Worksheet D236 Pathophysiology Patho Lesson 6&7 2025 Western Governors University
Worksheet D236 Pathophysiology – Section 4
Lesson 6 Cardiovascular System
Learning Objectives
1. Describe pathogenesis of cardiovascular disorders and injury.
2. Describe the manifestations of cardiovascular disorders and injury.
3. Explain complications and variations of cardiovascular disorders and injury.
Learning Objective 1: Describe pathogenesis of cardiovascular disorders and injury.
Text 329-343
a) Complete the following table:
Layers of Structure Function
artery wall
Tunica The innermost It is a metabolically active tissue that releases
intima layer of the artery substances, reacts to chemical mediators, and
responds to blood contents. The endothelium is the
wall primary site of damage of arteriosclerosis and
atherosclerosis.
Tunica The middle layer The smooth muscle is innervated by autonomic
media of the artery wall. nerves, which are the sympathetic (also called
adrenergic) and parasympathetic (also called
It is composed of cholinergic) nerve fibers. There are alpha-adrenergic
, smooth muscle and beta-adrenergic nerves. Alpha- adrenergic nerve
that can constrict fibers are excitatory and cause vasoconstriction,
whereas beta-adrenergic fibers are inhibitory and
and dilate to cause vasodilation. The vascular smooth muscle
change the relies on extracellular calcium for depolarization.
artery’s diameter. Calcium enters membrane channels to evoke
contraction and vasoconstriction.
Tunica The outermost It is largely composed of connective tissue that
externa covering of the provides support for the artery.
artery wall; it is
also called the
tunica adventitia.
b)
b)Distinguish between laminar and turbulent blood flow.
-Laminar blood flow is smooth and parallel to horizontal lines of vessels.
-Turbulent blood flow is perpendicular to vessel walls and causes stagnant blood
flow
c) Explain cardiac output.
Cardiac output equals blood pressure divided by pulmonary vascular
resistance which then equals blood flow from the hearts left ventricle per
minute. SV*HR=CO.
Normal cardiac output is 5 L of blood per minute
d) Explain how BP is usually increased using the equation CO X PVR
= BP. PVR ^ BP & ^ CO= Baroreceptors – (RAAS) ADH and
Naturieses.
Lesson 6: Cardiovascular Page 1 of 5
System
, e) Explain how damaged arterial endothelium can lead to clot formation.
Turbulent blood flow can cause blood stasis, therefore promoting clot formation.
f) Using LaPlace’s Law, explain why there is a critical pressure where the
blood vessels collapse and can no longer maintain blood flow.
In hypertension (HTN), arterial vessel walls hypertrophy and become thicker,
thereby reducing the tension and minimizing the wall stress. Laplace’s law
can be applied to the pressure required to maintain the patency of small
blood vessels. When the thickness of the vessel wall remains constant, it
takes more pressure to overcome wall tension and keep the vessel open as
its radius decreases in size. There is a critical pressure where the vessels
collapse and blood can no longer flow through them.
Distention and Compliance
Compliance is the distention capacity of a blood vessel; distention capacity
allows for increased blood flow with each mm Hg rise in blood pressure. The
high distention capacity of the aorta and large arteries allows them to
accommodate the high output of the heart.
g) If a patient’s CO is 4600 mL/minute with a heart rate of 57, what is
their SV? 4600/57=80.7 ml
h)How does the body maintain BP when CO decreases?
As PVR increases, BP and CO increase. As PVR decreases, BP and CO decrease.
BP sensors known as baroreceptors. When baroreceptors detect a drop in BP,
they respond rapidly by stimulating the sympathetic nervous system (SNS). The
SNS stimulates an increase in HR and contractility and stimulates contraction of
vascular smooth muscle in the arteries. The increase in HR, contractility, and
vasoconstriction causes BP to quickly increase in response to the drop in BP.
i) Why is it important to have baroreceptors in some of our arteries?
. They can sense a drop in BP. The sensitivity of baroreceptors is key to the maintenance of B
j) How does the sympathetic nervous system respond to low blood pressure?
1. Baroreceptors located in the arterial wall sense decreases in BP and stimulate the
SNS. The SNS stimulates the heart to increase rate and activates arterial
vasoconstriction. 2. The RAAS is activated when the kidneys sense low blood pressure.
The effect of the RAAS is increased blood volume and vasoconstriction. 3. The posterior
pituitary gland senses low perfusion and secretes ADH, which acts at the nephron to
increase water reabsorption; this raises blood volume and blood pressure.
k) Does the RAAS system serve to decrease or increase BP? Create a
diagram to explain including a description of the function of ACE.
