Circulation 1 Flashcards
5 purposes of the circulatory system
- Carry nutrients, oxygen
- To carry waste products, CO2 to organs of excretion
- To move signaling molecules from one part of the body to another.
- To move immune cells around body
- Regulate body temperature
Diffusion over long distances
Slow
Time necessary to diffuse a molecule between two points is proportional to:
Square of the distance between them
Bulk flow is what type of transport
Convective flow
How is bulk flow controlled
Tubes & Pumps
Types of bulk flow
- Contractile chamber
- External pump
- Peristaltic contraction
Two types of circulatory system
Open & closed
4 components of a circulatory system
- Tubes
- Circulatory fluid
- Muscular pump
- Interface with the environment
What are the components of the vertebrate circulatory system
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
Which animals have single circuit circulatory systems and which have double circuit systems?
Single: Fishes
Double: Mammals and Birds
Describe the single circuit circulatory system
- Heart only has one atrium and one ventricle
- Heart goes to gill circulation (oxygenation)
- Gill circulation goes directly to systemic circulation
Describe the double circuit circulatory system
Same as human circulatory system
Amphibian circulatory system
Same structure as human, except the pulmonary artery goes to both the lungs & the skin (called the Pulmocutaneous circuit)
Reptile circulatory system
Same as human circulatory system, except a 3rd tubule (right systemic aorta) comes out from right ventricle to pump blood to the systemic circuit
Law of Bulk Flow
Fluids flow down pressure gradient (high to low pressure). Resistance opposes this movement.
Law of Bulk Flow equation
Q=DP/R
Q=flow, DP=pressure gradient, R=resistance
The resistance is proportional or inversely proportional to what
Inversely proportional to its radius by the fourth power (1/r^4)
Ohm’s Law + Bulk Flow
Substances (electrons or fluid) move because they are acted upon by a force. Such movement is impeded by resistance
Why are circulatory systems named as circuits?
Because they are analogous to circuits and their respective series and parallel components.
When you add resistors in series the total resistance ___
Increases
When you add resistors in parallel the total resistance ___
Decreases
Which system would have a higher flow rate, series or parallel?
Parallel
Resistors in parallel flow rate
Divide up the incoming flow rate equally among the three
Units of flow
Volume/Time
Is flow rate larger in an artery or a capillary?
Artery
The resistance in a blood vessel is proportional or inversely proportional to what?
Inversely proportional to cross-sectional area of the tubule
The smaller the blood vessel, the greater the ___
Resistance
Because of resistance, flow rate is proportional or inversely proportional to what?
Directly proportional to the cross-sectional area of the vessel
The smaller the blood vessel, the smaller the ___
Flow rate
Velocity of flow is dependent on __ & __
Pressure & Cross-sectional area
Velocity is proportional or inversely proportional to what?
Inversely proportional to the cross-sectional area
The velocity of flow is greater in which: Artery or Capillary?
Capillary
When considering capillaries, we need to consider ___
The whole capillary bed (in terms of cross-sectional area)
The velocity of flow will be greater through which? Artery or Capillary bed?
Artery
Ranking cross-sectional area
(Arteries=Veins)<Capillary bed
Ranking velocity blood flow
(Arteries=Veins)>(Arterioles=Venules)>Capillary bed
The heart as a pump creates __
Pressure gradients
Define Diastole
Relaxtion. Negative Pressure. Blood flows in.
Define Systole
Contraction. Positive Pressure. Blood flows out.
The valve between the right atrium and ventricle is called ____
Right Atrioventricular Valve (Tricuspid)
The valve between the left atrium and ventricle is called ___
Left Atrioventricular Valve (Bicuspid)
When do the right and left atrioventricular valves open? close?
Open: Ventricular contraction
Close: Ventricular relaxation
What cells have intercalated discs?
Cardiac muscle cells
What are intercalated disks?
Comprised of desmosomes and gap junctions
What is the role of gap junctions in cardiac muscle cells?
To spread electrical activity from one cell to another
Characteristics of cardiac muscle:
- Uninucleated
2. Short and branched