Cardiovascular SystemCardiovascular System

I. Functions of the heart.I. Functions of the heart.

1. Generating _______________.1. Generating _______________.

2. Routing ________________.2. Routing ________________.

3. Ensuring blood moves 3. Ensuring blood moves __________.__________.

4. _______________ blood supply.4. _______________ blood supply.

Cardiovascular SystemCardiovascular System

II. HeartII. HeartA. General CharacteristicsA. General Characteristics

1. ____________time/day1. ____________time/day

2. ____/day = ____ 2. ____/day = ____ gallonsgallons

3. ________ miles of 3. ________ miles of blood vesselsblood vessels

4. Center of the 4. Center of the circulatory Systemcirculatory System

5. Center of the 5. Center of the Thoracic Cavity, Thoracic Cavity, between the lungsbetween the lungs

6. ____ on the left side6. ____ on the left side

7. ______ in size after 7. ______ in size after the age of 65.the age of 65.

B. Coverings of the heartB. Coverings of the heart1. ___________ - covers the heart, 2 main layers1. ___________ - covers the heart, 2 main layers

a. ___________________(pericardial sac)a. ___________________(pericardial sac)

••OuterOuter••Loose fittingLoose fitting

1. _________ - Outer, thick, 1. _________ - Outer, thick, tough tough dense connective dense connective tissue.tissue.

Protects & anchors to the Protects & anchors to the diaphragmdiaphragm

2. _________ - Inner, thin, 2. _________ - Inner, thin, Squamous epitheliumSquamous epithelium

b. _____________________(Epicardium)b. _____________________(Epicardium)

••Attaches to the surface of Attaches to the surface of the the heartheart

••Considered to be the outer Considered to be the outer most most layer of the heart.layer of the heart.

c. ________________c. ________________••Space filled with ________Space filled with ________••______________________________••____________ - swelling of ____________ - swelling of

spacespace

ReviewReview

What is the main function of the What is the main function of the heart?heart?

What is the general size & shape of What is the general size & shape of the heart?the heart?

Which cavities contain the heart?Which cavities contain the heart?

C. Heart WallsC. Heart Walls______ layers - middle is the most ______ layers - middle is the most

important - important - ____________________________________________

1.1. _________ - Thin protective _________ - Thin protective barrier of the heartbarrier of the heart

Serous membraneSerous membraneFat depositsFat deposits

2. ___________ -Bulk of the heart2. ___________ -Bulk of the heart

_______________- bundles of _______________- bundles of connective tissueconnective tissueLayer that contractsLayer that contracts

3. ___________- Inner most layer3. ___________- Inner most layerSmooth white layerSmooth white layer ____________________________________

D. Heart ChambersD. Heart ChambersSuperiorSuperior1.1. ______________ - Receiving ______________ - Receiving

chambers for bloodchambers for blood

__________role in pumping__________role in pumping

_________- ridges of muscle_________- ridges of muscle

_________- separates the _________- separates the atrium into right & left atrium into right & left halveshalves

_________- oval depression _________- oval depression of the heart believed to of the heart believed to be an opening in the fetal be an opening in the fetal heartheart

a. ____________- a. ____________- receives receives from the vena from the vena cavacava

b. b. _____________receives _____________receives from from the lungsthe lungs

InferiorInferior

2. _______________ - forces blood 2. _______________ - forces blood through the bodythrough the body

____________- Irregular folds ____________- Irregular folds of muscle in the of muscle in the endocardiumendocardium

__________________- Slender __________________- Slender projections off of the projections off of the trabuclae carnaetrabuclae carnae Attaches to valves & Attaches to valves &

aids in functionaids in function

__________________- Separates __________________- Separates ventricles into left & right ventricles into left & right halveshalves

__________________- Externally __________________- Externally separates the atrium & separates the atrium & ventriclesventricles

ReviewReview What are the 3 layers of the heart from What are the 3 layers of the heart from

outer to inner most?outer to inner most?

