Cardiovascular System (Part 1 - Anatomy and Antithrombotics)

The heart and blood vessels transport [blank_start]oxygen[blank_end], [blank_start]nutrients[blank_end], [blank_start]waste products[blank_end], and [blank_start]heat[blank_end] around the body rapidly

What are the four functions of the CV system? 1. [blank_start]Rapid convective system[blank_end] 2. [blank_start]Control system[blank_end] 3. [blank_start]Regulates body temperature[blank_end] 4. [blank_start]Reproduction[blank_end]

What is the maximum distance diffusion can occur over? (in micrometers) [blank_start]10[blank_end]

What is the rate at which blood is pumped around the body? (in cm per second)

The heart has two [blank_start]synchronous[blank_end] pumps. The right and left [blank_start]ventricles[blank_end]

The ventricles are filled from reservoirs, also known as the right and left [blank_start]atrium[blank_end].

The [blank_start]right ventricle[blank_end] pumps [blank_start]deoxygenated[blank_end] blood through the [blank_start]heart to the lungs[blank_end]. [blank_start]Four[blank_end] [blank_start]pulmonary[blank_end] veins return oxygenated blood from the lungs to the [blank_start]left[blank_end] side of the heart. This is called [blank_start]pulmonary circulation[blank_end].

What is roughly the pressure at which blood is pumped from the heart to the lungs? (in mmHg)

What is roughly the pressure at which blood is pumped from the heart through the aorta? (in mmHg)

Blood is pumped to the body to tissues, and partly [blank_start]deoxygenated[blank_end] blood is returned to the heart via two veins. The [blank_start]superior[blank_end] and [blank_start]inferior[blank_end] vena cava.

When blood returns to the heart via two veins, this is known as [blank_start]systemic[blank_end] circulation.

The right ventricle has a greater muscle mass than the left ventricle because it pumps blood at a higher pressure (to all the body).

The [blank_start]ventricles[blank_end] are composed mainly of cardiac muscle, and fill with blood while the muscle is [blank_start]relaxed[blank_end]. Relaxation is known as [blank_start]diastole[blank_end], and contraction is known as [blank_start]systole[blank_end].

If heart rate is between 60-75 bpm, and the stroke volume is 70-80ml... what will be the cardiac output? (in L/min) [blank_start]5[blank_end] L/min

[blank_start]Mean arterial pressure[blank_end] = [blank_start]Cardiac output[blank_end] x [blank_start]Total peripheral resistance[blank_end]

Cardiac output can increase greatly in response to increased peripheral oxygen demand, rising 10 to 12 fold during strenuous human exercise.

Blood pressure definition = The [blank_start]force[blank_end] exerted by [blank_start]circulating blood[blank_end] on the walls of the [blank_start]blood vessels[blank_end].

Because blood pressure is different in different areas of the body, what type of blood pressure is stated?

The circulation of blood is in a [blank_start]parallel[blank_end] arrangement. This means it is divided into [blank_start]individual[blank_end] circuits, each supplying a specialised tissue/organ.

The [blank_start]first[blank_end] branch from the heart is called [blank_start]coronary circulation[blank_end]. This means blood is supplied to the heart itself.

The left ventricular output is distributed to the tissues of the body in proportion to their metabolic rate. The muscle takes 20% of O2 consumption at rest and receives 20% of the cardiac output. This is different in the [blank_start]kidneys[blank_end] because its [blank_start]excretory[blank_end] function requires a [blank_start]high[blank_end] blood flow. This causes other tissues to receive less e.g. [blank_start]cardiac muscle[blank_end]. To compensate, it extracts an unusually [blank_start]high[blank_end] proportion of the O2 (~[blank_start]65-75[blank_end]%), whereas normal = ~[blank_start]25[blank_end]%. It is very [blank_start]efficient[blank_end] at taking [blank_start]oxygen[blank_end] from blood.

Venules and small veins are more numerous than arterioles and arteries.

Because of their large number and size, veins and venules contain about a 1/2 of circulating blood.

Veins and venules are known as ______ vessels.

Systemic arteries are known as resistance vessels

Drugs that act on the blood are called [blank_start]antithrombotic[blank_end] drugs

There are three types of antithrombotic drugs. What are the classes called?

A [blank_start]thrombus[blank_end] is a blood clot that forms in a vessel and remains there.

An [blank_start]embolism[blank_end] is a clot that travels from the site where is formed to another [blank_start]location[blank_end] in the body.

Name three antiplatelet drugs. 1. [blank_start]Aspirin[blank_end] 2. [blank_start]Clopidogrel[blank_end] 3. [blank_start]Dipyridamole[blank_end]

Name three anticoagulants. 1. [blank_start]Warfarin[blank_end] 2. [blank_start]Heparin[blank_end] 3. [blank_start]Rivaroxaban[blank_end]

Name two thrombolytic drugs. 1. [blank_start]Streptokinase[blank_end] 2. [blank_start]Tenecteplase[blank_end]

In terms of a cut, homeostasis is the [blank_start]human's response to blood vessel injury[blank_end] and bleeding. This results in a [blank_start]blood clot[blank_end] and the bleeding [blank_start]stopping[blank_end].

