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Mercer County Community College
Science & Allied Health Division
Bio 104 Lecture Outline
Chapters 17, 18, 19, 20
Course Coordinator:
L. Falkow
Revised 1/06
The Cardiovascular System
Introduction & Overview of the CV System
Science
Pulmonary circuit
Systemic circuit:
Coronary circulation:
Arteries
Capillaries
Veins
Anatomy of the Heart
A. Location & Size
1. Mediastinum
2. Size
B. Pericardium
1. fibrous pericardium
2. serous pericardium
parietal pericardium
[pericardial cavity]
visceral pericardium
3. Disorders
pericarditis
cardiac tamponade
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C. Superficial Anatomy
Auricle
Coronary sulcus
Interventricular sulcus
Base
Apex
D. Internal Anatomy
4 Chambers: 2 atria and 2 ventricles
1. Right Atrium
SVC
IVC
Coronary sinus
Foramen ovale
< Right atrioventricular (AV) valve>
2. Right Ventricle
chordae tendinae
papillary muscles
<Pulmonary Semilunar valve>  _____________
 LUNGS  _________________
3. Left Atrium
<Left Atrioventricular (AV) valve>
4. Left Ventricle
<Aortic Semilunar valve>
 ascending aorta
 openings to coronary arteries
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5. Structural differences between ventricles
RV wall –
LV 6. Heart valves
AV valves:
Semilunar valves:
E. Heart Wall
1. Epicardium
2. Myocardium
3. Endocardium
cardiac muscle tissue characteristics
F. Coronary Circulation
1. Right coronary artery
└> marginal branch
└> posterior interventricular branch
(post. descending artery)
2. Left coronary artery
└> circumflex branch
└> anterior interventricular branch
(left anterior descending artery)
3. Coronary veins
great cardiac vein
└> coronary sinus  ________________
G. Cardiac Muscle Cells
Contractile cells do the pumping (99%) of all cardiac cells.
Conducting system (specialized cells) regulate actions of contractile
cells.
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Conduction System and ECG
A. Conducting system includes:
Nodal tissue
SA (sinoatrial) node
AV (atrioventricular) node
AV bundle (of His)
Bundle branches
Purkinje fibers
ACh (PSN)
Ectopic pacemakers
B. Electrocardiogram (ECG)
- measure of electrical changes that accompany each cardiac cycle
(heartbeat)
1. Wave forms:
P wave
QRS complex
T wave
2. Intervals
P-R interval:
Q-T interval:
3. Conduction system problems
a. heart block
ex. SA node block
AV node block
b. arrhythmias
bradycardia < 60bpm
tachycardia >100bpm
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C. Cardiac Cycle
1. Consists of:
systole – contraction phase
diastole – relaxation phase
2. Average heartrate: ~75 bpm (70-80bpm)
3. Heart sounds
auscultation
“lubb” =
“dupp”
[MVP] mitral valve prolapse murmur -
Cardiodynamics
- movements & forces during contractions of the heart
A. Cardiac Output
CO
=
HR x SV
HR = heartrate (bpm)
SV = stroke vol. (ml/beat)
Normal CO:
CO = HR x SV
During exercise:
CO = HR x SV
B. Factors affecting stroke volume
[ EDV, ESV, ventricular stretching, contractility, hormones]
1. The EDV
EDV [end diastolic volume]
= amt. blood in ventricle at end of diastole (start of vent. systole)
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2. The ESV
ESV [end systolic volume]
= amt. of blood in ventricle after contraction
(at start of vent. diastole)
3. Frank-Starling principle (Starling’s law of heart}
“more in = more out”
4. Contractility
5. Hormones
C. Factors affecting heart rate
[ ANS, Atrial reflex, Hormones, Venous return]
1. ANS Innervation
CAC (cardioacceleratory center)
CIC (cardioinhibitory center)
2. Atrial reflex (Bainbridge)
3. Hormones
4. Venous Return
D. Exercise and Cardiac Output
C.O. varies to needs of body; metabolic needs of the cell.
athlete
nonathlete
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Blood Vessel Anatomy
Arteries
Arterioles
Capillaries
Venules
Veins
A. Structure of vessels
1. 3 basic layers (tunics)
a. tunica interna (intima)
<internal elastic lamina or membrane>
b. tunica media (middle coat)
<external elastic lamina or membrane>
c. tunica externa (adventitia)
2. Arteries
- 3 layers:
tunica interna
tunica media
tunica externa
- highest pressure [
]
Elastic arteries (conducting)
Ex.
