How can we help?

You can also find more resources in our Help Center.

184 terms

CARDIOVASCULAR SYSTEM

STUDY
PLAY
WHAT IS THE HEART'S FUNCTION?
Provides the driving force for the cardiovascular system
WHAT ARE THE FUNCTIONS OF THE CARDIO SYSTEM?
1) Transport and distribute essential substances to tissues 2) Remove metabolic byproducts 3) Regulation of body temp 4) Humoral communication 5) Adjustment of O2 and nutrient supply in diff. physiologic states
ARTERIES (EFFERENT VESSELS)
Carry blood away from the heart- serves as distribution channels to organs
VEINS (AFFERENT VESSELS)
Return blood to the heart and serves as blood reservoirs
CAPILLARIES
Small vessels that interconnect the smallest arteries and veins and thin wall permits diffusion of gases, nutrients and waste b/w plasma and interstitial fluids
MEDIASTINUM
Located in thoracic cavity
BASE
Superior border which the great vessels (largest veins and arteries) are attached
APEX
Located in LEFT ventricle- the pointed tip b/w 5th & 6th rib
RIGHT BORDER
Right atrium
LEFT BORDER
Left atrium
INFERIOR BORDER
Right and Left ventricles
SUPERIOR BORDER
Great vessels/ base of heart
3 LAYERS OF THE HEART WALL
1) Epicardium 2) Myocardium 3) Endocardium
EPICARDIUM (VISCERAL PERICARDIUM)
Outer layer of heart wall
MYOCARDIUM
Middle layer of heart wall; Bulk of the heart
ENDOCARDIUM
Inner Layer of heart wall; filled with simple squamous epithelium
LAYERS OF THE PERICARDIUM
1) Fibrous pericardium 2) Serous pericardium
PERICARDIUM
Double walled sac w/c encloses the heart
FIBROUS PERICARDIUM
Outermost layer of the heart; Prevents over distention from continuous filling of heart; Anchors heart to surrounding structures
SEROUS PERICARDIUM
2 Layers: 1) Parietal layer: outermost of 2 layers, lines the internal surface of fibrous pericardium 2) Visceral Layer (Epicardium) covers and adheres closely to outer surface of heart
PERICARDIAL CAVITY
Helps diagnose disease; Found b/w partietal and visceral layers; contains serous fluid secreted by membranes
PERICARDITIS
Infection of the pericardium; inflamed surfacrs rub together producing scratching sound heard through steth.
CARDIAC TAMPONADE
Compression of the heart due to fluid accumulation in pericardial cavity; caused by traumatic injuries causing bleeding into pericardial cavity
4 CHAMBERS OF THE HEART
2 Atria (left and right) and 2 Ventricles (left and right); Each side consisting of 1 atrium, 1 ventricle, 2 valves
LANDMARKS: INTERATRIAL SEPTUM & INTERVENTRICULAR SEPTUM
Much thicker when heart is divided longitudinally
ATRIOVENTRICULAR GROOVE
Visable on heart's surface
CORONARY SULCUS
Atrial ventricular sulcus; deep groove taht marks border b/w atria and ventricles; Wraps around circum of heart; contains fat; contains coronary vessels
ANTERIOR INTERVENTRICULAR SULCUS /POSTERIOR..
Separates the left an right ventricles, shallower groove; contains large amt of fat; contains coronary vessels.
