Open Vs Closed Circulatory Open Vs Closed Circulatory SystemSystem
OpenOpen
Open ended vessel which blood Open ended vessel which blood leavesleaves
Blood flows around cellsBlood flows around cells
Enters heart through openingsEnters heart through openings
ClosedClosed
Blood remains in vesselsBlood remains in vessels
Materials exchanged by diffusionMaterials exchanged by diffusion
More efficient then open system, More efficient then open system, Faster and flow can be Faster and flow can be increased/decreasedincreased/decreased
Blood VesselsBlood Vessels3 main types3 main types
1. 1. ArteriesArteries (A for Away from heart) (A for Away from heart)divide into smaller vessels- Arteriolesdivide into smaller vessels- Arterioles
2. 2. VeinsVeins (to heart) (to heart)divide into smaller veins- Venulesdivide into smaller veins- Venules
3. 3. CapillariesCapillariestiny vessel (1 cell in thickness), link tiny vessel (1 cell in thickness), link arteries & veinsarteries & veins
Arteries Vs VeinsArteries Vs Veins
What have they both got in common? What is different?
Arteries Vs VeinsArteries Vs Veins
Both have the same 3 layers.Both have the same 3 layers.
Main difference is in the middle layer.Main difference is in the middle layer. 3 layers3 layers
1.1. Outer, is tough, made of protein called Outer, is tough, made of protein called collagen which prevents wall from over collagen which prevents wall from over expanding.expanding.
2.2. Middle, is muscle and elastic, it can alter the Middle, is muscle and elastic, it can alter the size of the vesselsize of the vessel
3.3. Inner, are living cells called endothelium.Inner, are living cells called endothelium.
ValvesValves Blood pressure is the force blood applies Blood pressure is the force blood applies
against the wall of a blood vessel.against the wall of a blood vessel. Blood pressure is highest in arteries, this Blood pressure is highest in arteries, this
causes the arteries to expand, which causes the arteries to expand, which causes our pulse.causes our pulse.
Pressure in veins is very weak. Ordinary Pressure in veins is very weak. Ordinary muscles help push the blood by contracting muscles help push the blood by contracting and squeezing to return blood to the heart.and squeezing to return blood to the heart.
Because pressure is low, must prevent Because pressure is low, must prevent backflowbackflow
Valves control direction of blood flowValves control direction of blood flow
ArteryArtery VeinVein
Carries blood away Carries blood away from heartfrom heart
Carries blood to heartCarries blood to heart
Blood under high Blood under high pressurepressure
Blood under low Blood under low pressurepressure
Thick wallsThick walls Thin wallsThin walls
Small LumenSmall Lumen Large LumenLarge Lumen
Blood flows in pulseBlood flows in pulse No pulseNo pulse
Blood rich in oxygenBlood rich in oxygen Blood low in oxygenBlood low in oxygen
Valves absentValves absent Valves presentValves present
CapillariesCapillaries
Tiny, branched vesselsTiny, branched vessels Walls are permeable, allow materials Walls are permeable, allow materials
to move across the wallsto move across the walls 100,000 km 100,000 km
The HeartThe Heart
Made of cardiac (slow to fatigue) Made of cardiac (slow to fatigue) muscle, surrounded by a double muscle, surrounded by a double membrane called Pericardium.membrane called Pericardium.
It contracts 100,000 times a dayIt contracts 100,000 times a day Pumps 5-20 litres of blood per Pumps 5-20 litres of blood per
minuteminute Why such a difference? 5-20Why such a difference? 5-20
Structure of the HeartStructure of the Heart Divided into 2 side by a wall called Septum.Divided into 2 side by a wall called Septum.
4 chambers, 4 chambers,
2 upper = Atria, 2 lower = Ventricles2 upper = Atria, 2 lower = Ventricles Atria & ventricles are separated by valvesAtria & ventricles are separated by valves These valves are held in place by tendonsThese valves are held in place by tendons These tendons are held in place by Papillary These tendons are held in place by Papillary
Muscles.Muscles.
Valve on right has 3 flaps, tricuspid valveValve on right has 3 flaps, tricuspid valve Valve on left has 2 flaps, bicuspid valveValve on left has 2 flaps, bicuspid valve Semilunar valves prevent blood returning to Semilunar valves prevent blood returning to
heart heart
Left atriumRight atrium
Left ventricle
Right ventricle
Tricuspid valve
Bicuspid valveTendon
Papillary Muscle
SeptumCardiac Muscle
Pericardium
Semilunar valve Semilunar valve
Pacemaker
Superior vena cava
Inferiorvena cava
Pulmonary artery
Pulmonary vein
Aorta
Blood flow in the heartBlood flow in the heart
Step 1Step 1 Deoxygenated blood enters the right Deoxygenated blood enters the right
atrium through 2 venae cavae.atrium through 2 venae cavae.
