CARDIOVASCULAR SYSTEM
ALSO CALLED CIRCULATORY SYSTEM
COMPONENTS OF CARDIOVASCULAR SYSTEM
• Blood
• Heart
• Blood vessels – arteries, veins and capillaries
BLOOD
• 45% of blood is cells
• 99% Red Blood Cells (RBC), 1% White Blood Cells (WBC)
• 55% of blood is plasma
• Mostly water, some protein, electrolytes, nutrients and hormones
BLOOD FUNCTIONS
• Transport
• Regulation
• Protection
BLOOD AS A TRANSPORTER
• Transports:
• Oxygen (O2) to tissues from the lungs
• Carbon dioxide (CO2) removes CO2 from tissues and transports
to the lungs
• Nutrients obtained from diet
• From digestive tract to tissues
• Hormones
• Waste products
RED BLOOD CELLS (RBC)
• Contain Hemoglobin
• Each molecule carries one oxygen from the lungs, or one carbon dioxide
to the lungs
• Hemoglobin requires iron to function
• 280 million hemoglobin molecules/cell
• Lack mitochondria
• So can not use oxygen up for energy
RED BLOOD CELLS
• Lack a nucleus
• Increases surface area to volume ratio
• Allows it to fit through tight spaces and exchange lots of oxygen/carbon
dioxide
• Recycled every 120 days
• Destroyed in the spleen, liver and red bone marrow
ABO BLOOD TYPES:
ABO BLOOD TYPES
Blood type
A
B
AB
O
Antigen present:
A
B
A and B
None
Antibodies against:
B
A
None
A and B
Accepts blood from:
A and O
B and O
A, B, AB and O
O
Can give blood to:
A and AB
B and AB
AB
A, B, AB, and O
Universal acceptor
Universal donor
REGULATION
• Maintain homeostasis
• Control of pH
• Adjust body temperature
• Loses heat through veins close to the skin
• Maintains proper water content of cells
PROTECTION
• Clots to prevent excessive loss due to bleeding
• White blood cells (WBC) protect against disease
• Blood proteins – antibodies and interferons
• Antibodies neutralize viral particles
• Interferons help attack bacteria
WHITE BLOOD CELLS - LEUKOCYTES
• Several types of white blood cells
with different properties
• Neutrophils
• Bacterial infections
• Lymphocytes
• Viral infections
• Produce antibodies
• Attack cancerous/tumor cells
• Platelets
• Cell fragments that Promote blood
clotting
DISORDERS OF BLOOD
• Sickle-Cell disease
• A mutation in hemoglobin causes RBC to be crescent moon
shaped when de-oxygenated
• Causes blood cells to get clogged up in arteries and veins
• Typically found in African and East Indian populations.
• Sickle cells confer resistance to malaria virus
• Malaria is carried by mosquitos found in various parts of Africa and
east India
• Treatment may include blood transfusions
LEUKEMIA – RED BONE MARROW CANCER
• Cancer – cells which undergo uncontrolled replication
• Abnormal WBC multiply uncontrollably resulting in issues producing enough
RBC and WBC.
• Causes Anemia
• Insufficient RBC to deliver enough oxygen
• Risk factors:
• Chemotherapy, down syndrome, smoking, family history of leukemia (genetic
predisposition)
• Symptoms:
• Fatigue, weight loss, frequent infections, frequent nosebleeds, bone pain
• Diagnosis:
• Physical Exam, blood tests looking for increased WBC counts, bone marrow tests (from
hip bone)
LEUKEMIA TREATMENT
• Treatment:
• Chemotherapy
• Chemicals to kill leukemia cells
• Biological therapy
• Help your immune system attack leukemia cells
• Radiation therapy
• X-rays or other high energy beams are targeted towards specific spots where
leukemia cells are
• Targeted therapy
• Dependant on the type of leukemia different drugs may be used
• Stem cell transplantation
• Replace diseased bone marrow with stem cells from a donor or the patients
own non-diseased bone marrow
ETHICS IN HEALTH CARE
•
http://www.foundhealth.com/blog/2011/11/fighting-leukemia-a-survivor-tells-her-story-of-integrative-medicine/ a
personal story about leukemia and complementary treatment
•
http://www.cancercenter.com/leukemia/naturopathic-medicine/ naturopathic oncology provider website
•
http://www.cbc.ca/news/aboriginal/first-nations-girl-chooses-traditional-medicine-over-chemo-1.2644637
•
http://www.dailymail.co.uk/news/article-3034491/She-baby-time-no-matter-happened-Family-defend-pregnant-Jehovah-sWitness-died-baby-refusing-blood-transfusion-chemotherapy-C-section-religious-beliefs.html
•
http://www.dailymail.co.uk/news/article-3027599/Jehovah-s-Witness-baby-die-refuses-blood-transfusion-seven-monthspregnant-cancer-80-chance-surviving-treatment.html
•
Jehovah’s witness refuses blood transfusion
•
http://www.wsj.com/articles/SB121322824482066211
•
Christian scientists refuse medical care – changes to laws.