AURICLE
Broad, flattened process that resembles external ear; right auricle is Larger
ATRIA
2 left and 2 right; Upper chambers of heart; receiving chambers for blood returning to heart from both systemic circuit (rec'vd by right atria) and pulmnary circuit (rec'vd by left atria)
3 VESSELS OF THE HEART
1) Superior vena cava 2) Aorta 3) Branches of right pulmonary artery
LEFT PULMONARY ARTERY
Has 4 pulmonary veins; left and right, LV, RV, RA, LA
4 VALVES OF THE HEART
RIGHT SIDE: 1) Tricupsid Valve (RA-->RV) 2) Pulmonic Valve (RV-->PA) LEFT SIDE: 1) MItral Valve (LA-->LV) 2) Aortic Valve (VL-->Aorta)
FUNCTION OF VALVES
Regluate blood flow; Unidirectional; Prevents back flow
LEFT SIDE OF HEART
Works against higher pressure system
RIGHT ATRIUM
Blood returns here via 3 veins: Superior Vena Cava, Inferior Vena Cava, Coronary Sinus
SUPERIOR VENA CAVA (SVC)
Returns blood from the head, neck and thorax
INFERIOR VENA CAVA (IVC)
Returns blood from areas below the diaphragm
CORONARY SINUS
Collects blood draining from the myocardium itself
TRICUSPID ORIFICE
Area where the right atria pumps blood to the right ventricle
LEFT ATRIUM
Blood returns to left atrium via 4 pulmonary veins: 2 left & 2 right (best seen in posterior view of heart); returning blood is rich in O2
MITRIAL ORIFICE
Area where the left atria pumps blood to left ventricle
VENTRICLES
2 ventricles: Left and right; lower chambers of the heart, comprise most of the mass in heart; thick walled compared to atria
TRABECULAE CARNAE
Series of irregular muscle ridges in ventricular chambers (internal surfaces); includes MODERATOR BAND (right side) w/c contains portion of conducting system
PAPILLARY MUSCLES
Cone like muscle bundles assoc. w/ heart valves; attached to chordae tendineae; together anchoring valve flaps in closed position
RIGHT VENTRICLE
Forms most of heart's anterior surface; pumps blood through Pulmonary Semilunar Valve into the Pulmonary Trunk and into the lungs for gas exhange
PULMONARY SEMILUNAR VALVE
Separates the right ventricle and pulmonary trunk
PULMONARY TRUNK
First Vessel of the pulmonary circuit
LEFT VENTRICLE
Dominates inferior surface; more larger and musclular than right; more muscle nec. bec. LV pumps blood against greater pressure; Pumps blood into the systemic circuit
3 CARDIAC CIRCUITS
1) Pulmonary 2) Systemic 3) Coronary
AORTA
First vessel of the systemic circuit; needs high pressure to output to organs away from heart; Peripheral
AORTIC SEMILUNAR VALVE
Separtes the left ventricle and the right Aortic trunk
RIGHT & LEFT VENTRICLE
Pump the same volume of blood per beat
HEART VALVES
Regulate blood flow, prevent back flow; blood flow is unidirectional (from atria to ventricles to vessels);
4 HEART VALVES ENFORCE?
Unidirectional flow
CUSPS
Fibrous flaps that form Bicuspid and Tricuspid valves (AV Valves); prevents valves from opening backwards
CHORDAE TENDINEAE
Tiny white collagen cords attached to each AV valve flap; attached to papillary muscles
ATRIOVENTRICULAR (AV) VALVES
Found b/w atria and ventricle: 2 main valves: TRICUSPID & BICUSPID (MITRAL) valve; Located at base of atrio-ventricular junction; prevents backflow into atria when ventricles contract
TRICUSPID VALVE
Right AV valve
BICUSPID VALVE (MITRAL)
Left AV valve
VENTRICULAR DISTOLE
AV valves are open; allowing blood to flow into the ventricles
VENTRICULAR SYSTOLE
AV valves are closed; preventing backflow into atria
VENTRICULAR CONTRACTION
Blood pressure closes valve cusps
SEMILUNAR VALVES
Found b/w vetricle and artery; consist of 3 semilunar (half-moon shaped) cusps of thick connective tissue; arrangement of cusps prevent backflow into ventricle as ventricle relaxes
TWO SEMILUNAR VALVES
1) Aortic (LEFT) 2) Pulmonary (RIGHT); located at base of large vessels; prevent backflow into ventricles when relaxed
VALVULAR DISEASE (2 TYPES)
1)Regurgitation (insufficiency) or Prolapse; 2) Stenosis (Scarred down)
REGURGITATION (INSUFFICIENCY) PROLAPSE
1 TYPE of valvular disease; valve does not close properly; blood leaks backwards; results in reduced blood flow to organs
STENOSIS
2nd Type of valvular disease; Valve doesn't open fully, creates extra workload for heart, making heart bigger, which ultimately fails to compensate
PULMONARY CIRCUIT
Right side of heart;B/w heart and lungs: carries blood to and from gas exchange surfaces of lungs
SYSTEMIC CIRCUIT
Left side of heart; b/w heart and teh rest of the body tissues; carries blood to and from the body
CORONARY CIRCUIT
Provides nourishment ot heart muscle itself; irrigates heart; arising from base of aorta to Right coronary artery and left coronary artery to multiple cardiac arteries to capillaries to multiple cardiac veins to coronary sinus to right atrium.
