1. Unit II: Transport Cardiovascular System II
Chapter 18: pp
Chapter 17: pp

2. Cardiac Output (CO) Amount ejected by ventricle in 1 minute
Maximum for trained athletes
exercising at peak levels
Normal range
of cardiac
output during
heavy exercise
Average resting cardiac output
Some forms of
heart failure
Cardiac
output
(L/min) 5 10 15 20 25 30 35 40
Amount ejected by ventricle in 1 minute
Cardiac reserve:
 with fitness,  with disease
HR: 75 beats/min
SV: 80 mL/beat
CO: 6000 mL/min = x

3. Cardiac Output (CO) Factors affecting heart rate (HR)
Body
temperature
ANS
Hormones
Muscular
contractions
Blood
volume
Peripheral
blood flow
Venous return ↑
= ↑ SV
EDV
Influences the
efficiency of
ESV
↑ Filling time
= ↑ ESV
↑ afterload =
↓ pumping efficiency
and ↑ESV
Vasodilation
Vasoconstriction
↑ contractility =
↓ ESV
STROKE VOLUME (SV) = EDV – ESV
HEART RATE (HR)
CARDIAC OUTPUT (CO) = HR x SV
Factors affecting heart rate (HR)
Factors affecting stroke volume (SV)

4. Heart Rate Pulse: infants have HR of 120 bpm or more
young adult females avg bpm
young adult males avg. 64 to 72 bpm
HR rises again in the elderly
Tachycardia:
stress, anxiety, drugs, heart disease or  body temp.
Bradycardia:
in sleep and endurance trained athletes
Bradycardia
Tachycardia
Normal range of
resting heart
rates
60 bpm
100 bpm

5. Anatomy of Blood Vessels
Tunica externa
Tunica media
Tunica intima
Endothelium
Smooth muscle
Vein
The structure
of the wall of
a vein
LM x 60
Artery
Tunica interna: repels blood cells and platelets
simple squamous endothelium overlying a basement membrane
Tunica media: smooth muscle, collagen, elastic tissue
Tunica externa: loose connective tissue

6. Arteries 3 Categories by Size: Conducting (elastic) arteries
Capillaries
Arterioles
Distributing/Muscular Arteries
Conducting/Elastic Arteries
Internal elastic
layer
Tunica intima
Tunica media
Tunica externa
Smooth muscle cells
Endothelium
Endothelial cells
Basal lamina
3 Categories by Size:
Conducting (elastic) arteries
pulmonary, aorta & common carotid
Distributing (muscular) arteries
Brachial, femoral and splenic
Resistance (small) arteries
Arterioles

7. Veins thinner tunica media 3 Categories by Size: Small veins venules
Large Veins
Medium-sized Veins
Venules
Capillaries
Basal lamina
Endothelial cells
Pores
Endothelium
Tunica externa
Tunica media
Tunica intima
thinner tunica media
3 Categories by Size:
Small veins
venules
Medium veins
Radial, ulnar veins
valves prevent backflow
Large veins
Vena cava, pulmonary, jugular

8. Capillaries Smallest blood vessels
Only vessels that allow exchange of materials
Anatomy:
simple squamous endothelium with basement membrane
walls: µm thick; lumen: 5-9 µm diameter
Filtration Predominates
No Net
Movement
Reabsorption
Predominates
24 L/day
20.4 L/day
Arteriole
Venule
KEY
CHP (Capillary
hydrostatic pressure)
BCOP (Blood colloid
osmotic pressure)
NFP (Net filtration
pressure) 35 25 18 mm Hg
NFP =
+10 mm Hg
NFP = 0
–7 mm Hg
Capillary
CHP > BCOP
CHP = BCOP
BCOP > CHP

9. Capillary Beds Metarterioles connect arterioles to capillaries
Thoroughfare channel
connect capillaries to venule
Perfusion
precapillary sphincter

10. Types of Capillaries Continuous – (4nm)
Basal lamina
Endothelial cell
Nucleus
Continuous – (4nm)
endothelial cells have tight junctions
Fenestrated – (20-100nm)
organs that require rapid absorption or filtration
Ex. kidneys, small intestine
Sinusoids – (30-40nm)
Basal lamina
Endothelial cell
Nucleus
Gap between
adjacent cells

11. Circulatory Routes Most common route
heart  arteries  arterioles  capillaries  venules  veins  heart
Portal system
hypothalamus – pituitary
in kidneys
intestines – liver
Anastomoses
Arteriovenous anastomosis
Ears, fingers, toes, palms

12. Blood Pressure Force that blood exerts against a vessel wall
Measured at brachial artery of arm
Systolic pressure and diastolic pressure
Normal value, young adult: 120/75 mm Hg

13. Blood Pressure Importance of arterial elasticity
expansion and recoil maintains steady flow of blood throughout cardiac cycle, smoothes out pressure fluctuations and  stress on small arteries
BP rises with age: arteries less distensible

14. Blood Pressure BP determined by: cardiac output blood volume
peripheral resistance
Blood viscosity
Vessel length
Vessel radius (vasomotion)
Least
resistance,
greatest flow
at center
Greatest resistance,
slowest flow near surfaces
Internal surface area = 2
Internal surface
area = 1
Resistance to flow = 1
Flow = 1
Resistance
to flow = 2
Flow = ½

15. Arteries R. Common carotid R. Subclavian Brachiocephalic trunk
Axillary
Ascending aorta
Brachial
Radial
Ulnar
Femoral
Aortic arch
Descending aorta
Diaphragm
Renal
Common iliac
Arteries

16. Veins External jugular Internal jugular Subclavian Brachiocephalic
Axillary
Brachial
Radial
Ulnar
Femoral
Superior vena cava
Diaphragm
Inferior vena cava
Renal
Common iliac
Veins

17. Fetal Development and Circulation
Fetus = from 8 weeks until birth
Fetal circulation
umbilical-placental circuit
circulatory shunts
ductus venosus
foramen ovale
ductus arteriosus

18. Blood Circulation Before Birth
Foramen ovale
Ductus arteriosus
Pulmonary
trunk
Inferior vena cava
Ductus venosus
Umbilical arteries
Umbilical vein
Umbilical
cord
Placenta
Aorta
Liver