Lecture 26: Disease States - Diarrhea, Dehydration, and Heart Failure

Question 0

diarrhea

Answer 0

loss of electrolytes AND water

Question 1

hypovolemia

Answer 1

decreased blood volume

Question 2

diarrhea clinical signs

Answer 2

increased hematocrit, cold extremities (due to cutaneous vasoconstriction), reduced activity

Question 3

diarrhea causes decreased:

Answer 3

plasma volume, venous pressure, atrial pressure, venous return, ventricular end-diastolic volume, stroke volume, cardiac output, arterial pressure

Question 4

Angiotensin II triggers:

Answer 4

blood volume restoration

Question 5

arterial baroreceptor withdrawal in diarrhea triggers:

Answer 5

increase in sympathetic drive to non-essential beds

Question 6

dehydration

Answer 6

extreme loss of water with minimal loss of electrolytes

Question 7

results of dehydration

Answer 7

1) decreased plasma volume
2) renal vasoconstriction
3) decreased Na+ and H2O excretion, increased reabsorption
4) increased plasma osmolarity due to water loss

Question 8

increased plasma osmolarity –> vasopressin release?

Answer 8

increases

Question 9

2 main classes of heart failure:

Answer 9

1) systolic dysfunction

2) diastolic dysfunction

Question 10

systolic dysfunction

Answer 10

type of heart failure in which there is a problem with ventricular ejection

Question 11

diastolic dysfunction

Answer 11

type of heart failure in which there is a problem with ventricular filling

Question 12

most common cause of heart failure

Answer 12

impaired LV function

Question 13

decreased stroke volume –> sympathetic drive

Answer 13

increases (to help restore cardiac output)

Question 14

increased sympathetic drive –> water and Na retention

Answer 14

increases

Question 15

increased fluid retention –> venous return

Answer 15

increases

Question 16

increased fluid retention –> end-diastolic ventricular volume

Answer 16

increases

Question 17

CHF is often characterized by increased edema resulting from increased capillary hydrostatic pressure

Answer 17

.

Question 18

Causes of Left Heart Failure

Answer 18

systolic or diastolic dysfunction

Question 19

Causes of Right heart failure

Answer 19

increases in afterload: left-sided heart failure, increased pulmonary pressure

Question 20

Frank-Starling Compensatory Mechanism for heart failure

Answer 20

length-tension relationship. More stretch triggers a more forceful contraction.

Question 21

Ventricular hypertrophy compensatory mech. for heart failure

Answer 21

increase in cardiac mass to compensate for increased stress. Increases contractile force and reduces wall stress (however decreases compliance and increases diastolic ventricular pressures)

Question 22

Neurohumoral activation (compensatory mech. for heart failure)

Answer 22

Sympathoexcitation in response to decreased cardiac output. Elevates RAAS, vasopressin, intravascular volume, preload

Question 23

elevated vascular resistance –> CO

Answer 23

decreases

Question 24

CHF –> atrial pressure

Answer 24

increases

Question 25

inotropic drugs

Answer 25

increase ventricular contractility via increasing cytosolic calcium

Question 26

diuretic

Answer 26

decreases intravascular volume and fluid accumulation

Question 27

vasodilator drug

Answer 27

reduces total peripheral resistance and afterload