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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.