Download Unit H: Circulatory System

Unit H: Circulatory System
Program Area:
Health Occupations Education
Course Title:
Allied Health Sciences I
Unit Title:
Circulatory System
Suggested
Time for
Instruction:
Number: 7211
7 class periods (90 minute classes)
12 class periods (55 minute classes)
Course Percent:
8%
Unit Evaluation:
100% Cognitive
-------------------------------------------------------------------------------
Competency:
1H08. Analyze the anatomy and physiology of the circulatory
system.
Specific Objectives:
1H08.01
Explain the structure of the heart.
1H08.02
Analyze the function of the heart.
1H08.03
Analyze circulation and the blood vessels.
1H08.04
Discuss characteristics and treatment of common cardiac and
circulatory disorders.
Summer 2005 H.1
Unit H Master Outline
H
Circulatory System
1H08.01
Explain the structure of the heart.
A. Size, shape and location
1. Size of closed fist
2. In thoracic cavity
3. Apex
4. Four chambers
B. Layers
1. Pericardium
2. Myocardium
3. Endocardium
4. Septum
C. Structures to and from heart
1. Superior and inferior vena cava
2. Pulmonary artery and vein
3. Aorta
D. Chambers and valves
1. Atria (atrium)
2. Ventricles (ventricle)
3. Tricuspid valve
4. Mitral (bicuspid) valve
5. Pulmonary semilunar valve
6. Aortic semilunar valve
1H08.02
Analyze the function of the heart.
A. Four main functions of circulatory system
a. Pump
b. Blood transport system around body
c. Carries oxygen and nutrients to cells, carries away waste
products
d. Lymph system – returns excess tissue fluid to general circulation
B. Heart
a. Ave. 72 beats per minute, 100,000 beats per day
b. Superior and inferior vena cava bring deoxygenated blood to right
atrium
c. Cardiopulmonary circulation – circulation from the heart to the
lungs
d. Pulmonary artery takes blood from right ventricle to lungs
e. Pulmonary veins bring oxygenated blood from lungs to left atrium
f. Aorta takes blood from left ventricle to rest of body
g. Four heart valves permit flow of blood in one direction
C. Pump
a. Heart is a double pump
b. Right heart = right atrium  tricuspid valve  right ventricle 
pulmonary semilunar valve  pulmonary artery  lungs (for
oxygen)
c. Left heart = Lungs  pulmonary veins  left atrium  mitral
valve  left ventricle  aortic semilunar valve  aorta 
general circulation
Summer 2005 H.2
D. Heart sounds (lubb dupp)
E. Electrical activity
a. SA (sinoatrial) node = pacemaker, sends out electrical impulses,
spreads impulse over atria and makes them contract
b. AV (atrioventricular) node = carries impulse to bundle of His
c. Bundle of His = conducting fibers in septum, divides into right
and left branches in ventricles to Purkinje fibers
d. Purkinje fibers = cause ventricles to contract
1H08.03
Analyze circulation and the blood vessels
A. Cardiopulmonary circulation – carries blood from heart to lungs
1. Oxygenated and deoxygenated blood
2. Oxygen/carbon dioxide exchange
B. General circulation
1. Coronary arteries
2. Aorta
3. Systemic circulation
C. Blood vessels
1. Arteries
a. Carry oxygenated blood away from the heart to the
capillaries
b. Elastic, muscular and thick-walled
c. Transport blood under very high pressure
2. Arterioles
3. Veins
a. Carry deoxygenated blood away from capillaries to heart
b. Less elastic and muscular than arteries
c. Thin walled, collapse easily when not filled with blood
d. Superior and inferior vena cava carry blood to heart
4. Venules
5. Capillaries
a. Smallest blood vessels
b. Only seen with microscope
c. Connect arterioles and venules
e. Walls are one-cell thick, allow for selective permeability
6. Valves – permit flow of blood only in direction of heart
7. Capillaries
8. Jugular vein – located in neck
9. Carotid artery – carries blood to brain
D. Blood pressure
1. Systolic – ave = 120 (Systole is contraction phase)
2. Diastolic – ave = 80 (Diastole is relaxation phase)
E. Pulse – alternating expansion and contraction of an artery as blood
flows through it
1. Brachial
2. Carotid
3. Femoral
4. Pedal
5. Popliteal
6. Radial
Summer 2005 H.3
1H08.04
Discuss characteristics and treatment of common cardiac
and circulatory disorders.
