Powerpoint Notes Flashcards
The primitive atrium develops into the
Rough walled portion of R. and L. Atriua
The sinus venosus develops into the
Smooth walled portion of right atrium (sunus venosus)
The proximal pulmonary vein develops into the
Smooth walled portion of the left atrium
Transposition of the great arteries is usually associated with a
VSD, ASD, or patent ductus arteriosus
Too much potassium outside of the cell
Hyperkalemia
What is the effect of Hyperkalemia?
Makes RMP less negative
Not enough potassium outside of the cell
Hypokalemia
What is the effect of Hypokalemia?
Makes RMP more negative
Faster in myelinated than non-myelinated neurons
Action Potentials
In the SA node, ACh binds CM2 receptors and the G-protein then activates outward rectifying K+ currents which
Cause RMP to become more negative and slows heartrate
The plateu potential is seen in the
Myocardium
During the plateau phase (phase 2) there is an inward Ca2+ current from Type L channels and an outward K+ current. These two currents
Work against eachother and comprise the slow plateau
Bind voltage-gated Na+ Channels and lock them in inactive position
Local Anesthetics
At LOW SNS tone, what do the following receptors do?
- ) B1
- ) B2
- ) a1
- ) Raises cardiac function
- ) Vasodilation of skeletal muscle
- ) Vasoconstriction in arterioles
At HIGH SNS tone, what do the following receptors do?
- ) B1
- ) a1
- ) Elevates cardiac function
2. ) Vasoconstricts VSM
Important vasoconstrictor of vascular smooth muscle
a1
Located in the SA node, ventricular myocytes, and renal JG cells
-increases HR and contractility
B1
The adrenal medulla is innervated by
Pre-ganglionic sympathetic fibers
What is the neurotransmitter for the SNS?
Norepinephrine
What is the neurotransmitter for the PNS?
ACh
To decrease HR in the heart, ACh binds
CM2
Causes resporption of calcium from bone and forming urine
Parathyroid Hormone (PTH)
Sense tendon stretch as an indicator of muscle tension
Golgi Tendon Organs
Increase in muscle fiber diameter
Hypertrophy
Increase in number of muscle fibers
-only really happens in kids
Hyperplasia
Degraded and rebuilt about every 1-2 weeks
Muscle proteins (actin and myosin)
Activated in response to stimuli induced by work
-mediate regeneration in response to injury
Satellite cells
Form multinucleate myotubes which fuse with existing myofibers
-main source of muscle regeneration and growth
Satellite cells
Stimulate satellite cell proliferation and secretion of growth hormone and IGF-1
Anabolic androgen steroids (testosterone and dihydrotestosterone
Induces positive nitrogen balance and proteogenesis
-Secreted from somatotropes in anterior pituitary
GH
Growth hormone stimulates hapatic
IGF-1 production
Synergize with GH to stimulate proteogenesis and regeneration
-expressed in skeletal muscle
IGF-1
Induces satellite cell mitosis
IGF-1
Expressed by satellite cells where it blocks cell cycle progression and cell proliferation of satellite cells
Myostatin (GDF-8)
What is the
- ) Cardiac contribution to BP?
- ) Vascular contribution to BP?
- ) CO
2. ) TPR
The volume sensed by the baroreceptor system that is available for tissue perfusion
Effective Circulating Volume (ECV)
A lengthened PR interval suggests
Primary Heart Block
Activates CM2 receptors within the SA and AV nodes to decrease HR
ACh
Allows for development of rapidly and repeatedly exciteable regions of the myocardium which form so-called circus rythms leading to ectopic pacemaker activity and tachyarrythmias
Reentry
Perfusion pressure is measured as
Mean Arterial Pressure (MAP)
Mean Arterial Pressure (MAP) is typically between
80-100 mmHg
Period of atrial systole and ventricular relaxation/chamber filling
Diastole
Force of ventricular contraction and arterial resistance
Systolic arterial BP
Ejection fraction is typically between
55-75%
Tells us about the AV node
PR interval
Tells us about bundle branches and ventricular myocardium
QRS
In a healthy heart, all of the limb leads have a positive P, QRS, and T, ACCEPT
aVR
In a healthy heart, which of the precordial leads has the
- ) Smallest R wave?
