Lecture 2/11 - Cardiac Flashcards
Test 2
What is the main pressor in the CVS that is released in the blood?
NE
What is the Epi:NE ratio?
4:1
NE/Epi are released by ________ and put in circulation by the _______
nerves
adrenal gland
What are our pressure sensors (baroreceptors)? Where are they located?
Carotid baroreceptors: bifurcation of the carotid arterty (carotid sinus)
Aortic baroreceptors: aortic arch
The carotid baroreceptors are in the ______ and attached to the _______ via the __________ nerve
neck
brain stem
Glossopharyngeal
What are our protected circulatory beds? (2)
Coronary circulation
Central nervous system
(honorary mention: kidney –> will divert blood from here to protect other 2)
What is the main system we can shunt blood from?
GI
What are things that increase CO?
- Increase HR
- Vasopressin (modulated by osmolarity; increases SVR more than NE/Epi)
- Aldosterone (Activation of RAAS; part of SNS)
Where are stretch receptors reflexes located?
Large veins leading up to atria & in the atria
How does atria stretch/pressure reflex affect the kidneys?
Receptors detected increased volume in atria dt increased stretch/pressure in viens or atria –> Decreased SNS tone –> increased UO –> decreased blood volume
What does the atria stretch/pressure reflex help with?
- prevent overstretching in acute compensation state
- Prevent coagulapathies dt decreased circulatory rate (volume overload that heart cant keep up with)
The increase in output from the kidney involving stretch/pressure in the atria is via __________
Direct neural signal
What is ANF and ANP?
ANF: atrial natriuretic factor
ANP: atrial natriuretic peptide
These are both the same hormone
ANF/ANP is formed in the _______ atria. What causes this?
Right
(can be formed in the left as well, but mostly right)
When the atria is overstretched –> ANF/ANP released
What does ANP/ANF do?
Get rid of sodium –> increases urine output
What does BNP stand for?
Brain naturetic peptide
BNP is formed in the _____. What causes this?
Ventricles stretched out = increase release in BNP
What is BNP used for? What does its numbers indicate?
Used to gauge heart failure treatment
Decrease BNP = getting better (less strain on ventricle)
Increase = more strain
Plasma is _______ of ECF
1/4 to 1/5
ISF is ________ of ECF
3/4 to 4/5
What is the oncotic colloid pressure in the blood?
28 mmhg
What are the colloids that make up the pressure in the blood?
Albumin
Fibrinogen
Immunoglobulins
Hematocrit is _____
0.4
Where does fluid normally shift from during blood loss to the cardiovascular system?
ISF
What do we need to do as treatment during hemorrhage?
Best treatment: replace what is lost
How much NS stays in the CVS when given? Where does the rest go?
1/4 to 1/5
The rest goes to ISF
What are two molecules that we should use in place of blood products or albumin if we need to give colloids? What are these?
Dextran
Hetastartch
Large sugar molecules that produce plasma oncotic/colloid pressure
These are considered synthetic colloids –> they stay in the CVS
What is the stretch-relaxation response? What is its MOA?
Property of the large veins to temporarily increase BP –> then DECREASE BP when given IV fluids quickly
Smooth muscle in the large veins become too tight/distended (BP increases) –> smooth muscle senses this –> smooth muscle relaxes in response to this (BP decreases)
With the stretch-relaxation reflex, _____% of the IV fluids stay in the CVS system
20-25%
What is the reverse stretch relaxation response? What is its MOA?
if hemorrhage –> ANS makes the smooth muscles in the veins CONSTRICT/TIGHTEN
What is the strongest reflex response?
CNS ischemic response
What causes the CNS ischemic response. What are the responses to try to help?
low brain/brain stem perfusion for a few minutes from very low BP
Maximal level of these responses to try to increase BP:
SNS reflexes
NE/Epi
SVR
Contractility
HR
Vasopressin
RAAS/aldosterone
ANF/ANP reduction
What is shock?
Tissue dysfunction to all parts of the body that need nutrients that aren’t currently being delivered
What is a problem that we see would cell necrosis dt shock?
-Hyperkalemia (cell explodes –> intracellular K released)
-Acidosis
What organ goes bad the earliest with shock?
Liver
What are ways to measure cardiac output?
PA catheter
Flow track
Fick’s equation
What is Fick’s equation?
CO (L/min) = (lungs O2 consumption per minute (mL O₂/min)) / (Arterial oxygen content - Venous oxygen content (mL O₂/L blood))
Ex) 250 ml O2/min / (200 ml O2/min - 150 ml O2/min) –> 5L/min
1 dL = ___ L
.1 L
1 dL = ___ ml
10 mL
Normal arterial blood oxygen value:
20 ml O2/dL
200 ml O2/L <– use this number
Normal venous blood oxygen value:
15 ml O2/dL
150 ml O2/L <– use this number
Normal oxygen consumption in lungs value:
250 ml O2/min
What is Digoxin? What do we need to know about it for this lecture for the test?
Na/K ATP inhibitor
Cardiac glycocide/digitalis
Helps: assist diuretics –> decrease blood volume
Used when the body’s compensation still wont allow heart to meet CO demands
-Last effort drug
-Used even for a few days used to let heart heal
What pathologies do you not have any cardiac reserve?
Severe coronary thrombosis
Severe valvular disease
What is cardiac reserve?
Amount of CO you can get above normal
You have a max cardiac reserve of ______% in a healthy adult. The CO is ____.
400%
25L
(Take normal CO of 5 –> multiple that by 400% –> add that to the original 5)
some can reach 30 L or 500%
You have a max cardiac reserve of ______% in an athlete. The CO is ____. Why?
600%
40L
(Take normal CO of 5 –> multiple that by 600% –> add that to the original 5)
Reason: body building/training
What pathologies have reduced cardiac reserve from normal?
Old age
Mild valvular disease
Diphtheria
Moderate coronary disease
——————-
No cardiac reserve:
Severe coronary thrombosis
Severe valvular disease
T/F: Old age can decrease cardiac reserve
T
What is the most common valve disease?
Aortic stenosis
_____% of people have congenital bicupid valves
1-2%
What valve already has 2 cusps?
Mitral valve
What valve generally has congenital bicupid valves?
Aortic
