1. Circulatory System
Cardiovascular System = Heart, blood vessels, and blood
-Transports H2O, nutrients, waste, O2, CO2, hormones, and immune cells.
-Regulates heat, pH, and pressure.
-Associated with lymphatic system.
Lymphatic System = Lymphatic vessels, lymphatic hearts, & lymph

2. Human Cardiovascular

3. Blood and
Blood
Vessels

4. Vascular Terms
Anastamosis = intercommunication between separate vessels (net like).
Portal System = vessels that carry blood from capillaries to capillaries.
Sinus = region for “pooling” of fluids.
Aortic arch = arterial arches that extend from ventral to dorsal between pharyngeal openings.
Gnathostomes have 6 early in devel.

5. Vascular Arteries = Large; carry blood away from heart
Arterioles = Smaller; carry blood away from heart
Capillaries = Very small; gas & nutrient exchange occur here
Veinules = Smaller; carry blood to heart
Veins = Large; carry blood to heart

6. Vertebrate Blood
Blood = connective tissue; cells (in vertebrates) in a water-based matrix.
Plasma = matrix around blood cells. Transports: H2O, nutrients, waste, CO2, hormones
Erythrocytes = Contain hemoglobin; transport O2; No nuclei in mammals.
Leucocytes = Immune cells.
Platelets = Cell fragments, involved in clotting after damage.

7. Vertebrate Blood
Plasma

8. Hematopoesis – Blood Devel.
Hematopoesis = blood development.
Blood islands form in splanchnic mesoderm in yolk sac = 1st site of hematopoesis (always nucleate cells). Early fetal human red blood cells have nuclei.
Additional stem cells in splanchnic mesoderm around heart migrate to hematopoetic areas (spleen, kidneys, liver, & bone marrow in non-avian amniotes).

9. Vascular Development Mostly from splanchnic mesoderm.
Angiogenesis = blood vessel formation
Blood islands in yolk sac merge to form vessels that then extend into rest of embryo.
Cardiovascular system starts in yolk sac and spreads to rest of embryo.

10. Human Blood Islands

11. Basic Chordate Arterial Circ.
Blood moves from posterior and ventral to the pharynx (heart/sinus venosus)
Anteriorly under the pharynx (ventral aorta)
Dorsolaterally up through the pharynx (pharyngeal/aortic arches)
Then to the body anteriorly and posteriorly from the dorsal pharynx (dorsal aorta).

12. Lancelet Arterial Circulation
dorsal aorta (paired - median)
sinus venosus (median)
ventral aorta (median)

13. Lancelet Venous Circulation
Anterior & posterior cardinal veins (paired)
sinus venosus (median)
hepatic vein (median)

14. Lancelet Circulation anterior cardinal vein ventral common cardinal
s.v.
dorsal
aorta
ventral
s.v.
anterior
cardinal
vein
posterior
hepatic
common
cardinal
vein

15. Basic Amniote Circulation

16. Early Human Embryo Arterial
left & right
dorsal aortas
aortic
arch II
arch I IV
III
ventral aorta
(truncus arteriosus)
umbilical
artery
heart
sinus venosus
atrium
ventricle
bulbis cordis
vitelline
artery

17. Early Human Embryo Arterial
left & right
dorsal aortas IV VI
III
ventral aorta
(truncus arteriosus)
umbilical
artery
heart
vitelline
artery

18. Early Human Embryo Arterial
descending aorta IV
pulmonary VI
III
carotids
ventral aorta
(truncus arteriosus)
umbilical
artery
heart
vitelline
artery

19. Early Human Embryo Arterial

20. Embryonic Arteries ventral aorta dorsal aorta I II III IV V VI I II
HEART
I II III IV V VI

21. Human Embryonic Arteries
external carotid
internal carotid
common carotid I II
descending aorta
aortic arch
III IV
subclavian
pulmonary artery VI
ductus arteriosus
(before birth)
HEART

22. Human Embryonic Arteries

23. Human Aortic Arches

24. Human Fetal Circulation
Upper Left
Arch VI

25. Early Human Embryo Circulation
left & right anterior
cardinal veins
left & right posterior
cardinal veins
left & right
common
cardinal
veins
ventral aorta
(truncus arteriosus)
heart
sinus venosus
atrium
ventricle
bulbis cordis
allantoic
(umbilical) veins
vitelline
(hepatic)
veins

26. Early Human Embryo Circulation
azygous vein
jugular
veins
superior
vena
cava
inferior
hepatic
portal
vein
left & right anterior
cardinal veins
left & right posterior
cardinal veins
heart
allantoic
(umbilical) veins
vitelline
(hepatic)
veins

27. Human Anterior Venous Development

28. Basic Vertebrate Circulation

29. Blood Vessel Structure
Endothelium = simple squamous epithelium lining inside of blood vessels (tunica intima)
Tunica externa = fibrous connective tissue surrounding the outside of the vessel
Tunica media = between the tunica intima and tunica externa; elastic connective tissue and/or smooth muscle.