Superior - head, arms, chest.Superior - head, arms, chest.
Inferior – Lower part of body.Inferior – Lower part of body. The right atrium contracts forcing blood The right atrium contracts forcing blood
into right ventricleinto right ventricle The venae cavae close to prevent The venae cavae close to prevent
backflow backflow
Blood flow in the heartBlood flow in the heart
Step 2Step 2 When the right ventricle contracts When the right ventricle contracts
the tricuspid valve is forced closedthe tricuspid valve is forced closed Blood is then forced out of the heart Blood is then forced out of the heart
and into the lungs through the and into the lungs through the semilunar valve in the pulmonary semilunar valve in the pulmonary artery.artery.
Blood flow in the HeartBlood flow in the Heart
Stage 3 Stage 3 Oxygenated blood returns to the Oxygenated blood returns to the
heart from the lungs and enters the heart from the lungs and enters the left atrium through the pulmonary left atrium through the pulmonary veins (only vein to ever carry oxygen veins (only vein to ever carry oxygen rich blood)rich blood)
Pumped through bicuspid valve into Pumped through bicuspid valve into the left ventriclethe left ventricle
Blood flow in the heartBlood flow in the heart
Stage 4Stage 4 When the left ventricle contracts the When the left ventricle contracts the
bicuspid valve closes.bicuspid valve closes. Blood is pumped out of the heart Blood is pumped out of the heart
through the semilunar valve in the through the semilunar valve in the aortaaorta
When the ventricles relax these When the ventricles relax these valves close to stop backflowvalves close to stop backflow
Double CirculationDouble Circulation Heart is really a double pump. The 2 sides Heart is really a double pump. The 2 sides
of the heart are divided by the septum. of the heart are divided by the septum. Why is this necessary?Why is this necessary? Answer=Answer=
Hence humans have a 2-circuit circulatory Hence humans have a 2-circuit circulatory system.system.
The Pulmonary Circuit & The Systemic The Pulmonary Circuit & The Systemic CircuitCircuit
Double CirculationDouble Circulation
Pulmonary circuitPulmonary circuit
Right ventricle pumps de-oxygenated Right ventricle pumps de-oxygenated blood around the pulmonary circuit.blood around the pulmonary circuit.
This circuit is short so the walls of the This circuit is short so the walls of the ventricle are thinventricle are thin
Double CirculationDouble Circulation
Systemic CircuitSystemic Circuit
The Left ventricle pumps oxygenated The Left ventricle pumps oxygenated blood to head, arms, trunk and legs.blood to head, arms, trunk and legs.
This is a much longer route so the This is a much longer route so the walls are much thicker and stronger.walls are much thicker and stronger.
Double Vs Single CirculationDouble Vs Single Circulation
Allows oxygen rich and poor blood to Allows oxygen rich and poor blood to be kept separate.be kept separate.
Ensures the blood pressure is high Ensures the blood pressure is high
enough to reach all parts of the body.enough to reach all parts of the body.
Single circulation system can only Single circulation system can only produce low pressure, this restricts produce low pressure, this restricts activities of animal i.e. wormactivities of animal i.e. worm
Blood supply to the Heart Blood supply to the Heart itselfitself
supplied by the coronary arteriessupplied by the coronary arteries
These are connected by the aortaThese are connected by the aorta
coronary veins drain blood into the right coronary veins drain blood into the right atriumatrium
Blockage of the coronary arteries is a Blockage of the coronary arteries is a common cause for heart attackscommon cause for heart attacks
What Controls the What Controls the HeartbeatHeartbeat
The pacemaker or SA (Sino-atrial node), The pacemaker or SA (Sino-atrial node), located in the wall at the top of the right located in the wall at the top of the right atriumatrium
It sends out a regular electrical impulse It sends out a regular electrical impulse which causes the atria to contract, which causes the atria to contract, followed by the ventricles.followed by the ventricles.
Frequency of these impulses are controlled Frequency of these impulses are controlled by the brain & can speed up or slow down.by the brain & can speed up or slow down.
Pacemaker
Superior vena cava
Inferiorvena cava
Pulmonary artery Pulmonary vein
Aorta
Stages of heartbeatStages of heartbeat
DiastoleDiastole = Chambers relax = Chambers relax SystoleSystole = Chambers contract = Chambers contract
1.1. Blood enters heart (Atrial Diastole)Blood enters heart (Atrial Diastole)both Ventricles & Atria are relaxed. All both Ventricles & Atria are relaxed. All valves are closed.valves are closed.
