the cardiovascular system gps: sap4. students will analyze the physical, chemical, and biological...

The Cardiovascular SystemThe Cardiovascular SystemGPS:GPS: SAP4. Students will analyze SAP4. Students will analyze

the physical, chemical, and the physical, chemical, and biological properties of biological properties of process systems as these process systems as these relate to transportation, relate to transportation, absorption and excretion, absorption and excretion, including the including the cardiovascular, respiratory, cardiovascular, respiratory, digestive, excretory and digestive, excretory and immune systems.immune systems.b. Analyze, and explain the b. Analyze, and explain the relationships between the relationships between the respiratory and cardiovascular respiratory and cardiovascular systems as they obtain oxygen systems as they obtain oxygen needed for the oxidation of needed for the oxidation of nutrients and removal of nutrients and removal of carbon dioxide.carbon dioxide.

EQ:EQ: How is the circulatory How is the circulatory

system like a highway system like a highway system?system?

How does blood How does blood travel thru the travel thru the heart? heart?

The Cardiovascular SystemThe Cardiovascular System A closed system of the heart and blood A closed system of the heart and blood

vesselsvessels The heart pumps bloodThe heart pumps blood Blood vessels allow blood to circulate to all Blood vessels allow blood to circulate to all

parts of the bodyparts of the body The function of the cardiovascular system The function of the cardiovascular system

is to deliver oxygen and nutrients and to is to deliver oxygen and nutrients and to remove carbon dioxide and other waste remove carbon dioxide and other waste productsproducts

The HeartThe Heart LocationLocation

Thorax between the lungs in the inferior Thorax between the lungs in the inferior mediastinummediastinum

Orientation (fist-shaped)Orientation (fist-shaped) Pointed apex directed toward left hipPointed apex directed toward left hip Base points toward right shoulderBase points toward right shoulder

About the size of your fistAbout the size of your fist

The HeartThe Heart

Figure 11.1a–b

The HeartThe Heart

The Heart: ChambersThe Heart: Chambers Right and left side act as separate pumpsRight and left side act as separate pumps Four chambers:Four chambers:

2 Atria2 Atria• Receiving chambersReceiving chambers

Right atriumRight atrium Left atriumLeft atrium

2 Ventricles2 Ventricles• Discharging chambersDischarging chambers

Right ventricleRight ventricle Left ventricleLeft ventricle

The Heart Separations: Septa The Heart Separations: Septa Interventricular septum Interventricular septum

Separates the two ventriclesSeparates the two ventricles Interatrial septum Interatrial septum

Separates the two atriaSeparates the two atria

The Heart: ValvesThe Heart: Valves

Allow blood to flow in only 1 direction to Allow blood to flow in only 1 direction to prevent backflow.prevent backflow.

Four valvesFour valves:: 2 Atrioventricular (AV) valves—between atria & 2 Atrioventricular (AV) valves—between atria &

ventricles; prevent backflow into atria when the ventricles; prevent backflow into atria when the ventricles contract.ventricles contract.• 1. Bicuspid valve/AKA: mitral valve/ AKA: left AV valve1. Bicuspid valve/AKA: mitral valve/ AKA: left AV valve• 2. Tricuspid valve/ AKA: right AV valve 2. Tricuspid valve/ AKA: right AV valve

2 Semilunar valves—between ventricle & arteries2 Semilunar valves—between ventricle & arteries• 1. Pulmonary semilunar (SL) valve1. Pulmonary semilunar (SL) valve• 2. Aortic semilunar (SL) valve2. Aortic semilunar (SL) valve

The Heart: ValvesThe Heart: Valves AV valvesAV valves: :

Anchored in place by chordae tendineae (“heart Anchored in place by chordae tendineae (“heart strings”)strings”)

OpenOpen during heart/ ventricle relaxation & during heart/ ventricle relaxation & closedclosed during ventricular contractionduring ventricular contraction

Semilunar valvesSemilunar valves:: ClosedClosed during heart/ ventricle relaxation but during heart/ ventricle relaxation but openopen

during ventricular contractionduring ventricular contraction Notice these valves operate opposite of one another Notice these valves operate opposite of one another

to force a one-way path of blood through the heartto force a one-way path of blood through the heart

