Blood vessels, pressure and regulation

Question 1

What determines systemic circulation?

Answer 1

Anatomy of the circulatory system
Hemodynamis of blood flow
Regulatory mechanisms

Question 2

What are the functions of peripheral circulation?

Answer 2

Carry blood 
Exchange nutrients, waste products, gases 
Transport important substances 
Regulate blood pressure 
Direct blood flow

Question 3

What lines the entire cardiovascular system?

Answer 3

Endothelium

Simple squamous epithelium

Question 4

What is laminar flow?

Answer 4

Streamlined flow when the interior of the blood vessel is smooth

Question 5

What is turbulent flow?

Answer 5

Interrupted flow caused by constriction, sharp turns, rough surfaces

Question 6

What is blood flow?

Answer 6

The volume that passes a specific point per unit time

Question 7

What determines flow rate?

Answer 7

The pressure differenced between two points

Question 8

What is resistance?

Answer 8

How difficult it is for blood to flow between two points at any given pressure difference

Question 9

What is poiseuille’s law?

Answer 9

Flow decreases when resistance increases and vice versa

Question 10

What is viscosity?

Answer 10

Measure of resistance of liquid to flow

Question 11

What is hematocrit?

Answer 11

Percentage of red blood cells per total blood volume

Question 12

Where does resistance of blood flow occur?

Answer 12

In the arterioles

Question 13

Where is pressure held constant?

Answer 13

Larger arteries

Question 14

What is compliance

Answer 14

How stretchy the vessel is

Question 15

Why does blood pressure increase with age?

Answer 15

Because of the decrease in compliance of the vessels

Question 16

What are the two ways to control vasoconstriction/dilation?

Answer 16

Local controls

Extrinsic or reflex controls

Question 17

What are the 4 local controls?

Answer 17

Active hyperemia
Flow autoregulation
Reactive hyperemia
Local response to injury

Question 18

What are the 3 extrinsic controls?

Answer 18

Sympathetic nerves
Noncholinergic/nonadrenergic autonomic nerves
hormones

Question 19

What is active hyperemia?

Answer 19

Increased blood flow to the tisssues due to increased metabolic rate

Question 20

What is flow autoregulation?

Answer 20

If arterial pressure is reduced in an organ, arteriolar dilation will return flow back to normal

Question 21

What is reactive hyperemia?

Answer 21

When blood flow is blocked to a tissue, there is a profound transient increase in its flow

Question 22

What is the local response to injury?

Answer 22

Secretions during inflammatory response result in vasodilation to increase blood flow to the damaged tissue

Question 23

What do alpha 1 receptors cause?

Answer 23

Vasoconstriction

Question 24

What does sympathetic nerve stimulation cause?

Answer 24

Vasoconstriction

Question 25

Do parasympathetic nerves influence arterioles?

Answer 25

No

Question 26

What do noncholinergic/nonadrenergic autonomic neurons release?

Answer 26

Nitric oxide

Question 27

What does nitric oxide cause?

Answer 27

Vasodilation

Question 28

Where are noncholinergic/nonadrenergic neurons found?

Answer 28

In the digestive organs

Question 29

What do beta 2 receptors cause?

Answer 29

Vasodilation

Question 30

What does epinephrine cause?

Answer 30

Vasodilation

Question 31

What does angiotensin II cause?

Answer 31

Vasoconstriction

Question 32

What does ADH cause?

Answer 32

Vasoconstriction

Question 33

What does atrial natriuretic peptide cause?

Answer 33

Vasodilation

Question 34

What does endothelin 1 cause?

Answer 34

Vasoconstriction

Question 35

When is endothelin 1 released?

Answer 35

In response to mechanical and chemical stress

Question 36

What mainly controls the blood flow to the heart?

Answer 36

Local metabolic factors

Question 37

What is critical closing pressure?

Answer 37

Pressure at which a blood vessel collapses and blood flow stops?

Question 38

What is laplace's law?

Answer 38

Force acting on blood vessel wall is proportional to diameter of the vessel times blood pressure

Question 39

What are the 4 short term regulation mechanisms?

Answer 39

Baroreceptor reflex Chemoreceptor reflex Central nervous system ishemic response Adrenal medullary mechanism

Question 40

What happens during the baroreceptor reflex?

