Lecture 25: Blood Pressure I and II

Question 1

Mean arterial blood pressure

Answer 1

• Force exerted by the blood against a vessel wall
• Result of push exerted by cardiac contraction (volume of blood contained within the vessel) and the compliance (dispensibility/elasticity of the vessel wall)

Question 2

Mean arterial blood pressure is responsible for

Answer 2

Driving blood forward into the tissues throughout the cardiac cycle

Question 3

Mean arterial blood pressure is regulated by

Answer 3

1. Baroreceptor reflex

2. Renin-angiotension-aldosterone system

Question 4

Aortic arch baroreceptor location and purpose

Answer 4

• Located in arch of aorta

- Relays information about blood pressure in the circulation to the cardiovascular center in the medulla oblongata

Question 5

Carotid sinus baroreceptiors

Answer 5

• Triggers reflexes to maintain blood flow to the brain

- Pressure sensors that relay info about bp to the cardiovascular centers in the medulla oblongata

Question 6

What is the most important mechanism for short term (within seconds) regulation of bp

Answer 6

Baroreceptor reflex

Question 7

Purpose of baroreceptor reflex

Answer 7

Adjusts cardiac output and total peripheral resistance to control bp

Question 8

Baroreceptor reflex arc

Answer 8

1. Receptor
2. Afferent pathway
3. Integrating center
4. Efferent pathway
5. Effector organs

Question 9

When does baroreceptor accommodation occur?

Answer 9

When a receptor becomes less sensitive to a sustained stimulus over time

Question 10

Accommodation of baroreceptors is a significant complicating factor in the treatment of

Answer 10

high blood pressure

Question 11

Renin-Angiotension Aldosterone System

Answer 11

Involves adjusting total blood volume through mechanisms that regulate urine output and thirst

Question 12

Where is ANP produced?

Answer 12

Atrial muscle cells

Question 13

ANP release is regulated by

Answer 13

Atrial stretching

Question 14

What hormone opposes Angiotensin II?

Answer 14

ANP

Question 15

Three ways ANP opposes angiotension II

Answer 15

1. Promotes the loss of Na and H2O at the kidneys
2. Inhibits the secretion of water - conserving hormones such as ADH and aldosterone
3. Suppresses thirst

Question 16

Secretion form the posterior pituitary is increased by two types of stimuli

Answer 16

1. Increase in serum osmolarity

2. Decrease in arterial bp

Question 17

Two types of chemoreceptors

Answer 17

1. Peripheral

2. Central

Question 18

Peripheral chemoreceptors are located where?

Answer 18

In the carotid bodies near the carotid sinus, aortic bodies near aortic arch

Question 19

Central chemoreceptors are located where?

Answer 19

Medulla oblongata

Question 20

An increase in blood CO2 and a decrease in pH and blood O2 leads to

Answer 20

An increased heart rate, contractility, and vasoconstriction

Question 21

Do chemoreceptors regulate the cardiovascular system during normal conditions?

Answer 21

Nope only in emergency situations

Question 22

Chemoreceptor stimulation normally affects the ___ ___ in the ___ _____

Answer 22

Respiratory center

Medulla oblongata

Question 23

Coordination of cardiovascular and respiratory activity is vital because

Answer 23

accelerating tissue blood flow is only useful if the circulating blood contains adequate O2