending aorta that occur just above the aortic valve
- How many leaflets are found in the mitral valve?
-2–anterior (wide and short) and posterior (narrow and long)
- How many leaflets are found in the pulmonic valve?
-3
- Know between which major structures the 4 valves are located–mitral, tricuspid, pulmonic, aortic.
- Tricuspid valve separates the RA/RV
- Mitral valve separates the LA/LV
- Pulmonic valve separates the RV/PA
- Aortic valve separates the LV/aorta
- Know the major branches of the coronary arteries.
Right coronary artery supplies the posterior descending artery (PDA)
Left main coronary artery bifurcates to form:
- Left anterior descending (LAD) (diagonal branches)
- Left circumflex (obtuse marginales)
- What is the ramus intermedius?
-The additional branch in people who have a tri-furcation of the left main coronary artery.
- What determines dominance in regards to the coronary arteries?
The artery that supplies the posterior third of the interventricular septum—the posterior descending artery (PDA)—determines the coronary dominance.
In 85% of people, the right coronary artery supplies the posterior descending artery, so coronary circulation can be classified as “right-dominant.”
- Know the coronary artery blood supply to the various portions of the LV.
Left main coronary artery =
- Left anterior descending artery — diagonal branches
- Left circumflex artery — obtuse marginales branches
- In 37% of people—trifurcation of the left coronary artery = ramus intermedius (third branch of the left coronary artery)
