Exam 3: Lecture 11

Question 0

Describe long-term control of localized tissue regulation

Answer 0

Increases in sizes/numbers of vessels

Occurs over a period of days, weeks, or months

Question 1

Describe acute control of localized tissue regulation

Answer 1

Rapid changes in local vasodilation/constriction

Occurs in seconds to minutes

Question 2

What is vasomotion

Answer 2

Cyclical opening and closing of precapillary sphincters

Question 3

What is autoregulation

Answer 3

Tissues control how much blood they get/need
Blood flow returns to normal within minutes even with elevated pressure
Ranges from 75-175 mmHg

Question 4

What is the “Metabolic Theory of Autoregulation?”

Answer 4

Increase in blood flow->too much oxygen/nutrients->washes out vasodilators

Question 5

What is they “Myogenic Theory of Autoregulation?”

Answer 5

Stretching of vessels->reactive vasculature constriction

Question 6

What is the role of NO in vasodilation/vasoconstriction?

Answer 6

Damaged cells block production of NO which inhibits vasodilation, creating vasoconstriction

Question 7

What is humoral circulation control?

Answer 7

What’s in the blood that can control circulation

Question 8

What components of circulation control vasoconstriction?

Answer 8

Norepinephrine
Epinephrine
Angiotensin II
Vasopressin

Question 9

What components of circulation control vasodilation?

Answer 9

Bradykinins

Histamine

Question 10

T/F: The sympathetic nervous system innervates all vessels except capillaries which primarily results in vasodilation.

Answer 10

False, it primarily results in vasoconstriction

Question 11

What part of the brain is the “Vasoconstriction area of the brain?”

Answer 11

Anterolateral portions of upper medulla

Question 12

What are vasoconstrictor tones?

Answer 12

Continual firing of vasoconstriction area of brain

Question 13

What are vasomotor tones?

Answer 13

Partial state of contraction of blood vessels due to vasoconstriction area of brain

Question 14

Where in the brain is the “Vasodilation area of the brain?”

Answer 14

Bilateral in the anterolateral portions of lower medulla

Question 15

How does the vasodilation area of the brain function?

Answer 15

It causes vasodilation by inhibiting vasoconstriction at vasoconstriction are of brain in upper medulla

Question 16

What does the adrenal medulla secrete?

Answer 16

Epinephrine

Norepinephrine

Question 17

Neural rapid control of arterial pressure is simultaneously caused by…

Answer 17

Constriction of most systemic arteries (increases peripheral resistance)
Constriction of veins
Increased HR

Question 18

T/F: The simultaneous changes that control neural rapid arterial pressure all increase blood pressure.

Answer 18

True

Question 19

What do baroreceptors do?

Answer 19

Sense pressure changes
Stimulated by low arterial pressure
Carotid sinus stimulated by pressure <30 mmHg

Question 20

What are the 4 main functions of baroreceptors?

Answer 20

1) Inhibit vasoconstriction center
2) Excited vasodilator center
3) Cause either increase or decrease in arterial pressure
4) Reduce minute-by-minute variation in arterial pressure

Question 21

What is the effective range of baroreceptors?

Answer 21

~60-110 mmHg

Question 22

Describe chemoreceptors

Answer 22

Located in bifurcation of common carotids/aortic bodies
Sensitive to lack of O2, CO2, & H+ ion excess
Plays important role in respiratory control

Question 23

What are atrial reflexes?

Answer 23

Low pressure receptors located in atria and pulmonary arteries that play important role in minimizing arterial pressure changes in response to changes in blood volume

Question 24

An increase in atrial stretch reflex results in...

Answer 24

Reflex dilation of kidney afferent arterioles Increase in HR Signal hypothalamus to decrease ADH Atrial natriuretic peptide (ANP)->Kidneys->GFR or Na+ reabsorption

Question 25

What is the equation for atrial pressure?

Answer 25

Atrial pressure = Cardiac output x total peripheral resistance

Question 26

What are the 4 major causes of hypertension?