Blood clot formation. Step 1 = [blank_start]Vasoconstriction[blank_end] - this is triggered by [blank_start]endothelial[blank_end] cells Step 2 = [blank_start]Platelet Plug Formation[blank_end] - Platelets [blank_start]aggregate[blank_end] together and temporarily stop the blood flow. This is the stage where antiplatelets act on. Step 3 = [blank_start]Coagulation[blank_end] - Conversion of [blank_start]fibrinogen (soluble)[blank_end] to [blank_start]fibrin (insoluble[blank_end]). The insoluble [blank_start]fibrin[blank_end] forms a [blank_start]mesh[blank_end] around the platelet plug (causing platelets to [blank_start]bind[blank_end] to each other).

Antiplatelet drugs act on the venous system

Anticoagulant drugs act on the arteriole system

Anticoagulant drugs act on the venous system

Antiplatelet drugs can be used for what conditions?

Platelet formation

[blank_start]GPIa/IIa[blank_end] and [blank_start]GPIb[blank_end] are [blank_start]platelet receptors[blank_end] which bind to collagen and [blank_start]von Willebrand factor[blank_end] (vWF), causing platelets to adhere to the [blank_start]subendothelium[blank_end] of a damaged blood vessel.

PAR1 and [blank_start]PAR4[blank_end] are [blank_start]protease-activated[blank_end] receptors that respond to [blank_start]thrombin[blank_end] (IIa)

[blank_start]P2Y1[blank_end] and [blank_start]P2Y12[blank_end] are receptors for ADP. When stimulated by [blank_start]ADP[blank_end], they activate [blank_start]fibrinogen-binding protein[blank_end] GPIIa/IIIa and [blank_start]cyclooxygenase-1[blank_end] (COX-1) to promote platelet [blank_start]aggregation and secretion[blank_end].

[blank_start]Thromboxane A2[blank_end] is a major product of COX-1 involved in [blank_start]platelet activation[blank_end]. It is involved in the [blank_start]positive[blank_end] feedback process. It signals [blank_start]more platelets[blank_end] to join and become [blank_start]activated[blank_end].

[blank_start]Prostaglandin I2[blank_end] is synthesised by [blank_start]endothelial[blank_end] cells. It inhibits platelet activation. It is found naturally in the body, and is part of a [blank_start]negative[blank_end] feedback process of platelet aggregation - it slows the process down.

What three drugs are used to inhibit GPIIb/IIIa receptor?

What four drugs are used to inhibit the GPIa/IIa receptor?

Aspirin is a [blank_start]indirect[blank_end] inhibitor of [blank_start]PAR[blank_end] receptors.

Warfarin is a vitamin K antagonist

Warfarin works by [blank_start]blocking[blank_end] the regeneration of the [blank_start]reduced[blank_end] form of vitamin [blank_start]K[blank_end]

Vitamin [blank_start]K[blank_end] is [blank_start]lipo[blank_end]philic, and is required for the [blank_start]modification[blank_end] of certain blood [blank_start]coagulation proteins[blank_end]. Vitamin K is essential for the [blank_start]hepatic[blank_end] synthesis of factors [blank_start]II[blank_end], [blank_start]VII[blank_end], [blank_start]IX[blank_end], and X.

Warfarin [blank_start]inhibits[blank_end] the conversion of oxidised vitamin K [blank_start]epoxide[blank_end] into its [blank_start]reduced[blank_end] form, Vitamin K [blank_start]hydroquinone[blank_end].

Heparin are a family of [blank_start]sulphated[blank_end] [blank_start]glycoamino[blank_end]glycans.

Heparin activates [blank_start]antithrombin III[blank_end], and inactivates coagulant factors [blank_start]II[blank_end] and [blank_start]X[blank_end].

Heparin is given orally.

What are the two types of heparin?

Give four examples of LMWH (Low Molecular Weight Heparin)

LMWH are [blank_start]better[blank_end] than unfractionated heparin because they have a [blank_start]limited[blank_end] effect on platelet activation and a [blank_start]lower[blank_end] reported incidence of heparin induced [blank_start]thrombocytopenia[blank_end] - this is there is a deficiency of platelet in the blood which causes bleeding in the tissues and slow blood clotting.

Name three thrombin inhibitors. 1. [blank_start]Bivalirudin[blank_end] 2. [blank_start]Fondaparinux[blank_end] 3. Dabigatran

Anticoagulants are used for the prevention of:

INR = ([blank_start]PT ratio[blank_end]) to the power of [blank_start]ISI[blank_end]

[blank_start]Fibrinolysis[blank_end] is the breakdown of fibrin once it has already formed. [blank_start]Plasmin[blank_end] is the factor that breaks down fibrin. Endothelial cells secrete tissue [blank_start]plasminogen[blank_end] activator (t-PA) at sites of injury. t-PA binds to [blank_start]fibrin[blank_end] and converts [blank_start]plasminogen[blank_end] to [blank_start]plasmin[blank_end], which digests fibrin. [blank_start]Plasminogen[blank_end] activator inhibitors-[blank_start]1[blank_end] and -[blank_start]2[blank_end] (PAI-[blank_start]1[blank_end], PAI-[blank_start]2[blank_end]) inactivate t-PA; α2-antiplasmin (α2-AP) inactivates plasmin.

Streptokinase is a protein derived from streptococci which inactivates plasminogen

What are the uses of fibrinolytics?