human circulation ib master 2016

05/03/2305/03/23 01:2701:27 cottinghamcottingham

Transport - Transport - TheThe

CardiovascularCardiovascularSystemSystem

Essential IdeaEssential Idea The blood system The blood system

continuously transports continuously transports substances to cells and substances to cells and simultaneously transports simultaneously transports waste products away from waste products away from cells. cells.



General Functions ofGeneral Functions of TransportTransport SystemsSystems......

Maintain internal homeostasisMaintain internal homeostasis Deliver oxygen, nutrients, Deliver oxygen, nutrients,

hormoneshormones Remove CORemove CO22 and other metabolic and other metabolic

wastes (urea)wastes (urea) Maintain cells in a fluid Maintain cells in a fluid

environment that allows exchange environment that allows exchange of these many materialsof these many materials


Blood Blood VesselsVessels


Arteries are adapted to deal with blood under HIGH

pressureThick outer wall

Thick layer of muscle and elastic fibres

Narrow lumen(space through which blood flows)

Veins are adapted to deal with blood under LOW

pressure

Wide lumen

Thinner outer wall than arteriesThinner layer of muscle and elastic fibres than arteries


Which is the Artery and Vein???Which is the Artery and Vein???


Veins also have valves to……keep blood flowing in the right direction

…TOWARDS heart …AWAY

FROM heart

Valves open to allow blood to flow…

Valves close to stop blood flowing…


Carbon dioxide and other wastes diffuse from the cells to the

blood

Oxygen, nutrients, and hormones diffuse from the blood to the

cells

Capillaries are adapted for ……exchange of materials.

…only one cell thick

…allow plasma to leak in and out

(They are just large enough for a red blood cell to squeeze through)This means that blood in the capillaries moves very…SLOWLY

Gaps between cells in capillary wall…

Wall of capillary is very thin…

The capillaries are very narrow.

Cells in Body Tissues


The Smallest Blood VesselsThe Smallest Blood Vessels


ArteriesArteries Vessels that carry Vessels that carry

blood blood AWAYAWAY from the from the heart.heart.

Blood High in Blood High in oxygenoxygen (except (except Pulmonary Artery)Pulmonary Artery)


VeinsVeins Vessels that Vessels that

carry blood carry blood TOWARDTOWARD the the heart from body heart from body tissues. One tissues. One direction.direction.

Blood Low in Blood Low in Oxygen (Except Oxygen (Except Pulmonary Vein)Pulmonary Vein)

..


CapillariesCapillaries Smallest blood Smallest blood

vessels.vessels. 1 layer of 1 layer of

endothelial cells endothelial cells thick. HAVE ONE thick. HAVE ONE WAY VALVES.WAY VALVES.

Red blood cells Red blood cells pass through in pass through in single filesingle file

Gases diffuse in Gases diffuse in lungs.lungs.


Major Veins and ArteriesMajor Veins and Arteries Inferior and Superior Vena CavaInferior and Superior Vena Cava

– return blood to the right atrium – return blood to the right atrium (BLUE)(BLUE)

Pulmonary ArteryPulmonary Artery – carries blood – carries blood from heart to the lungs (BLUE)from heart to the lungs (BLUE)

Pulmonary Vein Pulmonary Vein – – carries blood carries blood from lungs to the heart (RED)from lungs to the heart (RED)

Aorta –Aorta – carries blood from the carries blood from the heart to all body parts. (RED)heart to all body parts. (RED)


Pathway of CirculationPathway of Circulation

You must be able to traceYou must be able to traceblood from anywhere in theblood from anywhere in thebody and back to that point.body and back to that point.

Pulmonary CirculationPulmonary Circulation – – involves the LUNGS and ALL involves the LUNGS and ALL parts to the heart except the parts to the heart except the LEFT VENTRICLE and AORTA.LEFT VENTRICLE and AORTA.

Systemic CirculationSystemic Circulation – – begins in the LEFT begins in the LEFT VENTRICLE and ends before VENTRICLE and ends before entering the RIGHT ATRIUM.entering the RIGHT ATRIUM.

