Download B20 C8 Notes Circulation Mar. 22 2016

Bio 20 Ch. 8 Circulation and Immunity
8.1 Structures of the Circulatory System p. 266 – 281
Overview of the Circulatory System: 3 Components, 3 Functions, 3 Pathways
Search Crash Course circulation (the url is 7 lines long!) – First part reviews respiratory system, 5:35
on discusses circulatory system.
• 3 major components make up the human circulatory system: the heart, blood vessels, and blood.
• The heart and blood vessels are collectively called the cardiovascular system
(cardio = heart, vascular = vessels).
• The circulatory system has 3 main functions
1. Links all systems to all parts of your body by transporting O2, nutrients,
wastes, hormones, medicines, enzymes, disease organisms, cells to fight disease, etc.
2. Regulates internal temperature.
3. Protects against blood loss from injury and against disease-causing microbes or toxic
substances introduced into the body.
• There are 3 circulatory pathways through the body:
1. The pulmonary pathway (heart to lungs and back)
2. The systemic pathway (heart to body and back )
3. The coronary pathway (heart to heart vessels and back)
THE HEART: a muscular pump with 4 chambers, 4 valves and 3 functions
• The heart is a muscular pump with 4 chambers: 2 atria that receive blood and 2 ventricles that
propel blood through the body. It is a double pump, it pumps deoxygenated blood to the lungs to
pick up oxygen and get rid of CO2, and pumps oxygenated blood to the body.
• The heart has 3 functions:
1. Pumping blood through the body
2. Keeping oxygen-rich blood separated from oxygen-poor blood
3. Ensures that blood flows only in one direction through the body
Heart Structure
1. Heart muscle – unique to heart, found nowhere else in body. You cannot consciously
affect your heartbeat – it is involuntary, rhythmical
2. 4 chambers (2 atria, 2 ventricles)
3. Septum: separates chambers from eachother
4. 4 valves: maintain one-way blood flow
Open Heart Surgery: will your patient survive?
http://www.silvergames.com/heart-surgery
Heart Valves
Bicuspid (2 flaps) and tricuspid (3flaps) valves
separate the atria from the ventricles. These are
called the atrioventricular valves. The tricuspid
valve separates the right atria and ventrical, the
bicuspid valve separates the left atria and ventricle.
The semilunar valves (look like half moons) keep
the blood when it is pumped to the lungs and the
body from leaking back into the heart.
 Fill out BLM 8.1.1 “Heart Anatomy” and practice labeling the heart on the following site:
http://sciencelearn.org.nz/Contexts/See-through-Body/Sci-Media/Animation/Label-the-heart
What is the Route of Blood Flow Through the Heart?
 Use the following clip and pg. 269 – 270 to fill out BLM 8.1.2 “Flow of Blood Through the Heart.
https://www.youtube.cm/watch?v=AvpivJqGtzU&index=41&list=PLXwnjgs_UWpIyKAZ9yaEU
bv8Sz1AMve45
 Practice your understanding of blood flow with the following games:
http://www.quia.com/pp/55658.html?AP_rand=1392668722
http://www.quia.com/ba/81095.html heart flow battleship
 More Practice on Flow of Blood through Heart: fill out the following paragraph:
Word Bank: alveoli, aorta, atrium, away, ventricle, CO2, O2, deoxygenated (4x), diffusion,
inferior vena cava, into, rich, superior vena cava, vena cava
The right atrium of the heart receives _________________________________ blood from the body
through the superior and inferior ____________________ (remember veINs carry blood ________ the
heart). The ____________________________brings ___________________ blood from the head,
chest and arms into the heart. The _________________________ brings deoxygenated blood from
everywhere else. ____________________ blood flows from right atrium into right ventricle through
the tricuspid valve. _____________________ blood is pumped by right ventricle to the
________________ in the lungs through the pulmonary trunk and then the left and right pulmonary
arteries (remember arteries take blood __________ from the heart). In the alveoli _______ leaves the
oxygen poor blood, and ________ from the air in the lungs enters the blood _____________________.
