10 - Hemodynamics Flashcards
4 functions of microcirculation
- Delivery of oxygen and nutrients
- Distribution of salt and water over blood and extracellular fluid volume
- Removal of Co2 and other waste products
- Create a barrier between blood and tissues
Which organ gets the most blood flow?
The liver
Artery:
Mean diameter
Mean wall thickness
Thickest layer of wall
Artery:
Mean diameter - 4.0mm
Mean wall thickness - 1mm
Thickest layer of wall - Smooth muscle → elastic tissue → fibrous tissue → endothelium
Arteriole:
Mean diameter
Mean wall thickness
Thickest layer of wall
Arteriole:
Mean diameter - 30.0um
Mean wall thickness - 60.um
Thickest layer of wall - Smooth muscle → endothelium
no elastic tissue or fibrous tissue
Arteriole:
Mean diameter
Mean wall thickness
Thickest layer of wall
Arteriole:
Mean diameter - 30.0um
Mean wall thickness - 60.um
Thickest layer of wall - Smooth muscle → endothelium
no elastic tissue or fibrous tissue
capillary:
Mean diameter
Mean wall thickness
Thickest layer of wall
capillary:
Mean diameter - 8.0um
Mean wall thickness - 0.5um
Thickest layer of wall - Only has endothelium
How is the diameter of the capillary related to the size of red blood cells? Monocytes?
The mean diameter of a capillary is 8.0um
RBC are typically 6-8um
Monocytes are 12-20um
Venule:
Mean diameter
Mean wall thickness
Thickest layer of wall
Venule:
Mean diameter - 20.0um
Mean wall thickness - 1.0um
Thickest layer of wall - Fibrous tissue → endothelium (wall has only endothelium and fibrous tissue - no elastic tissue or smooth muscle)
Vein:
Mean diameter
Mean wall thickness
Thickest layer of wall
Vein:
Mean diameter - 5.0mm
Mean wall thickness - 0.5mm
Thickest layer of wall - smooth muscle → elastic tissue → fibrous tissue → endothelium
Velocity of blood flow depends on ________
Velocity of blood flow depends on the total cross-sectional area
What regulates how much blood flows into the capillary bed?
Response to metabolic needs
Precapillary sphincters
Local and CNS regulators
What is myogenic response? What does it cause?
Myogenic response is the intrinsic capacity of the vasculature to respond to an increase in hoop stress with vasoconstriction
Causes autoregulation of blood flow
The hoop stress, or tangential stress, is the stress around the circumference of the pipe due to a pressure gradient
Which breakdown product of ATP can modulate vascular tone?
Adenosine
- links hypoxia (low oxygen in blood) to vasodilation
What are two vasoconstrictors?
Adrenergic system
Angiotensin II
What is an example of a vasodilator?
Nitric oxide
What are 6 chemical vasoconstrictors?
- Norepinephrine (alpha receptor)
- Serotonin
- Substance P
- Endothelin
- Vasopressin
- Angiotensin II
Name the physiological role of each of the following vasoconstrictors
- Norepinephrine (alpha receptor)
- Serotonin
- Substance P
- Endothelin
- Vasopressin
- Angiotensin II
Name the physiological role of each of the following vasoconstrictors
- Norepinephrine (alpha receptor)
- Baroreceptor reflex
- Serotonin
- platelet aggregation
- sm mm contraction
- Substance P
- pain
- increase capillary permeability
- Endothelin
- paracrine mediator
- Vasopressin
- Increase blood pressure in hemorrhage
- Angiotensin II
- increase blood pressure
Name the source for each of the following vasoconstrictors:
- Norepinephrine (alpha receptor)
- Serotonin
- Substance P
- Endothelin
- Vasopressin
- Angiotensin II
Name the source for each of the following vasoconstrictors:
- Norepinephrine (alpha receptor)
- sympathetic neurons
- Serotonin
- Neurons
- GIT
- platelets
- Substance P
- Neurons
- GIT
- Endothelin
- Vascular endothelium
- Vasopressin
- Posterior Pituitary
- Angiotensin II
- plasma hormone
What type of chemical is each of the following vasoconstrictors?