Answer 26

Renal causes Endocrine causes Cardiovascular causes Neurologic causes

Question 27

What is atherosclerosis?

Answer 27

Type of arterioslcerosis | Characterized by lesions within tunica intima that protrude into lumen

Question 28

What are non-modifiable risk factors associated with atherosclerosis?

Answer 28

Age Gender Genetics

Question 29

What are modifiable risk factors associated with atherosclerosis?

Answer 29

Hyperlipidemia (esp. hypercholesterolemia) Hypertension Cigarette smoking Diabetes

Question 30

Name 6 other factors contributing to atherosclerosis.

Answer 30

``` Inflammation Hyperhomocystinemia Metabolic syndrome Lipoprotein (a) Factors affecting hemostasis Life style ```

Question 31

What are the stages of atherosclerosis formation due to accumulation of lipoproteins?

Answer 31

1) Accumulation in intima & oxidized by O2 free radicals 2) Oxidized LDL ingested by macrophages which become foam cells 3) Oxidized LDL stimulate release of growth factors, cytokines, & chemokines 4) Oxidized LDL is toxic to endothelial & smooth muscle cells

Question 32

What are the stages of atherosclerosis formation due to monocyte adhesion to endothelium?

Answer 32

1) Monocytes & T-cells bind to endothelium via VCAM-1 2) Monocytes become macrophages and engulf lipoproteins 3) T-cells stimulate chronic inflammatory response 4) Activated leukocytes & endothelial cells release growth factors that promote smooth muscle cell proliferation

Question 33

What is a "mature atheroma?"

Answer 33

Cap of smooth muscle cells, macrophages, foam cells, & other extracellular components overlying a necrotic center composed of cell debris, cholesterol, foam cells, & Ca++

Question 34

What is the process of atherosclerosis development?

Answer 34

``` Earliest lesions are fatty streaks Plaques impinge on lumen of artery (appear white/yellow) Plaques progressively enlarge Plaques often undergo calcification Plaques may rupture, ulcerate, or erode ```

Question 35

What are the most common arterial sites for atherosclerosis?

Answer 35

``` Lower abdominal aorta Coronary arteries Popliteal arteries Internal carotid arteries Circle of Willis ```

Question 36

How is short-term arterial pressure controlled?

Answer 36

Via SNS on total peripheral vascular resistance and capacitance (cardiac pumping ability)

Question 37

How is long-term arterial pressure controlled?

Answer 37

Via multiple nervous & hormonal controls | Via local control in kidneys that regulate salt/water excretion

Question 38

What are the primary determinants of long-term arterial pressure level?

Answer 38

Degree of pressure shift of renal output curve for water/salt Level of water/salt intake

Question 39

Define chronic hypertension

Answer 39

One's mean arterial pressure is grater than upper range of accepted normal measure

Question 40

What is the normal measure of BP?

Answer 40

90 mmHg | Ranging from 70-110

Question 41

What is the hypertensive measure of BP?

Answer 41

110 mmHg | Ranging from 90-135

Question 42

What is considered severe hypertensive measure of BP?

Answer 42

150-170 mmHg | Ranging from 130-220

Question 43

What are 5 causes of lethal effects of chronic hypertension?

Answer 43

1) Early heart failure 2) Coronary heart disease 3) Heart attack 4) Cerebral infarct 5) Destruction of areas of kidneys

Question 44

List 5 characteristics of primary hypertension

Answer 44

1) Increased cardiac output 2) Increased SNS activity 3) Increase in angiotensin II & aldosterone levels 4) Impairment of renal-pressure natriuresis mechanism 5) Inadequate secretion of salt/water

Question 45

T/F: Primary hypertension accounts for 90-95% of hypertension and has no known origin.

Answer 45

True

Question 46

What is secondary hypertension?

Answer 46

Hypertension caused by something else | EX: Renal artery constriction, Preeclampsia, Neurogenic hypertension, Genetic causes