Why is the inside of the heart coated Why is the inside of the heart coated with simple squamous?with simple squamous?

What are the chambers of the heart?What are the chambers of the heart?

What wall divides the right and left What wall divides the right and left sides of the heart?sides of the heart?

E. Heart valvesE. Heart valvesBlood flows in __________________Blood flows in __________________Prevents ___________________Prevents ___________________

1. _________________(AV) - between 1. _________________(AV) - between atrium & ventriclesatrium & ventricles

_______triangular flaps or _______triangular flaps or cuspscusps

Point downward into the Point downward into the ventriclesventricles

___________ between right ___________ between right Atrium & ventricle (3 flaps)Atrium & ventricle (3 flaps)

Bicuspid (mitral) between left Bicuspid (mitral) between left atrium & ventricle (2 flaps)atrium & ventricle (2 flaps)

Chordae tendinae - strands of Chordae tendinae - strands of connective tissue connective tissue

Anchors cusps to papillary walls of Anchors cusps to papillary walls of the ventriclesthe ventricles

Murmur - Cusps do not lose Murmur - Cusps do not lose completely - leaking of bloodcompletely - leaking of blood

2. Semilunar (SL) Valves2. Semilunar (SL) Valves

Between ventricles & blood leavingBetween ventricles & blood leaving

Pulmonary & AorticPulmonary & Aortic

3 half moon (semilunar) cusps3 half moon (semilunar) cusps

F. Blood flow through the F. Blood flow through the heartheart

G. Supply of blood to the heartG. Supply of blood to the heart

Coronary CirculationCoronary Circulation

Right & Left Coronary Arteries - carries fresh oxygenated Right & Left Coronary Arteries - carries fresh oxygenated blood blood (70% of oxygen, only 25% to skeletal muscles, increases to (70% of oxygen, only 25% to skeletal muscles, increases to 70% 70% during exercise)during exercise)

Great & Small cardiac veinGreat & Small cardiac vein

Coronary Sinus - large vein that collects blood leaving the Coronary Sinus - large vein that collects blood leaving the heartheart

II. Heart Physiology - Pumps blood through out the body

A. Cardiac Cycle - contraction of both the atria & then ventricle.

1. Systole - Contraction2. Diastole - Relaxation

B. Heart Sounds - LUB - DUB Closing of the heart valves

1. Lub - Closing of the AV valves2. Dub - Closing of the Sl valves

C. Heart Conduction - Each cardiac cycle is stimulated by special conducting cells in the heart.

1. Receives a signal form the autonomic nervous system.

2. Sinoatrial (SA) Node “Pacemaker” - cluster of pace setting cells

Initiates each cardiac cycle by generating an electric impulse.

Spread quickly through out the atrium.

Stimulates the second cluster of cells.

3. Atrioventricular (AV) Node, AV. bundle, Bundle of His - relays the signal to the ventricles.

Extends down the septum of the heart.

4. Purkinje fibers - branches of the AV node, passes further into the myocardium.

5. If the SA node is unable to produce the electrical impulse for the heart to contract, the AV node functions as the pacemaker

6. Slower – Ectopic beat.

D. Electrocardiogram (ECG or EKG) - measures the electrical events during a cardiac cycle

1. Detect changes in the electrical changes in the heart wall

2. Electrical changes produces a changes in the ionic flow through out the body

SA node fires send action potential.

P Wave - depolarization of the atria - action potential.

QRS Wave - depolarization of the ventricle.

T Wave ventricular repolarization of the ventricle

PQ interval – atria contract & begins to relax.

QT interval – ventricle depolarizes & repolarizes.

E. Cardiac Output - Volume of blood pumped1. Heart rate X Stroke Volume = Cardiac

Output 75 bpm X 70 ml = 5250 ml/min

(5.25 L/min)

2. Adjustments - exerciseHeart rate

Stroke Volume

3. Starling’s Law - Further the heart is stretched, the stronger the contraction.

Preload – pressure on the heart when the ventricles are stretched when filling with blood.

