Introduction to Circulatory Systems

Single-celled and Simple Multi-cellular Organisms:

• includes ___________, ___________, ____________, mosses, sponges, Cnidaria and flatworms

• nutrients, water, gases and wastes _______ or are transported directly between the _____________ (intracellular fluid, ICF) and the _________________ (extracellular fluid, ECF)

• do not require a _______________ system

ICF ECF

Very Simple Multi-cellular Plants and Animals:

Materials diffuse from the environment into/out of cells

A non-vascular plant

Planaria (a flatworm or platyhelminth)

Complex Multi-cellular Plants• includes all ____________ plants (______,

_______________ and _______________)• are too ________ for every cell to be in

close ____________ with the environment (_______ and _____)

• have specialized vascular tissues (_______ and __________) containing vascular fluid (_____) which transports water, nutrients, gases and wastes between _______, __________ and all other plant parts

Vascular System in Higher Plants Complex Multi-cellular Animals• includes all animals which have an ______• are too _______ and _______ for every

cell to be in close contact with the ___________________

• have specialized vascular tissues (______ __________) containing vascular fluid (________) which transports water, nutrients, dissolved gases and wastes between ________, __________ and ___________

The Vascular System of Complex

Multi-cellular Animals

Definitions:A ______________ system is a system of

__________ and ________ that transports nutrients and other substances to cells, and removes cellular wastes.

A _________________ system is a vascular system with a specific, _______________ pattern of ________.

A _____________________ system is a _________________ system which includes a _________ to pump the vascular fluid.

Cardiovascular systems can be:1. ________ Systems (eg. in ____________):• The blood is pumped by a _________ through

blood __________ but then __________ the blood vessels and _____________ over the cells, allowing nutrients, dissolved gases and wastes to diffuse ______________ between the __________ (ECF) and _________ (ICF)

• The blood collects in ______________, is returned to the blood _____________ and pumped again

Open Cardiovascular System in Insects

Blood leaves the blood vessels, washes over and around body cells, allowing diffusion.

Blood vessel

Heart

In Cross Section

Cardiovascular systems can be:2. ___________ Systems (eg. in ____________):• The blood is pumped by a _________ through

blood ___________ but blood does ____ leave the blood __________

• The smallest blood vessels (______________) are in close contact with individual ________

• Nutrients, dissolved gases and wastes ____________ between the _________, the ________ and the ________ of cells

Closed Cardiovascular System in an Earthworm

Blood does not leave the blood vessels. Materials diffuse between blood, ECF and ICF.

In a closed circulatory system, blood never leaves the blood vessels

Intracellular fluid (ICF)

Blood in a blood vessel (a capillary)

Extracellular fluid (ICF)

The Mammalian Cardiovascular (aka Circulatory) System functions to:

1. Deliver ____________ and dissolved __________ to all ________ of the body

2. Remove cellular ___________ from all cells of the body

3. Transport _____________ for cellular _____________________ between different parts of the body

4. Transport _______________ and __________ cells to fight ______________

5. Distribute _________ and regulate body ___________________

The Mammalian Cardiovascular System is a closed system that has

three components:1. The vascular _________ (_________)2. The vascular ____________ (blood

vessels)3. The ____________

1. The Vascular Fluid or Blood • has a volume of _____

litres in an adult human• is a type of

_____________ tissue made of a fluid _________ called _________ which carries _________ blood cells (_______), _______ blood cells (_______) and ________________ Whole blood spun in a

centrifuge to separate its components

Components of the Bloodwhite blood cells

(_______________________)

_________________

(cell __________________)

_______________(liquid)

red blood cells

(______________________)

Blood Plasma contains:• ______ water • blood proteins (____________________,

_____________ and _______________ for clotting)

• dissolved organic molecules such as ____________, _________________ and __________

• dissolved __________ such as CO2

• dissolved _________ such as Na1+, K1+, Ca2+, Mg2+, Cl1- and ________ (_______________)

White Blood Cells (Leucocytes)• WBCs are relatively _________,

_______________ and have a _______• include _______________immune cells

such as ________________ (‘_________’ cells) which _______________, engulf and destroy ___________ material

