Cardiovascular System Part 2: Vessels, Blood Pressure, and Fluid Dynamics

Vocabulary and terminology flashcards covering cardiovascular dynamics, vessel properties, blood components, and Starling forces as discussed in the Chapter 7 (Part 2) lecture.

Arteries

A general term for blood vessels that carry blood away from the heart; they are characterized as being elastic and muscular.

Veins

A general term for blood vessels that carry blood toward the heart; they are characterized as being compliant and frequently contain valves to prevent backflow.

Arterioles

Small arteries that serve as the main source of systemic vascular resistance ($SVR$) due to their small cross-sectional area.

Capillaries

Tiny vessels where oxygen and nutrient transfer takes place; they are one cell layer thick, and red blood cells travel through them in a single file line.

Venules

The smallest levels of veins that receive blood from the capillary interface and lead back toward larger veins.

Vena Cava

The great vein into which all roads of the venous system lead, eventually plugging into the right atrium.

Elasticity (in Arteries)

The property of arteries to resist change and push back against blood volume, thereby generating pressure.

Compliance (in Veins)

The property of veins to allow change and accommodate as much blood volume as is allowed to circulate through them.

Venus Stasis (Venus Pooling)

A condition occurring in heart failure where blood collects inside the veins because the heart is not strong enough to pump with sufficient pressure.

Vein Flattening

A sign observable on ultrasound indicating a patient has low blood volume or has bled out significantly, often seen in the inferior vena cava ($IVC$).

Systolic Pressure

The peak pressure generated by ventricular contraction; the maximum force required to pop open the aortic valve and peruse the body.

Diastolic Pressure

The pressure within the arterial system during peak ventricular relaxation.

Mean Arterial Pressure ($MAP$)

A reflection of average blood pressure, often calculated as $\frac{2}{3}$ the diastolic pressure plus $\frac{1}{3}$ the systolic pressure.

Cardiac Output ($CO$)

The total amount of blood exiting the heart per minute, calculated as $\text{Heart Rate (HR)} \times \text{Stroke Volume (SV)}$.

Stroke Volume ($SV$)

The volume of blood exiting the heart in a single beat, which is modulated by the total blood volume entering the heart.

Portal Veins

A secondary pathway of veins that pass through another organ or tissue bed before returning to the inferior vena cava ($IVC$).

Hypophyseal Portal System

A portal system where veins travel from the hypothalamus to the pituitary gland for hormone response.

Hepatic Portal System

A portal system where blood from the GI tract travels through the liver to metabolize nutrients, store substances, and detoxify toxins before entering general circulation.

First Pass Metabolism

The process by which medications taken orally are metabolized by the liver via the hepatic portal system before reaching systemic circulation.

Plasma

The liquid component of blood, making up approximately $55\%$ of its volume, containing proteins, ions, and sugars.

Erythrocytes

Red blood cells responsible for carrying oxygen; they are biconcave, lack organelles (including mitochondria), and recycle approximately every $90$ days.

Platelets

Not true cells, but cell fragments that aid in the coagulation cascade and blood clotting.

Hemoglobin ($HB$)

A protein in red blood cells that can carry four oxygen molecules; one red blood cell contains about $250 \times 10^6$ molecules of this protein.

Coordinate Covalent Bond

The type of bond formed when oxygen binds to the $d$ orbital of the iron atom within hemoglobin.

Universal Donor

Blood type $O$ negative, which lacks $A$, $B$, and $Rh$ antigens, making it safe for transfusion into any recipient.

Universal Receiver

Blood type $AB$ positive, as it has been sensitized to $A$, $B$, and $Rh$ antigens and will not attack them.

RhoGAM

A drug used in OBGYN to prevent an $Rh$ negative mother's antibodies from attacking the $D$ antigen of an $Rh$ positive fetus.

Interstitium

The space or 'third space' between the cells and the blood vessels where fluid can collect.

Hydrostatic Pressure ($P_c$)

The pushing force exerted by fluid in the capillary against the capillary wall.

Oncotic Pressure (Pi sub c)

A sucking pressure inside the capillary driven by the concentration of solutes and proteins that draws water from the interstitium into the bloodstream.

Van't Hoff Factor ($i$)

A factor in the oncotic pressure equation representing the number of particles a molecule dissociates into when in solution (e.g., $i=2$ for $NaCl$).

Albumin

A major protein synthesized by the liver that stays in the blood and contributes significantly to the oncotic pressure of the capillaries.

Ascites

The collection of fluid inside the peritoneal cavity (abdominal area) often caused by liver failure and the resulting decrease in oncotic pressure.

Diuretic (Furosemide)

Also known as a 'water pill,' this medication is used to treat third spacing and heart failure by helping the body remove excess fluid volume.