Ch. 42: Vertebrate Cardiovascular & Respiratory Systems Flashcards
Circulation systems link…
exchange surfaces with cells through the body
Coordinated cycles of heart contraction drive…
double circulation in mammals
Patterns of blood pressure and flow reflect…
the structure and arrangement of blood vessels
Blood components function…
in exchange, transport, and defense
Gas exchange occurs across
specialized respiratory surfaces
Breathing ventilates the…
lungs
Adaptations for gas exchange include…
pigments that bind and transport gases
Open Circulatory System
bulk flow
-i.e. Aurelia
Closed Circulatory System
- high-vs-low pressure
- high blood pressure enables effective delivery of O2 and nutrients to cells of larger and more active animals
- not as much body mass in hemolymph
- shunting blood
Systole
heart contraction
high pressure
pumping
Diastole
hear relaxes
lower pressure
passive flow
Flow =
F = ∆P / R
Flow = change in pressure / resistance
∆P is from heart
R is from vasculature
Hagen - Poiseuille Law for Newtonian-fluid dynamics
Flow = (P_in - P_out)*(pi/8)*(1/viscosity)*(r^4/L) ∆P = heart (pi/8)*(1/viscosity)*(r^4/L) = vessel
change flow by
- increase ∆P
- varying r
- i.e. artery/ smooth muscles
- artery is blood away from heart (∆P)
- (pi/8) = constant
- (1/viscosity) = walls of artery and blood resistance
- (r^4) = radius can change; contraction of smooth muscles
- L = length of artery of where the blood travels through
Why is blood pressure limited in fish?
- 2-chambered heart: 1 atria and 1 ventricle
- ∆P regions in pulmonary and systemic capillary beds
- > have high resistance, very narrow => r is small
- F = ∆P/R
Anatomical and physiological consequences (implications) of a 4-chambered heart in an endotherm such as a bird or mammal?
- 2 complete circuits
=> Pulmonary circuit: heart to lungs: Low P
=> Systemic circuit: heart to body: High P - get more O2
- increase metabolic rate
- more energy used
Series vs Parallel circuits
Parallel Circuit shows typical capillary bed
- higher SA and lower R since P is split
- More bracing, more SA
- decrease in velocity with friction and radius
F = ∆P/R
Series: all P goes through all R (lower overall F)
Why do arteries have thick layers of smooth muscle?
- take blood away from the heart under higher pressures
- Thick walls included band of smooth muscles (regulate diameter)
- shunt blood
Why do veins have one-way valves?
- delivery of blood to the heart
- ∆P, reduce pressure
- help with back-flow
- lower pressure
What is the function of a capillary
- exchange surfaces (i.e. heat, gas)
- thin walled, sometimes perforated
- high SA
What is the reason/role for the lymphatic system?
- immune function
- helps with diffusion
- loss of fluid and protein return to blood
- take lymph small intestine => blood
- drains into large veins of the circulatory system at the base of the neck
- lymph nodes are organs that house lymph and attack foreign cells such as veins and bacteria
- lymph vessels: like veins
What does ventilation maximize in Fick’s Law
F=DA*(∆P/∆x)
maximizes: ∆P
- creates pressure gradient
- keep “air” moving; i.e. breathing
Why do mammalian lungs have so many alveoli?
to increase/ maximize SA
Why is the advantage of having hemoglobin to be sensitive to pH?
more strategic of where to release O2
=> Lower pH
- more CO2
- retains less O2
- O2 to diffuse to cells
=> Higher pH
- binds better to O2
- allow more O2 to bind to blood
- get more O2/mL
Which vertebrates do you think is the ultimate aerobic performer? Explain.
Birds
- lungs always have O2
- unidirectional flow; 2 breaths
- more/continuos air flow
- get more O2/air than reptiles or mammals
2 chambered heart
- fish
- 1 atria
- 1 ventricle
- pressure keeps decreasing
- R1 and R2 in series; has to go through both R
3 chambered heart
- amphibians and reptiles (except crocodiles)
- 2 atria
- 1 ventricle but partially divided
- ventricle: (1) amphibians: very little separation of blood in ventricle
(2) reptiles: more separation of blood in ventricle - 2 circuits that are somewhat separate
- Pulmonary: lower P
- Systemic: higher P
- separate but same circuit with high P and low P zones
- R1 and R2 in parallel (overall lower P)
4 chambered heart
- crocodiles, birds, mammals
- 2 atria
- 2 ventricles
- 2 complete circuits
- Pulmonary circuit: low pressure
- Systemic circuit: high pressure
- increase in metabolic rates
- more energy
Arteries
- blood away from the heart
- main goal: delivery under high pressure
- thick walls include band of smooth muscle (regulate diameter)
- shunt blood
- carries blood under high pressure to body regions
- can be regulated to shunt blood
- form many capitally beds
Vasodilation
increase in diameter
decrease in R
increase in F
Vasoconstriction
decrease in diameter
increase in R
decrease in F
Capillary Bed
highly branched
thin-walled vessels
helps to increase SA
overall R decreased
Veins
- delivery (blood reservoir)
- low pressure (lower flow rates)
- not as thick walled
- one way valves: help with back flow and reduce P
ECG or EKG
electrical activity of the heart
3 events in total
1) heart contracts due to depolarization
SA node (peace maker) => AV node
Respiration
Cell: mitochondria
Whole Organism: => "Respiratory System" => O2 environment => Respiring tissues => H2O to fresh water: 6.6mL O2/ L H2O => H2O to marine water: 5.3mL O2/ L sea water => Air: ~21% O2 or 210mL O2/ L air
Key Steps (Fick’s law compliant)
1) ventilation (water or air) - convection
2) diffusion across thin respiratory membrane
3) bulk flow
4) diffusion across thin capillary membrane
5) diffusion to cells/mitochondria