• include ____________ immune cells such as _________which recognize and remember foreign _____________ and _________which produce ______________ to foreign antigens

Red Blood Cells (Erythrocytes)• RBCs are relatively ___________, ________-shaped

and do ______ have a nucleus. This increases their ___________________ to ___________ ratio and allows them to _________ and move more easily through _________________

• they are filled with _________________ molecules which contain _________ and give RBCs their ______ colour

• 1 hemoglobin can carry up to ___ O2

• hemoglobin picks up oxygen in the _________ and carries it to the ______ through the ____________

• O2 is used by cells for _______________________

Red Blood Cells Size and Shape Platelets• are ______ cells, they are ___________ of cells

that do ______ contain a ____________• involved in ___________________• as long as blood vessels are ________, clotting

should not occur

Blood Clotting (greatly simplified)

1. If a blood vessel is ___________, cells lining the blood vessel release _______________ which attract platelets.

2. Platelets are ______________. They change shape from round to irregular & _________. Some platelets __________ and release _______________ to initiate clotting.

Blood Clotting (cont.)

3. Chemicals released by platelets cause _______________, a blood ____________, to react with __________ ions in the blood (Ca2+) to form ___________. Thrombin is an ___________ that changes _____________, another blood protein, into ___________.

4. Fibrin __________ form a __________ over the ____________, trapping more ________________ and _________. This forms a _________ to stop the bleeding.

Blood Clotting (cont.)

5. The clot _______ and hardens into a _________ which ______________ the damaged area while new cells grow underneath it and __________ the wound site.

Clotting is tightly ________________ to prevent blood clots forming inside _____________ and __________.There are _____ different proteins (_____________ ___________) involved in clotting. If a person has a genetic _______________ and is ______________ one of these proteins, they have ___________________ and could bleed to death from a small _______ or ______________.

2. The Blood Vessels

Veins have _______, _______________ walls because they have________ blood pressure

Arteries have ________, muscular ____________ walls to withstand _____ pressure

Arterioles have bands of ______________ muscle around them which ____________ and ____________ to control the amount of blood entering the ___________________.

Blood Vessel Structure

Capillaries are very narrow, forcing blood cells to pass through in single file. Capillary walls are a single cell thick so gases, nutrients and wastes diffusereadily between blood cells, plasma and the ECF around cells.

Middle layer: smooth muscle and elastic tissue

Outer layer: tough connective tissue

Inner layer: lining, one cell thick

Capillary one cell thick

Comparing Arteries and VeinsARTERIES

• carry blood ________ from the heart

• _________ muscular walls to withstand _______ blood pressure during _________

• _________ inside diameter• no __________• blood is pushed along by

the _________ and _____________ of the arterial wall

• branch into ___________

VEINS• carry blood ___________

the heart• ____________ muscular

walls because blood is at __________ pressure

• ________ inside diameter• _______ prevent backflow• blood is pushed along by

contractions of _________ _____________ around the veins

• form when venules ______

Venous ReturnThe blood returning to

the heart is very ______ pressure.

Blood is pushed through veins in _________ by the contraction of __________ muscles.

___________ in veins prevent the blood from flowing ____________ when the skeletal muscles relax.

Extracellular fluid (ECF)

Intracellular fluid (ICF)

Arterioles branch into tiny capillaries

Capillaries join to form venules

Capillary Beds• Capillaries join ________________ and ____________ in all tissues

of the body• Cells are never very far from a ________________• Capillary walls are only a ___________________ thick, so dissolved

nutrients, gases and wastes _____________ between the blood plasma in the capillary and the ECF and ICF.

Capillaries

Blood pressure is higher at the arteriole end of a capillary, and it forces fluid with its dissolved proteins, minerals and gases out of the capillary into the tissues to become part of the ECF. Blood pressure is lower at the venule end of the capillary and this allows fluid and dissolved materials, including wastes, to re-enter the capillary.

