CV 4

Question 1

— is the driving force for blood flow to all organs.

Answer 1

MAP

Question 2

MAP = (3)

Answer 2

CO x TPR

MAP = (HR x SV) x TPR
MAP = (HR x (EDV-ESV)) x TPR

Question 3

Factors that influence MAP (3)

Answer 3

1. Flow In (CO) and Out (TPR) of Systemic Arteries
2. MAP α Total Blood Volume
3. Distribution of blood between arteries and veins

Question 4

Flow of blood through the blood vessels

can be thought of as the flow of a

Answer 4

fluid

through a tube.

Question 5

Flow in > Flow out;

Answer 5

Hydrostatic pressure in tube will increase due to

fluid accumulation.

Question 6

Flow in < Flow out;

Answer 6

Hydrostatic pressure in tube will decrease due to

fluid depletion.

Question 7

Systemic Circulation function can be thought of as the function
of — different tubes connected in series

Answer 7

three

Question 8

Venous System
Function: (2)
Regulation: (1)

Answer 8

PVP
VR

Systemic

Question 9

Arterial System
Function: (1)
Regulation: (1)
MAP =

Answer 9

Keep MAP constant
Systemic
CO x TPR

Question 10

Capillary System
Function: (2)
Control: (1)
Ftissue = 
Due to myogenic autoregulation, changes in the Rtissue used to regulate (2)

Answer 10

Deliver O2 and nutrients, Pick up CO2 and other metabolic waste
Local (Active Hyperemia)
MAP/Rtissue arteriole
Pc and flow

Question 11

Baroreceptor Reflex (4)

Answer 11

Short term response 
(minutes to hours) 
NS mediated 
homeostatic process
Alters CO and TPR to 
restore MAP to 
homeostatic levels
Override Local Control of 
blood flow

Question 12

Baroreceptor Reflex
Stimulus = 
Reflex Receptor =
Afferent Pathway = 
Integrating Center = 
Efferent Pathway = 
Effectors =  
Effector Response =  
Feedback Regulation =

Answer 12

Stimulus = ΔMAP
Reflex Receptor = Baroreceptors (Aortic Arch and Carotid Arteries)
Afferent Pathway = Visceral Sensory Neurons
Integrating Center = Medullary CV control centers in Medulla Oblongata (Brainstem)
Efferent Pathway = Autonomic Motor Neurons
Effectors = Cardiac Muscle (AR and Contractile cells), Arteriolar Smooth Muscle, Venous Smooth Muscle
Effector Response = Change rate and force of contraction (CO), Change arteriolar resistance (TPR), Change venous tone (VR>EDV >CO)
Feedback Regulation = Negative

Question 13

Other Baroreceptors

Answer 13

Large systemic veins, the pulmonary vessels, and the walls of
the heart also contain baroreceptors.

Question 14

Baroreceptor Function (3)

Answer 14

Immediate changes to restore MAP to homeostatic level
Allows time for other mechanisms to occur to eliminate
disturbance (ex. Total Blood Volume)
Adapt overtime (decrease rate of firing with prolonged increased MAP)

Question 15

Patients with chronically elevated MAP have baroreceptor

reflexes that function around a

Answer 15

higher than normal setpoint

Question 16

MAP affected by other stimuli and reflexes aside from baroreceptor reflex.
Changes triggered by signals from

Answer 16

other receptors or higher brain centers that activate Medullary CV control center or autonomic neurons directly

Question 17

Stimuli that increase MAP (8)

Answer 17

 decrease Arterial [O2]
 increase Arterial [CO2]
 decrease Brain Blood Flow
Pain Originating in skin
Stress
Anger
Eating
Sexual Activity

Question 18

Stimuli that decrease MAP (3)

Answer 18

Pain Originating in Viscera or joints
Sleep
Happy Mood

Question 19

Hypotension

Answer 19

Low blood pressure

Question 20

Hypotension causes (4)

Answer 20

1. Hemorrhage
2. Shock
3. Orthostatic
4. Other causes

Question 21

Hemorrhage Compensatory Mechanisms
Rapid (12-24 hours) (2)
Long Term (days to Weeks) (2)

Answer 21

1. Baroreceptor Reflex
2. Autotransfusion
3. Endocrine System
4. Behavior

Question 22

1. Baroreceptor Reflex (2)

Answer 22

Returns MAP toward normal

Increasing CO and TPR

Question 23

2. Autotransfusion (3)

Answer 23

Movement of interstitial fluid into capillaries
Arteriolar constriction > decreases PC
Net absorption of fluid into capillaries

Question 24

3. Endocrine System (2)

Answer 24

ANGII, Aldosterone, ADH - Restore volume and osmolarity

Erythropoietin – Restore Hematocrit

Question 25

4. Behavior (1)

Answer 25

Thirst and consumption of H2O

Question 26

Shock

Answer 26

This is a condition in which there is inadequate blood flow to meet tissue needs.

Question 27

Three types of shock

Answer 27

1. Hypovolemic shock 2. Vascular shock 3. Cardiogenic shock

Question 28

1. Hypovolemic shock (2) results from followed by (4)

Answer 28

‒ It results from a large loss of blood, so there is a drop in blood volume. ‒ This usually follows hemorrhage, severe vomiting, severe diarrhea, and extensive burns.