A. Heart diseases
1. Symptoms
a. Arrythmia (dysrrhythmia) – any change from normal heart
rate or rhythm
b. Bradycardia – slow heart rate (<60)
c. Tachycardia – rapid heart rate (>100)
2. Coronary artery disease
a. Angina pectoris – chest pain, lack of O2 to heart muscle,
treat with nitroglycerine
b. Edema – fluid in tissues, often caused by poor circulation
3. Myocardial infarction (MI, heart attack)
a. Lack of blood supply to myocardium
b. Symps – severe chest pain radiating to left shoulder, arm,
neck and jaw, nausea, diaphoresis, dyspnea
c. Rx – bedrest, oxygen, medication
d. Morphine for pain
e. Anticoagulant therapy to prevent further clots from forming
f. Surgery may be necessary
B. Vascular diseases
1. Aneurysm – ballooning of an artery, thinning and weakening
2. Arteriosclerosis – arterial walls thicken and lose elasticity
3. Atherosclerosis – fatty deposits form on walls of arteries and
block circulation
4. Hypertension
a. High blood pressure
b. Silent killer – usually no symptoms
c. Leads to strokes, heart attacks, kidney failure
d. Higher in African-Americans and post-menopausal women
e. Risk factors – smoking, overweight, stress, high fat diets,
family history
f. Treatment – relaxation, low fat diet, exercise, weight loss,
medication
5. Hypotension – low blood pressure, systolic <100
6. Embolism – traveling blood clot
7. Varicose veins
a. Swollen, distended veins
b. Heredity or due to poor posture, prolonged periods of
standing, physical exertion, age and pregnancy
C. Diagnosis and treatment
1. Electrocardiogram – electrical tracing of the heart
2. Coronary bypass – healthy vein from leg removed and attached
before and after the coronary obstruction, creating an alternate
route for blood supply to the myocardium
3. AED – automated external defibrillator
4. Defibrillation – electrical shock to bring the heart back to a
normal rhythm
5. CPR – cardiopulmonary resuscitation, used in presence of
cardiac arrest
6. Artificial pacemaker – when heart has conduction (electrical
impulse) defect, demand pacemaker fires when heart rate drops
below minimum, causes heart to contract
7. Angiogram – x-ray of blood vessel using dye
Summer 2005 H.4
Unit H:
Circulatory System
Competency 1H08:
Analyze the anatomy and physiology of the circulatory
system.
Materials/Resources
Scott, Ann Senisi and Elizabeth Fong. Body Structures & Functions. Delmar Publishers,
Current Edition. www.DelmarAllied Health.com
National HOSA Handbook: Section B. Published by HOSA, Flower Mound, Texas. Current
Edition. www.hosa.org
Teaching/Learning Indicators: The following letters are used to indicate specific
skills/areas required in the instructional activity.
R
W
M
H
Reading
SS
Social Studies
Writing
S
Science
Math
A
The Arts
Health professional/parent/community involvement
Summer 2005 H.5
Objective 1H08.01
Explain the structure of the heart.
Teaching/Learning Activities
 Cognitive
S
Have students label the diagram of the heart located in the appendix (Appendix 1H08.01
B). After learning about the circulation, students can then color the different structures of
the heart red or blue depending on the oxygenated or deoxygenated blood.
 Teamwork
S, A
Have students work in teams to produce a 3-D model of the heart following the
instructions in “Make a Heart 101” (Appendix 1H08.01C). Each team member must show
proof of participation. The teams will present the models to the class. Individual teams
will decide on the method to produce the models.
Before beginning the assignment, the teacher should obtain the following materials to be
used with the activity:
Latex gloves
Note cards
Markers
 Critical Thinking
Paper cups (4 per group)
Masking tape
S, A
Have students draw a heart on a plain sheet of paper. Do not give any instructions other
than to draw a heart. After the hearts are drawn, have students list all the words inside
the heart that they can think of having to do with the circulatory system. The students
must be able to explain the words to the class. It is good to require at least 5 words, but
the number can vary.
