Summary
Biol 216 Circulatory System Summary
- Course
- Biol216
- Institution
- Case Western Reserve University
This is a comprehensive and detailed summary on the circulatory system for Biol 216.
[Show more]
Content preview
CIRCULATORY SYSTEM Blood and its components:
o Plasma - aqueous solution of proteins, ions, nutrient molecules, and gases (91% water)
o Erythrocytes (RBC) - oxygen carriers of blood
o Leukocytes (WBC) - front line of defense against disease
o Platelets - induce blood clots that seal breaks in the circulatory system
Mammalian Blood
o Fluid connective tisse (4-5 liters in humans)
o Blood cells (erythrocytes, leukocytes, platelets)
o Suspended in fluid matrix (plasma)
o Human blood cells--> develop in red bone marrow of vertebrae, sternum, ribs, pelvis
Arise from multi-potent stem cells that give rise to:
Myeloid stem cells
Lymphoid stem cells
Plasma contains---> mostly water, Ions, Dissolved gases (O2 and CO2), Glucose, Amino acids, Lipids, Vitamins,
Hormones and plasma proteins
o Plasma proteins:
Albumins - osmotic balance, pH, transport hormones, waste, drugs
Globulins - transport lipids (cholesterol), fat soluble vitamins, immunoglobulin
Fibrinogen - blood clotting
o Plasma ions: (electrolytes) - Na+, K+, Ca2+, Cl-, HCO3-
Blood cells
o Erythrocytes (BRC) - contain hemoglobin (transports O2 from lungs to body)
Mature erythrocytes don't have a nucleus, do have organelles
Flexible - can squeeze through capillaries
Life span = 4months
o Leukocytes (WBC) - mostly involved in immune system
Defend body against infecting pathogens
Eliminate dead and dying cells, debris
o Platelets
Cell fragments enclosed in a plasma membrane
Trigger clotting - stick to collagen that is exposed when blood vessels are damaged--> release
factors to bring more platelets to the region--> seal off the damaged site
Hematocrit (Packed cell volume - PCV)/(erythrocyte volume fraction - EVF)--> volume percentage of red blood
cells in blood
o How much RBC is in blood
o Normally 45% for men, 40% for women
o Anemia - abnormally low hematocrit --> less RBC, less hemoglobin, less oxygen
Lub-up sound you hear through stethoscope placed over the heart is the---> valves being forced shut
The mammalian Heart
o A four-chambered pump
Two atria at top of heart
Two ventricles on bottom
Atrioventricular (AV) valves -
between atria and ventricles
Semilunar (SL) valves
o Blood is pumped into two separate circuits
- pulmonary and systemic
o Know above diagram ^
o Left and Right atria fill simultaneously =
period of diastole
,CIRCULATORY SYSTEM
Right atria fills with deoxygenated
blood - systemic circuit
Left atria fills with oxygenated
blood - pulmonary circuit
o When they fill up the pressure builds -
then blood flows through the AV valves to the
ventricles--> diastole--> getting ready to send
AP through cardiac muscle for contraction to
occur through the ventricles to pump blood
out
o Right side=tricuspid AV valve
o Left side=Bicuspid AV valve
Know the above diagram -
o Pulmonary vein = oxygenated blood
o Pulmonary ARTERY = deoxygenated
blood
o Arteries carry blood Away from the heart
What is an advantage of separate systems:
pulmonary/systemic?
o TWO COMPLETELY DIFFERENT PRESSURES
o Systemic circulation
HIGH blood pressure in the
arteries - pulsatile
Does NOT fall to zero between heartbeats
One the rise up = heart contracting
Slope down = heart relaxing
(even when heart relaxing, pressure still
above 0
o Pulmonary circuit - pressure is lower
o We do not want too much pressure in our lungs-->
exchange pathway is shorter with lower resistance:
fluid could leak out of vessels into the lungs
Design of transport systems
o Large tubes for bulk transport over distance
F(flow) = P (pressure)
R (resistance)
More resistance=less flow
Greater change in pressure=increase in flow
Note: when the heart beats, it creates higher pressure at the end of the tube (by the ventricle) than
the other end = delta P
R = 8L
r
= fluid viscosity
L = length of the tube
R=inside radius of the tube
Longer the tube=more resistance
As radius gets bigger==> resistance gets smaller
Keeping these relationships in mind: what will be the effect on fluid flow of increasing the radius by a
factor of 2?
Flow will increase by a factor of 16
Resistance will be 1/16 of what it was before--> flow will INCREASE by a factor of 16
, CIRCULATORY SYSTEM
Basic Heart beart
o Systole - ventricle contracting
o Diastole - ventricle relaxing--> chambers filling,
atria contracting
o Blood moves as a result of PRESSURE
DIFFERENCES
o Systole-diastole sequence is --> cardiac cycle
At rest - typical systolic BP = 110-140
mmHg;
diastolic BP = 60-90 mmHg
Thumping sound=systolic pressure
No turbulence, no sound = diastolic
pressure
The cardiac cycle
o Triggered by action potentials that spread across
the cardiac muscle cell membranes
o Systolic pressure - contraction of ventricles
pushes blood into arteries at peak pressure
Isovolumetric ventricular contraction -
both AV and semilunar valves closed
Ventricular ejection - AV valve closed;
semilunar valves=open
o Diastolic pressure - between ventricular contractions, blood pressure in arteries falls to a minimum
pressure
Isovolumetric ventricular relaxation -
both AV and semilunar valves closed
Ventricular filling - blood flows into
ventricle
AV valve=open to fill the
ventricle
Small period of time where
atrium contracts a little bit to squeeze
out the last bit of blood to get into the
ventricle
No valve going into right atrium--> have
constant flow of deoxygenated blood into it
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 anyiamgeorge19. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
72001 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now