Figure 11.5a, step 3

Blood returning tothe atria, putspressure againstAV valves; the AVvalves are forcedopen

As the ventriclesfill, AV valve flapshang limply intoventricles

Atria contract,forcing additionalblood into ventricles

Ventricles

Operation of the AV valves

AV valves open

(a)

Figure 11.5a, step 6

Ventricles contract,forcing bloodagainst AV valveflaps

AV valves close

Chordae tendineaetighten, preventingvalve flaps fromeverting into atria

AV valves closed(a)

Figure 11.5b, step 2

As ventriclescontract andintraventricularpressure rises,blood is pushedup againstsemilunarvalves, forcingthem open

Aorta

Pulmonarytrunk

Semilunar valveopen Semilunar valve

closed

As ventriclesrelax, andintraventricularpressure falls,blood flowsback fromarteries, fillingthe leaflets of semilunarvalves andforcing themto close

Operation of the semilunar valves

(b)

Systemic and Pulmonary Systemic and Pulmonary CirculationsCirculations

Systemic (body) circulationSystemic (body) circulation Blood flows from the left side of the heart Blood flows from the left side of the heart

through the body tissues & back to the right through the body tissues & back to the right side of the heartside of the heart

Pulmonary (lung) circulationPulmonary (lung) circulation Blood flows from the right side of the heart to Blood flows from the right side of the heart to

the lungs & back to the left side of the heartthe lungs & back to the left side of the heart

The Heart: Associated Great The Heart: Associated Great Blood VesselsBlood Vessels

ArteriesArteries AortaAorta

• Major artery leaving left ventricle; carries oxygenated blood Major artery leaving left ventricle; carries oxygenated blood through systemic circulation.through systemic circulation.

Pulmonary trunk/ pulmonary arteries (left & right)Pulmonary trunk/ pulmonary arteries (left & right)• Major artery leaving right ventricle; carries deoxygenated Major artery leaving right ventricle; carries deoxygenated

blood to left & right lungs to pick up oxygen (Oblood to left & right lungs to pick up oxygen (O22).).

VeinsVeins Superior & Inferior venae cavaeSuperior & Inferior venae cavae

• Enter right atrium; brings deoxygenated blood from body.Enter right atrium; brings deoxygenated blood from body. Pulmonary veins (four)Pulmonary veins (four)

• Enter left atrium; brings oxygenated blood from lungs.Enter left atrium; brings oxygenated blood from lungs.

Blood Flow Through the HeartBlood Flow Through the Heart

Superior & inferior venae cava (VC) dump Superior & inferior venae cava (VC) dump deoxygenated blood into the right atrium (RA).deoxygenated blood into the right atrium (RA).

From RA, through the tricuspid valve, blood From RA, through the tricuspid valve, blood travels to the right ventricle (RV)travels to the right ventricle (RV)

From the RV, blood leaves the heart as it From the RV, blood leaves the heart as it passes through the pulmonary SL valve passes through the pulmonary SL valve into the pulmonary trunk arteries. into the pulmonary trunk arteries. (Pulmonary trunk splits into right & left (Pulmonary trunk splits into right & left pulmonary arteries that carry blood to the pulmonary arteries that carry blood to the lungs to pick up Olungs to pick up O22).).

Blood Flow Through the HeartBlood Flow Through the Heart OO22 is picked up & CO is picked up & CO22 is dropped off by blood is dropped off by blood

in the lungs to be exhaled.in the lungs to be exhaled. Oxygen-rich blood returns to the heart through Oxygen-rich blood returns to the heart through

the four pulmonary veinsthe four pulmonary veins Blood enters the left atrium & travels through Blood enters the left atrium & travels through

the bicuspid valve into the left ventricle (LV).the bicuspid valve into the left ventricle (LV). From the LV, blood leaves the heart via the From the LV, blood leaves the heart via the

aortic SL valve & through the aorta to the body aortic SL valve & through the aorta to the body to deliver Oto deliver O22 to cells. to cells.