MARGINAL ARTERY
1ST BRANCH: irrigates right lateral aspect of the heart (R Ventricle)
CORONARY (SYSTEM) ARTERIES
Arising from base of aorta; RIGHT & LEFT
RIGHT CORONARY
2 BRANCHES that course right side of heart
LEFT CORONARY
2 BRANCHES that course left side of heart
POSTERIOR INTERVENTRICULAR ARTERY
2ND BRANCH: Posterior descending artery (clinical name);runs to apex of heart; supplies the posterior wall of heart
CIRCUMFLEX ARTERY
2ND BRANCH: Runs along atrioventricular groove; irrigates the left atrium and the posterior walls fo the left ventricle
ANTERIOR INTERVENTRICULAR ARTERY
1ST BRANCH: Left anterior descending artery (clinical name);irrigates the interventricular septum and the anterior walls of both vetnricles
CARDIAC VEINS
Collects venous blood (venous return); joined together making the Coronary Sinus w/c empties blood into the RA
CORONARY SINUS
5 tributaries: 1) The Great Cardiac Vein 2) Middle Cardiac Vein 3) Small Cardiac Vein 4) Posterior Cardiac Vein 5) Anterior Cardiac Vein
THE GREAT CARDIAC VEIN
Found in anterior interventricular sulcus; drains blood supplied by anterior interventricular artery
MIDDLE CARDIAC VEIN
Found in posterior interventricular sulcus; drains blood from the posterior interventircular artery
SMALL CARDIAC VEIN
Found along the right inferior margin; drains the posterior surface of the right atrium and ventricle
POSTERIOR CARDIAC VEIN
Drains blood supplied by the circumflex artery
ANTERIOR CARDIAC VEIN
Drains the anterior surface of the circumflex ventricle; empties directly into the right atrium
WHICH SIDE WORKS HARDER?
Left side; if coronary is blocked it is the most alarming situation
CONDUCTING SYSTEM
In a single cardiac contraction/ heartbeat, the entire heart contracts in series; frist atria then ventricles
2 TYPES OF CARDIAC MUSCLE CELLS
1) Conducting Cells (Autorhythmic Cells) 2) Contractile Cells
CONDUCTING CELLS (AUTORHYTHMIC CELLS)
Controls and coordinates heartbeat
CONTRACTILE CELLS
Produce the powerful contractions that propel blood
INTRINSICALLY
Force of contraction controlled by heart tissue itself
EXTRINSICALLY
Force of contraction controlled through the influences of nerve signals, hormones and other blood-borne substances
AUTOMATICITY
Cardiac muscle tissue contracts automatically
SINOATRIAL NODE (SA NODE)
Pacemaker; located in the posterior wall of the right atrium; communicates with AV node
TURBULENCE
Swirling action that disturbs smooth flow of liquid
TOTAL PERIPHERAL RESISTANCE (TPR)
The combined resistance of all blood vessels within the systemic circulation
RESISTANCE VESSELS
Small arteries and arterioles
MEAN ARTERIAL PRESSURE (MAP)
The driving force for blood flow
MEDULLA OBLONGATA
Adjusts cardiac output and peripheral resistance
CARDIOACCELERATORY CENTER
Contains sympathetic neurons w/c release norepinephrine onto the cardiac cells; increases heart rate and increases heart's contractile strength; projects to SA and AV nodes and bulk of myocardium
CARDIOINHIBITORY CENTER
Contains parasympathetic neurons; releasing acetylcholine onto cardiac cells; decreasing heart rate but NO change in heart's contractile strength; projects via vagus nerve, CNX to SA & AV nodes
PARASYMPATHETIC & SYMPATHETIC NEURONS
At rest both release neurotransmitters onto the heart, but parasympathetic neurons release more
