Arteries

Veins

Capillaries

Arterioles

Venules

Heart!

Ventricles

Atria

Blood Vessels

Arteriosclerosis = hardening of vessel wall.

Atherosclerosis = deposits of lipids in blood vessel wall, forming a plaque. results in hardening and narrowing of vessel.

Possible Disease States

Cross section of a normal, healthy coronary artery.

Cross section ofa coronary artery with advanced atherosclerosis.

Remember: R = 1/r4

Coronary Angiogram:

Showing 60%

obstruction (arrow)

of the anterior

interventricular

artery.

AorticAneurysm

Aneurysm:a weak pointin an arterywall (or heart);results in bulging dueto pressure in vessel.

Poses threat of hemorrhage.

Mean Arterial Pressure (MAP)

Basically determined by these 4 Factors:

1. Cardiac Output

2. Peripheral Resistance

3. Total Blood Volume

4. Distribution of Blood

Figure 15-10 in textbook

Control:1) Para => HR

2) Sym => HR, Force

Control:1) Sym => r (R)

2) Sym => r (R)

3) myogenic control

4) paracrines and hormones

fluid intake => MAP

fluid intake => MAP

Kidneys can conserve water to reduce loss but cannot make more water!

Most blood in venous system

If MAP, the mobilization of blood from venous to arterial system will MAP

Systemic vasoconstrictionof veins by ANS (Sym)

Baroreceptors (aortic arch & carotid a.a.)

If BP, then freq of Action Potential firing to M.O > changes to BP.

If BP, then freq of Action Potential firing to M.O > changes to

BP.

M.O.

∆’s to ↓BP

∆’s to ↑BP

↓

↑

BP

BP

The Baroreceptor Reflex

What is Cardiovascular Shock ?

It is a failure of the cardiovascular system to adequately perfuse the

tissues of the body

1. Cardiogenic

2. Volumetric

3. Anaphylactic

4. Septic

1. Cardiogenic = Failure of the Central Pump.

Examples:a) Heart attackb) Tompanade c) Congestive Heart Failure

Ultimately => ↓ MAP

Can lead to vascular pooling

2. Volumetric or Hemorrhagic Shock

Examples:a)Hemorrhage b)Sever dehydration

↓ MAP

Significant ↓ in total blood volume.

Class(Volume)

Blood Loss Response Treatment

I<15% (0.75L)

↑ HR Normal BP Minimal

II15-30%

(0.75-1.5L)↑ HR ↓BP I.V. fluids

III30-40% (1.5-2L)

↑↑ HR↓BP Confusion

I.V. fluids and RBCs

IV>40% (>2L)

Critical BP and HR

Aggressive interventions

3. Anaphylactic = Allergic Response.

Examples:a)Bee stingb)Food (fish, peanuts)c)Medications

A ‘harmless’ allergen triggers a massive immune response.

This is an ‘inappropriate’ immune response.

3. Anaphylactic = Allergic Response.

Involves the systemic release of histamine, leads to vascular pooling - ↓ MAP

Additionally causes:Severe swelling and constriction of bronchioles(↓ air flow). *Epi-Pen

4. Septic = Overwhelming InfectionAppropriate immune response!

Examples:a)Septicaemia = blood poisoning.b)Bacteria releasing -blockers.

-blockers prevent NE from counter-acting histamine, leads to vascular pooling (↓ MAP).

Septic Shock

Overwhelming infection → Neutrophils arrive to engulf the microbes; Macrophages release interleukin, Basophils and Mast cells release histamine, causing widespread vasodilation.

Also increases capillary permeability → lead to ↓↓MAP.

How does Respond to Shock?

Activation of the Sympathetic division of ANS

HR and Force (SV)

Venous Vasoconstriction

- Urine output

- pump (C.O.)

- venous reservoir.

Water conservation by Kidneys.

Filtration at capillaries - Interstitial Fluid

The Lymphatic System

Roles of the Lymphatic System

1) One-way drainage system.

2) Lipid Absorption from Small Intestine.

3) Produce & circulates Immune cells.

• One-way drainage of tissue fluid back to heart.

• About 2 L/day collected by lymph vessels.

re

Edema – an increase in interstitial volume

90% of filtrate

reabsorbed.

~10% goes?

Edema can occur in 2 main ways:

1) Transcapillary Fluid dynamics are Upset.

– HPi increases interstitial volume– COPi increases interstitial volume

– HPcap increases interstitial volume– COPcap increases interstitial volume

Transcapillary Fluid Dynamics

Edema can occur in 2 main ways:

1) Transcapillary Fluid dynamics are Upset.

2) Blockage of Lymphatic vessels.

– HPi increases interstitial volume– COPi increases interstitial volume

– HPcap increases interstitial volume– COPcap increases interstitial volume

Elephantiasis:An example ofblockage orobstruction oflymphatic vessels.