Blood Flow Through the HeartBlood Flow Through the Heart

From Body:From Body: → → S/I-VC S/I-VC → RA → → RA → TVTV

→ RV → → RV → PSVPSV → PA → → PA → Lungs →Lungs →

→ → PV → LA → PV → LA → BVBV → → LV → LV → ASVASV → Aorta → → Aorta → BODYBODY

Coronary CirculationCoronary Circulation Blood in the heart chambers does not Blood in the heart chambers does not

nourish the myocardium (heart muscle)nourish the myocardium (heart muscle) The heart has its own nourishing The heart has its own nourishing

circulatory system consisting of:circulatory system consisting of:1.1. Coronary arteries—branch from the aorta to supply Coronary arteries—branch from the aorta to supply

the heart muscle with oxygenated bloodthe heart muscle with oxygenated blood2.2. Cardiac veins—drain the myocardium of bloodCardiac veins—drain the myocardium of blood3.3. Coronary sinus—a large vein on the posterior of the Coronary sinus—a large vein on the posterior of the

heart, receives blood from cardiac veinsheart, receives blood from cardiac veins

Blood empties into the right atrium via Blood empties into the right atrium via the coronary sinus.the coronary sinus.

The Heart: Conduction SystemThe Heart: Conduction System Intrinsic conduction Intrinsic conduction

system (nodal system (nodal system):system): Heart muscle cells Heart muscle cells

contract, w/o nerve contract, w/o nerve impulses, in a regular, impulses, in a regular, continuous waycontinuous way

The Heart: Conduction The Heart: Conduction SystemSystem

Special tissue sets the paceSpecial tissue sets the pace• Sinoatrial node = SA node (“pacemaker”), is in the Sinoatrial node = SA node (“pacemaker”), is in the

right atriumright atrium• Atrioventricular node = AV node, is at the junction Atrioventricular node = AV node, is at the junction

of the atria & ventriclesof the atria & ventricles• Atrioventricular bundle = AV bundle (Bundle of Atrioventricular bundle = AV bundle (Bundle of

His), is in the interventricular septumHis), is in the interventricular septum• Bundle branches are in the interventricular septumBundle branches are in the interventricular septum• Purkinje fibers spread w/in the ventricle wall Purkinje fibers spread w/in the ventricle wall

musclesmuscles

Heart ContractionsHeart Contractions Contraction is initiated by the SA nodeContraction is initiated by the SA node Sequential stimulation occurs at other Sequential stimulation occurs at other

autorhythmic cellsautorhythmic cells Force cardiac muscle depolarization in Force cardiac muscle depolarization in

one direction—from atria to ventriclesone direction—from atria to ventricles

Heart ContractionsHeart Contractions

1.1. SA node depolarize to starts the heartbeatSA node depolarize to starts the heartbeat Impulse spreads to the AV node Impulse spreads to the AV node Then the atria contractThen the atria contract

2.2. At the AV node, the impulse passes At the AV node, the impulse passes through the AV bundle, bundle branches, through the AV bundle, bundle branches, and Purkinje fibers to the ventricles.and Purkinje fibers to the ventricles.

3.3. Ventricles contract: Blood is ejected from Ventricles contract: Blood is ejected from the ventricles to the aorta & pulmonary the ventricles to the aorta & pulmonary arteries.arteries.

Heart ContractionsHeart Contractions Tachycardia—rapid heart rate over 100 Tachycardia—rapid heart rate over 100

beats per minutebeats per minute Bradycardia—slow heart rate less than 60 Bradycardia—slow heart rate less than 60

beats per minutesbeats per minutes

The Heart: Cardiac CycleThe Heart: Cardiac Cycle Atria contract simultaneouslyAtria contract simultaneously Atria relax, then ventricles contractAtria relax, then ventricles contract Systole = contractionSystole = contraction Diastole = relaxationDiastole = relaxation

Filling Heart Chambers: Filling Heart Chambers: Cardiac CycleCardiac Cycle

Figure 11.7

Atrialcontraction

Mid-to-late diastole(ventricular filling)

Ventricular systole(atria in diastole)