- Norepinephrine (alpha receptor)
- Serotonin
- Substance P
- Endothelin
- Vasopressin
- Angiotensin II
- Norepinephrine (alpha receptor)
- neurotransmitter
- Serotonin
- paracrine
- neurotransmitter
- Substance P
- paracrine
- neurotransmitter
- Endothelin
- paracrine
- Vasopressin
- neurohormone
- Angiotensin II
- hormone
What are 9 vasodilators?
- Nitric oxide (NO)
- Bradykinin (via NO)
- Adenosine
- ⤓O2 ; ⤒CO2 ; ⤒H+ ; ⤒K+
- Histamine
- Epinephrine (beta2 receptors)
- Acetylcholine (via NO)
- Natriuretic peptides (example - ANP)
- Vasoactive intestinal peptide (VIP)
What is the physiological role of the following vasodilators:
- Nitric oxide (NO)
- Bradykinin (via NO)
- Adenosine
- ⤓O2 ; ⤒CO2 ; ⤒H+ ; ⤒K+
- Histamine
- Epinephrine (beta2 receptors)
- Acetylcholine (via NO)
- Natriuretic peptides (example - ANP)
- VIP
What is the physiological role of the following vasodilators:
- Nitric oxide (NO)
- paracrine mediator
- Bradykinin (via NO)
- increase blood flow
- Adenosine
- increase blood flow to match metabolism
- ⤓O2 ; ⤒CO2 ; ⤒H+ ; ⤒K+
- increase blood flow to match metabolism
- Histamine
- increase blood flow
- Epinephrine (beta2 receptors)
- increase blood flow to skeletal muscle, heart, liver
- Acetylcholine (via NO)
- erection of clitoris or penis
- Natriuretic peptides (example - ANP)
- reduce blood pressure
- Vasoactive intestinal peptide
- digestive secretion
- relax smooth muscle
Source of the following vasodilators
- Nitric oxide (NO)
- Bradykinin (via NO)
- Adenosine
- ⤓O2 ; ⤒CO2 ; ⤒H+ ; ⤒K+
- Histamine
- Epinephrine (beta2 receptors)
- Acetylcholine (via NO)
- Natriuretic peptides (example - ANP)
- VIP
Source of the following vasodilators
- Nitric oxide (NO)
- Endothelium
- Bradykinin (via NO)
- multiple tissues
- Adenosine
- Hypoxic cells
- ⤓O2 ; ⤒CO2 ; ⤒H+ ; ⤒K+
- Cell metabolism
- Histamine
- Mast cells
- Epinephrine (beta2 receptors)
- Adrenal medulla
- Acetylcholine (via NO)
- Parasympathetic neurons
- Natriuretic peptides (example - ANP)
- Atrial myocardium
- Brain
- Vasoactive Intestinal Peptide (VIP)
- Neurons
Type of chemical each of the following vasodilators:
- Nitric oxide (NO)
- Bradykinin (via NO)
- Adenosine
- ⤓O2 ; ⤒CO2 ; ⤒H+ ; ⤒K+
- Histamine
- Epinephrine (beta2 receptors)
- Acetylcholine (via NO)
- Natriuretic peptides (example - ANP)
- VIP
- Nitric oxide (NO)
- paracrine
- Bradykinin (via NO)
- paracrine
- Adenosine
- Neurohormone
- ⤓O2 ; ⤒CO2 ; ⤒H+ ; ⤒K+
- Paracrine
- Histamine
- Paracrine
- Epinephrine (beta2 receptors)
- neurohormone
- Acetylcholine (via NO)
- neurotransmitter
- Natriuretic peptides (example - ANP)
- hormone, neurotransmitter
- VIP
- neurotransmitter;
- neurohormone
What conversion inhibits platelet aggregation
Conversion of GTP to cGMP by Soluble guanylate cyclase