30. Vessel Structure Arteries = Large; carry blood away from heart;
thick tunica media composed primarily of smooth muscle;
accommodate high blood pressure
Capillaries = Very small; gas & nutrient exchange occur here;
lack tunica media and tunica externa

31. Vessel Structure
Veins = Vessels that carry blood to the heart; thin tunica media made primarily of connective tissue
one-way valves promote the return of blood under low pressure

32. Vertebrate Vessels
artery
vein
tunica intima
(endothelium)
capillary

33. Adult Human Arterial system

34. Adult Human Arterial system
external carotid
internal carotid
common carotid
vertebral
subclavian
axillary
brachial
radial
ulnar
internal thoracic
humeral circumflex
lateral thoracic
aorta*
coeliac*
superior mesenteric*
inferior mesenteric*
deep brachial
renal
gonadal
common iliac
external iliac
internal iliac
deep femoral
femoral circumflex
femoral
popliteal
anterior tibial
posterior tibial

35. Pulse Points

36. Carotid & Radial Pulse Points

37. Human Venous System
Azygous vein

38. Human Venous System

39. Human Arm Venous System

40. Human Leg Venous System

41. Human Varicose veins

42. Comparative
Circulation

43. Hematopoesis
In non-amniotes occurs primarily in the spleen, kidneys, and liver.
Especially the spleen.
Hagfishes, lampreys, & lungfishes = no spleen
In amniotes occurs in bone marrow (especially in humans and other mammals) as well as in other tissues. No bone marrow in birds.

44. Subphylum Vertebrata Chondrichthys Actinopterygii coelacanth
amphibians
hagfishes
lampreys
Mammalia
lungfish
Reptilia
spleen
lost *
hemato-
poesis in
marrow
discrete spleen
blood cells
*erythrocytes lack nuclei

45. Lancelet Circulation

46. Vertebrate Circulation
dorsal
aorta
external
carotid
heart
ventral
aorta
Iliac
artery
subclavian

47. Vertebrate Circulation
anterior & posterior
cardinal veins
renal portal
jugulars
heart
hepatic
portal
lateral
abdominal
vein
iliac
vein
subclavian
vein

48. Aortic Arches
Gnathostomes = Arch I lost in adults; 6 arches early in development
Sarcopterygiians = Pulmonary arteries from arch VI
Tetrapods & Actinopts. = Arch II lost
Amniotes = Arch V lost
Mammals = left Arch IV forms aorta; right Arch IV forms base of subclavian
Birds = right Arch IV forms aorta

49. Gnathostome Embryo Aortic Arches
internal
carotid
external I II
III
I II III IV V VI
dorsal
aorta
ventral IV V VI
heart
dorsal
aorta

50. Chondrichthyan Aortic ArchesII
III
I II III IV V VI IV V VI
heart

51. Teleost Aortic Arches I II
III
I II III IV V VI IV V VI
heart

52. Lungfish Aortic ArchesII
III
I II III IV V VI IV V VI
heart
pulmonary
artery

53. Amphibian Aortic Arches
internal
carotid
external I II
III
I II III IV V VI IV V VI
heart
pulmonary
artery

54. Lizard Aortic Arches internal carotid external I II III
I II III IV V VI IV V VI
heart
pulmonary
artery

55. Bird Aortic Arches internal carotid external I II III I II III IV V VI
heart
pulmonary
artery

56. Lepidosaur Aortic Arches
internal
carotid
external I II
III
I II III IV V VI IV V VI
heart
pulmonary
artery

57. Mammalian Aortic Arches
internal
carotid
external I II
III
I II III IV V VI IV V VI
heart
pulmonary
artery

58. Subphylum Vertebrata Myxini (hagfishes) Chondrichthys Actinopterygii
coelacanths
amphibians
lungfishes
lampreys
Mammalia
Reptilia
arch V
lost
arch II lost
arch II
lost
arch VI
forms pulmonary
connection
arch I
lost;
6 arches form in development

59. Amniota lizards & snakes crocodilians montremes marsupials eutherians
turtles
lizards & snakes
crocodilians
birds
right arch
IV forms
aorta
left arch IV
forms aorta; right
arch IV forms
right subclavian