Early diastole

Isovolumetriccontraction phase

Ventricularejection phase

Isovolumetricrelaxation

Ventricularfilling

Left atriumRight atrium

Left ventricleRight ventricle

The Heart: Cardiac CycleThe Heart: Cardiac Cycle Cardiac cycle—events of 1 complete heart Cardiac cycle—events of 1 complete heart

beatbeat Mid-to-late diastole—blood flows from atria Mid-to-late diastole—blood flows from atria

into ventriclesinto ventricles Ventricular systole—blood pressure builds Ventricular systole—blood pressure builds

before ventricle contracts, pushing out bloodbefore ventricle contracts, pushing out blood Early diastole—atria finish refilling, ventricular Early diastole—atria finish refilling, ventricular

pressure is lowpressure is low

The Heart: Cardiac OutputThe Heart: Cardiac Output Stroke volume (SV)= ml/ beatStroke volume (SV)= ml/ beat

Volume of blood pumped by each ventricle in one Volume of blood pumped by each ventricle in one contraction (each heartbeat)contraction (each heartbeat)

Usually remains relatively constant Usually remains relatively constant About 70 mL of blood is pumped out of the LV w/ About 70 mL of blood is pumped out of the LV w/

each heartbeateach heartbeat Cardiac output (CO) = ml/minCardiac output (CO) = ml/min

Amount of blood pumped by each side (ventricle) of Amount of blood pumped by each side (ventricle) of the heart in one minutethe heart in one minute

Heart rate (HR) Heart rate (HR) Typically 75 beats/min.Typically 75 beats/min.

The Heart: Cardiac OutputThe Heart: Cardiac Output CO = HR CO = HR SV SV Example: Example:

CO = HR (75 beats/min) CO = HR (75 beats/min) SV (70 mL/beat) SV (70 mL/beat) CO = 5250 mL/minCO = 5250 mL/min

Starling’s law of the heart—the more the cardiac Starling’s law of the heart—the more the cardiac muscle is stretched, the stronger the contractionmuscle is stretched, the stronger the contraction

Changing heart rate is the most common way to Changing heart rate is the most common way to change cardiac outputchange cardiac output

The Heart: Cardiac OutputThe Heart: Cardiac Output Stroke volume (SV)= ml/ beatStroke volume (SV)= ml/ beat

Volume of blood pumped by each ventricle in one Volume of blood pumped by each ventricle in one contraction (each heartbeat)contraction (each heartbeat)

Usually remains relatively constant Usually remains relatively constant About 70 mL of blood is pumped out of the LV w/ About 70 mL of blood is pumped out of the LV w/

each heartbeateach heartbeat Cardiac output (CO) = ml/minCardiac output (CO) = ml/min

Amount of blood pumped by each side (ventricle) of Amount of blood pumped by each side (ventricle) of the heart in one minutethe heart in one minute

Heart rate (HR) Heart rate (HR) Typically 75 beats/min.Typically 75 beats/min.

The Heart: Cardiac OutputThe Heart: Cardiac Output CO = HR CO = HR SV SV Example: Example:

CO = HR (75 beats/min) CO = HR (75 beats/min) SV (70 mL/beat) SV (70 mL/beat) CO = 5250 mL/minCO = 5250 mL/min

Starling’s law of the heart—the more the cardiac Starling’s law of the heart—the more the cardiac muscle is stretched, the stronger the contractionmuscle is stretched, the stronger the contraction

Changing heart rate is the most common way to Changing heart rate is the most common way to change cardiac outputchange cardiac output

The Heart: Regulation of The Heart: Regulation of Heart RateHeart Rate

Increased heart rate:Increased heart rate:1.1. Sympathetic nervous systemSympathetic nervous system

• Crisis- fight or flight responseCrisis- fight or flight response• Low blood pressureLow blood pressure

2.2. HormonesHormones• EpinephrineEpinephrine• ThyroxineThyroxine

3.3. ExerciseExercise

4.4. Decreased blood volumeDecreased blood volume

The Heart: Regulation of The Heart: Regulation of Heart RateHeart Rate

Decreased heart rate:Decreased heart rate:1.1. Parasympathetic nervous systemParasympathetic nervous system

2.2. High blood pressure or blood volumeHigh blood pressure or blood volume

3.3. Decreased venous return (Decreased venous return (↓↓ return of blood return of blood from veins/ vena cava)from veins/ vena cava)