 Special Needs
Each student will reach the highest level of mastery in the least restrictive environment as
recommended in the student’s IEP.
Summer 2005 H.6
Objective 1H08.02
Analyze the function of the heart.
Teaching/Learning Activities
 Critical Thinking
S, M
Have students complete the worksheet “Heart & Blood Math,” (Appendix 1H08.2A). To
be successful in this activity, the students and teacher will need to discuss why we have a
pulse, and the teacher should teach students how to take a radial pulse.
 Cognitive
S
As a follow up to the previous activity, discuss the transparency “Blood and the Heart Fun
Facts” (Appendix 1H08.2B).
 Employability Skills
S, H, W
Invite a cardiovascular technologist to demonstrate and talk about the electrical activity of
the heart, or visit the cardiovascular department at the local hospital and observe the
cardiovascular technologist. After the presentation have students to write a summary of
their conclusions about the function of the heart, based on their experiences with this
activity.
Note: Ask the speaker if he/she has an echocardiogram to share with the class. This
shows the pumping mechanism of the heart and the structures.
 Basic Skills S, W
Have students write a paper explaining the electrical activity of the heart. The paper
should be imaginative while factual. For example, SA node could be Shawn Adams who
gets a real charge out of life. The AV node could be Agnes Vernox who always gets a
charge out of other people. Assign points for creativity and realism.
 Teamwork
S, W
Have students divide into groups of 3-5 depending on the class size. Complete the “New
Beginnings,” activity. (Appendix 1H08.02C)
 Special Needs
Each student will reach the highest level of mastery in the least restrictive environment as
recommended in the student’s IEP.
Summer 2005 H.7
Objective 1H08.03
Analyze the circulation and the blood vessels.
Teaching/Learning Activities
 Cognitive S
Have students participate in a class discussion about blood vessels and circulation.
(Transparency Appendix 1H08.03A)
 Teamwork S
Have students draw note cards with the pulse sites and their locations listed. Put one site
on half the note cards and the location on the other half. Example:
Brachial
Bend of the arm
Pin note cards on each student’s back and have him/her search for his/her mate. The
students may ask only 3 questions of each person they meet. When they find their
partner, the students should stay together until the activity is over.
 Critical Thinking S
Show students how to feel pulses at various pulse sites and explain to the students what
pulses are. Have students listen to the heartbeat with a stethoscope and explain the
physiology behind the lubb dupp sound.
 Technology
S, A
Have students create a poster of the physiology of the blood vessels using the computer.
Students may want to try the web site: www.innerbody.com/indexbody.htm/ as an
anatomy and physiology resource.
 Teamwork
S, A
Have students become the different structures of the heart by making a sign to wear with
the name of their structure on it. Assign one student per structure and any remaining
students may be the blood. Assign each drop of blood a different direction to come from:
tip of nose, bottom of ear lobe, etc. The first time a drop of blood goes through the heart,
each structure holds up his/her sign to guide the way. The second time the blood goes
through, no signs are shown, but the blood may ask the structures who they are. The
third time the blood goes through, no questions are allowed. If the blood gets stuck, this
could be a good learning example of a clot, etc.
 Teamwork S
Have students participate in the circulation race. (Appendix 1H08.03B)
 Special Needs
Each student will reach the highest level of mastery in the least restrictive environment as
recommended in the student’s IEP.
Summer 2005 H.8
Objective 1H08.04
Discuss characteristics and treatment of common
cardiac and circulatory disorders.
Teaching/Learning Activities
 Employability
S, H, SS
Invite a cardiologist to class to explain current methods used for treating heart attack
patients, such as stints, cardiac bypass, angioplasty, transplants, etc.
 HOSA
S, W, R
Using the Researched Persuasive Speaking guidelines, have students research a
disorder assigned by the teacher, and then write a paper on the assigned topic. A main
focus of the paper and speech will be to persuade people to change behavior related to
the prevention or treatment of the disease assigned.
Students will present their persuasive speech in class while classmates take notes.
When two or more students are assigned the same topic, those speeches should be
given, one after the other, to allow students to focus on one disorder at a time.
 HOSA
S, SS
Using the guidelines for “Biomedical Debate” debate the topic “Heart Transplants – No
Restrictions.”
