2.kuliah ke2 cvs.ppt

7/28/2019 2.KULIAH KE2 cvs.ppt

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CardiovascularSystemMore than just the heart


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Cardiovascular SystemBlood

The Heart

The Vascular System


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Cardiovascular system

Main function is transportation Blood is transport vehicle or car

Blood transports oxygen, nutrients, cell

wastes, hormones, etc. Parts include:

- blood

- heart

- blood vessels (veins , arteries, &

capillaries)


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Location & size of theheart Heart is size of persons fist

Enclosed within mediastinum (middle cavity

of thorax)

Flanked on each side by the lungs

Apex: pointed structure of heart point,

towards left hip and rests in diaphragm

Base: place from which great vessels

emerge, broader part of heart, points towards

the R shoulder, lies beneath 2nd rib,


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Wall coverings of theheart Pericardium: encloses heart

Epicardium: hugs external surface and is part

of the heart wall

Parietal pericardium: part of superficial face

of the heart & reinforced by dense connective

tissue called fibrous pericaridium

Fibrous percardium: protects heart &

anchors it to surrounding struct.


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More heart walls: Composed of 3 layers:

1. outerepicardium

2. myocardium: consists of thick bundlesof cardiac muscle- layer that contracts

3. endocardium: thin, glistening sheet

that lines the heart chambers-continuous w/the linings of the blood

vessels leaving & entering the heart


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Chambers & GreatVessels Heart has 4 hollow chambers:

1. 2 atria (atrium singular)

2. 2 ventriclesSuperior atria: receiving chambers- not

involved in pumping activity of the heart

Ventricles: discharging chambers-thickwalled, and are the actual pumps of the

heart


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More heart anatomy Pulmonary veins: returns O

2rich

blood back to the heart on L side

Pulmonary circulation: circulation from the

R side of the heart, to the lungs, and back tothe L side of heart

R side of heart acts as pulmonary circuit

pump, receiving O2 poor blood from veins Aorta: where blood is pumped OUT of the

heart, from which systemic arteries branch to

supply blood to all other tissues


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Regulating heart activity 2 systems act to reg. heart activity

1. nerves of autonomic nervous system:

act as brakes & accelerators to increaseof decrease heart rate

2. intrinsic conduction system or nodal

system: built into heart tissue & sets its

basic rhythm enforces 75 beats per

minute


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Key parts of intrinsic conductionsystem

Sinoatrial node (SA node)- starts eachheartbeat and sets pace for entire heart AKA

the pacemaker

Atrioventricular node (AV node)- whereimpulse is delayed to give atria time to finish

contracting

Impulse then travels through- atrioventricular bundles (bundle of HIs0

- R&L bundle branches

- Purkinje fibers


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Bad Heart conditions

1. angina pectoris: crushing chest pain 2. myocardial infarction: heart attack or

coronary

3. Ischemia: lack of adequate blood supplyto the heart

4. Tachycardia: rapid heart rate

5. Bradycardia: substantially low heart rate

6. Fibrillation: rapid, uncoordinated

shuddering of the heart


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Cardiac cycle & CO Systole: contraction

Diastole: relaxation

Cardiac cycle: the events of 1 complete

heartbeat 3 parts1. mid-to-late diastole

2. ventricular systole

3. early diastoleCardiac output: amt of blood pumped out by

each side of the heart

CO= HR x SV (which is 70ml/beat)


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SV

Stroke volume: volume ofblood pumped out by a

ventricle w/ each heartbeat


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Heart Rate HR is affected by

1) parasymp. & symp. NS which stimulate

SA nodes

2) hormones- ie. Epinephrine

3) ion deficit i.e. lack of K

4) age, gender, exercise, body temp.