3. The Heart (see previous notes)• is a muscular ___________ pump which pumps blood

simultaneously through ______ circulatory systems:a) The ___________________ Circulatory System• deoxygenated blood from the body enters the ________

__________ and is pumped to the _________ by the ______________________ via the _______________ _____________

• oxygenated blood returns from the _________ to the ______________ via the _______________________

b) The _________________ Circulatory System• oxygenated blood from the lungs enters the ________

__________, and is pumped to the body by the ________________________ via the ___________

• deoxygenated blood returns from the body to the ______ __________ via the inferior and superior ____________

Vertebrate animals have a second vascular system called the ______________ system

• it is a ‘____________’ system that starts in the ___________

• lymph ___________ collect ________, ____________ and ________ from the tissues and return them to the superior ________________ via the __________________

• Lymph _________ contain ___________________ and play an important role in detecting and destroying _________________

Lymphatic and blood vessels are found together in the capillary beds:

Lymphatic vessel

Blood capillary

Tissue cells

ECF

Lymphatic capillary

Cardiovascular System: The Heart

The heart is at the centre of the cardiovascular system. It is a ________________________________. Each time the heart beats: 1. Oxygen-poor blood is delivered to the heart from the __________and ___________ via the

__________________ and _______________________________________. 2. The oxygen-poor blood goes into the ______________________, and from there into the ______

_______________. The _____________________________ between the right atrium and the right ventricle prevents the blood from moving backwards from the ventricle to the atrium.

3. The right ventricle pumps the oxygen-poor blood to the __________ via the ________________ _____________ (arteries always move blood ____________ from the heart).

4. In the lungs, the oxygen-poor blood moves through capillaries where _________________________________ occurs: a) carbon dioxide diffuses out of the ____________ and into the ________________, while b) oxygen diffuses from the _______________ into the ____________.

5. The oxygen-rich blood now returns to the heart via the ___________________________ (veins always bring blood _____________ to the heart). The oxygen rich blood goes into the _____________________ of the heart, and from there it goes to the _______________________. The ____________________________ between the left atrium and left ventricle prevents blood from flowing backwards from the left ventricle into the left atrium.

6. The left ventricle is __________________________ and contracts strongly to pump blood out to the _________ and ___________ through the _____________.

Blood Supply to the Heart

The heart is the strongest, most powerful muscle in the human body. It needs oxygen in order to pump. The heart muscle gets its oxygen from the coronary arteries that wrap around the surface of the heart, not from the blood that is pumped through the heart. There are four coronary arteries, as shown in the diagram below: Questions: 1. A “pulse” is felt when blood is pumped through an artery. Which chamber of the heart contracts

to produce the pulses you can feel in your body? ______________

2. True or False? a) Arteries always carry blood away from the heart. _________ b) The heart is the body’s strongest, most powerful muscle. _________ c) The blood in the coronary arteries is oxygen-rich. _________ d) The blood in the pulmonary artery is oxygen-rich. _________ e) The superior and inferior vena cava carry blood to the lungs. _________ f) The pulmonary vein delivers blood into the left atrium. _________ g) The jugular vein carries oxygen-rich blood to the brain. _________ h) The aorta is the main artery carrying oxygen-rich blood to the body. _________ i) When the right atrium contracts, the blood flows through the mitral valve. _________ j) When the right ventricle contracts, the blood flows to the lungs. _________ k) The blood in the right atrium is oxygen rich. _________ l) The heart muscle cells get their oxygen as passes through the left atria and left ventricle. ______ 3. Starting with the blood coming INTO the left atrium, list where the blood travels as it makes one

complete circuit through the body and back to the left atrium.

Electrical Conduction System of the Heart

During each heart beat (one _________________________), the following steps take place: 1. Specialized heart cells in the _____________________ ( ) ___________ in the _________ of the

______________________ release an ________________ impulse (a _________________________). This impulse spreads across the __________ and ____________________ and causes the heart muscle cells (_____________________ cells) in both atria to ________________. The right atrium contracts and pumps blood into the ______________________________. The left atrium contracts and pumps blood into the _____________________________.