60. Gnathostome Adult Aortic Arches
Chondrichthys
Actinopterygii
lungfishes I
lost II
gill arch
III IV V VI
arch
& pulmonary artery

61. Gnathostome Adult Aortic Arches
amphibians
turtles
lizards I
lost II
III
common carotids IV
l. and r. aortic arches V
aortic arch
(lost in frogs) VI
aortic arch & pulmonary artery
pulmonary artery

62. Gnathostome Adult Aortic Arches
crocodilians
birds
Mammalia I
lost II
III
common carotids
com. carotids / subclavian bases
common carotids & ext. carotid base IV
l. and r. aortic arches
l. lost
r. aorta
l. aorta
r. subclavian V VI
pulmonary artery

63. Venous System Gnathostomes = renal portal vein
Tetrapods = inferior vena cava from right hepatic; anterior cardinal veins form internal & external jugular veins
Mammals = inferior vena cava connects to & replaces renal portal
Some Mammals (humans, cats, etc.) = lose the left anterior cardinal vein (the right anterior cardinal vein = superior vena cava)

64. Venous System anterior cardinal sinus venosus common hepatic vein
posterior
common
sinus
venosus
hepatic
vein
portal

65. Shark Venous System internal anterior jugular cardinal subclavian
posterior
common
hepatic
vein
portal
renal
portal

66. Amphibian Venous System
internal
jugular
external
anterior
cardinal
subclavian
common
cardinal
hepatic
vein
posterior
cardinal
hepatic
portal
posterior
vena cava
renal
portal
iliac

67. Reptile Venous System internal jugular external anterior cardinal
subclavian
hepatic
vein
hepatic
portal
posterior
vena cava
renal
portal
iliac

68. Mammal Venous System internal jugular external anterior cardinal
subclavian
hepatic
vein
hepatic
portal
posterior
vena cava
renal
vein
iliac

69. Gnathostome Venous System
Veins
Chondrichthys
Actinopterygii
lungfishes
ant. card.
ant. cardinal
com. card.
com. cardinal
post. card.
post. cardinal
post. cardinal (rt. = posterior “vena cava”)
hepatic
2 hepatic veins
hep. portal
hepatic portal
renal port.
renal portal

70. Gnathostome Venous System
Veins
amphibians
turtles
Lepidosauria
ant. card.
ant. cardinal (jugular vein &
brachiocephalics)
com. card.
com. cardinal (s. vena cavas)
com. cardinal
(s. vena cavas)
post. card.
post. cardinal
l. lost
r. azygous vein
hepatic
l. hepatic vein
r. p. vena cava
hep. portal
hepatic portal
renal port.
renal portal

71. Gnathostome Venous System
Veins
crocodilians
birds
Mammalia
ant. card.
ant. cardinal (jugular vein &
brachiocephalics)
com. card.
com. cardinal
(s. vena cavas)
com. cardinal (s. vena cavas
-left s. v. c. lost in some)
post. card.
l. lost
r. azygous vein
hepatic
l. hepatic vein
r. i. vena cava
hep. portal
hepatic portal
renal port.
renal portal
lost

72. liver (with hepatic veins)
Hepatic Portal Vein
Vein from yolk sac to heart (vitelline vein) impinged on by hepatic diverticulum and forms hepatic capillaries.
gut
liver (with hepatic veins)
heart
hepatic portal vein
vitelline vein
(from yolk sac)

73. Subphylum Vertebrata Chondrichthys Actinopterygii coelacanths
amphibians
hagfishes
lungfishes
lampreys
Mammalia
Reptilia *
jugular veins;
rt. hepatic = posterior vena cava
renal portal; subclavians
*renal portal lost

74. The
Heart

75. Heart Heart = Muscular pump, moves blood via rhythmic contraction.
Contraction involuntary & initiated within the heart. (not-neuronal)
Modified branching (cardiac) muscle cells transmit contraction signal.
Chamber = Cavity for blood collection separated by valves
Valves = Flaps of tissue that prevent back-flow of fluid (in this case blood)

76. Human Heart Development
Formed from splanchnic mesoderm.
Endocardial tissue = forms simple squamous epithelium that lines the heart chambers and forms the heart valves
Myocardial = epithelium forms heart muscle
Hollow endocardial primordia form by splanchnic mesoderm ingression, then fuse to form a the endocardium (endothelium).
Epithelial splanchnic mesoderm surrounds the endocardium forming the cardiac muscle of the myocardium.