 Cognitive S
This exercise will be useful as a review for the entire unit on the circulatory system. Have
students play the game, “Speaking Of.” The game begins by the student making a
statement concerning the heart. The statement must be true and must begin with
“Speaking of.” For example: Speaking of the heart, it pumps 80 mL of blood with each
heartbeat. A student may jump in when he/she can make a statement using any word in
the previous sentence. For example: Speaking of each heartbeat, if you count it for 1
minute that will give you your pulse rate. The next student may pick up on pulse, heart,
beat, count, rate, etc. Use for 5-10 minutes or until you are satisfied students understand.
NOTE: Make sure students understand how to play. Each student may be responsible
for making at least one statement. If on teams, one team member may answer for the
whole team if there is joint input.

Teamwork S
This activity is best if it is done after the Researched Persuasive Speeches have been
given.
Have one team be a “host” panel. Each person on the team is allowed to ask the “guest”
team two questions. At the end of the questions, the host panel has 30 seconds to confer
and name the diseases. Students must answer questions truthfully, but should not
volunteer any information that is not asked. If the host panel guesses correctly, the
guests go home with nothing. If the host panel does not guess correctly, each host panel
member gives each guest panel member a piece of miniature candy.
Summer 2005 H.9
Objective 1H08.04
Discuss characteristics and treatment of common
cardiac and circulatory disorders.
Teaching/Learning Activities (Continued)
 Teamwork S
Have students divide into four or five teams. Give them 15 minutes to write 5 questions
about the diseases they studied. Each team gets to challenge any other team in the room
with their questions. If the other team answers the question correctly and guesses the
disease, they get the point. If not, the challenging team gets the point. Teammates who
are challenged have 20 seconds to confer and then they must answer. The turn passes
to the challenged team.
 Special Needs
Each student will reach the highest level of mastery in the least restrictive environment as
recommended in the student’s IEP.
Summer 2005 H.10
Unit H: Circulatory System
Terminology List
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
aorta
aortic semilunar valve
apex
arterioles
artery
atrium
Atrioventricular (AV) node
bicuspid/mitral
brachial
Bundle of His
capillaries
carotid
cardiopulmonary circulation
coronary arteries
deoxygenated
diastolic
endocardium
femoral
inferior vena cava
jugular
lubb dupp
myocardium
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
oxygen/carbon dioxide exchange
oxygenated
pacemaker
pedal
pericardium
popliteal
pulmonary artery
pulmonary semilunar valve
pulmonary vein
pulse sites
purkinje fibers
radial
Sinoatrial (SA) node
septum
superior vena cava
systemic circulation
systolic
tricuspid
valves
veins
ventricle
venules
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
coronary artery disease
CPR
edema
electrocardiogram (EKG and ECG)
embolus (embolism)
hypertension
hypotension
myocardial infarction
tachycardia
varicose veins
Disorders and Related Terminology
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
AED/defibrillation
aneurysm
angina pectoris
angiogram
arrhythmias
arteriosclerosis
artificial pacemaker
atherosclerosis
bradycardia
coronary bypass
Appendix 1H08.01A
Summer 2005 H.11
The Heart
Label the following structures of the heart:
1. right atrium
2. left atrium
3. right ventricle
4. left ventricle
5. septum
6. mitral valve
7. tricuspid valve
8. superior vena cava
9. inferior vena cava
10. aorta
11. myocardium
12. endocardium
13. pericardium
Appendix 1H08.01B
Summer 2005 H.12
Make a Heart 101
Your assignment is to work in you assigned groups (do not
change them) and using the materials in your heart packet,
construct a heart.
You may use the finger tips of the gloves for your valves.
You may use up to four cups, but you do not have to use all
of these if you are doing something else creatively. Your heart must
have all the chambers, valves, arteries, veins, etc.
The note cards can be cut into small pieces and used as labels. Your
heart must be labeled. The tape needs to be returned to the teacher at
the end of class to be used with other classes. The most accurate and
creative heart will win a prize.
To complete this assignment you must write a group essay in which you
use your particular model to teach a person about the heart. Make sure
you make reference to the different structures and the materials you
have used to make those structures. This essay will be graded for
content, grammar, and spelling. Please use paragraphs.