Exchange of gases on the Exchange of gases on the cellular level in capillaries.cellular level in capillaries.

Coronary CirculationCoronary Circulation – – supplies blood to the heart.supplies blood to the heart.

Hepatic Portal CirculationHepatic Portal Circulation – – from the digestive system to from the digestive system to the liver. Excess glucose the liver. Excess glucose leaves blood in the liver.leaves blood in the liver.

Renal CirculationRenal Circulation – carries – carries blood to and from the blood to and from the kidney.kidney.

WILLIAM HARVEYWILLIAM HARVEY1578-16571578-1657

READREAD about his discovery of about his discovery of the circulation of blood with the circulation of blood with

the heart acting as the pump.the heart acting as the pump.



THE HEARTTHE HEART


The Heart and Blood Flow in The Heart and Blood Flow in MammalsMammals

General:General: Double-sided pump.Double-sided pump.Blood content:Blood content: Right: low in O2, high in Right: low in O2, high in

CO2CO2 Left: high in O2, low in Left: high in O2, low in

CO2CO2Basic Structure:Basic Structure: Right and Left side Right and Left side

separated by the separated by the SEPTUM.SEPTUM.

AtriumAtrium – upper chambers. – upper chambers. VentriclesVentricles – lower – lower

chambers.chambers. Chambers separated by Chambers separated by

valvesvalves Flow from the heart Flow from the heart

separated by valves.separated by valves.


The Mammalian HeartThe Mammalian HeartINNER BODY

http://www.innerbody.com/anim/heart.html

Cardiac MuscleCardiac Muscle Myogenic - ABILITY OF

THE HEART TO CONTRACT WITHOUT BEING STIMULATED BY AN “OUTSIDE” NERVE.

Blood supplied by coronary arteries.

Involuntary Striated


Properties of Cardiac MuscleProperties of Cardiac Muscle Intercalated discs –

separate cardiac muscle cells. Allows for rapid

movement of ions Rapid conduction of

nerve impulse Branched – allow

impulses to move rapidly.



The Human HeartThe Human Heart


Valves and NodesValves and Nodes


ValvesValvesVALVESVALVES

Atrioventricular – allows Atrioventricular – allows blood to flow between atria blood to flow between atria and ventricleand ventricle

Semilunar – allows blood to Semilunar – allows blood to flow from ventriclesflow from ventriclesCardiac Angiography

http://www.entusa.com/coronary-angiography/videos/angiography_flv0.htm


CARDIAC CYCLE – Control of CARDIAC CYCLE – Control of the Heartbeat!!!the Heartbeat!!!

Nodes Nodes Sino Atrial – (SAN) – Sino Atrial – (SAN) –

Wall of right atriumWall of right atrium PacemakerPacemaker Initiates contractions Initiates contractions

Atrioventricular (AVN) – Atrioventricular (AVN) – Wall of lower RA.Wall of lower RA. Receives impulse from SANReceives impulse from SAN

Connecting Fibers – Connecting Fibers – BBundle of Hisundle of His connected to connected to Purkinje Purkinje

TissueTissue pass through septum to base of heart to all pass through septum to base of heart to all

parts of the ventriclesparts of the ventricles



• The “pacemaker” sets the tempo The “pacemaker” sets the tempo of the heartbeat.of the heartbeat.


Cardiac CycleCardiac Cycle


Cardiac CycleCardiac Cycle1.1. Walls of atria contract (Systole = 0-1)Walls of atria contract (Systole = 0-1)

SAN fires – ventricles about 70% fullSAN fires – ventricles about 70% full Pushes blood from atria to ventriclePushes blood from atria to ventricle AV open; Semilunar closedAV open; Semilunar closed Ventricles fill; volume risesVentricles fill; volume rises

2.2. Walls of ventricles contract(Systole = 1-Walls of ventricles contract(Systole = 1-4.2)4.2)

More powerful; More powerful; Initial rise in blood pressure in ventricles: AV valves close; Initial rise in blood pressure in ventricles: AV valves close; Further rise in BP: SL valves openFurther rise in BP: SL valves open Blood PUMPED into aorta and pulmonary arteryBlood PUMPED into aorta and pulmonary artery Volume decreaseVolume decrease

