Page 1
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
Circulatory System
Page 2
Human Cardiovascular
Page 4
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.
Vascular Terms
Page 5
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
Vascular
Page 6
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.
Vertebrate Blood
Page 7
Plasma
Vertebrate Blood
Page 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).
Page 9
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.
Vascular Development
Page 10
Human Blood Islands
Page 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).
Page 12
Lancelet Arterial Circulation
ventral aorta (median)
sinus venosus (median)
dorsal aorta (paired - median)
Page 13
Lancelet Venous Circulation
hepatic vein (median)
Anterior & posterior cardinal veins (paired)
sinus venosus (median)
Page 14
Lancelet Circulation
s.v.
dorsalaorta
dorsalaorta
ventralaorta
s.v.
anteriorcardinal
vein
posteriorcardinal
veinhepatic
vein
commoncardinal
vein
Page 15
Basic Amniote Circulation
Page 16
Early Human Embryo Arterial
heartsinus venosus
atriumventricle
bulbis cordis
umbilicalarteryventral aorta
(truncus arteriosus)
left & rightdorsal aortas
aorticarch II
aorticarch I
IIIIV
vitellineartery
Page 17
Early Human Embryo Arterial
heartumbilical
arteryventral aorta(truncus arteriosus)
left & rightdorsal aortas
IIIIV VI
vitellineartery
Page 18
Early Human Embryo Arterial
heartumbilical
arteryventral aorta(truncus arteriosus)
IIIIV VI
carotids
pulmonary
descending aorta
vitellineartery
Page 19
Early Human Embryo Arterial
Page 20
Embryonic Arteries
III
IIIIV
VI
I II III IV V VI
V
ventral aorta
dorsal aorta
HEART
Page 21
Human Embryonic Arteries
III
IIIIV
VI
HEART
external carotid
internal carotidcommon carotid
descending aorta
aortic arch
subclavian
pulmonary artery ductus arteriosus(before birth)
Page 22
Human Embryonic Arteries
Page 23
Human Aortic Arches
Page 24
Human Fetal Circulation
Upper LeftArch VI
Page 25
Early Human Embryo Circulation
heartsinus venosus
atriumventricle
bulbis cordis
ventral aorta(truncus arteriosus)
allantoic (umbilical) veins
vitelline(hepatic)
veins
left & right anterior cardinal veins
left & right posterior cardinal veins
left & right common cardinal
veins
Page 26
Early Human Embryo Circulation
heart
allantoic (umbilical) veins
vitelline(hepatic)
veins
left & right anterior cardinal veins
left & right posterior cardinal veins
azygous vein
jugular veins
superiorvenacava
inferiorvenacava
hepaticportalveinhepatic
vein
Page 27
Human Anterior Venous Development
Page 28
Basic Vertebrate Circulation
Page 29
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.
Blood Vessel Structure
Page 30
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
Vessel Structure
Page 31
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
Vessel Structure
Page 32
Vertebrate Vessels
vein arterytunica intima(endothelium)
capillary
Page 33
Adult Human Arterial system
Page 34
Adult Human Arterial system
deep brachial
subclavianaxillary
brachial
radialulnar
internal thoracichumeral circumflex
lateral thoracic
common iliacexternal iliacinternal iliac
deep femoralfemoral circumflex
femoral
poplitealanterior tibialposterior tibial
external carotidinternal carotid
common carotidvertebral
aorta*coeliac*
superior mesenteric*
inferior mesenteric*
renalgonadal
Page 36
Carotid & Radial Pulse Points
Page 37
Human Venous System
Azygous vein
Page 38
Human Venous System
Page 39
Human Arm Venous System
Page 40
Human Leg Venous System
Page 41
Human Varicose veins
Page 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.