Use other people in your group to proof-read your essay. You have only
this class period to complete this assignment, so do not waste time.
For maximum success, put your heart into this assignment!
Appendix 1H08.01C
Summer 2005 H.13
Heart and Blood Math
FACTS:
About 80 ml of blood is sent through the aorta with each contraction of
the left ventricle.
Your body contains about 5 L of blood.
Your heart weighs about one pound (10 oz.)
The adult heart is about 5 inches long and 5.5 inches wide.
QUESTIONS:
1. How much blood does your heart pump in one minute?
Pulse
Amount in ml
Amount in oz.
A)
at rest
_____
___________
___________
B)
jump in place for 1 min. _____
___________
___________
C)
run in place for 2 min.
___________
___________
_____
2. Is the entire volume of blood pumped through your body in more or less than a
minute?
3. How long and how wide is the heart in centimeters?
_____
4. How much does the heart weigh in grams?
_____
Appendix 1H08.02A
Summer 2005 H.14
BLOOD AND THE HEART FUN FACTS
 An average adult human contains
about 5 liters (5.3qt) of blood.
 The blood makes up about onethirteenth of the body’s weight.
 The adult heart weighs about 280 grams (10
oz.)
 At rest, the heart pumps out about 80 millimeters
(2.6 oz) of blood with each beat.
 The heart beats, on average, 70 times each
minute at rest.
 This means all the blood is circulated (goes
round the body once) in about one minute.
 During strenuous exercise the heart can pump
six to eight times the amount of blood that it
pumps at rest.
Appendix 1H08.02B
Summer 2005 H.15
New Beginnings
In a container place the slips of paper containing the “New Beginnings.” Have
each team to draw one “new beginning” out of the container. The team must take
their beginning and complete their story using ten of the anatomy terms found on
the terminology list in the appendix. Each team member must participate. Allow 20
minutes for the exercise. Terms must be used appropriately.
Examples of “New Beginnings”
John and Jillian were studying together when all of a sudden. . . . . .
Peter thought Chris was meeting him at the bus station. When he
walked through the door soaking wet. . . . . .
As the train careened around a steep turn. . . . . .
It was a bright and sunny day.. . . . . . . . . .
Newsflash! This is amazing!. . . . . . .
Help!. . . . . .
Appendix 1H08.02C
Summer 2005 H.16
As the Blood Flows
Deoxygenated Blood from Body Tissue 
Superior/inferior vena cava 
Right Atrium 
Tricuspid Valve opens 
Right Ventricle 
Pulmonic Valve  Pulmonary Artery 
Both Lungs 
CO2 - O2 exchange Alveolar via Pulmonary Veins 
Left Atrium 
Mitral Valve Opens 
Left Ventricle 
Aortic Valve Opens 
Aorta - Transporting Oxygenated Blood to Body
Cells
Appendix 1H08.03A
Summer 2005 H.17
Circulation Race

Prepare two envelopes. One envelope will be for the artery team (pink note cards) and
one envelope for the veins team (blue notecards.)

The following terms should be written on a note card (one term per note card). Each
team should have a complete set of terms in their envelopes. (Another alternative is to
copy this page on blue paper and on pink paper, and cut out the terms below.)

Before the race starts, appoint a team captain. Have the team captain distribute the
note cards, with the term facing down so the student does not know what it is. Make
sure each team member has at least one term. Some may have more depending on the
number of students per team.

When the whistle blows, the students are to race to see who can create a “circulation
circle” which follows the flow of blood through the circulatory system. Students can also
race against their own times to see if they pick up speed.