Events of the Cardiac CycleEvents of the Cardiac Cycle3. 3. Ventricles stop contracting Ventricles stop contracting (diastole = (diastole = 4.2-9)4.2-9)

Pressure fallsPressure falls Semilunar valves close – prevents Semilunar valves close – prevents

backflowbackflow Blood pressure in Vena cava push Blood pressure in Vena cava push

blood into atriablood into atria Ventricular pressure falls below atrial Ventricular pressure falls below atrial

pressure: AV valves openpressure: AV valves open



CONTROL OF HEARTRATECONTROL OF HEARTRATE1.1. MyogenicMyogenic

1.1. Pacemaker – region of the heart (wall of Pacemaker – region of the heart (wall of R.A.) responsible for initiating contraction.R.A.) responsible for initiating contraction.

2.2. Nerves from the brainstem carry Nerves from the brainstem carry messages to pacemaker - speed up messages to pacemaker - speed up heartbeatheartbeat

3.3. Adrenaline – carried to heart in blood Adrenaline – carried to heart in blood --- tells pacemaker to speed up --- tells pacemaker to speed up heartbeat.heartbeat.

CardiologyCardiology


Basic Techniques in Basic Techniques in CardiologyCardiology


Measuring Heart RateMeasuring Heart Rate Typically uses:Typically uses:

Radial artery in Radial artery in wristwrist

Carotid artery in Carotid artery in neckneck

DO NOT USE DO NOT USE THUMB!THUMB! It has its own pulse.It has its own pulse.

Variables affecting:Variables affecting:

Demand for oxygenDemand for oxygen Demand for glucoseDemand for glucose Removal of CORemoval of CO2 2 ExerciseExercise Body PositionBody Position TemperatureTemperature


Electrocardiograms (ECG)Electrocardiograms (ECG) P wave – atrial P wave – atrial

systolesystole

QRS – Ventricular QRS – Ventricular SystoleSystole

T – ventricular T – ventricular diastole diastole


Artificial PacemakersArtificial Pacemakers Inserted to treat Inserted to treat

malfunctioning SAN malfunctioning SAN OROR

A block in the A block in the conduction pathway.conduction pathway.

Can provide a regular Can provide a regular or just when needed or just when needed impusle.impusle.

Regulates heart rate Regulates heart rate and rhythm and rhythm


PacemakersPacemakers


DefibrillatorsDefibrillators Treats ventricular

fibrillation

Application of 2 paddles in a diagonal line – with the heart in the middle

Detects fibrillation Electrical shock to

return to normal rhythm


Stethoscopes and Heart SoundsStethoscopes and Heart Sounds

11stst sound – closing of AV valve (lup) sound – closing of AV valve (lup) 22ndnd sound – closing of SL Valve (dup) sound – closing of SL Valve (dup)


Measuring Blood PressureMeasuring Blood Pressure Cuff placed around Cuff placed around

upper arm (Brachial upper arm (Brachial Artery)Artery)

Blood is constrictedBlood is constricted Cuff slowly deflatedCuff slowly deflated Stethoscope used for Stethoscope used for

sounds of blood flowsounds of blood flow 11stst sound systolic sound systolic 22ndnd diastolic diastolic


Blood PressureBlood Pressure


Hypertension and Hypertension and ThrombosisThrombosis

Causes – not clear Risk factors:

Obesity Lack of exercise Too much salt Too much

alcohol/coffee Smoking Genetic

Consequences: Kidney damage CHD

Causes:Causes: High LDLHigh LDL High SAT/TRANS FATHigh SAT/TRANS FAT Inactivity Inactivity SmokingSmoking HypertensionHypertension EthnicEthnic GeneticGenetic

Consequences:Consequences: Heart AttackHeart Attack StrokeStroke Atherosclerosis Atherosclerosis


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human circulation ib master 2016

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