Cardiac Output RegulationCardiac Output Regulation

Figure 11.8

Blood Vessels: The Vascular Blood Vessels: The Vascular SystemSystem

Transport blood to the Transport blood to the tissues & backtissues & back Carry blood away from Carry blood away from

the heartthe heart• ArteriesArteries• ArteriolesArterioles

Exchanges between Exchanges between tissues and bloodtissues and blood

• Capillary bedsCapillary beds Return blood toward Return blood toward

the heartthe heart• VenulesVenules• VeinsVeins

Differences Between Blood Differences Between Blood VesselsVessels

Walls of arteries are the thickestWalls of arteries are the thickest Lumens (opening) of veins are largerLumens (opening) of veins are larger Larger veins have valves to prevent Larger veins have valves to prevent

backflowbackflow Skeletal muscle “milks” blood in veins Skeletal muscle “milks” blood in veins

toward the hearttoward the heart Walls of capillaries are only one cell layer Walls of capillaries are only one cell layer

thick to allow for exchanges between blood thick to allow for exchanges between blood & tissue& tissue

Movement of Blood Through Movement of Blood Through VesselsVessels

Most arterial blood is Most arterial blood is pumped by the heartpumped by the heart

Veins use the milking Veins use the milking action of muscles to action of muscles to help move bloodhelp move blood

Capillary BedsCapillary Beds Capillary beds consist of two types of Capillary beds consist of two types of

vesselsvessels Vascular shunt—vessel directly connecting an Vascular shunt—vessel directly connecting an

arteriole to a venulearteriole to a venule True capillaries—exchange vesselsTrue capillaries—exchange vessels

• Oxygen & nutrients cross to cellsOxygen & nutrients cross to cells• Carbon dioxide & metabolic waste products cross Carbon dioxide & metabolic waste products cross

into bloodinto blood

Capillary BedsCapillary Beds

Major Arteries of System Major Arteries of System CirculationCirculation

AortaAorta Largest artery in the bodyLargest artery in the body Leaves from the left ventricle of the heartLeaves from the left ventricle of the heart RegionsRegions

• Ascending aorta—leaves the left ventricleAscending aorta—leaves the left ventricle• Aortic arch—arches to the leftAortic arch—arches to the left• Thoracic aorta—travels downward through the Thoracic aorta—travels downward through the

thoraxthorax• Abdominal aorta—passes through the diaphragm Abdominal aorta—passes through the diaphragm

into the abdominopelvic cavityinto the abdominopelvic cavity Arterial branches of the ascending aortaArterial branches of the ascending aorta

Right and left coronary arteries serve the heartRight and left coronary arteries serve the heart

Major Arteries of Systemic Major Arteries of Systemic CirculationCirculation

Arterial branches of the aortia arch (BCS)Arterial branches of the aortia arch (BCS) Brachiocephalic trunk splits into theBrachiocephalic trunk splits into the

• Right common carotid arteryRight common carotid artery• Right subclavian arteryRight subclavian artery

Left common carotid artery splits into theLeft common carotid artery splits into the• Left internal and external carotid arteries Left internal and external carotid arteries

Left subclavian artery branches into theLeft subclavian artery branches into the• Vertebral arteryVertebral artery• In the axilla, the subclavian artery becomes the In the axilla, the subclavian artery becomes the

axillary artery axillary artery brachial artery brachial artery radial and ulnar radial and ulnar arteriesarteries


Arterial branches of the thoracic aortaArterial branches of the thoracic aorta Intercostal arteries supply the muscles of the Intercostal arteries supply the muscles of the

thorax wallthorax wall Other branches of the thoracic aorta supply Other branches of the thoracic aorta supply

thethe• Lungs (bronchial arteries)Lungs (bronchial arteries)• Esophagus (esophageal arteries)Esophagus (esophageal arteries)• Diaphragm (phrenic arteries)Diaphragm (phrenic arteries)