Afterload – pressure the heart must beat against.

F. Regulation of Heart Activity 1. Controlled by the reflex center

(cardioregulatory center) - medulla oblongata.2. Baroreceptors - detect the blood pressure.3. Parasympathetic fibers from the medulla

oblongata through the Vagus nerve extends to the heart.

Acetylcholine (Ach) slows the heartNorepinephrine (NE) speed the heart up

Barorecptor relfex

G. Cardiac cycleThree major events in the cycle.1. Systole –

a. Blood is pushed towards the atria, closely the AV valves.

b. Pressure increases in the ventricle forcing the SL

valves to open.

2. Diastole –a. Pressure in the ventricles decrease, the AV valves

open and blood fills the ventricles up to 70% of their volume.

3. End-Atria relaxes & fills with

blood, then contract & starts it over.

Cardiac Cycle

III. AgingA. By 70 output is reduced by 30%, by 85 30%-60%.B. Hypertrophy is common (enlargement of left ventricle), due to increase afterload (high blood pressure).

Leads to decreased elasticity & increased stiffness.

Increased left atria pressure and cause pulmonary edema, feel out of breath.C. Greater amount of time to contract & relax leading to decreased in maxmium heart rate.D. Connective tissue with the valves becomes less flexible.E. Development of coronary artery disease in 10% of people over 80.

VI. Cardiovascular diseases

A. Congestive heart failure - failure of the heart to pump blood to the body tissues.

B. Heart Block – Failure of the SA or AV. to generate impulses.

C. Heart fibrillation - Heart beats at a irregular pace.

D. Heart flutter - heart race up to 300 bpm.

E. Hypertension - elevated blood pressure.

F. Murmur - Leaking of blood through a closed valve.

G. Myocarditis - infection of the heart muscle.

H. Pericarditis - Infection of the pericardial sac which results in thicken or scarring.

Cardiovascular diseasesCardiovascular diseases

Blood Vessel and CirculationBlood Vessel and Circulation

FunctionsFunctions

1. Carry Blood1. Carry Blood

2. Exchange of nutrients2. Exchange of nutrients

3. Transport3. Transport

4. Regulate blood pressure4. Regulate blood pressure

5. Direct blood flow5. Direct blood flow

I Blood Vessels - Forms a closed I Blood Vessels - Forms a closed circulatory system (Arteries -circulatory system (Arteries ->Capillaries ->Veins)>Capillaries ->Veins)

Made up of three layersMade up of three layers

a. Lumen - space for the flow of blood.a. Lumen - space for the flow of blood.

b. Tunica Intima - inner lining.b. Tunica Intima - inner lining.

c. Tunica Media - smooth muscle, contractibility.c. Tunica Media - smooth muscle, contractibility.

d. Tunica Adventitia – anchoringd. Tunica Adventitia – anchoring

ReviewReview

1. State the functions of blood 1. State the functions of blood vessels.vessels.

2. What is the inner space called of 2. What is the inner space called of blood vessels?blood vessels?

3. What are the three layers of blood 3. What are the three layers of blood vessels?vessels?

A. Arteries - Carries blood away A. Arteries - Carries blood away from the heartfrom the heart

Strong & ElasticStrong & Elastic

1. Elastic Arteries – 1. Elastic Arteries – Largest in Largest in diameter. diameter.

Mainly elasticMainly elastic

2. Muscular arteries – 2. Muscular arteries – medium medium sized and small sized and small diameter. diameter.

Mainly smooth muscleMainly smooth muscle

3. Distributing arteries – 3. Distributing arteries – vasoconstriction -vasoconstriction -Vasomotor fibers of Vasomotor fibers of the (autonomic).the (autonomic).vasodilatation - vasodilatation -

nerve nerve impulse is inhibited impulse is inhibited - - muscle relaxes & muscle relaxes &

elastic fibers elastic fibers recoils.recoils.