Question 29

2. Vascular shock (6)

Answer 29

‒ Blood volume is normal, but circulation is poor due to abnormal expansion of the vascular bed caused by extreme vasodilation. ‒ Huge drop in TPR leads to a drop in MAP ‒ The most common causes: • loss of vasomotor tone associated with anaphylaxis (allergic reaction; anaphylactic shock) • a loss of nervous system regulation (neurogenic shock) • septicemia (septic shock; a bacterial infection).

Question 30

3. Cardiogenic shock (2)

Answer 30

‒ This is pump failure. The heart can not sustain adequate circulation. ‒ This is usually the result of myocardial damage following a severe MI or multiple MIs.

Question 31

Orthostatic Hypotension

Answer 31

Drop in MAP upon standing

Question 32

The effects of gravity cause a

Answer 32

``` decrease VR decrease EDV decrease SV decrease CO decrease MAP ```

Question 33

Hypertension

Answer 33

Chronically elevated MAP

Question 34

why is hypertension a silent killer?

Answer 34

because most people don’t know that they | have it until it has caused significant damage.

Question 35

Prolonged hypertension is the major cause of (4)

Answer 35

heart failure, renal failure, stroke, and vascular disease.

Question 36

Two major forms of hypertension

Answer 36

1. Primary (Essential) Hypertension | 2. Secondary Hypertension

Question 37

1. Primary (Essential) Hypertension (2)

Answer 37

90% of Hypertension Patients | Idiopathic

Question 38

2. Secondary Hypertension (3)

Answer 38

10 % of Hypertensive Patients Secondary to a disease state Treat disease state and MAP returns to normal

Question 39

Factors that are involved in the development of primary hypertension include: (8)

Answer 39

``` –Diet: high Na+, high cholesterol etc. –Diabetes mellitus –Obesity –Age (clinical signs appear ~40) –Gender (males get it more than females until menopause) –Genetics (runs in families, black more prevalent [salt sensitive forms] than whites) –Stress –Smoking ```

Question 40

can we cure Primary (Essential) Hypertension?

Answer 40

no We can manage it with diet, exercise, life-style changes, and medication.

Question 41

Diseases associated with secondary hypertension (6)

Answer 41

Tumor of the adrenal medulla (excess Epinephrine) Cushing’s disease (Glucocorticoid excess) Atherosclerosis of the renal arteries (RAS) Renal Hypertension (Kidney disease) (RAS) Arteriosclerosis Hyperthyroidism (TH excess)

Question 42

hypertrophic remodeling (5)

Answer 42

Large vessels that do not constrict in response to increased MAP Size of VSM cells increase Increase in EC matrix proteins to support wall increase total cross sectional area of vessel Makes large vessels stiffer (less compliant)

Question 43

inward eutrophic remodeling (3)

Answer 43

Small vessels that constrict in response to increased Map VSM growth around narrowed lumen (decrease r; increase R) No change in total cross sectional area of vessel

Question 44

1. Laminar Flow | When vessels are: (3)

Answer 44

straight endothelium is healthy smaller vessels

Question 45

With laminar flow, the velocity of flow is always greater in the

Answer 45

center of the vessel compared to the outside.

Question 46

Laminar Flow | --- profile of flow

Answer 46

Parabolic

Question 47

Shear:

Answer 47

When adjacent layers of blood move at different | velocities—can break up RBC aggregates

Question 48

Reynold’s Number (Re) is the calculation of the

Answer 48

tendency for turbulent flow If Re is greater than 2000, flow is most likely turbulent. Greater than 3000, always turbulent.

Question 49

Re =

Answer 49

(V d ρ)/ η Velocity of blood flow (V) Diameter of vessel (d) Density of blood (ρ) Viscosity of blood (η)—hematocrit

Question 50

Turbulent flow: | increases (3)

Answer 50

Increases friction and the energy required to drive flow Increases the risk of endothelial injury & plaque development Increases the possibility of thrombotic events

Question 51

Turbulent Blood Flow | in large vessels like (2)

Answer 51

Aorta and Pulmonary Artery

Question 52

Smaller vessels | (Arterioles) rarely have

Answer 52

turbulent flow

Question 53

Viscosity-

Answer 53

thickness or thinness of a fluid

Question 54

Density –

Answer 54

measures spaces between 2 particles in a solution

Question 55

Heart Failure (CHF)

Answer 55

Heart fails to pump adequate CO

Question 56

Two Types of CHF

Answer 56

1. Diastolic Dysfunction 2. Systolic Dysfunction *Many patients have elements of both

Question 57

1. Diastolic Dysfunction (4)

Answer 57

Ventricles have reduced compliance (wall stiffens) Creates problems with ventricular filling Reduced EDV Most common cause = Hypertension (ventricular hypertrophy)

Question 58

2. Systolic Dysfunction (3)

Answer 58

Ventricle has reduced contractility Decreased SV at any given EDV Most common cause = myocardial damage as result of myocardial infarct