Class 1 Flashcards
Functions of Cardiovascular System
- Transport Essential substances to the tissues
- Remove by-products
- Regulation of body temperature
- Humoral communication throughout body
- Adjustments of O2 and nutrient supply in different physiologic states
Why is the Heat considered 2 Pumps
Right Ventricle is for Pulmonary Circulation
Left Ventricle is for Systemic Circulation
Right Ventricle
Carries oxygen poor blood to lungs, where it unloads CO2 and picks up O2. Then it delivers O2 rich blood to the heart.
Left Ventricle
Delivers O2 rich blood to every part of the body.
Tricuspid Valves
It an atrioventricular (AV) valve.
Causes unidirectional flow from the right atrium to the right ventricle.
Pulmonary Semilunar Valve
Causes Unidirectional flow from RV to the pulmonary artery.
Mitral/Bicuspid Valve
AV valve
Causes Unidirectional flow of blood from the Left Atrium to the Left Ventricle.
Aortic Semilunar Valve
Causes Unidirectional flow from the LV to the aorta.
What part of circulation distributes blood to the tissues?
Systemic Circulation Carries oxygenated blood through the ARTERIES to the tissues.
What part of the circulation contains the majority of the total blood volume?
Veins
The greatest resistance to blood flow occurs in what part of the circulation?
Arterioles
What is the function of the Capillaries?
They are the primary exchange vessel in the body!
They are composed of only endothelial cells.
They have the greatest surface area for exchange.
O2, CO2, H2O, electrolytes, proteins, metabolic substrates and by-products and circulating hormones are exchanged across endothelium between plasma and tissue interstitum.
Blood flow in capillaries is
Non-pulsatile
As the cross-sectional area of a vascular bed increases
The velocity of blood flow decreases. It is inversely related.
What contributes to the optimal conditions for capillary function?
Slow blood flow velocity
What is the control of blood flow related to in the majority of the tissue beds in the body?
The blood flow to to the majority of tissue beds in the body is controlled in relation to the tissue needs.
Describe the boundaries of the mediastinum
The anatomical region located between the lungs from sternum to vertebral column and diaphragm to thoracic outlet.
Between the eternal angle and the inferior border of T4 vertebral body.
Thoracic inlet T4-T12 diaphragm to thoracic outlet
What part of the mediastinum is the heart located?
Middle part of the inferior mediastinum
Name the different layers of the pericardium
Visceral pericardium is in contact with the heart. It’s the inner most wall.
Pericardial cavity
Parietal pericardium
Fibrous is the outer layer
Which nerve travels across the pericardium to the diaphragm?
Phrenic Nerves
Which nerve roots does the phrenic nerves originate?
C3-C5 in the neck
What is the sympathetic innervation to the heart?
T1-T4
Cardiac accelerators
Stellate ganglia (cervicothoracic ganglia) and middle cervical ganglia
If fight or flight they increase HR and Contractility
SA, AV nodes and ventricle
What is the parasympathetic innervation to the heart?
T1-T4
Much innervation to SA and AV nodes
Little innervation to ventricles
originates in the medulla oblongata
Vagus nerves
Can only decrease contractility by 30%
What are the different parts of the conduction system?
Sinoatrial Node SA Node
- Interatrial conduction pathways (SA to LA)
- Internodal conduction pathways (SA to AV)
Atrioventricular Node
-Bundle of His
Bundle Branches
-Left bundle Branch
~Left anterior division
~ Left posterior division
-Right Bundle Branch
What structures are part of the right atrium?
Superior and Inferior Vena Cava
~Eustachian valve
Crista terminal is (divides the right atrium)
- right atrial appendage (right auricle)trabeculated
- smooth portion of atrium around vena cava
What is the coronary sinus?
A wide venous channel that receives blood from the coronary veins. And empties into the right atrium.
Venous drainage of the heart
What does the coronary sinus drain into?
Empties into the right atrium
Describe the tricuspid valve apparatus?
Separates right atrium from right ventricle
It is made up of 3 leaflets The annulus, the supporting chordae tendineae and the papillary muscle.
Anterior leaflet
Posterior leaflet
Septal leaflet
Right ventricle in cross-section is
Crescent shaped and thin.
Right ventricle compare thickness to left ventricle.
Right ventricle is thin compared to Left Ventricle.
What portion of the ventricle is common to both the RV and LV?
The septum
Describe the shape of the left ventricle in cross-section.
Circular
How many pulmonary veins are normally present?
4
What cardiac chamber do the pulmonary veins drain into?
Left atrium
Is pulmonary vein blood oxygenated or deoxygenated?
Oxygenated blood to you heart.
Where will blood clots form in the setting of atrial fibrillation?
Left atrial appendage
What is the function of papillary muscles?
During systole they contract to prevent inversion or prolapse of the mitral and tricuspid valves during systole.
Mitral and Tricuspid Valves
Have associated papillary muscles
How many leaflets are found in a normal aortic valve?
3 leaflets
Where are the origins of the coronary arteries in relationships to the aortic valve?
Right and Left Main Coronary Arteries originate from the Sinuses of Valsalva (dilatations of the ascending aorta that occurs just above the aortic valve.
Sino-tubular junction
How many leaflets are found in the Mitral Valve
2 leaflets
How many leaflets are found in the pulmonic valve?
3 leaflets
4 Heart Valves
Tricuspid between RA and RV
Pulmonary between RV and Pulmonary artery
Mital between LA and LV
Aortic LV and aorta
Main Branches of the Coronary Arteries
Right Coronary
-In 85% of ppl the RCA supplies the Posterior descending artery
Left Coronary
-Left Main bifurcated to form:
~ Left anterior descending
-diagonal branches
~Left Circumflex
- Obtuse marginal
Ramus Intermedius
37% of ppl have an additional branch there is a tri-furcation of the Left Main
What determines dominance in regard to the coronary arteries?
Which ever vessel that gives rise to the posterior descending artery
What supplies the LV
LAD- left anterior descending supplies the front and bottom LV
Circumflex- side and back of LV
RCA- bottom of LV
Right atrium pressure
Right atrium has low pressure 0-5 and the right ventricle 10-20 . Deoxygenated blood flows into the RA.