Oxygen rich blood then flows into the LEFT _____________ through the left and right pulmonary
veINs. (These are the only veins in the circulatory system that contain oxygen ______________
blood). Blood flows into the LEFT __________________ through the bicuspid valve then the blood is
pumped to all the body tissues through the largest vessel in the body: the _______________________.
 Learning Check!
1) Name the 4 chambers of our heart.
Which are on the top?
Bottom?
Which receive blood?
Which pump blood?
Which side of the heart contains deoxygenated blood?
Which side of the heart contains deoxygenated blood?
2) What is the function of the valves in the heart?
3) How are you going to remember which valve does what?
Blood Vessels p. 270
There are 3 types of blood vessels:
1) Arteries: carry blood Away from the heart. All arteries carry oxygen-rich blood except for the
pulmonary artery which carries oxygen – poor blood away from the heart to the lungs.
2) Veins: carry oxygen – poor blood towards or INto the heart. All veins carry oxygen- poor blood
except for the pulmonary vein which carries oxygen – rich blood from the lungs into the heart.
3) Capillaries: a network of capillaries join each artery and vein. Blood from arteries goes into
the capillaries where gases, nutrients, and other materials are transferred to body tissue cells,
and wastes, including gases are transferred from the body cells to the blood where it then
travels through the veins to the heart.
 Complete BLM 8.1.3 “Blood Vessels”
 Learning Check!
1. Which among the following statements is not true with regard to veins in the human body?
a.
b.
c.
d.
If a valve becomes weak, blood starts accumulating beneath, resulting in varicose veins
Valves enable veins to provide two-way conduction of blood
Veins have thinner walls than arteries
Veins transport blood towards the heart
2. Arteries, veins, and capillaries form the blood transportation system of the body. Blood
travels from an artery to the ___i___, where the exchange of nutrients and other materials takes
place. After depositing oxygen in the tissues and picking up wastes and CO2, the blood moves
into the ___ii___, and then to the heart. The statement given above is completed by
a. i - vein, ii - capillary
b. i - vein, ii - capillary
c. i - capillary, ii - vein
d. i - capillary, ii - arteriole
3.
4.
5.
6.
Which blood vessels carry blood away from the heart?
Which blood vessels carry blood to the heart?
Which blood vessels link the blood vessels mentioned in 3 and 4 above?
Briefly, compare structures of the 3 types of blood vessels and explain how the structure of
each suits it’s function.
 Fill out BLM 8.1.7 Circulatory Systems of the Body
How does our heart beat? The sinoatrial (SA) node (the “pacemaker”), the atrioventricular (AV)
node and the Purkinje fibres and Electrocardiograms (ECGs)
p. 272
An electrical signal from the heart itself triggers our heartbeats. The rate and strength of the beat
is regulated by the nervous system to maintain homeostasis. Check out this clip:
https://www.youtube.com/watch?v=fZT9vlbL2uA
The electrical signal originates in the sinoatrial (SA) node, a bundle of specialized muscle tissue.
The SA node stimulates the cardiac muscle to contract and relax in rhythm – hence is is often called the
“pacemaker.”
The SA node is in the right atria and stimulates both atria to contract simultaneously. This sends a
signal to the atrioventricular (AV) node, which delays the signal, to allow time for the ventricles fill.
The AV node sends a signal through specialized fibres called the bundle of His, and then through the
Purkinje fibres which stimulate the two ventricles to contract almost simultaneously.
 Label using Purkinje fibres, sinoatrial (SA)
node, bundle of His, atrioventricular (AV)
node
1)
2)
3)
4)
Electrocardiograms (ECGs) measure the change in voltage produced by the heart’s electrical signals.
Changes in the spacing or disappearance of any of the parts of the ECG are used for diagnosis of heart
problems.
 Study carefully Fig. 8.8 pg. 275 for a description of the electrical stimulus of the heart.
Use the pictures below as a summary and Learning Check.
A
C
B
D
 What is happening in the ECG labeled B? C? In ECG D describe what is happening at the
4 arrows A,B,C,D.
 What makes the “lub” (quieter) sound of our heart beat? the “dub” (louder) sound?
Blood Pressure
Blood pressure is the pressure blood exerts on blood vessel walls as it flows through.
