Review notebooks Flashcards
Diameter and conduction speed of fibers
Efferent Fibers
Alpha motor neuron -
100-200uM in diameter
70-120 m/s
Gamma-motor neuron
100-200uM
10-50 m/s
B fibers: myelinated preganglionic autonomic fibers
1-20 m/s
C fibers: unmyelinated postganglionic autonomic fibers
0.2-1.5uM in diamter
Normal efficiency of the heart
efficiency 20-25%
decreases to 5-10% in heart failure
Normal cardiac output and its increase during exercise
5 L/min
up to
35 L/min during maximal trained exercise
25 L/min max untrained
percentage of blood in systemic and pulmonary circulations
fraction of blood in veins vs arteries
85% systemic
9% pulmonary
7% in heart
approximately 4x as much blood in veins as arteries.
65% in systemic veins
13% in systemic capillaries
RBC diameter
Capillary diameter
Arteriole/Venule diamter
aorta and vena cava
RBC 6-8uM
Caps 7-10uM
art/venules 20uM
ateries 4mm
veins 5mm
aorta 25mm
vena cava 30mm
Reynolds number and the cutoff value it indicates
Estimates the tendency for turbulent flow
> 200 some turbulence at bends in the flow
2000 turbulence everywhere even in straight portions.Turbulence normally occurs in ao
Re= (velocity x diameter x density) / viscosity
Turbulence occurs in the aorta and pulmonary arteries and nowhere else.
conversion factor for mmHg to cm H20
1mmHg = 0.36 cm H20
Total Peripheral Resistance units and the normal range
Normal total pulmonary
What is the conductance, and what parameter of the vessel most strongly affects conductance?
Normal TPR = 1 PRU, 1 Peripheral Resistance Unit
Range from 0.2- PRUs
flow in ml/s = arterial venous pressure difference mmHg / TPR
normal Pulmonary resistance = 0.14 PRUs
approx 1/7th of systemic
conductance is the reciprocal of resistance.
it is proportional to the diameter of the vessel raised to the 4th power.
Normal blood viscosity value
3
What is distensibility of a vessel
and what is the compliance
The increase in volume of the vessel per increase in mmHg of hydrostatic pressure.
distensibility = delta Vol / delta P x original Vol
Compliance = distensibility x volume Compliance = delta Vol / delta Pressure
What is the normal central venous pressure
What are its lower and extreme upper limits
Normal = 0mmHg,
With serious heart failure or a very large blood transfusion 20-30 mmHg
lower limit is -3 to -5 mmHg, which is the pressure of the mediastinal cavity.
It approaches the lower limit when the heart is pumping very rapidly, or there is a hemorrhage
The venous pressures in a person standing completely still without any activity of the venous pumps/valves
changes with the pump activity
head/neck = 0
Cranial dural sinuses = -10mmHg
Shoulders 6 mmHg
Hands 36 mmHg
Feet 90 mmHg
With movement and venous pump activity,
feet pressure is reduced to 20 mmHg
Volume of the various venous blood reserves/plexuses
Spleen: 100ml
Liver 300-400ml
Abdominal plexus 300ml
skin plexus 300-400
capillary wall thickness
0.5uM
normal interstitial fluid pressure?
what causes it?
-3 mmHg in loose interstitial tissue
Lymphatic pumping of the fluid causes it.
What is the usual range of autoregulation, in actue and chronic phases
75-175 mmHg acute
50-200 mmHg long term, requires vessel growth/pruning/modification
List of vasoconstrictors
NE, E
AngII
Vasopressin/ADH
Endothelin
List of vasodilators
Histamine Bradykinin Adenosine, most potent coronary dilator AMP CO2 K+ H+ Lactate
NO –> guanylyl cyclase –> cGMP –> MLCphosphatase
CO2, most potent dilator in brain.
Mg++ is a potent dilator, inhibiting smooth muscle contraction
What specific types of vessels does the sympathetic NS cause constriction in?
what vessels does it NOT innervate?
Constricts:
Arteries, arterioles, veins, venules
Does NOT affect, metarterioles, precapillary sphincters, or capillaries.
Set point of the carotid and aortic baroreceptors
Carotid baroreceptors 100 mmHg
Aortic baroreceptros 130 mmHg
What kind of receptors are in the
Atria and Pulmonary artery
What reflex do the atrial receptors activate?
1) Low pressure baroreceptors,
Respond to elevated pressure in either of these low pressure systems
activate the baroreceptor response just like the carotid/aortic receptors in response to elevated atrial or pulmonary artery pressures.
2) The Atrial Stretch receptors activate the
BAINBRIDGE reflex, which activates the sympathetic activation of the heart, to increase heart rate and CO in order to prevent atrial damming/congestion of blood.
What kind of receptors are in the Carotid body and Aortic arch?
High-pressure baroreceptors
and
Chemoreceptors that measure blood O2 and CO2 content.
Describe how the inspiration/expiration affects venous return and CO
on inspiration, pulmonary vessel system has lower pressure and increased volume –> decreased venous return and decreased CO
expriation: pulmonary pressure increases and volume decreases, squeezes blood back to left ventricle –> increased venous return and increased CO
normal ventilation frequency
normal alveolar ventilation rate
12 breaths/min
alveolar ventilation, 4.2L/min
Normal total blood volume
Pulmonary blood volume
5L total blood volume
500ml Pulmonary blood ~9 or 10% of total, increased up to 700mL during exercise
Mean arterial pressure
Mean pulmonary artery pressure
between 90-100 mmHg
pumonary mean artery pressure 14 mmHG
Composition of the blood-air barrier and its thickness
1-2uM
type I pneumocyte
shared basement membrane w/ endothelial cell
endothelial cell of capillary
What is the normal rate of CSF production?
What is the normal intracranial pressure?
What happens to the rate of CSF if intracranial pressure goes above or below this point?
CSF production is constant at 0.35ml/min
intracranial pressure is 8mmHg
below this point, absorption rate of CSF will decrease
above this point, absorption will increase
What type of skin has the AV anastomoses and what kind does not?
Apical or Acral, hairless, sweatless, skin has the anastomoses, and is regulated solely by neural, autonomic regulation
Non-apical or non-Acral, Hairy skin does not.
Is regulated by metabolic demands and is autoregulated.
Non-Acral, hairy skin has Sweat glands.
What are the essential amino acids? (use the saying)
I Saw Loose Val, His Lice Try'dTo Meet Three Pharmacists