2. Once the electrical impulse from the _______________ has travelled across the __________ and caused

them to contract, it reaches the ____________________________ ( ) __________ found between the __________ and ___________________. The ventricles are _________________ from the atria, so the electric current cannot spread directly across the ventricles. Instead, the electrical impulse from the _____________ travels down to the ______________ of the heart via specialized fibres called the ________________________ and the ___________________________ found in the ______________ between the ventricles. The bundle branches divide into the __________________________ which carry the impulse rapidly along the __________ and over the _____________ of both ventricles and cause the muscle cells in __________________________ to ______________. The ventricles contract from the ____________ to the _______, so blood pumps more ______________________.

The right ventricle contracts and pumps blood to the ____________________________ to the _______. The left ventricle contracts and pumps blood into the ____________ to the _________ and ________.

The _____________ that the electrical impulse travels through different parts of the heart is critical to ensure that the heart pumps in an ________________, _________________ pattern.

While the ventricles are ____________________, the atria are __________________ and ______________ to get ready for the ______________________________.

When the ventricles are _______________ (open) and ____________ with blood, they are in ___________. When the ventricles are pumping blood (__________________), they are in _______________.

One way to remember the difference between depolarization and repolarization is that: Depolarization is when the cells are ______________________ or giving off an electrical impulse Repolarization is when the cells are __________________ or “____________” to get ready for another cycle

Electrocardiograms (also known as Electrokardiograms, EKGs)

An excellent animation of electrical impulses when heart contracts and corresponding ECG: http://en.wikipedia.org/wiki/Image:ECG_principle_slow.gif The _________________________________ that pass through the heart can be read using a device called an _______________________________. It produces a print out or trace called an _______ (_____________- ______________________. A normal human ECG looks like this:

During the “____” wave, the _____________ depolarizes. The electrical impulse travels over both _______ to the ______________, causing the muscle cells in both atria to _______________. During the “________” complex, the electrical impulse travels from the _______________, down the _______________________ (between the _______________), and along the _______________________, causing the cells in the ________________ to ______________. During this time, the muscle cells in the atria ___________________ and ___________. The atria ___________ getting ready for the next cycle. During the “_____” wave, the cells in the _____________ and __________________ repolarize, _________ and relax. The ventricles ____________ to get ready for their _______________________________.

When a person has a _______________________, some of the heart cells ________. The ________ or ______________ heart cells do not ______________ the electric impulse __________________ and this often ________________ the ______________________ pumping of the heart. The changes in conductivity can be seen on the _________ and can indicate what part of the heart has been _________________.

Homework Questions: 1. Label as many other structures on the diagram of the heart as you can (at least 8:) 2. What are the two nodes (pacemakers) and where are they found in the heart? 3. What is the correct name for the muscle cells in the heart? 4. What is the function of the Bundle of His? Where is it found? 5. What is the function of the Purkinje fibres? 6. Why is it important that the electrical impulses travel down to the bottom of the ventricles BEFORE they

cause the muscle cells in the ventricles to contract? 7. In which ventricle are the muscle walls thicker? Explain why. 8. What is happening during:

a) systole b) diastole

9. Explain the difference between depolarization and repolarization.

10. When a person has a heart attack, blood flow is blocked to part of the heart and this part of the heart dies. A heart attack is called a ‘myocardial infarction’. In medicine, infarction is tissue death (necrosis) caused by a lack of oxygen, due to an obstruction of the tissue's blood supply. The dead heart tissue causes scarring, and the scarred areas do not conduct electrical signals evenly.

a) What is the name of the arteries that supply blood to the heart tissue?

b) If the blood supply to the right atrium is blocked and part of the right atrium dies, how will this affect the conduction of the signal from the SA node to the AV node?

­ What effect will this have on blood flow through the heart?

­ Which part of the ECG will be changed as a result of damage to the right atrium?

c) If the blood supply to one of the ventricles is blocked and part of one of the ventricles dies, how will this affect the conduction of the signal by the Purkinje fibres?

­ What effect will this have on blood flow through the heart? ­ Which part of the ECG will be changed as a result of damage to a ventricle?

SBI3UI – PULSE AND BLOOD PRESSURE LAB NAME: ____________________ Part A) Pulse Pulse at Rest

1. Place your first and second finger in the groove between the radius bone (on thumb side) and the tendon at the wrist and press lightly.

