Transcript Circulatory System

The
Cardiovascular
System
Chapter 17, 18, 19
The Heart, Blood Vessels, Blood Types
BLOOD
Components of BLOOD
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Blood
Component
FUNCTION
PLASMA
BLOOD CELLS
Erythrocytes
(RED blood
cells/RBC)
Leukocytes
(WHITE blood
cells/WBC)
PLATELETS
Thrombocytes
Misc.
PLASMA
• Liquid portion of the blood.
• Carries nutrients & other
substances
• Contains clotting factors,
hormones, antibodies,
dissolved gases, nutrients
and waste
RED BLOOD CELLS
Erythrocytes
–Carry hemoglobin and
oxygen.
–Do not have a nucleus
–Live only about 120
days.
–Cannot repair
themselves
–Determine blood type
WHITE BLOOD CELLS
Leukocytes
–Fight infection
–Formed in the bone
marrow
–Five types:
1.
2.
3.
4.
5.
Neutrophils
Lymphocytes
Eosinophils
Basophils
Monocytes
PLATELETS
Thrombocytes
–Clot blood by sticking
together – via protein
fibers called fibrin.
–These are cell fragment
that are formed in the
bone marrow
ABO BLOOD TYPES
• Blood type is determines by the
presence or absence of blood proteins
called ANTIGENS located on the surface
of the erythrocytes.
• There are also ANTIBODIES on the
surface of erythrocytes.
• When incompatible blood proteins mix,
agglutination (blood clumping) results.
BLOOD TYPES
• There are 3 alleles
that determine
4 blood types:
– A (dominant)
– B (dominant)
– O (recessive)
Type
Type
Type
Type
A = AA, Ao
B = BB, Bo
AB = AB
O = oo
ABO blood groups
Blood
Type
Antigens
Agglutinogen
Antibodies
Agglutinins
Can receive from…
A
B
AB
A
B
AB
Anti-B
Anti-A
None
A, O
B, O
A, B, AB, O
O
none
Anti-A
Anti-B
Universal recipient
http://www.youtube.com/watch?v=oz4Ctau8mC8
O
Universal donor
Eucharistic Miracles
• http://www.youtube.com/watch?v=N6
SH93arrIE
When Things Go Wrong:
BLOOD
Complete handout. Then cut & paste into NB.
The Closed Circulatory System
•Humans have a closed circulatory system,
typical of all vertebrates, in which blood is
confined to vessels and is distinct from the
interstitial fluid.
–The heart pumps blood into large vessels
that branch into smaller ones leading into the
organs.
–Materials are exchanged by diffusion between
the blood and the interstitial fluid bathing the
cells.
BLOOD
VESSELS
BLOOD VESSELS
3 TYPES
Arteriesarterioles
• Take blood away from the heart
• 3 layers thick
VeinsVenules
• Returns blood to the heart
• 3 layers thick
• Contain VALVES to prevent backflow of blood
Capillaries
• One cell layer thick
• Form “capillary beds”
• Where gas exchange occurs
• O2 leaves capillaries and enters body cells
• CO2, a waste product of cellular respiration, enters capillaries
BLOOD VESSELS
Three layers of blood vessels:
1) Tunica intima (all types of BV)
•
•
•
•
Innermost layer
Single thin layer of endothelium
Provides a smooth surface to decrease
resistance to blood flow
The only tunic of capillaries
BLOOD VESSELS
2)Tunica media (arteries & veins)
• Bulky middle coat
• Contains smooth muscle and elastin
• The only tunic that plays an active role in
blood pressure regulation
1) Tunica externa (arteries & veins)
• Outermost layer
• Supporting, protective coat
• Also called the adventitia
THREE LAYERS OF BLOOD VESSELS
*Yellow = must know for quiz
1. vertebral
2. brachiocephalic
3. superior vena cava
4. brachial
5. inferior vena cava
6. renal
7. radial
8. common iliac
9. internal iliac
10. CROSS OUT
11.posterior tibial
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
VEINS
internal jugular
subclavian
axillary
cephalic
hepatic
median cubital
ulnar
femoral
popliteal
CROSS OUT
anterior tibial
ARTERIES
1. external carotid
2. vertebral
3. brachiocephalic
4. brachial
5. renal
6. aorta
7. radial
8. common iliac
9. internal iliac
10.popliteal
11.anterior tibial
12. internal carotid
13. common carotid
14. subclavian
15. axillary
16. celiac trunk
17. superior mesenteric
18. ulnar
19. external iliac
20. femoral
21. posterior tibial
When Things Go Wrong:
BLOOD VESSELS
Complete handout. Then cut & paste into NB.