EPINEPHRINE
Hormone released by adrenal medulla
THYROXINE
Hormone released by thyroid gland; increases metabolic rate, increases heartrate
4 PHASES OF CARDIAC CYCLE
1) Ventricular Filling 2) Isovolumetric Contraction 3) Ventricular Ejection 4) Isovolumetric Relaxation
VASOMOTOR CENTER
1) Vasoconstriction 2) Vasodilation
VASOCONSTRICTION
Controlled by adrenergic nerves
VASODILATION
Controlled by cholinergenic nerves
ADH
Targets kidney; Increases water reabsorption, blood volume, blood pressure
ANGIOTENSINOGEN
Produced by liver; Angiotensin I (ACE)(produced by Renin) to Angiotensin II causing vasoconstriction; Increases ADH secretion, Increases Aldosterone secretion
ALDOSTERONE
Produced by kidney; increases sodium reabsorption, blood volume, blood pressure
VENTRICULAR FILLING
Blood filling ventricle, AORTIC valve CLOSED, MITRAL valve OPEN
ISOVOLUMETRIC CONTRACTION
1st Heart sound (LUBB); Ventricle contracting but volume not changing. SL & AV valves CLOSED
VENTRICULAR EJECTION
Blood ejected from ventricle; AORTIC valve OPEN; MITRAL (AV) valve CLOSED
ISOVOLUMETRIC RELAXATION (DISTOLE)
2nd Heart sound (DUBB); Sl & AV valves CLOSED
ABSOLUTE REFRACTORY PERIOD
Period in w/c u cannot stimulate another/ propagate action potential
SYSTOLIC PRESSURE
Contraction; peak of contraction/ peak arterial pressure; Average = 120 mmHg
DIASTOLIC PRESSURE
Relaxation: lowest arterial pressure; Average = 70-80 mmHg
BLOOD VOLUME
Quanitity of blood in cardiovascular system; varies from Male 5-6 L and Femals 4-5 L
END DIASTOLIC VOLUME (EDV)
Volume of blood in ventricle before systole; 120 ml (normal)
END SYSTOLIC VOLUME (ESV)
Volume of blood left in ventricle at the end of systole; 50 ml (normal)
EJECTION FRACTION
The % of blood ejected per heart beat; ratio b/w EDV/ESV; avg= 70 ml (60-65% avg)
STROKE VOLUME
The amount of blood pumped out of each ventricle during a single beat (cycle) during the Ventricular Ejection phase; SV (70)= EDV (120) - ESV(50)
CARDIAC OUTPUT (CO)
Amount of blood pumped by each ventricle in one minute; CO =HRxSV; any change in EDV, ESV, HR affects CO
LEFT & RIGHT SIDE OF HEART
Have identical stroke volumes;What's happening on the left side is also happening on the right; only differ. is pressure involved
LEFT VENTRICLE
Must contract harder to open SL valve becuz systemic circuit is under higher pressure than pulmonary circuit
LV SV > RV SV
Blood would back up in the systemic circuit
LV SV < RV SV
Blood would back up in the pulmonary circuit
FRANK-STARLING LAW OF THE HEART
Ensures that the SV are equal in both LV & RV; more cardiac muscle is stretched w/in phisological limits the more forcibility it will contract (rubberband analogy)
HEART RATE (HR)
The # of cardiac cycles per minute (systolic/diasolic); Autonomic NS; MALE avg= 64-72/min; FEMALE avg= 72-80/min;
BLOOD PRESSURE
Force generated against arterial walls per unit of area in mm Hg
PRELOAD
Amount the ventricles are stretched; greater the EDV= the greater the preload;
AFTERLOAD
Amount of tension the contracting ventricle must produce to force open the SL valve and eject blood; afterload increases, SV decreases; Aortic blood pressure
CONTRACTILITY
The contractile force of the heart; CALCIUM IONS; the more Ca2+ the more forceful the contraction
CONDUCTING SYSTEM (ACTION POTENTIAL AUTORHYTHMICICTY; SA NODE)