 Learning Checks:
Blood pressure changes with the phases of your heartbeat. Blood pressure will increase/decrease
(choose one) during ventricular contraction.
Systolic Pressure = when blood pressure is at its highest (ventricular contraction).
Diastolic Pressure = when blood pressure is at its lowest (right before ventricles contract).
Normal blood pressure in a young healthy person is on average
120/80 (systolic/diastolic pressure). Units are mm Hg.
As heart rate increases (i.e. exercise), blood pressure will
increase.
 Measure your blood pressure using a blood pressure cuff
(sphygmomanometer) – don’t go over 140mmHg. Don’t
make a sound or you won’t be able to hear the change!
http://www.practicalclinicalskills.com/blood-pressuremeasurement.aspx
 What is the effect of vigorous exercise on both heart rate and blood pressure. Explain why this
change in heart rate is necessary.
 Do Heart Rate Lab
Cardiac Output and Stroke Volume
Cardiac output = heart rate x stroke volume Units = mL/min
The average person has a resting heart rate of 70 beats/min, and a stroke volume of 70 mL.
 What is the average cardiac output?
Since the average person has 5L of blood in their body, the total volume in the body circulates
through the heart about ______________ every minute.
 Read pg. 275 – 276. Why is “Individual C” considered exceptionally fit? Why does regular
cardiovascular exercise increase the resting stroke volume of your heart, and why should
cardiovascular exercise be a regular part of your exercise regime?
Blood Flow through the Coronary System
The coronary system is the 3rd circulatory system.
 What are the other two circulatory systems?
 Read page 277 and summarize blood flow through the coronary system.
Check out this clip (heart attack) https://www.youtube.com/watch?v=n8P3n6GKBSY
Cardiac Disorders and Treatments p. 277
Cardiovascular disorders are treated with lifestyle changes, medications, and/or surgery.
 Illustrate and describe in detail atherosclerosis, and the treatments used for someone who develops
1) a partial blockage and 2) a total blockage.
8.2 Blood and Circulation p. 282 - 291
Blood = Tissue with a solid and fluid portion.
a) Fluid portion = plasma. Transports blood cells,
nutrients, vitamins, minerals, hormones (chemical
messengers), O2, waste products, and CO2.
b) Solid portion: (also called “formed”) has 3 parts
1) red blood cells (erythrocytes, RBC)
2) white blood cells (WBC = leukocytes)
3) platelets
All of these are formed in the bone marrow
 Learning Check
1. Blood is a fluid tissue that plays a major role in the circulation of various materials in the body.
Blood consists of two distinct elements. The liquid portion is known as ____i_____ and the solid
portion is know as ____ii______. This statement is completed by the information in
A.
B.
C.
D.
i – lymph,
i - plasma,
i – lymph,
i - plasma,
ii – platelets
ii – formed
ii – formed
ii – platelets
THERE ARE 3 BLOOD CELL TYPES
1) Erythrocytes: Red blood cells (RBC)
Function = Transport oxygen from the lungs to the cells of the body & assist with CO2 removal
• Shape - a biconcave disc with large surface area, circular so can slip easily through blood
vessels and past each other without catching.
Can change shape to fit into capillaries.
• No nucleus/organelles necessary for cellular repair, growth, division (allows more room
for gas exchange)
• Contains hemoglobin- a special iron containing protein (Hb). In mammals this
protein makes up 96% of the RBC’s dry weight (35% wet weight). It is the binding
site of O2 for exchange in the lungs, as well as some of the respiratory CO2 and some
other gases. Each heme group (there are 4 of them) in hemoglobin has one Fe (iron) molecule,
which binds to oxygen.
• Short Life Span (~120 days), fragile - prone to rupture. Ruptured RBC’s are destroyed in
the spleen by phagocytic WBC’s that “clear the debris.”
 Check out this clip https://www.youtube.com/watch?v=9-XoM2144tk crash course
2) Leukocytes: White Blood Cells (WBC)
Function - Mobile units of the body’s defense system
- seek and destroy invaders (disease) and abnormal cells (ie: cancer ), by phagocytosis
- involved in allergic reactions, form antibodies (B-cells), clean up cellular debris like worn
out RBC
• All blood cells including leukocytes originate from the same undifferentiated stem cells in
the bone marrow and are produced in the bone marrow except for lymphocytes.
