Cardiovascular System Flashcards
Blood Vessels
- delivery system of dynamic structures that begins and ends at heart
- work with lymphatic system
- Transports nutrients (sugars, fats, proteins), oxygen, water, hormones, immune system, waste
Capillaries
- Smallest blood vessels with thin walls, facilitating the exchange of nutrients and waste
- Directly serve cellular needs, where delivery and pick up of fluid happens.
5 characteristics of capillaries
-Exchange nutrients and waste.
-Leaky to allow transfer in and out.
-Lowest pressure: thin walls offer minimal resistance to blood flow
-More numerous.
-Same amount of fluid should be going in and out.
Arteries
carry blood away from heart; oxygenated
Exception for Arteries and Oxygenated
pulmonary circulation and umbilical vessels of fetus contain deoxygenated blood
Veins
carry blood toward heart; deoxygenated
Exception for Veins and Deoxygenated
pulmonary circulation and umbilical vessels of fetus which bring oxygenated blood
Pressure in Artery vs Vein
High pressure in arteries and low pressure in veins
Muscle in Artery vs Vein
Arteries - more muscle to maintain pressure
Veins - Less muscle because blood must go through muscles to travel to heart
Valves in Artery vs Vein
- arteries do not have valves
- veins have valves to prevent backflow due to low pressure
Blood Color in Artery vs Vein
Artery - Red
Vein - purple
Tunica Intima in Arteries and Veins
thin layer endothelium
in both
Tunic Media in Arteries vs Veins
Arteries - thick muscle layer to allow for constriction to control pressure and amount of blood passing
Veins - thin muscle layer
Tunica Externa in Arteries vs Veins
Arteries - thin layer of collagen
Veins - thick layer of collagen
Lumen
- hole in the middle of both veins and arteries
Vaso Vasorum
smaller arteries and veins within the tunica externa
in both veins and arteries
Endothelium
- includes tight junctions and is lined with epithelial cells to prevent leaking of blood
4 causes of Edema
- Increased hydrostatic pressure
- Decreased osmotic pressure
- Increased capillary permeability
- Blocked lymphatics
Increased Hydrostatic Pressure
- When the pressure inside the blood vessels (capillaries) is too high, fluid is pushed out into the surrounding tissues.
- This can happen with conditions like high blood pressure, where the force of blood against the vessel walls is too strong.
Decreased osmotic pressure
- Proteins in your blood, especially albumin, create osmotic pressure to pull back fluid
- If there’s too little protein in your blood, perhaps due to liver or kidney disease, the fluid isn’t pulled back in as effectively, leading to swelling.
Increased Capillary Permeability
- When the capillaries become
more permeable, fluids and proteins leak out into the surrounding tissues, causing swelling
Blocked lymphatic
- If the lymphatic vessels are blocked or removed, as can happen with cancer treatment when lymph nodes are removed, fluid can’t drain properly, leading to swelling.
Blood Pressure (BP) Definition
- Force per unit area exerted on wall of blood vessel by blood.
BP Measurement
- Expressed in mm Hg; measured as systemic arterial BP in large arteries near heart.
Blood Pressure Function
Pressure gradient provides driving force that keeps blood moving from higher- to lower-pressure areas.
Two types of BP?
Systolic and Diastolic.
Systolic
- when heart contracts
Diastolic
Pressure in the arteries when heart relaxes.
Dos systolic or diastolic contribute more to BP and why?
Diastolic contributes more to mean pressure because heart spends more time relaxing.
Starling Equation
Net fluid movement = K_f * [(P_c - P_i) - σ(π_c - π_i)]
K_f in Starling Equation
filtration coefficient, a measure of capillary permeability.
P_c
the capillary hydrostatic pressure
P_i
is the interstitial hydrostatic pressure.
σ
the reflection coefficient, which indicates the impermeability of the capillary wall to proteins.
π_c
the capillary oncotic (osmotic) pressure.
π_i
the interstitial oncotic (osmotic) pressure
What does P stand for in the Starling Equation
- Hydrostatic Pressure: pushes fluid out of the capillaries and into the interstitial space (the space between cells).
- basically represents filtration
What does O stand for in Starlign Equation?
Oncotic/Osmotic Pressure: This is the “pulling” pressure created by large proteins (like albumin) in the blood.
- basically represents reabsorption
Relation between O and P in Starling Equation
-If the hydrostatic pressure (P) is greater than the oncotic pressure, fluid will tend to move out of the capillaries (filtration).
-If the oncotic pressure (O) is greater than the hydrostatic pressure, fluid will tend to move into the capillaries (reabsorption).
Too much reabsorption will lead to?
if reabsorption exceeds filtration, it can lead to decreased blood volume and potential dehydration.
Too much filtration will lead to?
it can lead to edema (swelling) in the tissues because fluid accumulates.
