1. T/F About Blood Pressure
Blood pressure begins with a heartbeat.
Blood pressure stays the same all day, every day.
Blood pressure helps the blood flow to all parts of the body.
A blood pressure reading has two numbers.
You can tell what your blood pressure is by the way you feel.
A healthy person could have a blood pressure of around 120/80.
Blood pressure should be checked every five years.
You can only tell what your blood pressure is by having it measured.
Being overweight can lower blood pressure.
Eating large amounts of food high in salt (sodium) can cause blood pressure to rise.
Regular exercise will help keep your blood pressure healthy.
Only a relaxed and easygoing person can have normal blood pressure.

2. Blood Pressure
Blood pressure is the force the blood exerts on the body tissue
Remember blood pressure is controlled by the pumping of the heart
Pressure is highest near the heart and decreases as it gets to the capillaries
Baroreceptors measure pressure in the blood, just as chemoreceptors measure the chemicals in the blood (CO2 mainly)
A Sphygmomanometer is used to measure Blood Pressure externally

3. Blood Pressure
Systole = Contractions of the ventricles; systolic pressure
High blood pressure created by the emptying of the left ventricle.
Diastole = is the relaxation phase of the ventricles when they are filling with blood.
Low Pressure maintained by the arteries between contractions
Normal Adult 120/80mmHg
Normal Child = 115/70 mmHg

4. Factors that Affect Blood Pressure
The amount of blood: blood can be lost as a result of injury or increased as a result of a disorder such as cancer. The less blood there is, the less pressure.
The heart rate: the faster the heart pumps blood, the greater the pressure which is built up. The pressure falls as the heart rate decreases, especially during rest or sleep.
The size of the arteries: when the arteries vasodilate the volume of the vessel increases and the pressure falls. If the arteries vasoconstrict the pressure is higher because of the extra resistance to blood flow.

5. Factors that Affect Blood Pressure
4. The elasticity of the vessels: the walls of the arteries must be flexible as a surge of blood is forced out of the heart, and then relax after the surge has passed. If they cannot stretch in this way, they are described as being “hardened”.
Hardening of the arteries is called “arteriosclerosis”
The viscosity of the blood: Blood which has a high viscosity is thick and sticky and does not flow as easily as thin watery liquids and the pressure will be higher due to the resistance of the blood to flow easily through the vessels.

6. Regulation of Blood Pressure
As blood is pumped from the heart to the various blood vessels, enough pressure is generated in order to send blood to all parts of the body.
HYPERTENSION: CHRONIC HIGH BLOOD PRESSURE
Small blood vessels in vital organs are most often affected
Blood vessels can be scarred, hardened and inelastic which will be blocked or possibly rupture.
Can lead to organ damage and failure if blood pressure is no regulated.
HYPOTENSION: CHRONIC LOW BLOOD PRESSURE
Blood is not pumped effectively through the systemic circuit of the body.
Body lacks blood supply to vital organs which means cells do not have enough oxygen
Reduces the amount of ATP a cell can generate which leads to fainting, dizziness and seizures.

7. T/F About Blood Pressure
Blood pressure begins with a heartbeat. TRUE
Blood pressure stays the same all day, every day. FALSE
Blood pressure helps the blood flow to all parts of the body. TRUE
A blood pressure reading has two numbers. TRUE
You can tell what your blood pressure is by the way you feel. FALSE
A healthy person could have a blood pressure of around 120/80. TRUE
Blood pressure should be checked every five years. FALSE
You can only tell what your blood pressure is by having it measured. TRUE
Being overweight can lower blood pressure. FALSE
Eating large amounts of food high in salt (sodium) can cause blood pressure to rise. TRUE
Regular exercise will help keep your blood pressure healthy. TRUE
Only a relaxed and easygoing person can have normal blood pressure. FALSE

8. Nervous Control of the Heart

9. Internal Control of Heart Rate
The heart or cardiac muscle beats involuntarily.
The beat of each cell of heart muscle is in synchrony or in pace with the beat of every other heart muscle cell.
Nervous impulses from a specialized bundle of nervous tissue called the Sinoatrial (SA) Node control the rate of the heart beat and also synchronize the beating of all cardiac cells.

10. Internal Control of Heart Rate
The sinoatrial or SA node is known as the pacemaker.
The SA node causes a wave of contraction to start in both the right and left atrium
This wave of contraction causes the Atrioventricular (AV) node to initiate contractions of the ventricles.

11. Internal Control of Heart Rate
The bundle of HIS carries the nervous stimuli to all parts of the ventricle via Purkinje Fibres which brings the impulse to each cardiac cell.
The SA node paces the heart at 72 beats/min which can be considered a “normal” resting heart rate.

