Circulatory System Flashcards
The depolarization rate of the heart increases and the membrane is more permeable to Sodium and Calcium, the ligand binds to beta-1 adrenergic receptors, what is the ligand? What portion of the nervous system releases it?
Sympathetic innervation and release of norepinephrine
A specific target tissue is saturated with oxygen, what is the capillary response?
Vasomotion - the opening and closing of precapillary sphincters. When Oxygen levels are high in the tissues then the precapillary sphincters are narrower or closed.
A person has shown to have a decrease in vascular conductance and blood flow, what is the probable cause of this?
A kidney removal
Limb amputation
These are both components of the parallel circuitry of the circulation system.
C-total=c1+c2+c3….
Are Veins or Arteries both more compliant and more distensible than the other?
What does this suggest by their elastin content?
Veins are 8 times more distensible and more compliant than arteries. This suggests that arteries have a higher content of elastin than veins.
More pressure, less distensible. High elastin, low compliancy
Upon examination the patient has a murmur, would this be caused by turbulent or laminar flow of the blood?
Turbulent flow
Why does blood pressure typically increase, and have a steady high value, in older people?
Because arteries decrease in compliancy with age. This increases the pulse pressure.
Which is not a factor that contributes to resistance of blood flow? A. Vessel Radius B. Blood Viscosity C. Vessel Length D. Blood Pressure
Blood pressure, is not a direct cause of resistance.
Laminar Flow is indirectly proportional to which of these variables A). Blood Velocity B). Vessel Diameter C). Blood Density D). Blood Viscosity
Blood Viscosity
What does the removal of a limb or kidney do to the parallel circuitry of the circulatory system?
Decreases vascular conductance and total blood flow
Increases total vascular resistance
All of the following control the vasomotor center in the medulla except:
A). Hypothalamus
B). Amygdala
C). Cerebral Cortex
D). Reticular Substance
The amygdala
What is acute local blood flow control?
Rapid local vasodilation or vasocontriction of systemic vessels (mostly arterioles). Rapid because it happens in mere seconds to minutes and is based on the vasodilator theory and the oxygen lack theory.
What is long-term local blood flow control?
an increase in size or number of systemic vessels. This occurs of a period of days, weeks or months.
Explain the two acute blood flow control theory’s:
Vasodilator Theory
Oxygen Lack Theory
Vasodilatory theory -
Increase metabolism leads to low O2 availability
And the formation of vasodilators (like histamine
Or acetylcholine)
Oxygen Lack Theory -
Lox Oxygen levels cause the blood vessels to relax ->
Vasodilation
Metabolic and myogenic theories of blood flow autoregulation
Metabolic theory: An increase in blood flow causes
Too much oxygen and nutrients
Which causes the vasodilators to
Wash out
Myogenic Theory: Stretching of vessels causes reactive
Vascular constriction
Humoral Vasoconstrictors
Norepinephrine/epinephrine
Angiotensin II - increases total peripheral resistance
Vasopressin (ADH - controls body fluid volume)