2. Count the number of beats in 15 seconds. 3. Multiple this by 4 to get the number of beats in 60 seconds (this # is your pulse). 4. Add your pulse to the class data on the front board (we will take an average at the end)

Beats/15 sec. Pulse (beats/60 sec.) Class average

Pulse after Exercise

1. Exercise moderately for 1 minute (run on the spot, push-ups, jumping jacks, stairs, etc.) 2. Immediately take your wrist pulse again. 3. Add your pulse to the class data on the front board (we will take an average at the end)

Beats/15 sec. Pulse (beats/60 sec.) Class average

Discussion Questions

1. Was your pulse higher or lower than the class average? Suggest possible reasons for this.

2. Which artery is felt when taking the pulse at the wrist? (you might have to look this up) Part B) Heart Sounds Heart Sounds at Rest

1. Place a stethoscope on your chest and listen for a heart sound. Move the stethoscope around the area to where the heart sounds are loudest. Do you hear the Lub-dub sound?

• LUB - The lub sound you hear is the blood from the ventricles causing the AV valves

(tricuspid & bicuspid) to snap shut. This happens when the ventricles contract and blood is pumped out of the ventricles into the aorta and pulmonary arteries.

• DUB – The dub sound you hear is blood in the aorta and pulmonary artery causing the aortic and pulmonary valves to snap shut when the ventricles are relaxed.

Part C) Blood Pressure Blood Pressure at Rest

1. Sit down and make sure arm is wrist up and at rest. 2. Roll sleeves up (or remove long sleeves) and place

cuff just above the elbow. 3. Place stethoscope bell under cuff on inner surface

of arm. 4. Pump cuff to about 150-160 mmHg, then slowly

release air while listening. 5. The first thuds that you hear = systolic pressure. 6. The last thuds you hear = diastolic pressure. 7. Do not move your arm during the reading. 8. Release remaining pressure in cuff as soon as reading is complete.

Systolic Pressure Diastolic Pressure BP (systolic/diastolic)

Blood Pressure after Exercise

1. Exercise moderately for 1 minute (run on the spot, push-ups, jumping jacks, etc.) 2. Take your blood pressure immediately after exercise.

Systolic Pressure Diastolic Pressure BP (systolic/diastolic)

Discussion Questions:

1. What was the effect of exercise on Blood Pressure?

2. How would the body benefit from this change in blood pressure during exercise?

3. What is considered normal average adult blood pressure?

4. In atherosclerosis, plaque builds up in the arteries. This decreases the volume inside the blood vessels. How would this affect blood pressure?

Diseases of the Cardiovascular System

The cardiovascular system has three components, the blood, blood vessels and heart. Disorders can affect any of these parts. 1. Disorders of the Blood a) Anemia • a lower than normal number of RBCs or amount of hemoglobin in the blood • may be due to excessive blood loss (including from menstruation), iron deficiency, vitamin B12

deficiency or many other reasons • the blood can not carry as much oxygen so the person is pale, tires easily and may have trouble

concentrating

b) Leukemia • a group of cancers which produce higher than normal number of WBCs in the blood • may be acute (rapid onset, very serious) or chronic (progress over a long period of time, less serious) • symptoms include fatigue, abnormal bruising, swollen lymph nodes (glands) • can be treated with chemotherapy and radiation 2. Disorders of the Blood Vessels: Atherosclerosis

a) Atherosclerosis in the Coronary Arteries • hardening and narrowing of the arteries due to a build up of plaque

inside blood vessel walls • plaque is made of cholesterol, fat and calcium • plaque causes arteries to lose their elasticity, increasing blood pressure • plaques may rupture, causing a blood clot to form which further

reduces blood flow • decreased blood to the heart may cause angina (heart pain) due to

reduced oxygen to the heart muscle cells or a heart attack if the blood supply is completely cut off by plaque or a blood clot

Symptoms of a heart attack include: ­ a tightness, squeezing or pressure in the chest ­ difficulty breathing ­ pain in the neck, shoulder, arm or chest,

especially on the left side ­ nausea or vomiting ­ profuse sweating Treatments for a heart attack include: • angioplasty (below)

