Ch.20 Blood Vessels 2

Question 0

Blood viscosity

Answer 0

Resistance to flow (thickness)

Ex: anemia- decreased viscosity-decreased resistance- increased blood flow

Question 1

Resistance

Answer 1

Amount of friction blood experiences traveling through vessels slowing it down affected by

• blood viscosity
• vessel length
• vessel radius

Question 2

Vessel length

Answer 2

Increase vessel length link
(example: weight gain)

Increased resistance
Decreased blood flow

Question 3

Vessel radius

Answer 3

Increased diameter

Decrease resistance

Increase total blood flow

Question 4

Blood pressure

Answer 4

Force per unit area of blood vessel wall (hydrostatic)

Question 5

Blood Pressure gradient

Answer 5

Highest in arteries and lowest in veins

Driving force in propelling blood through the vessels

Question 6

Arterial blood pressure

Answer 6

Pulsing b/c ventricles are contracting systolic P an relaxing diastolic P

Question 7

average blood pressure

Answer 7

120/80 mmHg

Question 8

Pulse pressure

Answer 8

Difference between systolic and diastolic blood pressure

(Ex: 180 come backkkk

Question 9

Pulse

Answer 9

Throbbing sensations associated with pulse pressure

Question 10

Capillary blood pressure

Answer 10

Pulse pressure and capillaries - 0
-low enough so that not to damage vessels behind
-high enough to ensure capillary exchange
-

Question 11

Mean arterial pressure (MAP)

Answer 11

Average of blood pressure forces on arteries

MAP= Diastolic pressure + 1/3 post pressure

Ex: ((80*2)+120)/3= 93

MAP<60 insufficient blood flow

Question 12

Capillary blood pressure at the arterial end is about…

Capillary blood pressure at the venous end is below…

Answer 12

…35mm Hg (filtration)

…16mm Hg (reabsorption)

Question 13

Venous blood pressure

Answer 13

• venous return
• 20mm Hg in venues =0 reaches right atrium
• small gradient may be insufficient to move blood when standing so moment is facilitated by valves & skeletal muscle & respiratory pumps

Question 14

Venous return

Answer 14

movement of blood back to the heart

Question 15

Skeletal muscle pump

Answer 15

Assists movement of blood within the limbs with each muscle contraction while valves help to prevent backflow

Prolonged inactivity leads to blood pooling in leg veins

Question 16

Respiratory pump

Answer 16

Assist movement of blood from abdominal >
thoracic cavity>
heart (due to action of the diaphragm)

Question 17

Short-term (neural) regulation of blood pressure

Answer 17

-occurs through autonomic resources
-monitors blood pressure & makes adjustments quickly by altering:
Cardiac output
Resistance (vessel diameter)

Question 18

Long term (hormonal) regulation of blood pressure

Answer 18

• Occurs through endocrine reflexes
• moniters blood pressure and makes adjustments slowly but altering:

Resistance (vessel diameter)
Blood volume (fluid intake or urine output)

Question 19

Cardiovascular center

Answer 19

Located in medulla

• cardiac center
• vasomotor center

Question 20

Cardiac center

Answer 20

Regulates heart activity

• cardioacceleratory (sympathetic) center
• cardioinhibitory center

Question 21

Vasomotor center

Answer 21

Controls the degree of vasoconstriction

• sympathetic pathways

Question 22

-cardioacceleratory (sympathetic) center

Answer 22

Increase heart rate and force

Increased cardiac output

Increased blood pressure

Question 23

cardioinhibitory (parasympathetic) center

Answer 23

Decreased heart rate

Decrease cardiac output

Decreased blood pressure

Question 24

Sympathetic pathways

Answer 24

Extend to various blood vessels Response will depend on the receptor type located on the vessel: - alpha receptors - beta receptors

Question 25

Alpha receptors

Answer 25

(In most vessels) Trigger vasoconstriction

Question 26

Beta receptors

Answer 26

Are present (in most vessels) (cardiac and skeletal muscles) trigger vasodilation

Question 27

Activation of vasomotor center leads to

Answer 27

A. Due to constriction of many vessels > increased blood pressure B. Increased circulating blood volume due to the shifting blood from venous reservoirs > increased blood pressure C. Redistribution of blood flow

Question 28

Cardiovascular center response is triggered by the information arriving from...

Answer 28

Baroreceptors & chemoreceptors

Question 29

Baroreceptors

Answer 29

Respond to the stretch in the vessel walls -aortic arch Carotid Sinus

Question 30

Aortic Arch

Answer 30

Monitor systematic blood pressure

Question 31

Carotid sinus

Answer 31

Monitor blood pressure in the head and the neck, more sensitive

Question 32

Chemoreceptors

Answer 32

(Carotid body & aortic bodies) Respond to: Increased CO2, Decreased pH Decreased O2

Question 33

Hypothalamus

Answer 33

Can increase cardiac output & resistance triggered by: - increased body temperature - fight or flight response

Question 34

Limbic system alters

Answer 34

Blood pressure in response to emotions