Arterial branches of the abdominal aortaArterial branches of the abdominal aorta Celiac trunk is the first branch of the Celiac trunk is the first branch of the

abdominal aorta. Three branches areabdominal aorta. Three branches are• Left gastric artery (stomach)Left gastric artery (stomach)• Splenic artery (spleen)Splenic artery (spleen)• Common hepatic artery (liver)Common hepatic artery (liver)

Superior mesenteric artery supplies most of Superior mesenteric artery supplies most of the small intestine and first half of the large the small intestine and first half of the large intestineintestine


Arterial branches of the abdominal aortaArterial branches of the abdominal aorta Left and right renal arteries (kidney)Left and right renal arteries (kidney) Left and right gonadal arteries Left and right gonadal arteries

• Ovarian arteries in females serve the ovariesOvarian arteries in females serve the ovaries• Testicular arteries in males serve the testesTesticular arteries in males serve the testes

Lumbar arteries serve muscles of the Lumbar arteries serve muscles of the abdomen and trunkabdomen and trunk


Arterial branches of the abdominal aortaArterial branches of the abdominal aorta Inferior mesenteric artery serves the second Inferior mesenteric artery serves the second

half of the large intestinehalf of the large intestine Left and right common iliac arteries are the Left and right common iliac arteries are the

final branches of the aortafinal branches of the aorta• Internal iliac arteries serve the pelvic organsInternal iliac arteries serve the pelvic organs• External iliac arteries enter the thigh External iliac arteries enter the thigh femoral femoral

artery artery popliteal artery popliteal artery anterior and posterior anterior and posterior tibial arteriestibial arteries

Major Veins of Systemic Major Veins of Systemic CirculationCirculation

Superior and inferior Superior and inferior vena cava enter the vena cava enter the right atrium of the right atrium of the heartheart Superior vena cava Superior vena cava

drains the head and drains the head and armsarms

Inferior vena cava Inferior vena cava drains the lower bodydrains the lower body


Veins draining into the superior vena cavaVeins draining into the superior vena cava Radial and ulnar veins Radial and ulnar veins brachial vein brachial vein

axillary vein axillary vein These veins drain the armsThese veins drain the arms Cephalic vein drains the lateral aspect of the Cephalic vein drains the lateral aspect of the

arm and empties into the axillary veinarm and empties into the axillary vein Basilic vein drains the medial aspect of the Basilic vein drains the medial aspect of the

arm and empties into the brachial veinarm and empties into the brachial vein Basilic and cephalic veins are jointed at the Basilic and cephalic veins are jointed at the

median cubital vein (elbow area)median cubital vein (elbow area)


Veins draining into the superior vena cavaVeins draining into the superior vena cava Subclavian vein receivesSubclavian vein receives

• Venous blood from the arm via the axillary veinVenous blood from the arm via the axillary vein• Venous blood from skin and muscles via external Venous blood from skin and muscles via external

jugular veinjugular vein Vertebral vein drains the posterior part of the Vertebral vein drains the posterior part of the

headhead Internal jugular vein drains the dural sinuses Internal jugular vein drains the dural sinuses

of the brainof the brain


Veins draining into the superior vena cavaVeins draining into the superior vena cava Left and right brachiocephalic veins receive Left and right brachiocephalic veins receive

venous blood from thevenous blood from the• Subclavian veinsSubclavian veins• Vertebral veinsVertebral veins• Internal jugular veinsInternal jugular veins

Brachiocephalic veins join to form the superior Brachiocephalic veins join to form the superior vena cava vena cava right atrium of heart right atrium of heart

Azygous vein drains the thoraxAzygous vein drains the thorax


Veins draining into the inferior vena cavaVeins draining into the inferior vena cava Anterior and posterior tibial veins and fibial Anterior and posterior tibial veins and fibial

veins drain the legsveins drain the legs Posterior tibial vein Posterior tibial vein popliteal vein popliteal vein femoral femoral

vein vein external iliac vein external iliac vein Great saphenous veins (longest veins of the Great saphenous veins (longest veins of the

body) receive superficial drainage of the legsbody) receive superficial drainage of the legs Each common iliac vein (left and right) is Each common iliac vein (left and right) is

formed by the union of the internal and external formed by the union of the internal and external iliac vein on its own sideiliac vein on its own side