1) Prepotential; K+ channels begin to close, Ca2+ begin to open 2) Depolarization Phase: Ca2+ channels OPEN (upstroke) K+ channels CLOSED, CALCIUM INFLUX 3) Repolarization Phase: Ca2+ channels CLOSED, K+ channels OPEN, POTASIUM EFFLUX
CONTRACTING SYSTEM (ACTION POTENTIAL)
1) Depolarization Phase: Na+ OPEN, K+ begin to CLOSE, Ca+ begin to OPEN; SODIUM INFLUX 2) Plateau Phase (early repolarization): Na+ channels CLOSE; Some K+ OPEN, Ca+ OPEN (producing plateau by slowing further repol.) CALCIUM INFLUX 3) Repolarization: Ca+ channels CLOSED, Many K+ OPEN; POTASSIUM EFFLUX
FUNCTIONS OF VESSELS
Carry blood,exchange,transport,regulate BP, direct blood flow
3 MAJOR TYPES OF VESSELS
1) Arteries 2) Capillaries 3) Veins
ARTERIES
Take blood AWAY from heart
CAPILLARIES
Smallest and most numerous single celled, simple squamous; permits exchange, provides direct acces to cells, Connects arteries and veins
VEINS
Take blood TOWARD heart; Contains valves to ensure blood flow in one direction;conduit; carrying deoxygenated blood from tissues to RA; Reservoir
3 TYPES OF ARTERIES
1) Elastic 2) Muscular 3) Arterioles
ELASTIC ARTERIES
Aorta, Carotid, Illiac; Thick medial layer; Elastin and Smooth muscle cells; Serves as blood reservoir (accmodates SV); Acts as a recoil system when ventricles relax
MUSCLUAR ARTERIES
Femoral; Serves as distributing channels; large lumen to wall thickness; Large lumen minimizes the pressure drop
ARTERIOLES
Has largest amount of smooth muscle; valves of the circulation; controls volume of blood flow to various vessels beds; Site of major pressure drop in Cardio syst. Thick layer smooth muscle; Narrow lumen; control of flow via smooth muscle tone
STRUCTURE OF BLOOD VESSELS
1) Tunica Interna (Intima); INNERMOST 2) Tunica Media; MIDDLE 3) Tunica Externa (Adventitia); OUTERMOST
3 TYPES OF CAPILLARIES
1) Continuous (most common) 2) Fenestrated (more porous; permeable) 3) Sinusodial ( Greatest Permeablity)
VEINS VS. ARTERIES
Veins have Valves Arteries don't
VEIN VALVES
Folds of tunica intimia; prevents backflow; compression pushes blood toward heart
LYMPHATIC VESSELS
Simple squamous; 1 cell layer thick; large pores; valves;smooth muscle; prevents edema; filariasis (elephantitis) transmitted by mosquitoes, block lymphatic flow; removes fluids from interstitium
VENOUS SYSTEM
Designed to store not pump
EFFECTS OF LEFT SIDE OF HEART
Shortness of breath; works harder
EFFECTS OF RIGHT SIDE OF HEART
Pineal edema
OHM'S LAW
Q = AP/R; Q =flow AP = pressure gradient b/w two points (pressure at heart, pressure at the peripheral capillary beds); R= Resistance; P & R directionaly proportional; Increase Pressure, Increase Flow
MAP (MEAN ARTERIAL PRESSURE FORMULA)
PP/3 + DP
PP (PULSE PRESSURE FORMULA)
SP-DP (SYSTOLIC PRESSURE - DIASTOLIC PRESSURE)
POISEUILLE'S LAW (LAMINAR FLOW)
Q= AP/R; R= 8uL/r4; u= viscosity (how thick/ diluted), L= length of tube (length to travel); r= radius of tube; increase radius, decrease resistance; vaslodialte or incrase force of cotnraction= increase of flow
RESISTANCE
Amount of friction blood encounters as it passes through the vessels; Peripheral resistance
3 IMPORTANT SOURCES OF RESISTANCE
1) Blood Viscosity 2) Total Blood Vessel Length 3) Blood Vessel Diameter
BLOOD VISCOSITY
Thickness or stickiness of blood; "water vs. shake" w/c is easier?