4. Small arteries4. Small arteries

5. Arterioles - 0.5 mm in 5. Arterioles - 0.5 mm in diameterdiameter

ReviewReview

1. What are the function of arteries?1. What are the function of arteries?

2. Why are arteries thick?2. Why are arteries thick?

3. How are arteries adapted to 3. How are arteries adapted to handle high blood pressure?handle high blood pressure?

B. Capillaries - Thin wall B. Capillaries - Thin wall blood vessels that permit blood vessels that permit exchanges of material.exchanges of material.

1. Connect arteries 1. Connect arteries to to veinsveins

2. 0.01 mm in 2. 0.01 mm in diameter - diameter - lumenlumen

3. Can only fit 1 3. Can only fit 1 RBC at a RBC at a time.time.

4. Form capillary 4. Form capillary beds or beds or networks.networks.

Thoroughfare channels Thoroughfare channels - connect arterioles - connect arterioles directly to veinsdirectly to veins

True Capillaries - 10-True Capillaries - 10-100 per bed100 per bed

Precapillary Sphincter - Precapillary Sphincter - valve that regulates flow valve that regulates flow of blood into those of blood into those capillaries.capillaries.

ReviewReview

1. What is the function of capillaries?1. What is the function of capillaries?

2. How are capillaries adapted for 2. How are capillaries adapted for their function?their function?

3. Describe a Thoroughfare channels. 3. Describe a Thoroughfare channels.

C. Veins - Carries blood toward the heartC. Veins - Carries blood toward the heart1. Thinner & collapse.1. Thinner & collapse.

2. Holds 65% of the body’s 2. Holds 65% of the body’s blood.blood.

3. Low blood pressure, too low to 3. Low blood pressure, too low to be pumped back to the heart.be pumped back to the heart.

1 way valves1 way valvesBody movement - Body movement - Skeletal contraction, Skeletal contraction,

breathing.breathing.

4. Made up of three layers - 4. Made up of three layers - same as arteriessame as arteries

5. Varicose veins - 5. Varicose veins - overstretched veins overstretched veins

from from blood pooling , hemorrhoids.blood pooling , hemorrhoids.

6. Venules – thinner versions 6. Venules – thinner versions of veinsof veins

ReviewReview

What is the function of veins?What is the function of veins?

How are veins adapted to handle low How are veins adapted to handle low pressure?pressure?

Name some ways that blood can be Name some ways that blood can be “PUSHED” through the veins.“PUSHED” through the veins.

II. Blood Pressure - force exerted by II. Blood Pressure - force exerted by blood against the inner walls of blood against the inner walls of vesselsvesselsA. Influenced by:A. Influenced by:

Cardiac OutputCardiac OutputBlood VolumeBlood VolumePeripheral Resistance Peripheral Resistance

which is which is regulated by regulated by nerve, kidneys, nerve, kidneys, hormones.hormones.

B. Moves from regions of higher B. Moves from regions of higher pressurepressure

to lower pressureto lower pressure

Systolic - Peak pressure - 120 Systolic - Peak pressure - 120 mmHgmmHg

Diastolic - Resting - 70 - 80 Diastolic - Resting - 70 - 80 mmHgmmHg

Sphygmomanometer - measures Sphygmomanometer - measures blood pressure.blood pressure.

Stethoscope – HearingStethoscope – Hearing

Korotkoff - tapping sound Korotkoff - tapping sound soundssounds

C. Pulse - rhythmic expanding & recoiling of an arterial C. Pulse - rhythmic expanding & recoiling of an arterial wallwall

Average Average Adult 70 - 90 bpmAdult 70 - 90 bpmChild 80 - 140 bpm Child 80 - 140 bpm

tachycardia - heart rate is above 100 bpm at resttachycardia - heart rate is above 100 bpm at restbradycardia - heart rate is lower than 60 bpm at restbradycardia - heart rate is lower than 60 bpm at rest

Auscultatory MethodAuscultatory MethodSphygmomanometerSphygmomanometerStethoscopeStethoscopeKorotkoff soundsKorotkoff sounds

D. Blood PressureD. Blood Pressure

ReviewReview Define blood pressure.Define blood pressure.