Veins draining into the inferior vena cavaVeins draining into the inferior vena cava Right gonadal vein drains the right ovary in Right gonadal vein drains the right ovary in

females and right testicle in malesfemales and right testicle in males Left gonadal vein empties into the left renal Left gonadal vein empties into the left renal

veinvein Left and right renal veins drain the kidneysLeft and right renal veins drain the kidneys Hepatic portal vein drains the digestive Hepatic portal vein drains the digestive

organs and travels through the liver before it organs and travels through the liver before it enters systemic circulationenters systemic circulation


Veins draining into Veins draining into the inferior vena cavathe inferior vena cava Left and right hepatic Left and right hepatic

veins drain the liverveins drain the liver

Arterial Supply of the BrainArterial Supply of the Brain

Internal carotid arteries divide intoInternal carotid arteries divide into Anterior and middle cerebral arteriesAnterior and middle cerebral arteries These arteries supply most of the cerebrumThese arteries supply most of the cerebrum

Vertebral arteries join once within the skull to Vertebral arteries join once within the skull to form the basilar arteryform the basilar artery Basilar artery serves the brain stem and cerebellumBasilar artery serves the brain stem and cerebellum

Posterior cerebral arteries form from the division Posterior cerebral arteries form from the division of the basilar arteryof the basilar artery These arteries supply the posterior cerebrumThese arteries supply the posterior cerebrum

Circle of WillisCircle of Willis Anterior and posterior Anterior and posterior

blood supplies are blood supplies are united by small united by small communicating communicating arterial branchesarterial branches

Result—complete Result—complete circle of connecting circle of connecting blood vessels called blood vessels called cerebral arterial circlecerebral arterial circle or or circle of Williscircle of Willis

Fetal CirculationFetal Circulation Fetus receives exchanges of gases, Fetus receives exchanges of gases,

nutrients, and wastes through the placentanutrients, and wastes through the placenta Umbilical cord contains three vesselsUmbilical cord contains three vessels

Umbilical vein—carries blood rich in nutrients Umbilical vein—carries blood rich in nutrients and oxygen to the fetusand oxygen to the fetus

Umbilical arteries (2)—carry carbon dioxide Umbilical arteries (2)—carry carbon dioxide and debris-laden blood from fetus to placentaand debris-laden blood from fetus to placenta

Fetal CirculationFetal Circulation Blood flow bypasses the Blood flow bypasses the

liver through the ductus liver through the ductus venosus and enters the venosus and enters the inferior vena cava inferior vena cava right right atrium of heartatrium of heart

Blood flow bypasses the Blood flow bypasses the lungs lungs

Blood entering right atrium is Blood entering right atrium is shunted directly into the left shunted directly into the left atrium through the foramen atrium through the foramen ovaleovale

Ductus arteriosus connects Ductus arteriosus connects the aorta and pulmonary the aorta and pulmonary trunk (becomes ligamentum trunk (becomes ligamentum arteriosum at birth)arteriosum at birth)

Hepatic Portal CirculationHepatic Portal Circulation Veins of hepatic portal circulation drainVeins of hepatic portal circulation drain

Digestive organsDigestive organs SpleenSpleen Pancreas Pancreas

Hepatic portal vein carries this blood to the liver Hepatic portal vein carries this blood to the liver Liver helps maintain proper glucose, fat, and Liver helps maintain proper glucose, fat, and

protein concentrations in bloodprotein concentrations in blood Major vessels of hepatic portal circulationMajor vessels of hepatic portal circulation

Inferior and superior mesenteric veinsInferior and superior mesenteric veins Splenic veinSplenic vein Left gastric veinLeft gastric vein

Hepatic Portal CirculationHepatic Portal Circulation

Figure 11.16

PulsePulse PulsePulse

Pressure wave of Pressure wave of bloodblood

Monitored at Monitored at “pressure points” in “pressure points” in arteries where pulse arteries where pulse is easily palpatedis easily palpated

Pulse averages 70–Pulse averages 70–76 beats per minute 76 beats per minute at restat rest