Mean Arterial Pressure (MAP)
• Average blood pressure in aorta
• MAP=CO x PR
– CO is amount of blood pumped by heart
per minute
• CO=SV x HR
– SV: Stroke volume of blood pumped during each
heart beat
– HR: Heart rate or number of times heart beats per
minute
• Cardiac reserve: Difference between CO at rest and
maximum CO
– PR is total resistance against which
blood must be pumped
Factors Affecting MAP
THE
HEART
INTERNAL
1. SA node
2. AV node
3. AV bundle
(Bundle of His)
4. Bundle branches
5. Purkinje fibers
6. Pulmonary valve
7. Aortic valve
8. Mitral
(bicuspid) valve
9. Tricuspid valve
RIGHT
side
LEFT
side
EXTERNAL
1. Right atrium
2. Left atrium
3. Right ventricle
4. Left ventricle
5. Superior vena cava
6. Inferior vena cava
7. Aorta
8. Pulmonary trunk
9. Left pulmonary artery
10.Right pulmonary artery
11.Right pulmonary veins
12.Left pulmonary veins
13.Coronary circulation
14.Apex
15.Ligamentum arteriosum
8. Mitral (bicuspid) valve
9. Tricuspid valve
The HEART
 Cardiac muscle tissue
 Highly interconnected
cells
 FOUR chambers
•Right atrium
•Right ventricle
•Left atrium
•Left ventricle
Function of the Heart Valves
Blood Flow Through Heart
Circuits
•Pulmonary Circulation
–The blood pathway
between the right side
of the heart, to the
lungs, and back to the
left side of the heart.
•Systemic Circulation
–The pathway between
the heart and the rest of
the body
Coronary Circulation
• From RIGHT side
of heart
• To outer muscle of
heart
• Back to LEFT side
of heart
Size, Shape, Location
of the Heart
•Size of a closed fist
•Shape
–Apex: Blunt rounded
point of cone
–Base: Flat part at
opposite of end of
cone
•Located in thoracic
cavity in
mediastinum
Pericardium
Heart Wall
• Three layers of tissue
– Epicardium: This serous membrane of
smooth outer surface of heart
– Myocardium: Middle layer composed
of cardiac muscle cell and
responsibility for heart contracting
– Endocardium: Smooth inner surface
of heart chambers
Heart Wall
Systemic and Pulmonary
Circulation
Heart Skeleton
•Consists of plate of
fibrous connective
tissue between atria
and ventricles
•Fibrous rings around
valves to support
•Serves as electrical
insulation between
atria and ventricles
•Provides site for
muscle attachment
Cardiac Muscle
•
•
•
•
•
Elongated, branching cells containing 1-2 centrally located nuclei
Contains actin and myosin myofilaments
Intercalated disks: Specialized cell-cell contacts
Desmosomes hold cells together and gap junctions allow action
potentials
Electrically, cardiac muscle behaves as single unit
Conducting System of Heart
Electrical Properties
• Resting membrane potential (RMP)
present
• Action potentials
– Rapid depolarization followed by rapid,
partial early repolarization. Prolonged
period of slow repolarization which is
plateau phase and a rapid final
repolarization phase
– Voltage-gated channels
Action Potentials in
Skeletal and Cardiac Muscle
SA Node Action Potential
Refractory Period
• Absolute: Cardiac muscle cell completely
insensitive to further stimulation
• Relative: Cell exhibits reduced
sensitivity to additional stimulation
• Long refractory period prevents tetanic
contractions
Electrocardiogram
• Action potentials
through myocardium
during cardiac cycle
produces electric
currents than can be
measured
• Pattern
– P wave
• Atria depolarization
– QRS complex
• Ventricle
depolarization
• Atria repolarization
– T wave:
• Ventricle repolarization
Cardiac Arrhythmias
• Tachycardia: Heart rate in excess of
100bpm
• Bradycardia: Heart rate less than 60 bpm
• Sinus arrhythmia: Heart rate varies 5%
during respiratory cycle and up to 30%
during deep respiration
• Premature atrial contractions:
Occasional shortened intervals between
one contraction and succeeding,
frequently occurs in healthy people
Alterations in Electrocardiogram
Cardiac Cycle
• Heart is two pumps that work together,
right and left half
• Repetitive contraction (systole) and
relaxation (diastole) of heart chambers
• Blood moves through circulatory system
from areas of higher to lower pressure.
– Contraction of heart produces the pressure
Cardiac Cycle
Events during Cardiac Cycle
Heart Sounds
• First heart sound or “lubb”
– Atrioventricular valves and surrounding fluid
vibrations as valves close at beginning of ventricular
systole
• Second heart sound or “dupp”
– Results from closure of aortic and pulmonary
semilunar valves at beginning of ventricular diastole,
lasts longer
• Third heart sound (occasional)
– Caused by turbulent blood flow into ventricles and
detected near end of first one-third of diastole
Location of Heart Valves
When Things Go Wrong:
HEART
Complete handout. Then cut & paste into NB.
Effects of Aging on the Heart
• Gradual changes in heart function,
minor under resting condition, more
significant during exercise
• Hypertrophy of left ventricle
• Maximum heart rate decreases
• Increased tendency for valves to
function abnormally and arrhythmias to
occur
• Increased oxygen consumption required
to pump same amount of blood