In angioplasty, a catheter is inserted into the blocked artery. A balloon in the catheter is inflated to compress the plaque, opening the artery. A metal stent is left behind to hold the blood vessel open, maintaining blood flow.

a) Atherosclerosis in the Coronary Arteries (continued) • if a coronary artery is too badly blocked to be opened with angioplasty, coronary bypass surgery may

be required • a healthy blood vessel is stitched into place to “bypass” (get around) the clogged artery b) Atherosclerosis in the Arteries to the Brain • atherosclerosis in an artery that supplies blood to the brain

may cause an ischemic stroke • the brain tissue past the blockage dies due to lack of oxygen Symptoms of a Stroke (FAST) include: ­ uneven features in the face: the eyes, pupils, eyebrows,

smile, mouth, wrinkles or creases ­ weakness in one side of the body,

especially one arm ­ slurred or garbled speech; the

inability to speak • if you suspect that a person is

having a stroke, respond immediately

• giving a person tPA (tissue plasminogen activator from snake venom) within a few hours of an ischemic stroke can dissolve any clots and restore blood flow to the brain, preventing permanent brain damage

Atherosclerosis may be prevented by: • staying active, maintaining a normal body weight and eating a healthy diet • taking anticoagulants (“blood thinners”) such as aspirin (or cinnamon…be

careful!!) which prevent platelets from sticking to one another and forming clots 2b) Disorders of the Blood Vessels: Aneurysms • a ‘weak spot’ which creates a bulge in the wall of an artery • as blood continues to flow through the artery, the bulge may burst, causing

serious internal bleeding • occurs most commonly where arteries branch (bifurcate) • can occur anywhere in the body • if an aneurysm ruptures in the brain, it can cause a hemorrhagic stroke

(bleeding in the brain). This must NOT be treated with tPA or blood thinners!! • aneurysms can be corrected with surgery

A single bypass (one coronary artery was blocked)

A triple bypass (three coronary arteries were blocked)

2c) Disorders of the Blood Vessels: Varicose veins • enlarged, twisted veins due to valves in the veins weakening and allowing blood to flow backward • blood pools in the vein below the weakened valve, stretching and distorting the vein 3. Disorders of the Heart: a) Heart Valve problems ­ one or more of the valves in the heart does not open or close properly ­ if a valve does not close properly, blood flows backward through the valve, creating a “murmur”

(‘pshhh’ sound) ­ valve problems decrease the efficiency of blood flow so the person feels light-headed, tired and may

pass out during exertion ­ can be treated with drugs or surgery to put in replacement valves b) Arrhythmias (‘without rhythm’) • a condition in which the electrical activity and pumping of the resting heart is abnormal (too slow,

too fast, or irregular) • blood is not pumped effectively, so the person feels light-headed, tired and may pass out • if the arrhythmia is caused by a problem with the SA node in the right atrium, treatment may involve

implanting a pacemaker under the skin of the chest to regulate the heart rate • if the arrhythmia causes the ventricles to beat too quickly (ventricular tachycardia or ventricular

fibrillation), the person may be treated with a defibrillator (eg. AED, automatic external defibrillator) • the defibrillator sends an electric current through the heart which stops the heart from beating • it is hoped that once the SA node resumes firing, the heart will come back into rhythm Homework Questions: Use the information in this note and on pages 316 – 319 of your text to answer the following questions: 1. Why are women more likely to

develop anemia during their reproductive years?

2. What is the difference between acute and chronic leukemia?

3. What causes a heart attack and what are its symptoms?

4. What causes a stroke and what are its symptoms?

5. How are angioplasty and coronary bypass surgery the same? How are they different?

6. If a person has surgery to bypass two blocked coronary arteries, what would this procedure be called? 7. If a person has hemophilia, are they more or less likely to be at higher or lower risk of a heart attack?

Explain.

8. What are the two types of strokes? Explain the difference in the causes of these types of strokes.

9. What is a pacemaker used for? What is an AED and what is it used for? 10. How can a heart attack cause an arrhythmia? (use this note and refer to the homework questions on

ECGs)