Circulation and Perfusion

Question 1

What is the cardiac cycle?

Answer 1

-contraction of the atria followed by contraction of the ventricles

Question 2

What is electrical conduction as it relates to the heart?

Answer 2

electrical activity that initiates contraction of the myocardium

Question 3

What is the sinoatrial (SA) node? Location?

Answer 3

• pacemaker

- right atrium

Question 4

What is the atrioventricular (AV) node?

Answer 4

electrical activity passes from AV node to bundles of HIS and purkinje fibers to ventricles

Question 5

Difference between arteries, arterioles, and capillaries?

Answer 5

arteries- thick elastic walls
arterioles- smaller and thinner than arteries, made of smooth muscle, controlled by sympathetic nervous system
capillaries- one cell thick, exchange gases, nutrients, and wastes between tissue and blood

Question 6

Purpose of veins and venules?

Answer 6

• thin, muscular, inelastic

- contract or relax in response to sympathetic nervous system (holding tank for changes in blood volume)

Question 7

What does hemoglobin do?

Answer 7

carries oxygen

Question 8

What are coronary arteries for?

Answer 8

• supply the heart with blood

- the coronary sinus fills with blood during diastole (only arteries in the body that fill during diastole)

Question 9

What are baroreceptors? Location?

Answer 9

• sensitive to pressure changes
• located in walls of heart and vessels (esp aortic arch and carotid artery)
• example- if they sense a drop in pressure, they send a message to stimulate the sympathetic nervous system to increase heart rate and vasoconstriction

Question 10

What are chemoreceptors? Location?

Answer 10

• sensitive to changes in pH, o2 levels, co2 levels

- located in aortic arch and carotid arteries

Question 11

What is the vasomotor center for?

Answer 11

controls sympathetic stimulation of the heart and vascular system

Question 12

What is the cardioinhibitory center for?

Answer 12

controls parasympathetic slowing of the heart rate

Question 13

How does developmental stage affect cardiac function?

Answer 13

Adults: lifestyle (tobacco), stress, hereditary, diet, exercise, obesity
Older adults: thicker and more rigid valves, decreased heart strength, lower exercise tolerance

Question 14

How does stress affect the heart?

Answer 14

• stimulates release of catecholamines from sympathetic nervous system
• results in increase in heart rate, vasoconstriction, blood clotting

Question 15

How do allergens affect the heart?

Answer 15

histamine and protease cause -blood vessels to dilate

• local tissue damage from protease
• fluid leaking into tissues from increased capillary permeability

Question 16

How does altitude affect the heart?

Answer 16

• increased RBC production
• increased vascularity of tissues
• increased ability of tissue to use oxygen

Question 17

How do heat and cold affect the heart?

Answer 17

Heat:
-vasodilation
-increased metabolism
Cold
-vasoconstriction
-decreased metabolism
-less o2 demand
-decreased heart rate

Question 18

How does lifestyle affect the heart?

Answer 18

Pregnancy:

• high o2 demand
• increased blood volume
• need for additional iron to make blood

Nutrition:

• high saturated fat diets causes athersclerosis, coronary artery disease, hypertension
• low-fat, low-sodium, low-cholesterol diets are heart healthy

Obesity:

• excess fat around heart decreases the effectiveness of the heart as a pump
• workload of the heart is more, because more tissue

Exercise:

• improves perfusion
• increases metabolic demand
• increased heart rate
• heart is strengthened

Tobacco:
-risk for stroke, peripheral arterial disease, aortic aneurysm, heart disease, atherosclerosis, hypertension, decreased HDL

Substance abuse:

• depress respiratory, cardiac, and vasomotor centers
• alcohol use causes fat in heart, thrombi in arteries, heart enlargement, dysrhythmias

Question 19

What are beta-adrenergic blocking agents used for?

Answer 19

• reduce workload of the heart
• reduce dysrhythmias
• control hypertension

Question 20

What are calcium channel blocking agents?

Answer 20

• block flow of calcium into cells of heart and vessels
• decrease blood pressure
• decrease strength of contractions
• slow heart rate
• dilate arteries

Question 21

What are signs of peripheral arterial abnormalities?

Answer 21

• pallor
• pain
• weak/absent pulse
• poor capillary refill
• cool skin
• tissue dysfunction

Question 22

What are signs of peripheral venous abnormalities?

Answer 22

• edema
• brown skin discoloration
• stasis ulcers

Question 23

What are oxygen transport abnormalities?

Answer 23

Anemia- low levels of RBCs, hemoglobin or both

Carbon monoxide- binds to hemoglobin making o2 transport impossible

Question 24

What to assess for during a physical exam of the heart?

Answer 24

Pain: location, duration, frequency, radiation
Fatigue: pts subjective experience, level 1-10
Dyspnea: hypoxia, anxiety
Peripheral circulation: pulses, color and temp of skin, hair on extremities, edema, ulcers

Question 25

How to test blood oxygenation?

Answer 25

• pulse oximetry
• capnography
• ABGs (arterial blood gases)

Question 26

What is an ECG?

Answer 26

Electrocardiogram

-rendering of electrical activity of the heart, NOT mechanical (what the heart actually does)

Question 27

What are some nursing diagnosis’ for the cardiovascular system?

Answer 27

• decreased cardia output
• risk for decreased cardiac tissue perfusion
• ineffective tissue perfusion
• risk for shock

Question 28

What is a thrombus?

Answer 28

stationary clot adhered to the vessel

Question 29

What is a embolus?

Answer 29

clot that travels the bloodstream

Question 30

What are the signs of cardiac arrest?

Answer 30

• pale/grey, cool skin
• absence of carotid pulse
• apnea
• pupil dilation