Circulatory System  Transport System
We have two Circulatory Systems
1. Cardiovascular System 2. Lymphatic System
Thoracic
Cavity
Heart
w/in
mediastinum
4 valves prevent
backflow & blood
moves in 1 direction
Aortic Semilunar
Pulmonary Semilunar
Lt ventricle  Aorta
Rt ventricle 
Pulmonary Artery
Bicuspid/mitral A/V valve
(2 flaps)
Tricuspid A/V valve
(3 flaps)
Chordae
Tendinae
Right
Left
DeO2
O2
Our Heart is like 2 Hearts in One
The Right Heart
The Left Heart
•Right Atrium
•Left Atrium
•Right Ventricle
•Left Ventricle
•Receives DeO2 blood
•Pumps O2 Blood
from body
to Body
Right
Left
start
start
Systemic Circulation
Movement of blood from Lt Ventricle
 body
includes hepatic portal circulation of liver
& renal circulation of kidneys
Coronary Circulation
To myocardium
Rt coronary
artery
Rt coronary
vein
Lt coronary artery
Lt coronary vein
Angina Pectoris: Severe chest pain when
myocardium deprived of adequate O2.
Coronary artery no longer supplies enough
O2 to heart muscle.
Veins harvested for bypass (prevent graph
vs host rejection).
Pg 259 fig 11-4
Heart Attack  Myocardial Infarction
Flow to a section of heart muscle becomes
blocked.
If not restored quickly, section of heart muscle
damaged from lack of oxygen & begins to die.
Damaged heart muscle
loses its ability to contract
Remaining heart muscle
must compensate for
weakened area.
Deflated balloon catheter inserted into narrowed coronary
artery. Balloon is inflated, compressing the plaque &
restoring size of artery. Relieves chest pain caused by
reduced blood flow to the heart.
Minimize damage to the
heart muscle during a heart
attack. This damage occurs
when blood flow is totally
cut off to an area of the
heart.
Stents: tiny mesh tube that
is inserted in narrowed area
to keep it open. Some
coated with medication to
help prevent the artery from
closing again.
AbioCor artificial heart
2 pounds
life expectancy 30 days – 6months
Can extend life for those awaiting heart transplant donor
Heart Conduction
Heart contracts in absence in external stimuli
4 structures embedded in heart wall
 generate & conduct electrical impulses
through heart muscle
 cause atria & then ventricles to contract
Sinoatrial Node (SA node)  Pacemaker in Rt Atrium wall
Impulse starts & spreads in all directions through
both atria  contraction
Impulse reaches
Atrioventricular Node (AV node) between Rt atrium &
Rt. ventricle
Relayed to
Bundle of His (AV bundle) Rt & Lt branches along
septum
and
Purkinje fibers 0ff 2 AV bundles
To ventricles  contraction
Disease can damage
conduction system
Artificial Pacemaker
Electrical device  causes heart contractions
 maintains adequate blood flow
2 components to pacemaker
*pulse generator, computer chip
(brains) & battery
*wires (leads) carry electrical
signals to & from heart.
Pulse generator under skin
sends electrical signal to
heart. 2 leads inserted
through an arm vein are
attached to the heart's Rt
atrium or Rt ventricle or both.
Electrocardiogram (ECG or EKG)
Heart conduction generates electrical currents
 picked up from body surface
Graphic record of heart’s electrical activity
3 waves: deflection represents electrical activity
associated with contraction & relaxation
of atria & ventricles
Damage to cardiac muscle affects conduction system
 distinct changes in ECG  diagnosis & treatment
Depolarization: electrical activity w/ contraction of heart
muscle
Repolarization: relaxation of heart muscle
P wave: atrial depolarization
(contraction)
QRS complex: ventricular
depolarization (contraction)
T wave: ventricular
repolarization (relaxation)
*Atrial repolarization wave
masked by QRS complex
Vessel Structure Arteries & Veins: 3 layers
Tunica Externa  outermost
Tunica Media  middle
Thicker in arteries vs veins  maintain BP for blood
distribution to body
Smooth muscle: Autonomic NS control
Tunica Interna  innermost (fibrous, endothelial tissue)
CNS (brain/spinal cord)
NS
sensory
PNS
somatic (skeletal muscle/effecters)
motor
autonomic (sm & cardiac muscle & glands/effecters)
↑sympathetic
adrenaline ↑ SA node impulses
↓parasympathetic
acetylcholine ↓ SA Node impulses
veins
Arteries
•Carry blood Away from the Heart
•Are DEEP, near Bones for protection
Blood Vessels
Arteries: carry blood away from heart
 Arterioles  capillaries
O2 (except for pulmonary arteries)
•under pressure
•pre-capillary sphincters regulate blood
flow into capillaries (deeper than veins)
Blocked carotid artery  stroke
Prevent with Endarterectomy
Arteries have a thick (Invol.)