Stages of HeartbeatStages of Heartbeat
PM cause atria to PM cause atria to contract (how?), this contract (how?), this pumps blood into pumps blood into ventricle. ventricle.
The tri & bi-cuspid The tri & bi-cuspid valves open while the valves open while the venae cava & venae cava & pulmonary veins close. pulmonary veins close. Semi-lunar valves Semi-lunar valves remain closed. remain closed.
2.2.Blood is pumped from atria to Blood is pumped from atria to ventriclesventricles
(Atrial systole)(Atrial systole)
Stages of heartbeatStages of heartbeat33. . Blood leaves the heart (Ventricular Systole)Blood leaves the heart (Ventricular Systole)
Atria relax, impulses from AV (atrio-ventricular) Atria relax, impulses from AV (atrio-ventricular) nodes cause ventricles to contract. This forces nodes cause ventricles to contract. This forces blood out through the pulmonary artery & Aortablood out through the pulmonary artery & Aorta
The pressure forces open The pressure forces open semi-lunar valves & semi-lunar valves & closes the tri & bi-cuspid closes the tri & bi-cuspid valvesvalves
Ventricles relax, closing Ventricles relax, closing the semi-lunar valves.the semi-lunar valves.
Sound of HeartbeatSound of Heartbeat
““Lub-dub” soundLub-dub” sound
Caused by valves being forced shutCaused by valves being forced shut
Lub due to bi & tri-cuspid valves closingLub due to bi & tri-cuspid valves closing
Dub due to semi-lunar valves snapping Dub due to semi-lunar valves snapping shutshut
PulsePulse When left (thick) ventricle contracts, When left (thick) ventricle contracts,
pressure of blood forced in the aorta pressure of blood forced in the aorta causes it to expand & then contractcauses it to expand & then contract
This forms a wave down the arteries This forms a wave down the arteries called pulsecalled pulse
Average adult pulse rate is 72 Average adult pulse rate is 72 beats/minbeats/min
Most people between 60-100Most people between 60-100
Blood PressureBlood Pressure
This is the force exerted by the blood This is the force exerted by the blood against the walls of the blood vesselsagainst the walls of the blood vessels
Human blood pressure is measured by Human blood pressure is measured by finding the amount of pressure needed finding the amount of pressure needed to stop the flow of bloodto stop the flow of blood
This produces 2 readings This produces 2 readings
1. When there is a pulse 2. When no pulse1. When there is a pulse 2. When no pulse
Blood PressureBlood Pressure Typical blood pressure in adults is Typical blood pressure in adults is
120/80 mm of mercury. These values 120/80 mm of mercury. These values rise with age.rise with age.
If the lower value goes over 95 mm of Hg If the lower value goes over 95 mm of Hg the person suffers from high blood the person suffers from high blood pressurepressure
High blood pressure is caused by High blood pressure is caused by blockages in arteries.blockages in arteries.
Effects of smoking on HeartEffects of smoking on Heart
Tabacco contains 400 harmful chemicals, Tabacco contains 400 harmful chemicals, including nicotine (more addictive then including nicotine (more addictive then heroin)heroin)
Nicotine causes increased heart rate & blood Nicotine causes increased heart rate & blood pressurepressure
Carbon monoxide reduces O2 carried by Carbon monoxide reduces O2 carried by bloodblood
In Ireland 7000 people a yr die form smokingIn Ireland 7000 people a yr die form smoking
Effects of exercise on HeartEffects of exercise on Heart When we exercise our muscles get bigger When we exercise our muscles get bigger
& stronger this is the same for our heart& stronger this is the same for our heart
Exercise improves circulation and Exercise improves circulation and reduces body weightreduces body weight
Most beneficial exercise is aerobic Most beneficial exercise is aerobic exercise e.g. Walking, jogging, running, exercise e.g. Walking, jogging, running, swimming and Dancing so get your feet swimming and Dancing so get your feet moving.moving.
Effects of Diet on HeartEffects of Diet on Heart 3 main factors = salt, fat & being 3 main factors = salt, fat & being
overweightoverweight
Harmful fats found in red meat & dairy, Harmful fats found in red meat & dairy, they contain Cholesterol which forms they contain Cholesterol which forms blockagesblockages
1 packet of processed foods contains your 1 packet of processed foods contains your entire days intake of saltentire days intake of salt
Obesity causes high blood pressure & heart Obesity causes high blood pressure & heart attacksattacks