Most new lymphocytes are produced by colonies of cells in lymphoid tissues, such as
lymph nodes and tonsils.
• Inflammatory Response: WBC numbers increase in response to invasion of infectious
organisms – WBC count is used in medicine to diagnose infection.
3) Platelets:
Function: Clotting of blood at a site of injury
• Cell fragments bound to special cells in the bone marrow (megakaryocytes) “bud off” and are
released into the blood. They are not whole cells.
• platelets form a web-like mesh that traps blood cells. These harden forming a clot, or "scab."
 Check out this clip https://www.youtube.com/watch?v=HQWlcSp9Sls crash course –
reviews parts of blood, and blood clotting.
 Use BLM 8.2.1 “The Cellular Components of Blood”
1) complete BLM 8.2.2 “Blood Cell Activity” (with good scientific answers – using data and
depth!). Make sure you study the information on BLM 8.2.1 for your tests.
2) Identify Blood Cells on a Blood Smear. p. 285.
The Blood’s Role in Maintaining Homeostatis
Regulation of Body Temperature, Blood pressure and O2 Supply, pH
Shivering, Sweating, Vasodilation, Vasoconstriction, Countercurrent Heat Exchange System p.
286 – 287.
Too warm? Vasodilation of blood vessels near the skin brings more blood to the surface and your
body heat dissipates to the cooler outside environment. Sweating - evaporative cooling of sweat from
your skin cools you down (endothermic). Dehydration in really hot weather is a serious problem for
electrolyte blood chemistry imbalance but also because you can’t sweat.
Too cold? Vasoconstriction of blood vessels near the skin keeps more of the warm blood deep
inside, decreasing loss of body heat to the cold outside environment. Shivering – energy for these
muscle contractions increase the need for energy from cellular respiration which generates the
byproduct of HEAT!
Countercurrent heat exchange – we’re like
seals! See Fig. 8.20 pg. 287. We have deep
veins and surface veins for returning blood
from our extremities.
When we are in cold environments, our blood
returns by the deep veins which are next to
deep arteries that warm the returning venous
blood, keeping our core warm. When we are
not in cold stressed environments our blood
returns by the surface veins.
Check out this clip https://www.youtube.com/watch?v=v43ej5lCeBo How dynamic your blood
vessels are in many aspects, including vasodilation and vasoconstriction.
Blood pressure too high? The brain sends a nervous signal to your blood vessels to vasodilate,
decreasing your blood pressure.
Blood pressure too low? The brain sends a nervous signal to your blood vessels to vasoconstrict,
increasing your blood pressure.
Need more blood flow to the tissues (i.e. during exercise)? The brain sends a nervous signal to
your blood vessels to vasodilate, increasing your blood flow.
Check out this clip https://www.youtube.com/watch?v=ZVklPwGALpI How blood pressure is
regulated in your body, and the medical implications of this.
Alcohol and nicotine interfere with the vasoconstriction/vasodilation homeostasis mechanism.
Alcohol and nicotine promote vasodilation and cause blood to rush to the skin surface promoting heat
loss and decrease in blood pressure.
Learning Checks!
 Draw and label Figure 8.19 p. 286 and explain how vasodilation and vasoconstriction help
regulate body temperature. Include the use of sweating and shivering in discussing the
regulation of body temperature.
 Describe how vasodilation and vasoconstriction help regulate blood pressure. What is the
trigger for this action?
 How does exercise trigger your body to change its blood flow during exercise and after
exercise? Why is this adaptive?
 How do alcohol and nicotine interfere with your body’s ability to regulate temperature?
 Draw and label Fig. 8.20 - the countercurrent heat exchange mechanism. This exchange mechanism
is crucial in maintaining our internal body temperature constant despite external temperature
differences, or a rise in heat when you are exercising vigorously owing to muscle activity Which vein
(surface or deep) will your body use when you are shivering with cold? Which vein will your body use
when you are playing beach volleyball?