TOTAL BLOOD VESSEL LENGTH
Longer the length the greater the resistance (more friction); "short straw vs. long straw"; relatively normal in healthy indiv.
BLOOD VESSEL DIAMETER
Diameter changes often; most impt. of 3 sources
AORTA VS. CAPILLARIES
Aorta= one; Capillaries= millions; makes pressure higher in aorta than capillaries
LAMINAR FLOW
Less resistence; Smooth orderly flow
TURBULENT FLOW
The motion of a fluid having local velocities and pressures that fluctuate randomly
FACTORS THAT INCREASE ARTERIAL BLOOD PRESSURE
Increased HR, Increased Peripheral resistance; Increased SV
CAPILLARY BLOOD PRESSURE
Very low- blood is now far from heart, much of energy has been lost to friction
BARORECEPTOR REFLEX
Reflex is initiated by stretch; found primarily in aortic arch and carotid sinuses
CAPILLARY FILTRATION
When blood goes from arterial to venous it's more concentrated b/c of hydrostatic pressure; pushes fluid out of capillaries (filtration) into intersistial space
CAPILLARY HYDROSTATIC PRESSURE
Tends to force fluid out of capillary
EKG/ ECG (ELCTROCARDIOGRAPHY)
Diagonstic tool for evaluation of cardiovascular (CV) diseases; measures electrical activites; checks conductivity & rhythm; monitor or evaluate heart conditions
4 TYPES OF SHOCK
1) Hypovolemic 2) Cardogenic 3) Septic 4) Neurogenic
MURMER
Vibrations of longer duration than the heart sounds
2 TYPES OF MURMERS
1) Systolic murmer (most common) 2) Diastolic murmer (bad one)
PATHWAY OF BLOOD
Deoxygenated blood from body tissues, SVC, IVC, coronary sinus drain into RA, Tricuspid valve, RV, Pulmonary SL valve, pulmonary trunk, pulmonary arteries, lung tissues, pulmonary veins (now oxygenated), LA, bicuspid valve, LV, Aortic SL valve, aorta, body tissues and coronary arteries
SYSTEMIC CIRCUIT (TO & FROM BODY)
LV, Aorta, Systemic arteries, Systemic Capillaries,Systemic veins, Venae Cavae, RA
PULMONARY CIRCUIT (TO & FROM GAS EXCHANGE SURFACE OF LUNGS)
RV, Pulmonary Trunk, Pulmonary Arteries, Pulmonary Capillaries, Pulmonary Veins, Left Atrium
CORONARY CIRCULATION
LV, Aorta, R & L coronary arteries, Coronary Capillaries, Coronary Veins, Coronary Sinus, RA
P WAVE
Always positive; atrial depolarization; contractions occur after the atrial depolarization wave
QRS WAVE (COMPLEX)
Negative; deflects downward; ventricular depolarization
Q & S WAVES
Both Negative
R WAVE
Always positive
T WAVE
Ventricular Repolarization
U WAVE
Follows T Wave; represents LATE ventricular repolarization of Bundle of HIS and Purkinje fibers; not on all ECG's; prescence can indicated elctrolyte imbalance