Bell Ringer

1
Bell Ringer

• Venules and veins carry ________________ blood.

deoxygenated
2. Two properties of arteries that help them in
moving blood are __________________ and
____________________.
elasticity
contractibility
3. The name of the inner lining of the heart
__________________.
endocardium
4. The name of the chamber of the heart with the
thickest muscular wall ______________________.
Left ventricle
5. The tricuspid valve is between the
___________________ and the ______________________
__.
Right atrium
ventricle
Aortic pulmonary
6. Name one of the two semi-lunar valves of the
heart _____________.
7. Myocardium is this type of muscle fibre
__________________.
Slow Twitch (I)
SA node (Sinoatrial)
8. The ___________________ initiates electrical
signals within the heart.
The Cardiorespiratory System
2
Coronary Circulation

• Right and left coronary arteries nourish the
  myocardium

• Left and right cardiac veins remove waste from
  the myocardium

Blood travels from coronary arteries to capillary
beds in the myocardium where O2 is exhcanged.
Blood then flows into cardiac veins which empty
into the coronary sinus and the right artium.
The Cardiorespiratory System
3
Coronary Circulation and Disorder
Coronary circulation the delivery of oxygen and
nutrient-rich arterial blood to cardiac muscle
tissue and the return of oxygen-poor blood from
this active tissue to the venous system
Coronary arteries (right and left) aortas
first branches whose openings lie behind the
flaps of the aortic semi-lunar valves
Coronary Artery Disease (CAD) an occlusion or
obstruction of the hearts arteries resulting
from atherosclerosis.
Angina pectoris severe chest pain occurring
when myocardium is deprived of adequate oxygen
Angina is a warning sign that coronary arteries
are no longer able to supply enough blood (and
oxygen) to the heart muscle
The Cardiorespiratory System
4
Coronary Circulation and Disorder
Myocardial infarction (heart attack) death of
heart tissue caused by a lack of oxygen, brought
on by a coronary thrombus (stationary blood clot)
or embolism (mobile clot)
Recovery is possible if there is enough undamaged
heart muscle to keep up the needs of the heart
and body.
CAD and Treatments
http//www.tmc.edu/thi/cad.html
The Cardiorespiratory System
5
Coronary Collaterals
Normally the right and left coronary arteries
supply the right and left myocardium with blood
respectively.
Left coronary artery.
Right coronary artery.
An occlusion of one of these arteries can result
in death of myocardium. In some cases, the body
can adapt to save the heart tissue. Collateral
arteries, arteries not normally active are
stimulated to open and allow blood to flow to
areas affected by occluded arteries in a sort of
self-by-pass.
The Cardiorespiratory System
6
Coronary Circulation and Disorder - Treatments
Treatments for CAD include

• medicines (nitroglycerin, beta blockers, calcium
  channel blockers

• angioplasty (w or w/o stenting)

• atherectomy, laser ablation

• coronary artery by-pass surgery

• transmyocardial laser revascularization (TMLR)

The Cardiorespiratory System
7
Cardiac Cycle
Cardiac cycle the series of events that occurs
through one heart beat (contraction and
relaxation)
Two phases 1. Diastole (relaxation of
ventricles) 2. Systole (contraction of
ventricles)
Diastole
Atria contract (0.1sec) and blood is pumped into
ventricles (relaxed) Time 0.5 seconds
Systole
Ventricles contract and blood is pumped to the
lungs and to systemic circulation (rest of body)
Time 0.3 seconds
At rest, each cycle lasts 0.8 seconds (72
beats/per minute)
The Cardiorespiratory System
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Cardiac Cycle

• Ventricular Systole
• ventricles contract
• ventricular contraction regulated by AV node
• semilunar valves (to aorta pulmonary arteries)
  open
• atrioventricular valves close ("lub")

• Ventricular Diastole
• ventricles relax, atria contract
• atrial contraction regulated by SA node
  (pacemaker)
• semilunar valves close ("dupp")
• atrioventricular valves open

The Cardiorespiratory System
9
Cardiac Cycle
Cardiac output (Q) -
volume of blood per minute that the left
ventricle pumps into circulation (5 L/min R.H.R.
72bpm)
Stroke volume (SV)-
volume of blood ejected from the left ventricle
each time it contracts ( 75 mL/ beat)
Cardiac output depends on

• Pulse rate

2. Stroke volume
Cardiac output can increase about five fold
during heavy exercise.
The Cardiorespiratory System
10
Blood Pressure
Blood pressure -
the pressure that the blood exerts against the
arteries
Systolic pressure pressure while ventricles are
contracting (120 mm Hg)
Diastolic pressure pressure while ventricles
are relaxed (80 mm Hg)
Commonly reported as systolic over diastolic.
e.g. 120/80 normal blood pressure
Factors affecting blood pressure

• Cardiac output

• Peripheral resistance

• Blood volume

The Cardiorespiratory System
11
Venous Flow
After gas exchange in the capillaries, blood
moves into venules and then veins. These vessels
have relatively thin walls. Blood flow is slower
and requires a system of one-way valves and
contraction of muscles to make the return journey.
Three methods of returning blood to the
heart

• Thoracic pump

2. Venoconstriction
3. Skeletal muscle pump
The Cardiorespiratory System
12
Blood

• Erythrocytes - Red blood cells
• Leukocytes - White blood cells
• Plasma
• Thrombocytes - Platelets
• Color (hemoglobin)
• Arterial (red blood)
• Venous (blue blood)

The Cardiorespiratory System
13
Blood
The Role of Erythrocytes (Red Blood Cells)
Characteristics of Erythrocytes(Red Blood Cells
- RBC)

• Made in bone marrow
• Hemoglobin is a specialized protein
• located on the RBC
• Transport nutrients and waste

• Carry oxygen
• Remove waste
• Carry carbon dioxide
• Carry nutrients

Characteristics of Plasma
Characteristics of Leukocytes (White Blood Cells)

• Fluid component of blood
• Transport medium
• Mostly water
• Makes up 55 percent of blood
• Other dissolved substances in
• plasma
• - Gases
• - Nutrients (protein)
• - Ions (electrolytes)

• Destroy foreign elements
• Critical in the function of the immune
• system
• Help in the healing of bone and multiple
• other cellular activity