RECAP OF WHERE WE ARE
• Last week we began looking at the cardiovascular (circulatory) system
• So far we’ve looked at blood and its components
• The main functions of blood are:
•
Transport (oxygen, carbon dioxide, nutrients, waste products)
•
Protection (white blood cells, blood clotting)
•
Regulation (homeostasis- temperature, pH and water balance)
• Blood contains – plasma (water, proteins – antibodies in particular, nutrients) and cells (red and white).
• Diseases involving blood
•
sickle cell disease (misshaped RBC, help protect against malaria)
•
Leukemia (risk factors, symptoms, diagnosis, treatment)
• Up next the heart and blood vessels
Superior vena
cava
Inferior vena
cava
Pulmonary veins
THE CYCLE
• Blood cycles through the body transporting O2 to tissues and CO2 to the
lungs.
• You can start the cycle anywhere but we will start at the inferior and
superior vena cava
• 1. Deoxygenated blood (blood with low O2 and high CO2) enters the Right
atrium via the inferior and superior vena cava
• Atrium = entrance
• 2. The right atrium contracts, the increased pressure forces open the
tricuspid valve sending blood into the right ventricle.
• This pressure in the right ventricle closes the tricuspid valve preventing back-flow
THE CARDIAC CYCLE
• 3. Ventricular Systole - The right ventricle contracts causing the pulmonary
valve to open
• Deoxigenated blood is pushed through the pulmonary artery
• Ventricle Diastole begins when the ventricles relax
• 4. The pulmonary artery leads to the left and right lung where RBC’s
exchange CO2 for O2
• Oxygenated blood (high in O2) leaves the lungs via pulmonary veins
• 5. Oxygenated blood enters the left atrium
THE CARDIAC CYCLE
• 6. After filling, the left atrium then contracts forcing open the mitral valve and
pushing blood into the left ventricle
• The mitral valve closes and the pressure within the ventricle prevents back-flow
• 7. Ventriclar Systole - The left ventricle contracts causing the aortic valve to open
pushing oxygen rich blood into the aorta.
• The aortic valve closes preventing back-flow of blood into the ventricle.
• Ventricle Diastole begins when the ventricles relax
• 8. Blood is dispersed throughout the body carrying nutrients and exchanging O2 for
CO2
• Deoxygnated blood returns to the heart via the superior and inferior vena cava.
1. And 5.
Blood enters atria
4. And 8.
2. And 6.
Blood travels throughout the
body exchanging CO2O2
Atrai contract
Blood enters ventricles
3. And 7.
Ventricular Systole
Ventricles contract, blood enters
arteries
After contraction ventricles relax
resulting in Ventricular Diastole
5
4
1
8
6
2
7
3
ARTERIES, CAPILLARIES AND VEINS
• Blood exits the ventricles via arteries
• Arteries have the highest blood pressure
• Thick walls to handle the pressure
• Pulmonary arteries have lower pressure than the aorta (an artery)
• This is because of the aorta’s need to push blood to the brain and all other parts of
the body
• From arteries blood travels to arterioles, which are narrower
• Pressure decreases as blood moves away from the heart
CAPILLARIES
• From arterioles blood enters capillaries
• Extremely small, only a single RBC can flow through at once
• Walls are thing (single cell thick) to allow diffusion of nutrients from blood to interstitial
fluids
• Interstitial fluids – fluids between cells within tissues of the body
• Very low flow rate due to vast network of capillaries
• Blood from capillaries flows into venules, at this point the blood is
deoxygenated
CAPILLARIES
• Capillaries are where exchange of gasses and nutrients/occur.
• Thin walls of capillaries allow for easy exchange
• Blood pressure tends to cause water to exit capillaries
• Near the arteries pressure is higher so water exits the capillaries
• Osmotic pressure (pressure from water) tends to cause water to enter capillaries
• Near the veins blood pressure is lower so water enters the capillaries
VENULES AND VEINS
• Deoxygenated blood from capillaries flows to venules
• Venules have slightly thicker walls and are wider than capillaries
• From venules blood flows into veins
• Veins have slightly thicker walls and are wider than venules
• Both venules and veins have valves which prevent back-flow of blood
• Low pressure in veins requires this as there is not enough force to keep blood flowing
back to the heart.
