Chapter 21 part 2 Flashcards Preview

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Flashcards in Chapter 21 part 2 Deck (73)
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1

Peripheral resistance (PR)

opposition to blood flow caused by friction of blood against the wall of the blood vessel

2

6 factors affecting blood pressure

1. vessel diameter
2. vessel length
3. viscosity
4. cardiac output
5. Blood volume
6. blood flow

3

vessel diameter
-changes mostly occur in ____
-2 types

-arterioles
-1. vasoconstriction
2. vasodilation

4

vasoconstriction
-definition
-effect on PR
-effect on BP

-diameter decreases
-increases
-increases

5

vasodilation
-definition
-effect on PR
-effect on BP

-diameter increases
-decreases
-decrease

6

Vessel length
-2 functions

1. growth
2. weight gain

7

vessel length increases
-effect on PR
-effect on BP

-increases
-increases

8

vessel length decreases
-effect on PR
-effect on BP

-decreases
-decreases

9

viscosity
-definition

thickness of the blood (hematocrit)

10

increase thickness of blood
-effect on PR
-effect on BP

-increases
-increases

11

decrease thickness of blood
-effect on PR
-effect on BP

-decreases
-decreases

12

increased cardio output
-formula
-effect of BP

-HR x SV
-increases

13

decreased cardio output
-formula
-effect on BP

-HR x SV
-decreases

14

increased blood vol.
-effect on SV
-effect on CO
-effect on BP

-increases
-increases
-increases

15

decreased blood vol
-effect on SV
-effect on CO
-effect on BP

-decreases
-decreases
-decreases

16

increased blood flow
-effect on BP

-increases

17

decreased blood flow
-effect on BP

-decreases

18

Autoregulation
-definition
-2 components

-LOCAL regulation within capillary bed of tissue in response to localized changes
-1. local vasoconstrictors
2. local vasodilators

19

what does the term "local" mean

happens at the tissue level

20

local vasoconstrictors
-2 examples
-released by what
-response to

-1. protaglandins
2. thromboxanes
-activated platelets and WBCs
-damage to vessels

21

local vasodilators
-5 functions

1. decrease tissue O2
2. increase tissue CO2
3. increase K+ or H+
4. Histamines
5. increase temp

22

central nervous system
-definition
-when is it brought in
-location
-2 centers

adjusts cardiac output and peripheral resistance to maintain blood flow
-when autoregulation cant keep up we bring this in
-medulla oblongata
-1. cardiac center
2. vasomotor center

23

cardiac center
-2 centers within this

1. cardioaccelatory center
2. cardioinhibitory center

24

cardioaccelatory center
-NS
-effect on CO

-sympathetic
-increases

25

cardioinhibitory center
-NS
-effect on CO

-parasympathetic
-decreases

26

vasomotor center
-contains what
-2 components

-contains 2 populations of neurons
-1. vasoconstriction
2. vasoconstriction

27

Vasoconstriction is vasomotor center
-releases what
-type of receptor
-effect on PR

-norepinephrine
-adrenergic
-increases

28

vasodilation is vasomotor center
-releases what
-type of receptor
-effect on PR

-epinephrine
-cholinergic
-decreases

29

Chemical and hormones regulating BP
-definition
-vasoconstrictors (3)
-vasodilators (2)

-enhances short term effects and directs long term changes
-norepinephrine, angiotensin, antidiuretic hormone
-nitric oxide (NO), atrial natriuretic peptide

30

regulation of blood pressure: baroreceptors (response to an increase in BP)
-location
-5 steps

-in the carotid sinus, wall of atrium and ascending aorta
1.homeostasis is disturbed = increase in BP
2. Reflex response: baroreceptors stimulated
3. Vasomotor center inhibited -> vasodilation -> decrease in BP
3. AND cardioinhibitory center stimulated and cardioaccelatory center inhibited
4. decrease CO
5. decrease BP
6. homeostasis restored