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Be able to list materials that are transported through the CVS. Note if going to
from a particular region (Table 14-1).
- material entering the body
- -Oxygen from lungs to all cells
- -nutrients and water from intestines to all cells
- material moved from cell to cell
- -wastes from intestines to liver for processing
- -immunes cells, antibodies, clotting proteins from blood at all times to any cell that needs them
- -hormones from endocrine cells to target cells
- stored nutrients from liver and adipose tissue to all cells
- material leaving the body
- -metabolic cells from all cells to kidneys
- -heat from all cells to skin
- -CO2 from all cells to lungs
Distinguish between systemic and pulmonary circuits.
systemic circuit is the blood pumped from the left ventricle to the rest of the body and back to the right atrium.
pulmonary circuit involves the blood pumped from the right ventricle-->pulmonary artery-->lungs (exchange of O2 and CO2)-->pulmonary vein-->left atrium-->left ventricle
Define artery and vein.
arteries bring oxygenated blood to body.
veins return deoxygenated blood back to the heart
Note how pressure effect blood flow.
The Cardiovascular sys is a closed circuit, as the heart contracts, it creates a pressure gradient; it will to from a high pressure region to a low pressure region
List how blood pressure may be influenced in the body.
- pressure gradients
- hydrostatic pressure
- friction of the vessels
- as radius of a tube decreases, the resistance to flow increases
Explain flow α ΔP.
Flow through the tube is directly proportional to (α) the pressure gradient (ΔP)
-Where ΔP=P1-P2 the higher the P gradient, the greater to the fluid flow
-If P1 and P2 are the same there is no flow
-100mmHg-75mmHm=25mmHg and 50mmHg-25mmHg=25mmHg, then flow flow rate is equal
Explain and give the relationship between blood flow and resistance.
Blood flow is the amount of liquid moving through a vessel. It can be affected by pressure in static and flowing fluids, pressure gradients, and resistance. Flow is directly proportional (∞) to the pressure gradient (ΔP)
- Resistance can be influenced by the radius of the tube, length, and viscosity of fluid.
- Flow is inversely proportional to resistance.
- Flow ∞ 1/R
- if resistance ↑ flow ↓
Compare flow rate and velocity of flow for blood.
- flow rate measures how much (volume) blood flows past a point in a given period of time.
- velocity is a measure of how fast blood flows past a point.
- velocity of flow through a tube=the flow rate(Q) /the tube's cross-sectional area(A).
Identify the following heart components:
Trace blood through the chambers and valves in order from entrance to exit.
Compare cardiac muscle excitation with skeletal muscle, especially noting the role of the ions involved and refractory period
- Skeletal muscle
- events leading to threshold potential- Na+entry through ACh operated channels
- rising phase of action potential-Na+ entry
- repolarization phase-rapid;caused by K influx
- hyperpolarization-due to excessive K efflux at high K permeability. When K channels close; leak K and Na restores potential to resting state
- refractory period-generally brief
- Contractile Myocardium
- events leading to threshold potential-depolarization enter via gap junctions
- rising phase of action potential-Na+ entry
- repolarization phase-Extended plateau caused by Ca2+ entry;rapid phase caused by K efflux
- refractory period-long because rerestting of Na+ channel gates delayed until end of action potential
Compare autorhythmic and contractile cells of the heart.
autorhthmic cells has unstable pacemaker potential usually starting at -60mV, threshold-Na and If channels reinforced by Ca, rising phase of action potential-Ca entry, repolarization-Rapid;K influx, hyper polarize-normally none when it hits -60 If channels open, refractory period-not significant in normal function
Explain what a “funny” channels are, and why funny?
"funny" refers to the unstable resting membrane potential of a auto rhythmic cells, when If are open, the pacemaker potential gradually becomes less negative until
List the order of path of the EC system of the heart
auto rhythmic cells give AP-->signal spreads fast via intercalated disk with gap junctions-->SA node-->internodal pathway-->AV node-->AV bundle(Bundle of His)-->L & R bundle branches-->purkinje fibers-->
define fibrillation, compare atrial and ventricular fibrillation.
- Fibrillation is the disorganized contraction of myocardial cells.
- A-fib is common, often w/o symptoms, can be a precursor to a stroke
- V-fib is life threatening and requires immediate medical attention
Explain heart block, what causes and how treated
a heart block is when the SA node doesn't reach the AV node. Caused by damage auto rhythmic cells. A pacemaker can be surgically install to correct the problem
What is the function of the Einthoven's triangle?
Einthoven's triangle is what we know as an ECG. Electrodes are placed on a persons limbs which gives the electrical activity of the heart.
Draw and label an ECG
- P wave-artail depolarization
- QRS complex-progressvie wave of the ventricular depolarization
- T wave-repolarization of the ventricles
- PR or PQ interval-the slowing of electrical activity as it passes through the AV node and bundle
- QT interval-EC travels down L & R bundle branches to purkinje fibers and contract the ventricles
- ST segment-ventricles contract
Correlate the ECG and mechanical events in the cardiac cycle
- Late diastole-both chamber are relaxed and fill passively
- Atrial diastole-atrial contraction and push blood into the ventricles
- Isovolumic ventricular contraction-"LUBB", 1st phase of ventricular contraction pushes AV valves closed but does not push semilunar valves open.
- Ventricular ejection-blood ejected as pressure rise and exceed
- Isovolumic ventricular relaxation-"DUBB",blood falls back and closes valves
Identify the EDV, ESV, and stroke volume and pressure in the ventricle
- EDV-when the ventricle has reach is maximum capacity
- ESV-is the amount of blood left in the ventricle after it has contracted
- stroke volume-EDV-ESV=stroke volume
Compare CO with HR an SV
Cardiac out=heart rate x stroke volume
What does Starling Law state
the relationship of stroke volume is proportional to EDV, as blood enters the heat contracts more forcefully and ejects more blood.
the heart pumps out all the blood that is returned.
Name three ways venous return is affected
- contraction or compression of veins returning blood to the heart( the skeletal muscle pump)
- pressure changes in the abdomen and thorax during breathing (respiratory pump)
- sympathetic innervation of veins.