Flashcards in Chapter 21 part 2 Deck (73)
Loading flashcards...
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