When the BP or blood volume in the body is diminished, the kidney is sensitive to the
drop in BP. Renin is an enzyme that is released by the juxtaglomerular apparatus of the
nephrons in response to decreased perfusion. When circulation to the kidney is
diminished, renin is released into the
, Lesson 6: Cardiovascular System Page 2 of 5
Worksheet D236 Pathophysiology – Section 4
Lesson 6 Cardiovascular System
Learning Objectives
1. Describe pathogenesis of cardiovascular disorders and injury.
2. Describe the manifestations of cardiovascular disorders and injury.
3. Explain complications and variations of cardiovascular disorders and injury.
Learning Objective 1: Describe pathogenesis of cardiovascular disorders and injury.
Text 329-343
a) Complete the following table:
Layers of Structure Function
artery wall
Tunica The innermost It is a metabolically active tissue that releases
intima layer of the artery substances, reacts to chemical mediators, and
responds to blood contents. The endothelium is the
wall primary site of damage of arteriosclerosis and
atherosclerosis.
Tunica The middle layer The smooth muscle is innervated by autonomic
media of the artery wall. nerves, which are the sympathetic (also called
adrenergic) and parasympathetic (also called
It is composed of cholinergic) nerve fibers. There are alpha-adrenergic
, smooth muscle and beta-adrenergic nerves. Alpha- adrenergic nerve
that can constrict fibers are excitatory and cause vasoconstriction,
whereas beta-adrenergic fibers are inhibitory and
and dilate to cause vasodilation. The vascular smooth muscle
change the relies on extracellular calcium for depolarization.
artery’s diameter. Calcium enters membrane channels to evoke
contraction and vasoconstriction.
Tunica The outermost It is largely composed of connective tissue that
externa covering of the provides support for the artery.
artery wall; it is
also called the
tunica adventitia.
b)
b)Distinguish between laminar and turbulent blood flow.
-Laminar blood flow is smooth and parallel to horizontal lines of vessels.
-Turbulent blood flow is perpendicular to vessel walls and causes stagnant blood
flow
c) Explain cardiac output.
Cardiac output equals blood pressure divided by pulmonary vascular
resistance which then equals blood flow from the hearts left ventricle per
minute. SV*HR=CO.
Normal cardiac output is 5 L of blood per minute
d) Explain how BP is usually increased using the equation CO X PVR
= BP. PVR ^ BP & ^ CO= Baroreceptors – (RAAS) ADH and
Naturieses.
Lesson 6: Cardiovascular Page 1 of 5
System
, e) Explain how damaged arterial endothelium can lead to clot formation.
Turbulent blood flow can cause blood stasis, therefore promoting clot formation.
f) Using LaPlace’s Law, explain why there is a critical pressure where the
blood vessels collapse and can no longer maintain blood flow.
In hypertension (HTN), arterial vessel walls hypertrophy and become thicker,
thereby reducing the tension and minimizing the wall stress. Laplace’s law
can be applied to the pressure required to maintain the patency of small
blood vessels. When the thickness of the vessel wall remains constant, it
takes more pressure to overcome wall tension and keep the vessel open as
its radius decreases in size. There is a critical pressure where the vessels
collapse and blood can no longer flow through them.
Distention and Compliance
Compliance is the distention capacity of a blood vessel; distention capacity
allows for increased blood flow with each mm Hg rise in blood pressure. The
high distention capacity of the aorta and large arteries allows them to
accommodate the high output of the heart.
g) If a patient’s CO is 4600 mL/minute with a heart rate of 57, what is
their SV? 4600/57=80.7 ml
h)How does the body maintain BP when CO decreases?
As PVR increases, BP and CO increase. As PVR decreases, BP and CO decrease.
BP sensors known as baroreceptors. When baroreceptors detect a drop in BP,
they respond rapidly by stimulating the sympathetic nervous system (SNS). The
SNS stimulates an increase in HR and contractility and stimulates contraction of
vascular smooth muscle in the arteries. The increase in HR, contractility, and
vasoconstriction causes BP to quickly increase in response to the drop in BP.
i) Why is it important to have baroreceptors in some of our arteries?
. They can sense a drop in BP. The sensitivity of baroreceptors is key to the maintenance of B
j) How does the sympathetic nervous system respond to low blood pressure?
1. Baroreceptors located in the arterial wall sense decreases in BP and stimulate the
SNS. The SNS stimulates the heart to increase rate and activates arterial
vasoconstriction. 2. The RAAS is activated when the kidneys sense low blood pressure.
The effect of the RAAS is increased blood volume and vasoconstriction. 3. The posterior
pituitary gland senses low perfusion and secretes ADH, which acts at the nephron to
increase water reabsorption; this raises blood volume and blood pressure.
k) Does the RAAS system serve to decrease or increase BP? Create a
diagram to explain including a description of the function of ACE.
When the BP or blood volume in the body is diminished, the kidney is sensitive to the
drop in BP. Renin is an enzyme that is released by the juxtaglomerular apparatus of the
nephrons in response to decreased perfusion. When circulation to the kidney is
diminished, renin is released into the
, Lesson 6: Cardiovascular System Page 2 of 5