77. Human Heart Development
endocardium
myocardium

78. Human Heart Development
(ventral aorta)
Sinus Venosus

79. Heart Chambers & Valves
Sinus venosus = slightly muscular chamber; receives blood from cardinal veins = sinoatrial node (“pacemaker”) in amniotes.
Sinoatrial valve = between s.v. & atrium.
Atrium = slightly muscular chamber.
Atrioventricular valve = between atrium & ventricle.
Ventricle = highly muscular chamber.
Conus arteriosus/ Bulbus arteriosus = chamber after ventricle (muscular with valves = conus; elastic, no valves = bulbus ; embryonic = bulbis cordis)

80. Human Heart Development

81. Human Heart Development
Sinus Venosus lost except some cells that become the sinoatrial node (“pacemaker”)
Sinoatrial valve lost.
Atrium divides into right and left.
Atrioventricular valve divides to form (right) tricuspid and (left) bicuspid/mitral valves
Ventricle divides into right and left.

82. Human Heart Development
Bulbis cordis lost.
Ventral aorta (truncus arteriosus) divides to become
- (left) ascending aorta that will maintain connection to aortic arches III & IV and
- (right) pulmonary trunk artery that will maintain connection to aortic arch VI.

83. Human Heart Blood Flow

84. Human Heart Blood Flow

85. Heart Chambers & Valves

86. Heart Position/Stethoscope

87. Comparative
Heart

88. Blood Flow From Heart
high oxygen
low oxygen

89. Heart Chambers & Valves
Teleost

90. Heart Chambers
Sarcopterygiians = at least partially developed interatrial septum
Tetrapods = complete interatrial septum
Amniotes = conus arteriosus lost during devel; sinus venosus incorp. into right atrium; at least partially developed interventricular septum
Mammals & Archosaurs = complete interventricular septum

91. Heart Chambers & Valves

92. Heart Chambers & Valves

93. Subphylum Vertebrata Chondrichthys Actinopterygii coelacanths
amphibians
hagfishes
lungfishes
lampreys
Mammalia
Reptilia
bulbus arteriosus
complete
interatrial
septum
partial interatrial
septum
heart (sinus venosus, atrium, ventricle, conus arteriosus)

94. Amniota lizards & snakes crocodilians montremes marsupials eutherians
turtles
lizards & snakes
crocodilians
birds
complete
interventricular
septum
complete
interventricular
septum
conus arteriosus lost in adult;
incomplete interventricular septum;
sinus venosus lost (in rt. atrium)

95. Gnathostome Heart Chambers Chondrichthys Actinopterygii lungfishes
Sinus Venosus
sinus venosus
Atrium
atrium
atrium (partially l.-r. divided)
Ventricle
ventricle
venticle
Conus Arteriosus
conus arteriosus
bulbus arteriosus (not muscular)

96. Gnathostome Heart Chambers amphibians lizards turtles Sinus Venosus
sinoatrial node (incorp. in rt. atrium)
Atrium
left atrium
right atrium
Ventricle
ventricle
ventricle (partial. left-right divided)
Conus Arteriosus
conus arteriosus
lost

97. Gnathostome Heart Chambers crocodilians birds Mammalia Sinus Venosus
sinoatrial node (incorp. in rt. atrium)
Atrium
left atrium
right atrium
Ventricle
left ventricle
right ventricle
(connected by foramen of Panizza)
Conus Arteriosus
lost

98. Lymphatic
System

99. Lymphatic System
Plasma in capillaries is forced into the tissues by blood pressure.
Edema = swelling of tissues due to accumulation of fluid (plasma/lymph).
Usually, edema is avoided because…
plasma in tissues diffuses into blind lymphatic capillaries and is called lymph.

100. Lymphatic System artery heart capillaries vein HIGH PRESSURE
LOW PRESSURE

101. Lymphatic System
Lymphangitis = inflamation of a lymph vessel. (ROOT WORDS)
Lymphangitis of the vessel indicated by the arrow caused the edema in the middle finger.

102. Lymphatic System
Lymph vessels = thin walled vessels with valves (similar in structure to veins, but with weak contractile ability); return lymph to venous system.
Lymph nodes (lymphatic cisterns) = expanded lymph vessels filled with connective tissue and leukocytes. Immunological filters.
Lacteals = lymph vessels in villi of the jejuno-ileum (small intestine) absorb fats.

103. Lymph Vessel

104. Lymph Node & Lg. Vessel (in mesentary proper)

105. Human Cephalic Lymph System

106. Human Lymphatic System

107. Lymphatic System
Contractile lymph vessels exist in most vertebrates (Form localized Lymph Hearts in hagfishes, lungfishes, amphibians, turtles, liz. & snakes, & ostriches+related birds)
Lacteals = lymph vessels in the intestinal villi – Only in TETRAPODS.
Lymph nodes / sacs / cisterns = expanded lymph vessels filled with connective tissue and leukocytes. Only in AMNIOTES.