• https://www.youtube.com/watch?v=HNuPWdfjDoc
• Blood flows back to the heart via veins with the help of skeletal musclular
pumps
• As muscles move they compress the veins pushing blood up towards the heart
ARTERIES, VEINS AND CAPILLARIES
Veins
Heart
Arteries
Venules
capillaries
Arterioles
HOW MUCH BLOOD GETS PUMPED
• Average about 4.5-5.5 L of blood in an adult (varies based on body size/weight)
• The heart pumps about 7,500 L of blood every day
EXCHANGE OF GASSES/NUTRIENTS
• When there is a lower amount of water in the capillaries the concentration of
solutes (gasses, nutrients and waste products) is high inside the capillaries
• This causes exchange of these solutes across the capillary walls
• Solutes travel from low concentration to high concentration
• 4 important areas where exchange occurs
• Lungs, tissues, kidneys and small intestine
EXCHANGE IN LUNGS
• Blood entering lungs has low oxygen (O2) and high carbon dioxide (CO2)
• Exchange occurs in alveoli (we’ll learn more about these later) and capillaries
within the lungs
• The lungs have high concentration of O2 and low concentration of CO2
• Solutes travel from high concentration to low
• Oxygen enters the blood stream from the lungs
• CO2 exits the capillaries and enters the lungs.
EXCHANGE IN SMALL INTESTINE
• The small intestine has large
concentrations of nutrients which are
passively or actively transported into
cells lining the intestine
• These nutrients are then transported into
the capillaries lining the small intestine
EXCHANGE IN TISSUES
• In tissues the red blood cells have high concentrations of oxygen
• Tissues have a high concentration of carbon dioxide
• There is also a high concentration of nutrients within the blood
• Tissues have a high concentration of waste products
• Nutrients and oxygen travel from high concentration in the blood to low
concentration in the tissues
• Carbon dioxide and waste products travel from high concentration in tissues to low
concentration in the blood
EXCHANGE IN THE KIDNEYS
• The renal arteries and veins go to
and from the kidneys respectively
• Their main role is to eliminate waste
while retaining water and nutrients.
• Waste products are eliminated by first
being transported into the kidneys
where mass filtration occurs
• Filtration is based on size of molecules
(small ones exit blood stream larger
ones stay in)
• The kidneys then actively transport
back into the blood nutrients which are
desired
THE CARDIAC CYCLE – NERVOUS SYSTEM CONTROL
• The cardiac cycle is driven by pacemaker cells
• The heart is controlled by the brain stem via the Vagus nerve and Cardiac
accelerator nerves
CONDUCTANCE OF CARDIAC CYCLE
• The sinoatrial node (SA node) initiates
electrical signal
• Signals atria to contract
• The signal travels to the Atrioventricular
(AV node)
• AV node delays the signal from getting to
ventricles too quickly
• Signal is sent along AV bundle and spreads
out to the ventricles causing them to
contract
CARDIAC CYCLE AND ECG/EKG
• P – causes atria to contract
• QRS complex – signals
contraction of the ventricles
• T – ventricle relaxes
EKG
• EKG’s can find problems in the conductance of
the heart
• I have something called Wolff-Parkinson-White
syndrome
•
Extra wiring that can bypass the AV node causing
very irregular heartbeats
•
Doesn’t always show up unfortunately
• Lets see if we can read get someone’s EKG.
BLOOD PRESSURE,
HEART RATE AND EKG’S
• Typical blood pressure is 120mm Hg/80mm Hg
•
The top number is the systolic pressure (when the ventricles are contracting)
•
The bottom number is the diastolic pressure (when the ventricles are relaxed)
• Resting heart-rate is typically 60-100 beats per minute
• Electrical signals within he heart are much more complicated
RESTING HEART RATE
• Place your index/ring on the radial pulse, just below your
thumb as pictured to the right
• DO NOT use your thumb, your thumb has its own faint
pulse which will make it harder to detect the radial pulse.
• Once everyone has found their pulse I’ll start a timer and
you will count how many beats you feel in 60 seconds.
CLASS DATA
Heart rate
40-50
(beats/60 seconds)
Number of
students
50-60
60-70
70-80
80-90
90-100
100-110
110+
STUDENT LAB ACTIVITY
• We are going to measure blood pressure and heart rate during a variety of activities
•
There will be 8 groups (3-4 people, 3 is best)
•
We will be recording heart rate while sitting, standing, laying down and during/after exercise
•
We will also be recording blood pressure while sitting, standing, laying down and during/after exercise.
ASSIGNMENT
• Investigate how the an alternative therapy is meant to improve heart health
• Choose from any of the following therapies:
• Acupuncture, Reiki, homeopathy, naturopathy, First Nations traditional healing, traditional Chinese therapy, yoga,
tai chi, massage/chairopractic therapy.
• If you are interested in another type of therapy please ask me if I am willing to approve it (I probably will).
• You may present your information in any format you feel appropriate including: Presentation (to the
whole class or just to me at lunch time), written report, poster board, story, artwork, website, song….
Essentially any format you want so long as you can convey all of the information required.
• Information required:
• Background on the type of treatment
•
What is it, how is it done?
• How the treatment is intended to help with heart health specifically (if there is another area of the body you
would rather investigate feel free to talk to me).
•
Potential benefits, can it be used in conjunction with other treatments?
• Has been formal research about this type of treatment?