Muscular arteries (distribution arteries)
Ex.
3. Arterioles
- resistance vessels
- greatest change in pressure [
]
As arteries ____in size  elastic tissue ____
 smooth muscle ____
Elastic arteries can withstand sudden _____ in BP as blood leaves the heart.
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Arterioles can regulate distribution of blood to different capillary beds
by ______ and _____ .
4. Capillaries
- one cell thick
- low pressure [
]
a. Continuous capillaries
BBB
b. Fenestrated capillaries
c. Capillary beds
precapillary sphincter
anastomosis
5. Venules
- 2 layers thick (interna, externa)
6. Veins
- 3 layers
- low pressure [
- reservoir
- valves:
- muscle pump:
]
- respiratory pump:
B. Structural differences between Arteries and Veins
Arteries
Wall thickness:
X-section:
Tunica media:
Elastic fibers:
Valves:
Veins
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Cardiovascular Physiology
A. Pressure and Resistance
Hydrostatic pressure (HP)
Circulatory pressure
Blood pressure (BP)
Peripheral resistance (PR)
B. Overview of CV Pressures
1. Vessel diameter
2. Total cross-sectional area
3. BP
4. Velocity
C. Capillary Exchange
- movement of materials across capillary walls:
1. Diffusion - water, ions, small organic molecules, water-soluble,
lipid soluble
2. Filtration - hydrostatic pressure forces water & small solutes
across capillary wall
Capillary hydrostatic press. (CHP) = BP in capillary
3. Reabsorption
Osmotic pressure (OP) = water drawing power
Blood colloid osmotic pressure (BCOP)
= blood proteins draw fluids into capillary
4. Interplay between Filtration and Reabsorption
Net hydrostatic pressure = [CHP-IHP]
[tends to move H2O & solutes out of cap.]
CHP (capillary hydrostatic pressure)
arterial end = 35 mmHg; venous end = 18 mmHg
IHP (hydrostatic press. of interstitial fluid)
[~ 0 mmHg]
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Net colloid osmotic pressure:
[tends to pull H2O & solutes into cap.]
BCOP (blood colloid osmotic press.)
ICOP (interstitial fluid osmotic press.)
NET FILTRATION PRESSURE = Net hydrostatic pressure - Net colloid osmotic pressure
(NFP)
=
(CHP - IHP)
(BCOP – ICOP)
Arterial end:
NFP = (35-0) - (25-0) = 10 mmHg
{moves fluid out of cap.}
Venous end:
NFP = (18-0) - (25-0) = -7 mmHg
{moves fluid into cap.}
:. more Filtration occurs than Reabsorption and excess fluid flows into
lymphatic vessels
----> venous (blood) circulation
Edema: = excess fluid in interstitium (fills spaces between cells)
Causes:
1) damage to capillaries:
2) starvation:
3) increased BP:
4) blockage of lymphatic vessels:
5) kidney damage:
Cardiovascular Regulation
A. Autoregulation
1. Local VD
2. Local VC:
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B. Neural Control
CV center in brain =
1. Baroreceptors - monitor stretch in vessel walls
carotid sinus aortic sinus atrial baroreceptors
If BP increases… what happens ?
1.
2.
If BP decreases… what happens?
1.
2.
2. Chemoreceptors
- respond to changes in CO2, O2, pH in blood & CSF
carotid bodies
aortic bodies
If
CO2 or
pH or
O2
C. Hormones
ADH (Antidiuretic Hormone)
- post. pituitary
- promotes water retention; released when decr. blood vol.
[conserves water]
Angiotensin II
ACE
- Angiotensin I ---------> Angiotensin II in lungs
- powerful VC; incr. BP
[Drugs called ACE-inhibitors]
- stim. thirst
EPO (Erythropoietin)
- from kidneys, released if BP decr. or [O2] decr.