 Learning Check
1) When the body’s internal environment is too warm vasodilation/vasoconstriction (choose
one) occurs.
2) When the external environment is cold your body conserves heat by body’s
vasodilation /vasoconstriction (choose one).
3) What are 3 factors that can trigger vasoconstriction or vasodilation?
Circulation and Action of Capillaries
 Read p. 287 – 288 to answer the following questions.
1. What is the surface area of your capillaries?
2. What is interstitial fluid?
3. Give 2 examples of how capillaries flow is modified to maintain efficient use of blood flow to
suit the body’s needs.
Blood Disorders
 Read p. 288 – 290 and briefly define hemophila, leukemia, and anemia and their
treatment.
8.3 The Lymphatic System and Immunity
p. 292-300
The lymphatic circulatory system is the second vascular transport system in your body (the
cardiovascular circulatory system is the other one). It is a network of vessels with associated glands
or nodes, that extends throughout the body and is closely associated with the cardiovascular system.
 See Fig. 8.24 and 8.25 p. 292.
https://www.youtube.com/watch?v=tPlTe0Q1wIs The lymph system simplified!
The lymphatic system has a number of functions:
1) Balances fluids in our bodies. It is responsible for the removal of extracellular fluid
(interstitial fluid) from body tissues. Interstitial fluid is formed from blood plasma that leaves
the capillaries to bathe the cells. Interstitial fluid is returned to the blood through lymph
vessels that empty into large veins near the heart.
2) Absorbs and transports fats from the digestive system
3) Produces and transports WBCs, B-cells and T-cells when an immune response is
stimulated. Lymph nodes contain macrophages which trap and destroy bacteria circulating
within the body. When you get an infection your lymph nodes swell because they are making
lots of macrophages and other lymphocytes.
We have 3 Lines of Defense (BLM 8.3.2) in the Constant War Against Pathogens
 https://www.youtube.com/watch?v=gcSm38tu2zM
defense system simplified!
1st Line of Defense: Physical and Chemical Barriers keep pathogens (viruses, bacteria, fungi and
parasites) out of our bodies
• our skin is the largest barrier - inhospitable to bacteria – physically it is dry and tough
because it is made of indigestible keratin, chemically skin’s oil contains bactericides and
perspiration forms an acid layer;
• eyelashes, cilia of respiratory tract, tears, stomach acid are also barriers.
2nd line of defense: When disease organisms enter the body, swelling and fever 2nd line of defense
is our 2nd line of defense as your body tries to limit and contain the attack at the site of entry.
3rd line of defense: If the attack spreads internally, a Non-Specific Defense kicks in and kills
the pathogens using 3 types of WBC – macrophages, neutrophils, monocytes – that
constantly circulate our body in the blood, lymph and interstitial fluid. All 3 WBC kill
pathogens they encounter by phagocytosis.
After the macrophages have killed the pathogen, a Specific Defense, the antigen – antibody
response builds up your immune army whose goal is to destroy all the pathogens before
they can reproduce and build up their armies, and then to build up your antibodies so that you will be
better prepared to fight this type of pathogen if it invades again.
Antibody-mediated immunity is carried out by 2 types of lymphocytes in the circulatory system.
Their names refer to where they mature – B cells mature in bone marrow and T- cells that mature in
the thymus gland (near the heart).
Antigens are molecules on the surface of all cells (yours and pathogens). = identification system.
Antigen receptors on T and B cells recognize foreign vs self antigens.
Antibodies are proteins that recognize foreign substances and either neutralize or destroy
them. Owing to your genetic make-up and exposure during your lifetime to various pathogens
each of you develop an immune system that is unique to you!
Steps in the Antigen-Antibody Response
a) IDENTIFY AND KILL THE INVADERS, MOBILIZE THE TROOPS:
• The antigens from the destroyed/immobilized pathogen protrude from the cell membrane of the
macrophage.
• Receptor sites on the surface of helper T cells bind to the pathogen’s antigens.
• Chemical messengers from both cells make T cells multiply, “building up the troops”
which invade the site of infection, killing more pathogens, hopefully before the pathogens
have time to reproduce.
b) antibodies on B cells bind to antigens on pathogens and help DESTROY them.
c) Now we must REMEMBER THE INVADERS FOR ANY FUTURE ATTACKS!
