Class notes
Aantekeningen colleges 1-10 | 8WB00 Heart And Blood
- Course
- Institution
- Book
Aantekeningen colleges 1-10 + Terminologie
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
Test Bank For Medical Physiology, 3rd - 2017 All Chapters - 9781455743773
-
Class notes BIO413 Medical Physiology
-
Class notes BIO413 (bio5413) Medical Physiology med phys notes
Seller
Followjesselandoulsi
Content preview
Notes college 1- The Cardiovascular system and Hemodynamics -
Functions of the cardiovascular system:
1. Primary:
- Distribution/transport of dissolved gasses and other molecules for nutrition,
growth and repair
2. Secondary:
- Fast chemical signaling to cells: hormones, neurotransmitters
- Dissipation of heat: delivery of heat from core to body surface
- Mediation of inflammatory and host defense responses
Transport in the cardiovascular system: Simplified version of the entire crdvscr syst:
,Facts
1. Heart:
- Beats 70x/min, 2.3 billion times in a lifetime
- Weighs ~ 300 grams
- Pumps 71 ml/beat, 5-25 L/min, 7200 L/day, 400 million L/life
2. Vessels:
- 0.006 - 35 mm in diameter
- Total length 100000 km
3. Blood:
- 300 - 400 mL (baby) to 5 L (adult)
- Average speed 11 km/h, one round in 22 seconds
- Completely replaced in 1 week
Hemodynamics
1 mmHg = 133.32 Pa
Pressure
Three ways of exerting pressure in tubes:
1. Driving pressure - axial
- Pressure difference between the arterial and venous ends of the circulation.
- Only generator of blood flow when the vascular system is viewed horizontally.
2. Transmural pressure - radial
- Pressure difference between inside (lumen) and outside vessel (interstitial)
- Governs vessel diameter → determines resistance R
3. Hydrostatic pressure - vertical
- Pressure difference between different height locations
- Exists even in the absence of blood flow
-
Pressure (difference) law, also called the Ohm’s law of hemodynamics:
- P = Pressure difference
- F = Flow ( volume/time)
- R = Resistance
Pressure formula :
- P = Pressure
- p = density of liquid in the column
- g = gravitational constant
- h = height of column
,Flow
Main formula for total flow calculation:
- CO = Cardiac Output (total blood flow in circulation)
- SV = Stroke Volume (output during single heartbeat)
- HR = Heart Rate
CO ~ 5L/min at rest
Flow the displacement of volume (ΔV) per unit time (Δt), also the
movement of fluid with cross-section area A with mean velocity v.
Poiseuille’s law:
Flow of fluid with viscosity η in a straight, rigid, cylindrical tube of
radius r and length L:
Conditions for Poiseuille’s law:
- The fluid must be incompressible.
- The tube must be straight, rigid, cylindrical, unbranched and have
a constant radius.
- The velocity of the thin fluid layer at the wall must be zero (no “slippage”)
- The flow must be laminar (i.e. flowing smooth paths in layers)
- The flow must be steady (i.e. not pulsatile → flow with periodic variations)
- The viscosity of the fluid must be constant
Viscosity = Property of the fluid, expressing the degree of lack of slipperiness in the fluid. In
cylindrical vessels, viscosity results in a bullet-like velocity/flow profile.
Unit: Pa.s or Poise or cP (centi Poise)
- 1 cP = 0.01 Poise = 0.001 Pa.s = 1 mPa.s\
Examples:
- Water (20 C): 1 cP
- Blood (37 C): 3.2 cP
- Olive oil: 80 cP
- Honey : 2000 - 10000 cP
, Terminology
Hemodynamics → The study of the forces involved in the circulation of blood.
Cardiovascular system → The anatomical system consisting of the heart and blood vessels.
Pulmonary circulation → Of or relating to, or affecting the lungs.
Systemic circulation → Of or relating to systems or a system.
Volatile → Evaporating readily at normal temperatures and pressures.
Venous → Dark, no oxygen
Arterial → Bright, oxygen rich
Transmural → Existing or occurring across the entire wall of an organ or
blood vessel.
Hydrostatic → Relating to or denoting the equilibrium of liquids and the pressure
exerted by liquid at rest.
Rigid → Not flexible or pliant.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller jesselandoulsi. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.13. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
48298 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 15 years now