- stim. RBC production
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ANP (Atrial Natriuretic Peptide )
- from heart (RA);
- released when chamber wall stretches during diastole;
- reduces blood vol. & BP
D. CV Response to Hemorrhage
1. Short-term elevation of BP
2. Long-Term restoration of blood vol.
Selected Blood Vessels
A. Pulmonary circulation
Pulmonary arteries
Pulmonary veins
B. Systemic Circulation
1. Aorta
Ascending aorta:
 right & left coronary arteries
Aortic arch:
1)
2)
3)
Descending aorta
2. Hepatic portal circulation
- inferior mesenteric vein
- splenic vein
- superior mesenteric vein
Splenic v. & superior mesenteric v. join to form
hepatic portal vein --> liver
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3. Fetal circulation
umbilical arteries (2) - drain deoxygenated blood from fetus
umbilical vein (1) - carries oxygenated blood from placenta
Placenta --> umbilical v. --> ductus venosus to liver --> IVC -->
RA ---> foramen ovale --> LA ---> LV --> aorta (head &
upper extremities)
Blood from upper extremities --> SVC --> RA --> RV (mostly)
 pulm. artery (lungs) but most flows through
 ductus arteriosus to aorta --> rest of body---> return via umbil. arteries
 to placenta
Tetralogy of Fallot:
“blue baby” -> 4 defects:
Pulmonary stenosis
Enlarged RV
Ventricular septal defect
Patent ductus arteriosus
Blood
A. Functions
1. Transportation
nutrients
wastes
respiratory gases
heat
hormones
2. Regulation
pH
electrolytes
body temp. (VC, VD)
3. Restriction
4. Defense
B. Physical Characteristics
1. viscosity:
2. pH:
3. volume:
4. specific gravity:
5. Hct:
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Components of Blood
A. Plasma [~55%]
1. Differences between plasma & interstitial fluid
Components of plasma:
92% - water
7% plasma proteins
1% other stuff (electrolytes, nutrients, and wastes)
2. Plasma proteins
- albumins [60%]
- globulins [35%]
- fibrinogen [4%]
B. Formed Elements [~45%]
1. Erythrocytes
RBCs
2. Leukocytes
WBCs
3. Thrombocytes
Platelets
C. Hemopoiesis
- production of formed elements
stem cells
hemocytoblasts
myeloid stem cells
lymphoid stem cells
all formed elements
except lymphocytes
lymphocytes
HemopoiesisSites of production:
D. Erythrocytes
1. Abundance
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RBC count:
Hct:
2. Structure
3. Hemoglobin
Hb
globin: protein part
heme: Fe-containing pigmented part
Hb + O2 ----> HbO2
(reduced
(oxyhemoglobin)
hemoglobin)
4. RBC Lifespan & Circulation
5. Erythropoiesis
- RBC production
6. Blood Types
Type A
Type B
Type AB
Type O
RBC
antigen A
antigen B
antigens A,B
none
Plasma
anti-B antibodies
anti-A antibodies
none
anti-A & anti-B
antibodies
agglutinogens = surface antigens
Rh factor:
Rh positive =
Rh negative =
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cross-reaction - antibody meets its specific antigen => clumping of RBCs
HDN (hemolytic disease of the newborn)
or erythroblastosis fetalis
- mother is Rh neg., baby is Rh pos.
1970’s: Rho-Gam
7. Clinical disorders
anemia
hematuria
hemophilia
E. Leukocytes
1. Characteristics
- nucleated
Lifespan: a few hours to a few days
WBC count:
2. Types
Granulocytes:
Neutrophils
Eosinophils
Basophils
%
Description
50-70% multi-lobed nucleus
2-4% 2-lobed nucleus,
red granules
<1%
dk.blue granules,
obscure nucleus
Agranulocytes:
Lymphocytes 20-30% round nucleus,
little cytoplasm
Monocytes
2-8% Kidney bean shaped nucleus
Function
phagocytosis
incr. during
allergic rxn.
inflam.
response
immune
response
macrophages
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3. Formation
Red bone marrow:
Lymphoid tissue:
4. Clinical
leukopenia
leukocytosis
F. Thrombocytes
1. Characteristics
2-4 μm
cell fragment
150,000 - 500,000 /mm3 [avg. 350,000]
9-12 days
2. Functions
- blood clotting
3. Formation
megakaryocytes
4. Clinical
thrombocytopenia
thrombocytosis
Hemostasis
- prevention of blood loss
A. Vascular phase
vascular spasm - VC of SMC
B. Platelet phase
platelet plug formation
platelets release:
C. Coagulation phase
clotting factors:
extrinsic & intrinsic pathways
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Lymphatic System
A. Functions
1. production of lymphocytes
2. return lymph (tissue fluid) to venous circulation
3. distribution of hormones, nutrients, and wastes to circulation
B. Lymph vessels
lymphatic capillaries --> vessels (lymphatics)
---> cisterna chyli --> thoracic duct ==>left subclavian vein
--> right lymphatic duct => rt. subclavian v.
C. Lymph tissues
Tonsils
Lymph nodes
Thymus
Spleen
Aggregate lymphoid nodules
Appendix