BIO 3302 Midterm: REVIEW OF TOPIC 1 - CIRCULATION
15 Dec 2016
School
Department
Course
Professor
TOPIC 1
-
Circulatory Physiology
Noradrenaline reuptake inhibitor cocaine 1.
Noradrenaline = sympathetic stimulation = vasoconstriction
Pre
-
capillary sphincter
–
capillaries site of gas exchange
o
Would not affect gas exchange, but would affect blood flow to other organs
Area
–
capillaries = high SA
Blood velocity slows dramatically, capillaries = very thin therefore blood moves very
slowly
Total blood flow
–
blood flow remains constant throughout circulatory system just runs
at different pressures and velocities
*Fahraeus Lindqvist effect = rbs accumulate in centre of blood stream, reducing
apparent viscosity (and resistance) for small blood vessels
Assuming a constant pressure difference across a blood vessel, blood flow through the vessel
will be increased OR
decreased
(
select one
) by a factor of
8
if the radius and length of the vessel
are both halved.
2.
The pacemaker of the vertebrate heart is considered to be
myogenic.
3.
NICE!
REVIEW
Monday, December 12, 2016 4:38 PM
ANIMAL PHYS Page 1
4.
Fluid and
proteins
that are lost from the capillaries are returned to the circulatory system by
means of the
lymphatic
system.
5.
Neuronal adrenaline acts on b
2
adrenoreceptors to elicit vasodilation
Neuronal noradrenaline acts on a
1
adrenoreceptors to elicit vasoconstriction6.
An increase in SV at a given END
-
diastolic volume can be elicited through
7.
Sympathetic stimulation of the heart
b
1
adrenergic receptors in ventricle – activated by noradrenaline, initiate cAMP
and release Ca into cytosol
o
Frank starling = SV directly correlated with diastolic filling, therefore would occur during
diastolic
End
-
diastolic pressure determined by venous filling pressure
(a
) the monoamine oxidase inhibitor phenelzine
(note that synaptic catecholamines are
degraded by monoamine oxidase)
(b) the ß
1
-
adrenoreceptor antagonist atenolol
(c) the acetylcholinesterase inhibitor physostigmine
(d) the ß
2
-adrenoreceptor agonist salbutamol
Windkessel vessels
Aorta, large arteries
Dampen pressure oscillations (elastic walls) to maintain
continuous flow
Pre-capillary resistance
vessels
Smallest arteries, arterioles
Small diameter = high resistance
Largest fall in pressure
Control over regional BF and BP
Administration of which of the following drugs would be counterproductive in the treatment of
high blood pressure (circle one)?
8.
ANIMAL PHYS Page 2
Innervated by SYMPATHETIC
Pre
-
capillary sphincters
Determine capillary exchange area
Metabolites = local chem factors
Capillaries
Thin walled vessels = transfer site
Low blood velocity (1-3s)
Site of water balance
Exchange by diffusion
Post
-
capillary resistance
vessels
Venules, small veins
R can be adjusted
–
adjusting P across capillary beds
Capacitance vessels
Large veins
Compliant walls
–
VOLUME RESERVOIR
SYMPATHETIC innervation
Major influence on cardiac output through venous return
Consolidate your knowledge:
9.
windkessel - elastic walls to dampen oscillations
a.
These vessels serve to dampen pressure oscillations in blood leaving the heart, and to
maintain blood flow while the heart relaxes.
1.
Pre cap res vessels
-
smooth muscle in the vessel walls to adjust p and flow to be
adjusted.
a.
These vessels regulate regional blood flow and determine arterial blood pressure.
1.
Capacitance
-
smooth muscle and thin walls to be adjusted to match blood that is
there.
a.
These vessels serve as a volume reservoir
1.
For each of the following, identify the vessel (functional types) and list one structural
characteristic of the vessel that is essential to its function.
If the osmotic and hydrostatic pressures of the interstitial fluid are 3 mmHg and 1 mmHg,
respectively, and the blood osmotic pressure is 29 mmHg, there would be a net gain OR
net loss
OR neither (
circle one
) of fluid from the capillary at a blood pressure of 33 mmHg.
10.
Fluid is monitored and adjusted, filtered by p differences
Convective exchange of water to maintain fluid balance
o
Hydrostatic p = bp, hydrostatic is higher
Called a filtration force, force moves water out of capillary
An absorbtive force moves water out of intersitisal fluid onto capillary
Diff in osmpostic pr between interstiltal fluid. Done by plasma proteins
Hydrostatic pressure: capillary > interstitial fluid
®
filtration force
Plasma proteins (albumin)
Colloid osmotic pressure: plasma > interstitial fluid
®
absorption force
Net filtration pressure = (BP
–
P
IF
)
–
(OP
blood
–
OP
IF
)
Driven by hydrostatic and osmotic pressure gradients
o
Water loss at arterial end of capillary matched by water gain at venous end of
capillary
Net fluid loss and need for lymphatic system
Starling-Landis hypothesiso
Fluid exchange
ANIMAL PHYS Page 3
Document Summary
Would not affect gas exchange, but would affect blood flow to other organs. Pre-capillary sphincter capillaries site of gas exchange o. Blood velocity slows dramatically, capillaries = very thin therefore blood moves very slowly. Total blood flow blood flow remains constant throughout circulatory system just runs at different pressures and velocities. Assuming a constant pressure difference across a blood vessel, blood flow through the vessel will be increased or decreased (select one) by a factor of 8 if the radius and length of the vessel are both halved. *fahraeus lindqvist effect = rbs accumulate in centre of blood stream, reducing apparent viscosity (and resistance) for small blood vessels. The pacemaker of the vertebrate heart is considered to be myogenic. Fluid and proteins that are lost from the capillaries are returned to the circulatory system by means of the lymphatic system. Neuronal noradrenaline acts on a1 adrenoreceptors to elicit vasoconstriction. Neuronal adrenaline acts on b2 adrenoreceptors to elicit vasodilation.