-resting HR is fastest in resting fetus

- HR is faster in females than in males

- Heat increases HR by increasing metabolic

rate of heart cells


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Anatomy of blood vessels

Walls of blood vessels have 3 coats/tunics1. tunica intima: lines interior of vessel

2. tunica meduim: bulky middle coat,

mostly smooth muscle and elastic

tissue

3. tunica externa: composed of fibrous

connective tissue- support and

protects the vessel


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Circulation & BP

Vital signs:indicate efficiency of onescirculatory system, includes

1. respiratory rate

2. body temp

3. arterial pulse

4. BP

pulse: pressure wave created with expansion

and recoil of an artery

Pulse rate (pressure surges per minute)=

heart rate


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Arterial Pulse points Pulse/ pressure points: where arteries are close

to body surface & pulse can be taken- same pointsare also compressed to stop hemorrhaging

1. wrist

2. temperal artery

3.facial artery

4. carotid artery

5. radial artery

6. Brachial artery

7. Femoral artery 8.Popliteal artery

9. Posterior tibial artery

10. dorsalis pedis artery


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Blood pressure BP: pressure blood exerts against inner walls of

blood vessels &force that keeps blood circulatingbetwn heartbeats

Systolic pressure: pressure in arteries @peak

of ventricular contraction

Diastolic pressure: pressure when ventricles are

relaxing

Systolic pressure written above diastolic, units

mmHg using the ausculatory method (arm)


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Factors Affecting BP1.

peripheral resistance: amt. of frictionencountered by the blood as it flows

2. age, weight, body position, emotional state

3. neural factors: autonomic NS- cancause vasocontriction (narrowing of

blood vessels)


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More BP factors4. renal factors- kidneys can retain water,

which incr. blood volume or allow morewater to leave, decr. blood volume

5. temperature- cold is a vasocontrictor

& heat is a vasodilator

6. chemicals: histamine, alcohol,

epinephrine, nicotine

7. diet: diets low in salt, fat & cholesterol

helps prevent hypertension


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Characteristics of BloodAmount

ColorpH

Viscosity


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4 6 liters

38 to 48% various cells52 62% Plasma

Color

pH Viscosity


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Color

Bright red is arterial O2 rich

Dark red is venous O2 depleted

pH

Viscosity


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Color

pH7.35 to 7.45 on pH scale alkaline

Venous blood is slightly lower due

to CO2

Viscosity


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Color

pH

Viscosity (thickness)

Blood is 3 to 5 times thicker than water

Thickness contributes to BloodPressure


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Blood Make-up Plasma

91.5% Water

7% Proteins fibrogen, globulins,albumins

1.5% Other nutrients, hormones,

nitrogenous wastes, respiratory gases,electrolytes

Blood Cells


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Blood CellsErythrocytes RBCs ~ 95%

Thrombocytes Platelets ~ 4.8%

Leukocytes WBCs ~ .2%


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Blood Cells

Erythrocytes RBCs ~ 95% Contain hemoglobin bonds with O2

Live about 120 days

Produced in red bone marrow

Stem cell-> Normoblasts-> Reticulocytes->Erythocytes

Thrombocytes Platelets ~ 4.8%



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Blood Cells Erythrocytes RBCs ~ 95%

Thrombocytes Platelets ~ 4.8% Cell fragments

Last 5 9 days

Primarily responsible for clotting mechanisms (3

mechanisms) Vascular spasm Platelet plugs Chemical clotting



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Blood Cells

Erythrocytes RBCs ~ 95% Thrombocytes Platelets ~ 4.8%


5 types separated into two groups

Granular Leukocytes: neutrophils eosinophils basophils Agranular Leukocytes: lymphocytes - monocytes

Protect the body from Infectious disease

Provide Immunity to certain diseases


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Blood TypesABO group 4 blood types

A - has A antigens on the cell membrane

B - has B antigens on the cell membraneAB - has A & B antigens on the cell

membrane

O - has neither A nor B antigens on the cell

membrane Rh factor


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Blood TypesABO group

Rh factorRh+ have the Rh antigen

Rh- do not have Rh antigen


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Blood Clotting3 types of Clotting

Vascular spasmPlatelet plugs

Chemical clotting


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Blood Clotting Vascular spasm

When a large artery or vein is severed, smooth

muscle in its wall contracts. Platelets release

serotonin which brings about vasoconstriction,

creating a smaller area to block with clots

Platelet plugs

Chemical clotting


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Blood Clotting Vascular spasm

Platelet plugs

When capillaries rupture, the damage is too slight toinitiate the formation of a clot. The rough shape

causes the platelets to change shape (become

spiky) and become sticky. They stick to each other

and the edges of the capillary Chemical clotting

2.kuliah ke2 cvs.ppt

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