Starling Equation Function
- describes the balance between the forces pushing fluid out of the capillaries into the surrounding tissues (filtration) and the forces pulling fluid back into the capillaries (reabsorption)
Mean Arterial Blood Pressure Calculation
- MAP is calculated by adding the diastolic pressure to one-third of the systolic pressure.
How is BP measured?
measured indirectly using a sphygmomanometer with a stethoscope.
Where is the cuff wrapped when BP is measured and why?
- The cuff is wrapped around the upper arm, superior to the elbow, to compress the brachial artery.
How does a spyghometer stop blood flow?
- The pressure in the cuff is increased until it exceeds the systolic pressure in the brachial artery, temporarily stopping blood flow.
Why does a spygomanameter stop blood flow?
to make blood flow lamellar (smooth and non turbulent)
What does the examiner examine as the blood pressure cuff is released?
- examiner listens for sounds of Korotkoff with the stethoscope.
Sounds of Korortkoff
- generated when a blood pressure cuff changes the flow of blood through the artery
- The first sound heard indicates the systolic pressure, and the point where the sound disappears indicates the diastolic pressure.
Systolic Pressure Measure (Normal)
- This is normally less than 120 mm Hg.
- pressure as blood starts to spurt through the artery during the cardiac cycle.
Normal Diastolic Pressure
- This is normally less than 80 mm Hg.
-It is the pressure when sounds disappear because the artery is no longer constricted, and blood is flowing freely.
Hypertension Measurement and Effects
- Defined as 140/90 mm Hg or higher.
- Hypertension can increase the risk of heart disease, stroke, and other cardiovascular conditions.
Hypotension (Low Blood Pressure):
Defined as below 90/60 mm Hg.
- Usually not a concern unless it causes inadequate blood flow to tissues, leading to symptoms like dizziness or fainting.
Cardiac Muscle Characteristics
Striated
Has one nucleus
Voluntary
Branched cells
Automaticity
the ability to beat on its own
What are the four chambers of the heart?
Right Atrium
Left Atrium
Right Ventricle
Left Ventricle
Atrium
Atrium: Receives blood, low blood pressure, thin walls.
Ventricle
Ventricle: Pumps blood out, higher blood pressure, muscular walls.
Function and Process of Right Atrium/ Ventricle
Takes blood from the body (atrium) and sends it to the lungs (ventricle), lower pressure, less muscle (thinner walls), delivers deoxygenated blood.
Function and Process of Left Atrium/ Ventricle
Takes blood from the lungs (atrium) and sends it to the body (ventricle), stronger because the body is larger, higher pressure, more muscle (thicker walls), delivers oxygenated blood.
Vena Cava (Step 1 of Blood Flow)
These veins drain blood from the body into the right atrium of the heart.
Right Atrium into Right Ventricle through the Tricuspid Valve (Step 2 of Blood Flow)
The right atrium contracts, pushing blood through the tricuspid valve into the right ventricle.
Pulmonary Artery (Step 3 of Blood Flow)
The right ventricle pumps blood through the pulmonic valve into the pulmonary artery, which carries the blood to the lungs for oxygenation.
Pulmonic Valve (Step 4 of Blood Flow)
- This valve prevents the backflow of blood from the pulmonary artery into the right ventricle.
Step 5 - Pulmonary Veins (4)
Oxygenated blood from the lungs returns to the heart via the pulmonary veins, which empty into the left atrium.
Step 6 - Left Atrium into Left Ventricle through the Mitral Valve
The left atrium contracts, pushing blood through the mitral valve into the left ventricle.
Step 7 - Aorta
The left ventricle pumps blood through the aortic valve into the aorta, the body’s largest artery, which carries oxygenated blood to the rest of the body.
Types of Valves
Tricuspid valve
Pulmonic valve
Mitral valve
Aortic valve
Tricuspid Valve
between right atrium and ventricle
Pulmonic Valve
between right ventricle and pulmonary artery
Mitral valve
between left atrium and ventricle
Aortic Valve
between left ventricle and body
Interior atrial septum
wall that separates atriums
Interior ventricular septum
wall that separates ventricles
Murmur
Extra sound because of interrupted blood flow
Which direction does blood flow in?
Blood flows from left to right side because higher to low pressure
Lub (S1 Sound)
closing of tricuspid and mitral valve
Dub (S1 heart sound)
closing of the pulmonic and aortic close
Right Coronary Artery (RCA)
Supplies the front right side of the heart, including the right atrium and right ventricle.
Also known as the right artery and ventricle.
Left Anterior Descending (LAD) Artery:
Supplies the front of the left ventricle.
Important because the left ventricle provides blood to the body and its blockage can be fatal.
Left Circumflex Artery
Bends around the heart to supply blood to the back of the left ventricle.
Left Common Coronary Artery
Anastomosis where the left circumflex and LAD meet up
- Ventricle won’t die because LAD will compensate
Anastomosis
When arteries run into each other and create bridges
Posterior coronary artery
where the left circumflex and right coronary artery meet at the back