Describe blood pressure movement.Describe blood pressure movement.

Define pulse.Define pulse.

III Capillary ExchangeIII Capillary Exchange

10 Billion capillaries10 Billion capillaries

Materials (gases, nutrients) move Materials (gases, nutrients) move across capillary walls by across capillary walls by diffusion, osmosis, facilitated diffusion, osmosis, facilitated diffusion & active transport.diffusion & active transport.

Small amount of fluid also moves Small amount of fluid also moves across the capillary walls:across the capillary walls:

Hydrostatic pressure - blood Hydrostatic pressure - blood pressure within the capillariespressure within the capillaries

Osmotic pressure - movement of Osmotic pressure - movement of fluid from cells to plasmafluid from cells to plasma

90% reabsorbed back into the 90% reabsorbed back into the bloodblood

10% returned back by the 10% returned back by the lymphatic systemlymphatic system

ReviewReview

What are the functions of capillaries?What are the functions of capillaries?

What is the purpose of hydrostatic pressure? What is the purpose of hydrostatic pressure?

How does hydrostatic pressure compare to How does hydrostatic pressure compare to osmotic pressure?osmotic pressure?

Which part of the capillary bed has the highest Which part of the capillary bed has the highest hydrostatic pressure and osmotic pressure?hydrostatic pressure and osmotic pressure?

IV. Regulation of blood pressure - IV. Regulation of blood pressure - regulation of steady pressure is regulation of steady pressure is important.important.

A. Nervous Control - Adjusts A. Nervous Control - Adjusts cardiac output & peripheral cardiac output & peripheral resistant by autonomic fibers to resistant by autonomic fibers to the SA node & reflex center the SA node & reflex center (vasomotor center in the medulla (vasomotor center in the medulla oblongata & pons).oblongata & pons).

1. Peripheral resistance - control 1. Peripheral resistance - control by activity of vasomotor by activity of vasomotor between the smooth muscle & between the smooth muscle & reflex center of Medulla reflex center of Medulla (Vasomotor tone, increases = (Vasomotor tone, increases = constriction).constriction).

2.2. Control of vasomotor center Control of vasomotor center (MAP)(MAP)

Map = CO X PRMap = CO X PR

a.a.Baroreceptors – located in Baroreceptors – located in major vessels above the major vessels above the heart & detect changes in heart & detect changes in the blood pressure. the blood pressure.

Moment to moment controlMoment to moment control

b. Chemoreceptors - Sensitive b. Chemoreceptors - Sensitive to changes in oxygen levels to changes in oxygen levels or hydrogen ions (pH) level.or hydrogen ions (pH) level.

carotid bodies – carotid carotid bodies – carotid sinussinus

aorta bodies - aortaaorta bodies - aorta

ReviewReview

What is the job of baroreceptors & What is the job of baroreceptors & chemoreceptors?chemoreceptors?

V. Cardiovascular diseasesV. Cardiovascular diseases

A.A. Aneurysm - formation Aneurysm - formation of a sac within the of a sac within the heart or blood vessels heart or blood vessels due to stretchingdue to stretching

B. Arteriosclerosis - Loss B. Arteriosclerosis - Loss of elasticity in arterial of elasticity in arterial wallswalls

C. Atherosclerosis - C. Atherosclerosis - narrow of arteries by narrow of arteries by plaque build upplaque build up

Cardiovascular diseasesCardiovascular diseases

1. What are the three types of blood 1. What are the three types of blood vessels and how are they different?vessels and how are they different?

2. What is the difference between 2. What is the difference between vasodialation & vasoconstriction?vasodialation & vasoconstriction?

3. What are the 3 layers of the blood 3. What are the 3 layers of the blood vessels?vessels?

4. Does blood ever flow in reverse within 4. Does blood ever flow in reverse within the blood vessels?the blood vessels?