Download Cardiac task

STRENGTHENING OF MYOCARDIAL
CONTRACTION WHILE INCREASING
THE INITIAL LENGTH OF MUSCLE
FIBERS IS PROVIDED:
Accelerates and intensifies cardiac
function:
by intracellular autoregulation
THE BUTMOTROPIC EFFECT OF
CARDIAC ACTIVITY IS A CHANGE:
Of myocardial excitability (ability to generate AP)
THE INOTROPIC EFFECT OF CARDIAC
ACTIVITY IS A CHANGE:
Of contraction force (contractility)
THE DROMOTROPIC EFFECT IN
CARDIAC ACTIVITY IS A CHANGE IN:
myocardial conduction (the rate of electrical impulses)
A CHRONOTROPIC EFFECT IN
CARDIAC ACTIVITY IS A CHANGE IN:
heart rate and rhythm
SYMPATHETIC NERVES HAVE AN
EFFECT ON THE HEART^
Excess entering of calcium ions(Ca2+)


positive inotropic
positive chronotropic
MUSCLE EFFECTS (name of
neurotransmitter):
Noradrenaline
THE VAGUS NERVE ENDINGS
RELEASE MEDIATOR:
Acetylcholine
THE CENTER OF SYMPATHETIC
INNERVATION OF THE HEART IS
LOCATED IN:
THE CENTER OF PARASYMPATHETIC
INNERVATION OF THE HEART IS
LOCATED IN:
AN INCREASE IN HEART RATE IS
OBSERVED:
In the upper thoracic segments of the spinal cord
VAGUS NERVE STIMULATION IS
INDUCED IN ATYPICAL
CARDIOMYOCYTES:
In the medulla oblongata
under the influence of the sympathetic nerve( cardiac
accelerate center)


increase in the permeability of the membranes of
sinus node pacemakers for potassium ions,
slowing HR and cardiac arrest in diastole
What are the effects of
parasympathetic stimulation on the
heart?
What are the effects of sympathetic
stimulation on the heart?
-slows rate of SA node depolarization
-longer than usual AV node delay
-weaker contraction of atria
-speeds up rate of SA node depolarization
-reduces AV node delay
-speeds up ap through conduction pathway
-stronger contraction of atria and ventricles
Atrial systole (steps)
1. atria contract,
2. ventricles relax;
3. AV valves open
Early ventricular systole
1. atria relax, ventricles contract;
2. all valves closed;
3. isovolumetric contraction
Late ventricular systole
1. semilunar valves open,
2. ventricular ejection phase;
3. ventricles don't empty completely
Cardiac output (CO) =
heart rate (HR) x stroke volume (SV)
Start out the contraction of the heart
by sending an action potential from
the:
SA (sinoatrial) node
Cardioacceleratory center sends
nerve signals along (_____) nerves,
which results in a/an (______)in both
heart rate and force of contraction.
Cardioinhibitory center sends nerve
signals along (_____) ,which results
in a/an (_____) in heart rate.
1) (Sympathetic);
2) (an increase)
60 BPM is the same as:
1 contraction per second or 1 action potential per
second.
120 BPM is the same as:
2 contractions per second or 2 action potentials per
second.
The hormones (____) and (____)
increase heart rate.
1) epinephrine (adrenaline);
2)( thyroxine)
(Ions) both inside and outside of the
cell are very important for heart
contraction.
Ca++, Na+, K+, Mg++
(Calcium, Sodium, Potassium, Magnesium)
1) vagus nerves (CN X);
2) (a decrease)
Amount of blood ejected from the
left ventricle per contraction.
(Per beat) /(mL)
Stroke Volume (SV)
Amount of blood returned to the
heart through the veins.
Venous Return (VR)
If average stroke volume for an adult
at rest is 70 mL of blood per beat
and average heart rate for an adult
at rest is 75 beats per minute then
average cardiac output for an adult
at rest is:
If average stroke volume for an adult
at rest is 85 mL of blood per beat
and average heart rate for an adult
at rest is 65 beats per minute then
average cardiac output for an adult
at rest is:
Frank-Starling Law of the Heart
states that:
Your result:
In other words, Frank-Starling Law of
the Heart is saying that:
The amount that you stretch out the heart determines
how hard you contract and eject the blood out.
Your result:
Preload, or degree of stretch, of cardiac muscle cells
before they contract is the critical factor controlling
stroke volume.