Answer 40

Increases in blood pressure in the vicinity of the receptors will increase the number of action potentials from the receptors to the CNS and motor impulses will alter heart rate and BP

Question 41

What does stimulation of the vasomotor center cause?

Answer 41

Vasodilation of blood vessels

Question 42

What does stimulation of the cardio regulatry center cause

Answer 42

Increase in parasympathetic stimulation to the heart

Question 43

What is the bainbridge reflex?

Answer 43

Receptors in the right atrium get stimulated by increase in volume and causes an increase in heart rate

Question 44

What happens during the chemoreceptor reflex?

Answer 44

When oxygen levels drop, increase in action potential to vasomotor center occurs, causes vasoconstriction, increased BP, and reduced PCO2 and increased PO2

Question 45

What happens during the adrenal medullary mechanism?

Answer 45

Release of epi and norepi during sympathetic dominance in the body, causes increased HR, stroke volume, vasoconstriction, BP

Question 46

When does the CNS ischemic response happen?

Answer 46

In emergency situations when blood flow to the brain is severely restricted

Question 47

What happens during the CNS ischemic response?

Answer 47

Sympathetic stimulation, vasoconstriction and increased BP

Question 48

What are the 4 long term blood pressure regulation mechanisms?

Answer 48

Renin-angiotensins-Aldosterone mechanism Vasopressin mechanism Atrial natriuretic mechanism Fluid shift

Question 49

What causes the RAAS mechanism?

Answer 49

Reduction in blood pressure

Question 50

What is the result of the RAAS mechanism?

Answer 50

Increased blood pressure from vasoconstriction

Question 51

What stimulates the vasopressin mechanism?

Answer 51

Increase in plasma osmolarity or drop in BP

Question 52

What is the result of the vasopressin mechanism?

Answer 52

Vasoconstriction of arterioles Reabsorption of water Increased BP

Question 53

What stimulates the atrial natriuretic mechanism?

Answer 53

Increased venous return, stretching of atrial walls, and increased blood pressure

Question 54

What is the result of the atrial natriuretic mechanism?

Answer 54

Loss of sodium through kidneys Vasodilation Decreased BP

Question 55

When does the fluid shift mechanism occur?

Answer 55

In response to changes in pressure across capillary walls

Question 56

What is a continuous capillary?

Answer 56

No gaps betwen the endothelial cells making them less permeable to large molecules

Question 57

Where are continuous capillaries found?

Answer 57

Muscle and nervous tissue

Question 58

What are fenestrated capillaries?

Answer 58

Have pores in the endothelial cells making them highly permeable

Question 59

Where are fenestrated capillaries found?

Answer 59

Intestinal villi, ciliary processes of eye, choroid plexus, glomeruli of kidney

Question 60

What are sinusoidal capillaries?

Answer 60

Large diameter with large fenestrae and less basement membrane

Question 61

Where are sinusoidal capillaries found?

Answer 61

In endocrine glands

Question 62

What is the most important means of exchange in the capillaries?

Answer 62

Diffusion

Question 63

What 3 things affect movement of fluid from capillaries?

Answer 63

Blood pressure Capillary permeability Osmosis

Question 64

What is the net filtration pressure?

Answer 64

Force responsible for moving fluid across capillary walls

Question 65

What affects the net filtration pressure?

Answer 65

Hydrostatic pressue and osmotic pressure

Question 66

Hydrostatic pressure

Answer 66

Physical pressure of blood flowing through the vessels or of fluid in interstitial spaces

Question 67

Osmotic pressure

Answer 67

Movement of fluid through the plasma membrane in the presence of a non-diffusible solute

Question 68

Net filtration pressure equation

Answer 68

Net hydrostatic pressure minus net osmotic pressure

Question 69

What is the net hydrostatic pressure equation?

Answer 69

Blood pressure minus interstitial fluid pressure

Question 70

What is the net osmotic pressure equation?

Answer 70

Blood colloid osmotic pressure minus interstitial fluid colloid osmotic pressure

Question 71

Edema is from

Answer 71

Fluid moving from the capillaries into the interstital fluid

Question 72

What four things can cause edema?

Answer 72

Chemicals of inflammation Decrease in plasma concentration of protein Blockage of veins increases capillary blood pressure Blockage or removal of lymphatic vessels

Question 73

How does gravity effect blood pressure?

Answer 73

Increased below the heart and decreased above the heart