- ) Tallest R wave?
- ) V1
2. ) V5
The vulnerable period on the downward phase of the T wave occurs during which phases of the pacemaker potential?
Late phase 3 / early onset of phase 4
Disruption in unidirectional relay which can lead to arrythmias
Reentry
Has a vagomimetic effect as well as a positive inotropic effect
Digoxin
AP’s can not be generated during
Absolute refraction
In chronic hypertension, high pressure baroreceptors can become desensitized. This is why chronic hypertension is not associated with
Increased urinary output
Increasing resistance (R) means an increase in
Pressure, because Q is relatively constant
The vascular network is comprised of which 3 functional components?
- ) Resistance (arteries and arterioles)
- ) Exchange (capillaries)
- ) Capitance (veins)
Greatest coronary blood flow and maximal O2 uptake occurs during
Diastole
Pressure exerted against the vascular walls at zero flow
Unstressed volume (Pmcf)
Unstressed volume that is recruited to increase pressure and flow
Stressed Volume (Effective Circulating Volume; ECF)
Minutes into exercise, we see a slight rise in the venous pressure of
CO2
-no change in arterial PCO2
Imparied contractility
-Ejection fraction (CO) reduced
Systolic HF
Impaired filling. Stiff ventricle
-Preserved ejection fraction
Diastolic HF
When your BP drops when you stand up
Orthostasis
Drives secondary active transport of Ca2+ by NCX
-Inhibited by Digoxin
Na+/K+ ATPase
Produced by the adrenal glands to promote muscle catabolism
-Inhibit IGF-1
Glucocorticoids
Promotes myostatin, which decreases skeletal muscle mass
Cortisol
Have AP’s dependent on Type L Ca2+ channels
Smooth Muscle
As the ventricular myocardium stretches during diastole, we see stretch-induced
Ca2+ release
ESPVR is higher, meaning that EF is decreased with greater
- Increased O2 demand
- Decreased SV
Afterload
Receptor in the SA node that ACh binds to decrease HR
CM2
Shows AV nodal and His perkinje system
PR interval
In a healthy heart, Leads I and II have a
Positive QRS and upward T
In a healthy Heart, lead aVR has
Negative QRS and T
Describe left axis deviation (LAD)
Lead I = positive
aVL = strongly positive
aVF = strongly negative
Lead II = negative
SA nodal depolarization occurs right before the
P wave
If there is no P wave than there is no
Sinus Rythm
To check the P wave, look at leads
II and V1
If we are missing a P wave or the P waves are out of place than the problem is in the
SA node
Left atrial enlargement from HTN can cause
A-fib
We can see a notched R wave in
-can use precordial leads to determine which type
Bundle Branch Block
Has no P wave and a widened QRS
PVC
Repolarization anomolies that will manifest in the T wave or ST segment
Hyper/Hypokalemia
Depolarization anomalies that will manifest in the P wave or QRS complex
Hyper/Hypocalcemia
Prolonged QT due to longer contraction from increased intracellular Ca2+
Hypocalcemia
Shows very large T waves
Hyperkalemia
One of the main causes of A-fib is
Thyroid problems
What two receptors can be targeted to target the SA node?
B1 and CM2
Normal in children, but in adults sigifies LVV overload and HF
-represents rapid ventricular filling
S3
S1 is seen on the ECG with the
Q wave
S2 is seen on the ECG with the
T wave
Monitors PCO2 as H+
Medulla
Involved in:
- ) LVH
- ) Vascular Disease
- ) Kidney Damage
RAAS
Highest arterial BP is seen on an ECG at the peak of the
T wave
Osmotic pressure in the capillaries is mostly due to the protein
Albumin
How would ischemia affect and ECG?
ST deviations and inverted T waves
Shows inverted T waves and horizontal or downsloping ST depression
Chronic stable angina
Doesn’t change Pv but decreases CO
Venoconstriction
A small increase in CO leads to a large increase in
Pa
A normal respiratory rate is
15/min