Blood PressureBlood Pressure Measurements by health professionals are Measurements by health professionals are

made on the pressure in large arteriesmade on the pressure in large arteries Systolic—pressure at the peak of ventricular Systolic—pressure at the peak of ventricular

contraction contraction Diastolic—pressure when ventricles relaxDiastolic—pressure when ventricles relax Write systolic pressure first and diastolic last Write systolic pressure first and diastolic last

(120/80 mm Hg)(120/80 mm Hg) Pressure in blood vessels decreases as Pressure in blood vessels decreases as

distance from the heart increasesdistance from the heart increases

Comparison of Blood Pressures Comparison of Blood Pressures in Different Vesselsin Different Vessels

Figure 11.19

Measuring Arterial Blood Measuring Arterial Blood PressurePressure

Figure 11.20a

Blood Pressure: Effects of Blood Pressure: Effects of FactorsFactors

BP is blood pressureBP is blood pressure BP is affected by age, weight, time of day, exercise, BP is affected by age, weight, time of day, exercise,

body position, emotional statebody position, emotional state CO is the amount of blood pumped out of the left CO is the amount of blood pumped out of the left

ventricle per minuteventricle per minute PR is peripheral resistance, or the amount of friction PR is peripheral resistance, or the amount of friction

blood encounters as it flows through vesselsblood encounters as it flows through vessels Narrowing of blood vessels and increased blood Narrowing of blood vessels and increased blood

volume increases PRvolume increases PR BP = CO BP = CO PR PR

Blood Pressure: Effects of FactorsBlood Pressure: Effects of Factors Neural factorsNeural factors

Autonomic nervous system adjustments (sympathetic Autonomic nervous system adjustments (sympathetic division)division)

Renal factorsRenal factors Regulation by altering blood volumeRegulation by altering blood volume Renin—hormonal controlRenin—hormonal control

TemperatureTemperature Heat has a vasodilating effectHeat has a vasodilating effect Cold has a vasoconstricting effectCold has a vasoconstricting effect

ChemicalsChemicals Various substances can cause increases or Various substances can cause increases or

decreasesdecreases DietDiet

Factors Determining Blood Factors Determining Blood PressurePressure

Figure 11.21

Variations in Blood PressureVariations in Blood Pressure Normal human range is variableNormal human range is variable

NormalNormal• 140–110 mm Hg systolic140–110 mm Hg systolic• 80–75 mm Hg diastolic80–75 mm Hg diastolic

HypotensionHypotension• Low systolic (below 110 mm HG)Low systolic (below 110 mm HG)• Often associated with illnessOften associated with illness

HypertensionHypertension• High systolic (above 140 mm HG)High systolic (above 140 mm HG)• Can be dangerous if it is chronicCan be dangerous if it is chronic

Capillary ExchangeCapillary Exchange Substances exchanged due to Substances exchanged due to

concentration gradientsconcentration gradients Oxygen and nutrients leave the bloodOxygen and nutrients leave the blood Carbon dioxide and other wastes leave the Carbon dioxide and other wastes leave the

cellscells

Developmental Aspects of Developmental Aspects of the Cardiovascular Systemthe Cardiovascular System

A simple “tube heart” develops in the A simple “tube heart” develops in the embryo and pumps by the fourth weekembryo and pumps by the fourth week

The heart becomes a four-chambered The heart becomes a four-chambered organ by the end of seven weeksorgan by the end of seven weeks

Few structural changes occur after the Few structural changes occur after the seventh weekseventh week

Developmental Aspects of Developmental Aspects of the Cardiovascular Systemthe Cardiovascular System

Aging problems associated with the Aging problems associated with the cardiovascular system includecardiovascular system include Venous valves weakenVenous valves weaken Varicose veinsVaricose veins Progressive atherosclerosisProgressive atherosclerosis Loss of elasticity of vessels leads to Loss of elasticity of vessels leads to

hypertensionhypertension Coronary artery disease results from vessels Coronary artery disease results from vessels

filled with fatty, calcified depositsfilled with fatty, calcified deposits

the cardiovascular system gps: sap4. students will analyze the physical, chemical, and biological...

Documents

heart slide

heart ventricle relaxation

heart figure

ventricle slide

heart separations

heart location thorax

valves av valves

right av valve2