Superior Vena
Cava
Inferior Vena
Cava
Right Atrium
Tricuspid
Valve
Right Ventricle
Pulmonary
Valve
Pulmonary
Artery
Lungs
CO2 and O2
Exchange
Pulmonary
Vein
Left Atrium
Bicuspid
(Mitral) Valve
Left Ventricle
Aortic Valve
Aorta
Arteries
Arterioles
Capillaries
Venules
Veins
Appendix 1H08.03B
Summer 2005 H.18
Unit H:
Circulatory System
OVERHEAD TRANSPARENCY
MASTERS
Summer 2005 H.19
Functions
1. Pump
2. Blood transport system around body
3. Carries O2 and nutrients to cells, carries away
waste products
4. Lymph system – returns excess tissue fluid to
general circulation
Structure – Circulatory system involves:
 Heart
 Arteries
 Veins
 Capillaries
 Blood and lymph are part of circulatory system
Major Blood Circuits
 General (Systemic) circulation
 Cardiopulmonary circulation
Summer 2005 H.20
Summer 2005 H.21
The Heart




Muscular organ
Size of a closed fist
Weighs 12-13 oz
Location – thoracic
cavity
 APEX – conical tip, lies
on diaphragm, points left
 Stethoscope –
instrument used to hear
the heartbeat
Structure
 Hollow, muscular, double pump that circulates
blood
 At rest = 2 oz blood with each beat, 5 qts./min.,
75 gallons per hour
 Ave = 72 beats per minute
 100,000 beats per day
 PERICARDIUM – double layer of fibrous tissue
that surrounds the heart
 MYOCARDIUM – cardiac muscle tissue
 ENDOCARDIUM – smooth inner lining of heart
 SEPTUM – partition (wall) that separates right
half from left half
Summer 2005 H.22
 Superior vena cava and
inferior vena cava – bring
deoxygenated blood to right
atrium
 Pulmonary artery – takes
blood away from right
ventricle to the lungs for O2
 Pulmonary veins – bring oxygenated blood
from lungs to left atrium
 Aorta – takes blood away from left ventricle to
rest of the body
Chambers and Valves




SEPTUM divides into R and L halves
Upper chambers – RIGHT ATRIUM and LEFT
ATRIUM
Lower chambers – RIGHT VENTRICLE and
LEFT VENTRICLE
Four heart valves permit flow of blood in one
direction
Summer 2005 H.23
TRICUSPID VALVE – between right atrium and
right ventricle
BICUSPID (MITRAL) VALVE – between left atrium
and left ventricle
Semilunar valves are located where blood leaves
the heart - PULMONARY SEMILUNAR VALVE
and AORTIC SEMILUNAR VALVE
Summer 2005 H.24
PHYSIOLOGY OF THE HEART
The heart is a double pump. When the heart
beats…
Right Heart
Deoxygenated blood flows into heart from vena
cava  right atrium  tricuspid valve  right
ventricle  pulmonary semilunar valve 
pulmonary artery  lungs (for oxygen)
Left Heart
Oxygenated blood flows from lungs via pulmonary
veins  left atrium  mitral valve  left ventricle
 aortic semilunar valve  aorta  general
circulation (to deliver oxygen)
Summer 2005 H.25
Blood Supply to the Heart – from CORONARY
ARTERIES
Heart Sounds = lubb dupp
Summer 2005 H.26
Control of Heart Contractions
SA (sinoatrial) NODE = PACEMAKER
 Located in right atrium
 SA node sends out electrical impulse
 Impulse spreads over atria, making them
contract
 Travels to AV Node
AV (atrioventricular) NODE
 Conducting cell group between atria and
ventricle
 Carries impulse to bundle of His
BUNDLE OF HIS
 Conducting fibers in septum
 Divides into R and L branches to network of
branches in ventricles (Purkinje fibers)
PURKINJE FIBERS
 Impulse shoots along Purkinje fibers causing
ventricles to contract
Summer 2005 H.27
ELECTROCARDIOGRAM (EKG or ECG)
Device used to record the electrical activity of the
heart.