More T cells bind to B cell antibody-antigen complex. This causes the B cell to divide and it
makes a plasma cell and a memory cell. Plasma cells produce antibodies at an amazing rate
(2000/second). The antibodies are released into blood stream. Antibodies and memory cells
remain in blood, ready to fight a new infection by the same pathogen.
Most antibodies are specific so they can only bind with one type of antigen – so can only kill one type
of pathogen. After the infection has been fought off, memory B cells remain in blood, ready to trigger
another immune response when necessary. The next time you encounter the pathogen, your B cells are
ready and the immune response is much more rapid and you get a much higher number of antibodies
(Fig. 8.28 pg. 295 and BLM 8.3.4)
Different types of T- cells
Helper T cells Recognize the antigens from the destroyed pathogens and mobilize the rest of the
immune system by sending chemical messages to stimulate action of B cells, other T
(T4cells)
cells and macrophages to continue the fight! They are prime target of the HIV virus.
A low T-4 cell count tells you that your immune system is not capable of responding
properly and you need to take medications to prevent AIDS-related infections.
Killer T cells
Bind with infected cells and destroy them so pathogens in them cannot use the cell as
a place to reproduce.
Suppressor T Slow down and suppress cellular immunity to ensure that normal tissue does not get
destroyed
cells
in blood stream – ready to react quickly if you get an infection a second time.
Memory T
cells
 Learning Check: Why do babies and young children contract infectious diseases more frequently
than adolescents?
Blood Types: the ABO system, another antigen-antibody system
p. 296
Early blood transfusions saved lives, but in some cases transfusions caused illness and sometimes death
and no one knew why. Scientists later discovered that humans have different blood types. Your blood
type is an inherited characteristic and is defined as the presence or absence of type A and type B
antigens on your red blood cells and the antibodies in your plasma. The transfusion problem was an
antigen-antibody reaction between the donor blood and the recipient’s blood antibodies.
.
Fig. 1. The Human Blood Types- A, B, AB, and O
Remember – antigens are
molecules on cell surfaces that serve
as identification markers.
Antibodies are proteins that
recognize the antigens of foreign
substances and either neutralize or
destroy them.
So if you have Type A blood, you
have anti-B antibodies in your
plasma which means you will
clump and destroy any RBC with
B antigens. You CANNOT
receive Type B or AB donor
blood, because your anti-B
antibodies will attack and clump
(agglutinate) the donor blood
causing major clots which will
damage your tissues and organs, and
sometimes cause death.
 Check out these clips:
https://www.youtube.com/watch?v=ttjn1jVACk8 blood compatibility SciShow
https://www.youtube.com/watch?v=KXTF7WehgM8 Bozeman blood types
 Do the Blood Type lab.
 Why is the Canadian Blood Service so concerned to have enough Type O blood cells available
for transfusions?
The Rh System
Rh factor is another antigen found on RBC. If you have this factor you are Rh positive (Rh+). If
you don’t have it you are Rh negative (Rh-). People with Rh- blood usually do not have antibodies
against Rh factor – but may make them when they are exposed to the Rh factor during a blood
transfusion or pregnancy.
Rh factor problems in pregnancy – pg. 297. If mom is Rh- and baby is Rh+ problems can arise,
usually in the 2nd pregnancy with a Rh+ baby. In the first pregnancy mom is exposed to the Rh antigens
of the baby near birth and builds up antibodies to Rh+ RBC. These can cross the placenta and destroy
the next Rh+ babies RBCs, causing brain damage, deafness and death. This problem is alleviated by
injecting mom with anti-Rh antibodies within 72 hours of birth of the first baby. These antibodies kill
any baby cells circulating in mom’s blood system, and prevents the immune response building Rh
antibodies.
Immune System Disorders p. 298 - 299
 Read p. 298 – 299. Define autoimmune disorder.
Describe briefly the following autoimmune disorders:
1) rheumatoid arthritis
2) Type 1 (insulin dependent) diabetes
3) Allergies
4): Asthma