108. Human Lymphatic System

109. Subphylum Vertebrata Chondrichthys Actinopterygii coelacanths
amphibians
hagfishes
lungfishes
lampreys
Mammalia
Reptilia
lymph
nodes &
cisterns
lacteals

110. Respiratory
System

111. General Respiratory Systems
Ventilation = movement of air or water across a respiratory surface.
Apnea = cessation of ventilation
Unidirectional ventilation = air/water moves 1 direction over resp. surface
Bidirectional ventilation = air/water moves 2 directions over resp. surface. (tidal)
Concurrent & Counter current exchange

112. Concurrent Same Direction Current water or air blood from body (heart)
to body

113. Counter Current Counter Current System water or air blood to body
from body (heart)

114. Human Trachea & Lung Development

115. Human Respiratory System
nasal cavity
pharynx
larynx
trachea
bronchus
bronchiole
alveolus in
lung

116. Human Respiratory System

117. Human Larynx

118. Human Lungs

119. Human Ventilation

120. Comparative
Respiration

121. Aquatic Respiratory Structures
Skin is a significant respiratory surface in many NON-amniotes.
Gills = aquatic pharyngeal respiratory surfaces. (Internal = within pharynx;
External = protrude from pharynx)
salamander (axolotl)
reedfish
lungfish

122. Internal Gills
Chondrichthys
Actinopterygii

123. Gills Gill = bony pharyngeal arch and two sets of filaments.
Absent in Amniotes and adult Lissamphibians
Each filament bears many lamellae (small, flat projections) & blood passes through capillaries in the lamellae.
Blood movement through lamellae sets up a counter current system.

124. Gills

125. Counter Current

126. Gill Filament
afferent
lamella
efferent

127. Lungs/Swimbladders
Lung(s) = aerial gut diverticulum respiratory surface. (Osteichthys)
In fishes called swimbladder & usually used for buoyancy as well.
Pneumatic duct = Connection to digestive tract in Actinopterygii & Dipnoi.
Trachea (in Tetrapods) is a pneumatic duct held open with cartilage rings.

128. Lungs/Swimbladders
Respiratory lungs/swimbladders are often compartmentalized.
Faveoli = non-mammal lung chambers.
Alveoli = rounded mammal lung chambers.

129. Lungs/Swimbladders (Osteichthys)
Ancestral lungs/swimbladders:
Ventral trachea/pneumatic duct.
Two “lungs”
Swimbladder of non-reedfish actinopterygiians:
Dorsal pneumatic duct.
One lung dorsal to esophagus.
(Pneumatic duct lost in some teleosts.)

130. Lungs/Swimbladders Actinopterygii lungfish Amia calva Polypterus carp
salamander
bass

131. Craniate Respiration Chondrichthys Actinopterygii coelacanths
amphibians
hagfishes
lungfishes
lampreys
Mammalia
Reptilia
alveoli
gill
filaments
lost
trachea
(with
cartilage
“rings”)
lungs
(swimbladder)
respiratory gills with filaments

132. Class Actinopterygii sturgeons & paddlefish Amia calva bowfin TELEOSTS
reedfishes
TELEOSTS
gars
single dorsal lung with
dorsal connection to
digestive tract

133. Aerial Respiratory Modifications
Ancestrally - amphibians & “fishes”
- “Swallow” air – push into lungs
- Elastic lungs recoil to push air out.
Prehepatic diaphragm (mammals)
- Negative pressure pulls air into lungs
- Body cavity contraction pushes air out.
Posthepatic diaphragm (crocodilians)
- Liver pushes air out of lungs.

134. Ventilation
“swallow” air
prehepatic
posthepatic

135. Bird Respiration
Parabronchi (birds) = one-way, passageways through the lung faveoli.
Lungs not very compressible.
Air Sacs (birds) = membranous sacs for containing air (9 off of each lung)
Air moved by expansion & contraction of air sacs.
Countercurrent, constant flow of O2 rich air over capillaries even when exhaling.

136. Avian Lungs

137. Avian Inhalation

138. Avian Exhalation

139. Avian Respiration

140. Amniota lizards & snakes crocodilians monotremes marsupials eutherians
turtles
lizards & snakes
crocodilians
birds *
air sacs;
parabronchi
prehepatic
diaphragm
* posthepatic diaphragm