SYSTOLE = contraction phase
DIASTOLE = relaxation phase
Baseline of EKG is flat line
P = atrial contration
QRS = ventricular contract
T = ventricular relaxation
Summer 2005 H.28
CARDIOPULMONARY CIRCULATION – heart
and lungs
SYSTEMIC CIRCULATION – from the heart to the
tissues and cells, then back to the heart
Cardiopulmonary Circulation
“As the Blood Flows” Appendix MD08.03A
ARTERIOLES – small arteries
VENULES – small veins
Systemic Circulation
AORTA – largest artery in the
body
 First branch is coronary artery
 Aortic arch
 Many arteries branch off the
descending aorta
Summer 2005 H.29
Blood Vessels
Summer 2005 H.30
ARTERIES
 Carry oxygenated blood away from the heart to
the capillaries
 Elastic, muscular and thick-walled
 Transport blood under very high pressure
CAPILLARIES
 Smallest blood vessels, can only be seen with
a microscope
 Connect arterioles with venules
 Walls are one-cell thick and extremely thin –
allow for selective permeability of nutrients,
oxygen, CO2 and metabolic wastes
VEINS
 Carry deoxygenated blood away from
capillaries to the heart
 Veins contain a muscular layer, but less elastic
and muscular than arteries
 Thin walled veins collapse easily when not
filled with blood
 VALVES – permit flow of blood only in direction
of the heart
 JUGULAR vein – located in the neck
Summer 2005 H.31
Blood Pressure
Surge of blood when heart pumps creates
pressure against the walls of the arteries
SYSTOLIC PRESSURE – measured during the
contraction phase
DIASTOLIC PRESSURE – measured when the
ventricles are relaxed
Average systolic = 120
Average diastolic = 80
PULSE – alternating expansion and contraction of
an artery as blood flows through it.
Pulse sites:





BRACHIAL
CAROTID
RADIAL
POPLITEAL
PEDAL
Summer 2005 H.32
Diseases of the Heart
ARRHYTHMIA (or dysrrhythmia) – any change
from normal heart rate or rhythm
BRADYCARDIA – slow heart rate (<60 bpm)
TACHYCARDIA – rapid heart rate (>100 bpm)
Coronary Artery Disease
ANGINA PECTORIS – chest pain, caused by lack
of oxygen to heart muscle, treat with nitroglycerin
to dilate coronary arteries
MYOCARDIAL INFARCTION
 MI or heart attack
 Lack of blood supply to myocardium causes
damage
 Due to blockage of coronary artery or blood clot
atherosclerosis – plaque build-up on arterial
walls, or arteriosclerosis – loss of elasticity and
thickening of wall.
 Amount of damage depends on size of area
deprived of oxygen
Summer 2005 H.33
 Symptoms – severe chest pain radiating to left
shoulder, arm, neck and jaw. Also nausea,
diaphoresis, dyspnea.
 Immediate medical care is critical
 Rx – bedrest, oxygen, medication
 Morphine for pain, tPA to dissolve clot
 Anticoagulant therapy to prevent further clots
from forming
 Angioplasy and by-pass surgery may be
necessary
Heart Surgery
CORONARY BY-PASS – usually, a healthy vein
from the leg removed and attached before and
after the coronary obstruction, creating an
alternate route for blood supply to the
myocardium.
PACEMAKERS
Demand pacemaker – fires only when heart rate
drops below programmed minimum
CPR – cardiopulmonary resuscitation, used in the
presence of cardiac arrest
Summer 2005 H.34
DEFIBRILLATION – electrical shock to bring the heart
back to a normal rhythm.
AED – automated external defibrillator
Disorders of the Blood Vessels
ANEURYSM – ballooning of an artery, thinning
and weakening
ARTERIOSCLEROSIS – arterial walls thicken,
lose elasticity
ATHEROSCLEROSIS – fatty deposits form on
walls of arteries
EMBOLISM – traveling blood clot
VARICOSE VEINS – swollen, distended veins –
heredity or due to posture, prolonged periods of
standing, physical exertion, age and pregnancy
Summer 2005 H.35
HYPERTENSION
 High blood pressure
 “silent killer” – usually no symptoms
 Condition leads to strokes, heart attacks, and
kidney failure
 140/90 or higher
 Higher in African-Americans and postmenopausal women
 Risk factors = smoking, overweight, stress,
high fat diets, family history
 Treatment = relaxation, low fat diet, exercise,
weight loss, medication
HYPOTENSION – low blood pressure, systolic
<100
Diagnostic Tests
CARDIAC CATHETERIZATION – catheter fed into
heart, dye injected, x-rays taken as dye moves
through coronary arteries
STRESS TESTS – determine how exercise affects
the heart, pt. on treadmill or exercise bike while
electrocardiogram recorded
ANGIOGRAM – x-ray of a blood vessel using dye
Summer 2005 H.36