Arterial And Venous System + Body Fluid Compartments - Quiz 5 Flashcards
What tissues make up the wall of the artery?
Endothelium
Elastic Tissue
Smooth Muscle
Fibrous Tissue
What are the 3 tissue layers in the artery wall?
Tunica Externa (Adventitia)
Tunica Media
Tunica Intima
What are the Arteriole Wall tissues?
Endothelium & Smooth Muscle
What are the Vein wall tissues?
Endothelium
Elastic Tissue
Smooth Muscle
Fibrous Tissue
Primary function of Arterial System
Distribute blood to capillary system
What do the Arterioles do?
Regulate distribution of blood flow to various capillary beds
Where is the pressure lowest as blood goes from aorta to RA?
Vena Cava - close to zero
What is pulse pressure?
Difference b/t systolic and diastolic BP
How to Caculate MAP
MAP = [2DBP + SBP] / 3
or
MAP = [CO x SVR] + CVP
Waveform as blood moves away from heart to extremities?
- High frequency components of pulse (incisura) become damped, then disappear
- Systolic part of wave narrow and elevate
- Hump appear on diastolic part of wave
SBP in the foot vs aorta
Higher in the foot d/t gravitational pressure
How is pulsatile flow converted to continuous flow?
Hydraulic filter makes flow continuous to minimize workload of the heart
Pumping blood thru rigid vessels is ______ work for the heart
More
What factors increase pulse pressure?
- Increased Stroke Volumes
- ↑Preload, ↑Intropy, ↓HR, ↓Afterload
- Decreased Aortic Compliance
- Age, HTN, Ateriosclerosis
Why do arteries get stiffer with age?
Loss of elastic tissue
Vein Functions
Reservoir - 70% of blood volume
Pumps blood forward for venous return
What regulates CVP
Balance of heart to pump blood out the RA and RV to lungs
and
Blood flow back to RA
What factors increase CVP
- ↓Cardiac Output
- ↑TBV
- ↑Respiratory Activity
- Venous Contriction
- Arterial Dilation
- Gravity - standing to supine
- Skeletal Muscle Pump - exercise
In a standing position, where are the highest and lowest venous pressures?
Lowest: Sagittal Sinus (Head) = -10mmHg
Highest: Feet = 90mmHg
Major risk of sitting position in neurosurgery
Air Embolism?
How does Respiration effect Venous Return?
- Spontanous Breathing
- Inspiration increases venous return, vice versa
- Mechanical Breathing
- Positive Pressure –> ↑RA pressure –> ↓venous return
- Valsalva Maneuver
- ↑Thoracic Pressure –> ↓venous return
How much TBV is in Venous System?
70%