13. External Control of Heart Rate
The Medulla Oblangata in the brain controls the nerves that influence heart rate.
O2 and CO2 concentration levels in the blood are measured by chemoreceptors that stimulate one of two nerves to the heart in order to maintain homeostasis.
Increased or accelerated heart rate is caused by stimulation of the sympathetic nerve.
Decreased or slowing of the heart rate is caused by the stimulation of the parasympathetic nerve.
Pressure sensitive baroreceptors in the arteries respond to changes in the blood pressure.
Increased heart rate will cause increase O2 delivery and increase CO2 pick up/ removal

14. Heartbeat Sounds
If you listen to your heartbeat through a stethoscope you hear 2 characteristic sounds that repeat over and over as the heart continues to beat: Lub-dub, lub-dub…
Lub
The sound which is a result of the closing of both atrio-ventricular valves (tricuspid/bicuspid)
Occurs during Systole, or ventricular contraction (i.e. atricular relaxation)
Is louder and longer of the 2 sounds

15. Heartbeat Sounds
Dub
The sound which is the result of the closing of both semi-lunar valves (pulmonary/aortic)
Occurs during Diastole, or Ventricular relaxation (or atrial contraction)
Is the softer and shorter of the 2 sounds.

17. THE CARDIAC CYCLE = 1 Full Heart Beat
THE PULSE – Results from the rhythmic expansion of the arteries as blood spurts from the left ventricle. Pulse corresponds to Heart Rate
STEP 1: Atrial Systole and Ventricular Filling
The Ventricles relax & blood flows into them from the atria. 70% flows passively, 30% moved when atria contract
STEP 2: Ventricular Systole
The atria relax and blood is pumped from the ventricles into the aorta and pulmonary artery. (1st heart sound: Lub)
STEP 3: There is a short period of atrial & ventricular relaxation. Semilunar valves prevent backflow of blood & the cardiac cycle starts again.

18. ECG/EKG: Electrocardiograms
Heart rate is monitored by the brain – it monitors the level of CO2 in the blood and alters the heart rate accordingly
The tiny electrical current produced each time the heart contracts can be recorded on a machine that produces an electrocardiogram or ECG/EKG
An ECG machine records the changing currents produced by contractions of the heart and helps to detect any abnormalities

19. ECG STAGES
POLARIZATION: Anything that has two poles, one positive and one negative is polarized
Example a battery, the Earth, Elements, Magnet
DEPOLARIZATION: When the poles switch positions
When you body is sending out an electrical signal to get your heart pumping
REPOLARAIZATION: When the poles are switched back to the original positions
When your body is recharging or getting ready to fire another electrical signal to tell your heart to beat

20. P Wave Passing of electrical impulse or signal from the SA node
Depolarization of the Atria
Causes the atria to contract
Contraction is mechanical the signal is electrical
Contraction happens after the P wave, but before the Q wave
Known as the PQ interval

21. QRS Wave Form the QRS Complex
This is the big spike in your graph
Electrical impulse from your AV node through your ventricles
Causes your ventricles to contract
After Q wave but stops at the T wave
Called QT interval
Depolarization of ventricles

22. T Wave Repolarization of the ventricles
This is when the AV node is getting refueled to fire again
What about Repolarization of the Atria?
Does happen during the EKG but is covered by the QRS complex
This interval is known as the QS interval

23. http://www. youtube. com/watch
beL2h84&safety_mode=true&persist_saf ety_mode=1&safe=active

24. Factors Affecting Heart Rate
Activity: the heart increases its rate to provide oxygen to all the parts of the body that require it
Emotions: Such as fear or shock and tension will all affect the heart rate
Chemicals: such as carbon monoxide, nicotine, alcohol and adrenaline, all affect the rate of the heart

25. TACHYCARDIA: When your heart beats more than 72 beats per minute, such as during exercise or from the consumption of caffeine or nicotine.
BRADYCARDIA: When the heart beats very slowly, less than 72 beats per minute, such as athletes who have an elevated cardiac output even during rest.
ARRYTHMIA: abnormal heart rhythm

27. Chemical Control of the Heart
Chemicals (hormones) are released by your body tissue in response to stimulus from specific situations.
Hormones are received by the brain, which sends the nervous signal to cause the heart rate to speed up or down
PHYSICAL ACTIVITY:
increase in activity level causes an increase in CO2 in the blood
brain detects the increase of CO2
brain sends impulses along the nervous system to release noradrenaline

28. Chemical Control of the Heart
Noradrenaline reaches the heart and makes the SA node fire more rapidly, causing the blood to be oxygenated more quickly
EMOTIONS:
Body experiences a sudden shock, sharp pain, gets excited, angry or nervous
Adrenaline is released by the adrenal glands on the kidneys
Which causes heart rate to increase and blood flow to increase to muscles
Noradrenaline: a hormone that is released to slow the heart rate
Adrenaline: a hormone that is released to speed up the heart rate