muscular wall
Blood is moving very fast,
under high pressure
Smaller Arteries branch into
smaller Arterioles
Many arterioles have
sphincters
Veins: carry blood to heart are superficial
 Capillaries  venules  veins
DeO2 (except for pulmonary veins)
•little to no pressure
•valves prevent backflow
•muscle contractions keep blood moving
in veins towards heart
(more superficial than arteries)
Varicose Veins
Faulty valves in the veins blood pools  distends veins
Treatment
Sclerotherapy: Injection causes
vein to seal shut  scars  fades
Laser surgery: Direct & Accurate
Sends strong bursts of light onto
vein  fades
Surgical Ligation and Stripping:
Veins tied & removed
Deeper veins take over circulation
for treated veins
Comparison of Artery and Vein
Capillaries Connect Artery to Vein
Capillary bed  diffusion
gas/nutrient exchange
O2
arteriole
DeO2
venule
Where does Blood
do All its Work?
WHY???
Walls of Arteries &
Veins are too thick and
Blood is moving much
too fast to do its work!
Blood Pressure forces some of the Plasma
minus large blood proteins to leak out of
Capillary (Filtration) into the Tissues
Exchange of ALL Nutrients, Gases, &
Wastes occurs here
Too much Tissue Fluid = Edema
Major Arteries & Veins
Major Arteries & Veins
Hepatic Portal Circulation
Blood flow through liver
Veins from
(pg 268 fig 11-13 & overhead)
spleen, stomach, pancreas, gallbladder, intestines
Sent to liver via PORTAL VEIN
(lies between 2 capillary beds) for
glucose absorption  glycogen
Detoxification
Blood leaves liver via HEPATIC VEIN
 Inf. Vena Cava
Renal Circulation
Blood flow through kidneys (excretory system)
Dirty (O2) blood in
through renal artery
Clean (DeO2) blood
out through renal vein
Fetal Heart Structures
(pg 270 fig 11-14)
Ductus Venosus:
bypass immature liver  Inf Vena Cava
To Bypass Non Functional Lungs
Foramen Ovale:
shunts blood from Rt to Lt Atrium
Ductus Arteriosis:
connects Aorta & Pulmonary Artery
(shunts blood in Rt. Ventricle to Pulmonary
Artery  Aorta
amniocentiesis/FLM (fetal lung maturity)
http://www.wellesley.edu/Biology/Courses/111/mammalian.html
Fetal Circulation
Nutrient-Waste exchange with mom via Placenta
3 umbilical vessels
2 sm umbilical arteries
1 lg umbilcal vein
Pulse: Artery expanding & recoiling
Radial
Temporal
Carotid
Brachial
*Dorsal Pedis (front surface of foot, below ankle bend)
Adult 70 beats/min
Child 100 beats/min (No steam, sauna)
Tachycardia ↑ heart beat
Bradycardia ↓ heart beat
Blood Pressure: pressure or push of blood
Measure of pressure on arterial walls in mm of
Hg with sphygnomonometer & stethescope
Exists in all vessels
Highest in arteries (aorta) – Lowest in veins (vc)
Gradient keeps blood circulating
Force to keep blood moving
aorta  arteries  arterioles  capillaries
CLOSED SYSTEM
High BP  hypertensive
can rupture vessels  stroke
Low BP  hypotensive ↓circulation so ↓O2
hemorrhage leads to rapid ↓ in BP
BP result of volume in vessels
↑ blood volume in arteries = ↑ pressure on artery
walls
↓ blood volume in arteries = ↓ pressure on artery
walls
BP changes
↑ with exercise for ↑ O2 to muscles
↑ metabolism for ↑ energy
Normal BP 120
80
systolic (as ventricles contract)
diastolic (as ventricles relax)
Closed circuit
Volume of blood in arteries determined by
*amount of blood heart pumps into arteries
*how much arterioles drain out of them
Cardiac Output: vol of blood pumped into arteries
Diameter of arterioles determines how much blood drains
into capillaries
Stronger heart beat ↑ BP
Weaker heart beat ↓ BP
If ↑ heartbeat
& vol out of Lt ventricle not ↓
leads to ↑ BP
If ↑ heartbeat
& vol out of Lt ventricle (cardiac output) ↓ b/c of
rapid pumping,
leads to ↓ BP
Blood Pressure & Viscocity
↓ viscocity = ↓ BP
Hemorrhage  fluid from interstitial spaces moves
into & dilutes blood
Transfuse plasma to ↓ viscocity
Lymphatic System
•Some Plasma (minus blood proteins filters (“leaks”) out of
capillaries into Tissues
•Now called Tissue (Extra cellular) Fluid, much will drawn back into
capillaries by Serum Albumin
•More Tissue Fluid will be drawn into Lymphatic vessels, now called
Lymph
•Lymph will pass through Lymph Nodes where it will be purified by
WBCs
•Lymph is emptied into Subclavian Veins where it is now part of the
Plasma
Cellulites: Infection of deep subcutaneous layer