Cardiovascular

Fun Facts

Fun Facts

1. heart is a hollow muscular organ roughly the size of your fist (+) and weighs less than 1-lb

2. fully developed about 8 weeks after conception (begin beating at 4 weeks)

3. every minute the heart pumps our entire supply of blood through the body. about 5 quarts

4. women have faster heart beats than men

5. normal pulse is 70 heart beats per minute

Pulse points

Label: -Dorsalis pedis artery -brachial artery -popliteal artery -temporal artery -radial artery -posterior tibial artery -carotid artery -femoral artery -facial artery

Function

To deliver O2 and nutrients and to remove CO2 and other waste products

Heart anatomy- Location

-Medially in the thoracic cavity -Pointed tip (apex) directed toward left hip *the apex is 9cm to the left of the midsternal line

Heart anatomy- coverings

1. outer coverings

• pericardium- a double membrane, protective sac around the heart visceral pericardium- inner layer parietal pericardium- outside layer -serous fluid fills the space between pericardium layers

2. inner coverings -walls of the heart are made of 3 layers of tissue outer layer--> epitheal tissue... called epicardium middle layer--> cardiac muscle tissue... called endocardium inner layer--> epitheal tissue... called endocardium

Heart anatomy- chambers

1. Atria- the top chambers (receiving)

2. Ventricles- bottome chambers (the actual "pumps" in the heart)

Valves

1. Bicuspid valve (Mitral valve) - left side

• Atrioventricular - between atria and ventricles

2. Tricuspid vlve - right side

• Atrioventricular - between atria and ventricles

3. Pulmonary Semilunar valve

• Semilunar valves - between ventricle and artery

4. Aortic Semilunar valve

• Semilunar valves - between ventricle and artery

#1 and #2 prevent backflow into atria #3 and #4 prevent backflow into ventricle -held in place by chordae tendineae - "heart strings"

Biological valve (human or porcine) and Mechanical valve

-Porcine - pig -Bovine - cow -Biological needs future replacement and does NOT require blood thinners (10-15 years) -Mechanical lasts forever BUT requires use of blood thinners

Vessels

1. Vena cavas- superior and inferior -brings deoxygenated blood from the body tissues back to the heart

2. Pulmonary arteries -carries deoxygenated blood away from the heart and to the lungs

3. Pulmonary veins -brings oxygenated blood from the lungs to the heart

4. Aorta -carries oxygenated blood away from the heart and to the body tissues -size of a garden hose

*arteries carry blood away from the heart *veins carry blood tot he heart

Exterior heart diagram

Label: -Apex -Right ventricle -Left coronary artery -Left common carotid artery -Superior vena cava -inferior vena cava -Brachiocephalic artery -right pulmonary artery -left subclavian artery -left ventricle -right atrium -left atrium -right pulmonary veins -ascending aorta -pulmonary trunk -aortic arch -left pulmonary artery -left pulmonary veins -great cardiac vein

interior heart diagram

Label: -Aorta -Mitral valve -left atrium -left pulmonary artery -tricuspid valve -left pulmonary artery -aortic semilunar valve -left ventricle -papillary muscle -interventricular septum -myocardium -apex -inferior vena cava -chordae tendineae -right ventricle -right pulmonary artery -fossa ovalis -right pulmonary veins -right atrium -bicuspid valve -superior vena cava

Circulation-Pulmonary

path -right side of heart --> lungs --> left side of heart function -carry blood to the lungs for gas exchange *right ventricle = pulmonary pump

Circulation- systemic

path -left side of heart --> body tissues --> right side of heart function -supply oxygen and nutrients rich blood to all body systems *left ventricle = systemic pump

Circulation-cardiac

-blood in heart chambers does not nourish the myocardium -heart has its own nourishing circulatory system -coronary arteries -cardias veins

the path of the blood through the heart

Vena cavas right atrium tricuspid valve right ventricle pulmonary semilunar valve right and left pulmonary arteries lungs right and left pulmonary veins left atrium mitral valve left ventricle aortic semilunar valve aorta body tissues

Heart surgery- heart-lung machine

Cardio-pulmonary bypass

Heart surgery- body cooling

More time for surgery without causing brain damage (56 degrees.... approx. 4-6 hours)

Heart surgery- KCI injections

Paralyzes the heart muscle, temporarily

heart surgery- artificial heart transplant

Dr. robert jarvik began in mid 70s; success in 1982

Heart physiology

Intrinsic conduction system (nodal system)

Nodes

specialized tissue that functions as both muscle and nervous tissue; contracts like muscle tissue and generates impulses like nervous tissue

LABEL nodes on internal heart

1. Sinoatrial Node (pacemaker)

2. Atrioventricular node (Av node)

3. AV bundle (Bundle of His)

4. Bundle branches

5. Purkinje fibers

6. right atrium

7. left atrium

8. interventricular system

9. superior vena cava

path for the transmission of an impulse in the intrinsic conduction system of the heart

sinoatrial node--> atrioventriular node--> atrioventricular bundle--> right and left bundle branches--> purkinje fibers

electrocardiogram

= EKG/ECG --> maps the electrical activity of the heart

cardiac cycle

events of one complete heartbeat (.8s)

Polarization

refers to the heart at rest. no impulse, no stimulation, no contraction and no measurable activity

Depolarization

another word for the discharge of electrical energy or the activity of the heart during the impulse that causes contraction but not the contraction itself can by measured by ECG

repolarization

the electrical recovery of the heart as the cells recharge themselves

3 main EKG waves

1. P wave: represents depolarization of both atria

2. QRS wave: represents ventricular depolarization

3. T wave: ventricular repolarization ST segment: important in identifying pathology such as myocardial infarctions (elevations) and ischemia (depressions)

when does atrial repolarization take place?

QRS segment

LABEL EKG wave

1. p wave

2. t wave

3. QRS complex

4. atrial depolarization

5. atria contract

6. ventricular depolarization

7. atrial repolarization

8. ventricle contract

9. ventricular repolarization

10. polarization

11. Time (s)

12. electrical potential (m)

Systole Diastole

Systole= contraction Diastole= relaxation

Cardiac sounds

LUB -closing of AV valves DUB -closing of SL valves

irregularity of the hearts

Arrhythmia- irregular heart beat heart murmur- extra heart beat fibrillation- rapid, irregular, and unsynchronized bradycardia- below 60 tachycardia- above 100 arteriosclerosis- build up of fat/plaque on the artery wall

Difibulator

Machine used to stop the heart

composition of blood vessels

Heart->arteries->arterioles->capillary beds->venules->veins->heart and repeat

three layers of blood vessels (tunics)

1. tunica interna- endothelium (ET)

2. tunica media- smooth muscle tissue (MT)

3. tunica externa- mostly fibrous connective tissue (CT)

Arteries

-narrow lumen -more muscle/elastic tissue -transports blood under higher pressure -do not have valves (except the SL valves) -carry oxygenated blood

Veins

-wide lumens -less muscle/elastic tissue -transports blood under lower pressure -have valves throughout the main veins of the body -carry deoxygenated blood

Sphincters

loose= red like juice (red) tight= really really white (pale)

Renal

=kidney

Hep

=Liver

LABEL Artery man

common carotid subclavian aortic arch coronary thoracic aorta renal radial ulnar deep femoral internal carotid external carotid vertebral brachiocephalic axillary ascending aorta brachial abdominal aorta common iliac external iliac internal iliac digital femoral popliteal anterior tibial posterior tibial

LABEL vein man

subclavian brachiocephalic cephalic brachial renal external jugular vertebral internal jugular superior vena cava axillary great cardiac hepatic inferior vena cava ulnar radial common iliac external iliac internal iliac digital femoral great saphenous popliteal posterior tibial anterior tibial

pressure points

• pulse- pressure wave of blood

• monitored at "pressure points" where pulse is easily palpated

recording blood pressure

-measurements by health professionals are made on the pressure in large arteries

systolic

pressure at the peak of ventricular contraction (norm=120)

diastolic

pressure when ventricles relax (norm=80)

Steps for taking blood pressure

Normal blood pressure

110-140mm Hg systolic 75-80mm Hg diastolic

Hypotension blood pressure

low systolic (below 110mm Hg) -often associated with illness (heat=vasodilation)

Hypertension blood pressure

high systolic (above 140mm Hg) -can be dangerous if it is chronic

Blood pressure effects

-temperature -chemicals -diet

LABEL vessel compositions

1. epithelial tissue

2. smooth muscle tissue

3. fibrous connective tissue

what blood vessel has the highest blood pressure

aorta

during cardio-pulmonary bypass, what vessels are clamped?

-superior vena cava -aorta -inferior vena cava

what vessels are part of cardiac circulation

-coronary sinus -cardiac vein -coronary artery

what vessel receives blood during right ventricular systole:

pulmonary trunk