Page 44
Subphylum Vertebrata
hagfis
hes
lam
preys
Chondrichth
ys
Actin
optery
gii
coel
acan
th
lungfis
h
amphib
ians
Mam
mal
ia
Reptil
ia
hemato-poesis inmarrow
blood cells *erythrocytes lack nuclei
*
discrete spleen
sple
enlo
st
Page 45
Lancelet Circulation
Page 46
Vertebrate Circulation
heart
ventralaorta
externalcarotid
dorsalaorta
Iliacartery
subclavianartery
Page 47
Vertebrate Circulationanterior & posterior
cardinal veins renal portal
iliacvein
lateralabdominal
veinsubclavian
vein
heart hepaticportal
jugulars
Page 48
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
Aortic Arches
Page 49
Gnathostome Embryo Aortic Arches
heart
I
II
III
IV
V
VI
internalcarotid
externalcarotid
dorsalaorta
ventralaorta
dorsalaorta
I II III IV V VI
Page 50
heart
Chondrichthyan Aortic Arches
I
II
III
IV
V
VI
I II III IV V VI
Page 51
heart
Teleost Aortic Arches
I
II
III
IV
V
VI
I II III IV V VI
Page 52
Lungfish Aortic Arches
pulmonaryartery
heart
I
II
III
IV
V
VI
I II III IV V VI
Page 53
Amphibian Aortic Arches
heart
I
II
III
IVVVI
internalcarotid
externalcarotid
pulmonaryartery
I II III IV V VI
Page 54
Lizard Aortic Arches
heart
I
II
III
IVVVI
internalcarotid
externalcarotid
pulmonaryartery
I II III IV V VI
Page 55
Bird Aortic Arches
heart
I
II
III
IVVVI
internalcarotid
externalcarotid
pulmonaryartery
I II III IV V VI
Page 56
Lepidosaur Aortic Arches
heart
I
II
III
IVVVI
internalcarotid
externalcarotid
pulmonaryartery
I II III IV V VI
Page 57
Mammalian Aortic Arches
heart
I
II
III
IVVVI
internalcarotid
externalcarotid
pulmonaryartery
I II III IV V VI
Page 58
Subphylum Vertebrata
Myx
ini (
hagf
ishes
)
lam
preys
Chondrichth
ys
Actin
optery
gii
coel
acan
ths
lungfis
hes
amphib
ians
Mam
mal
ia
Reptil
ia
arch Vlost
arch VIforms pulmonaryconnection arch I
lost; 6 arches form in development
arch IIlost ar
ch II
lost
Page 59
Amniota
montre
mes
mar
supia
ls
euth
eria
ns
turtl
es
lizar
ds & s
nakes
croco
dilian
s
birds
right archIV formsaorta
left arch IVforms aorta; rightarch IV formsright subclavian
Page 60
Gnathostome Adult Aortic Arches
Aortic Arch Chondrichthys Actinopterygii lungfishes
I lost lost lost
II gill arch lost gill arch
III gill arch gill arch gill arch
IV gill arch gill arch gill arch
V gill arch gill arch gill arch
VI gill arch gill arch arch
& pulmonary artery
Page 61
Gnathostome Adult Aortic Arches
Aortic Arch amphibians turtles lizards
I lost lost lost
II lost lost lost
III common carotids
common carotids
common carotids
IV l. and r. aortic arches
l. and r. aortic arches
l. and r. aortic arches
V aortic arch(lost in frogs)
lost lost
VI aortic arch & pulmonary
artery
pulmonary artery
pulmonary artery
Page 62
Gnathostome Adult Aortic Arches
Aortic Arch crocodilians birds Mammalia
I lost lost lost
II lost lost lost
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 lost lost lost
VI pulmonary artery
pulmonary artery
pulmonary artery
Page 63
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)
Venous System
Page 64
Venous System
sinusvenosus
hepaticvein
hepaticportal
anteriorcardinal
posteriorcardinal
commoncardinal
Page 65
Shark Venous System
anteriorcardinal
posteriorcardinal
commoncardinal
renalportal
internaljugular
subclavian
hepaticvein
hepaticportal
Page 66
posteriorcardinal
Amphibian Venous System
anteriorcardinalcommoncardinal
renalportal
hepaticvein
hepaticportal
subclavian
internaljugular
externaljugular
posteriorvena cava
iliac
Page 67
Reptile Venous System
anteriorcardinal
renalportal
hepaticvein
hepaticportal
internaljugular
externaljugular
posteriorvena cava
iliac
subclavian
Page 68
Mammal Venous System
anteriorcardinal
hepaticvein
hepaticportal
internaljugular
externaljugular
posteriorvena cava
iliac
subclavian
renalvein
Page 69
Gnathostome Venous System
Veins Chondrichthys Actinopterygii lungfishes
ant. card. ant. cardinal ant. cardinal ant. cardinal
com. card. com. cardinal com. cardinal com. cardinal
post. card. post. cardinal post. cardinal post. cardinal (rt. = posterior “vena cava”)
hepatic 2 hepatic veins 2 hepatic veins 2 hepatic veins
hep. portal hepatic portal hepatic portal hepatic portal
renal port. renal portal renal portal renal portal
Page 70
Gnathostome Venous SystemVeins amphibians turtles Lepidosauria
ant. card. ant. cardinal (jugular vein &
brachiocephalics)
ant. cardinal (jugular vein &
brachiocephalics)
ant. cardinal (jugular vein &
brachiocephalics)
com. card. com. cardinal (s. vena cavas)
com. cardinal(s. vena cavas)
com. cardinal(s. vena cavas)
post. card. post. cardinal l. lostr. azygous vein
l. lostr. azygous vein
hepatic l. hepatic vein
r. p. vena cava
l. hepatic vein
r. p. vena cava
l. hepatic vein
r. p. vena cava
hep. portal hepatic portal hepatic portal hepatic portal
renal port. renal portal renal portal renal portal
Page 71
Gnathostome Venous SystemVeins crocodilians birds Mammalia
ant. card. ant. cardinal (jugular vein &
brachiocephalics)
ant. cardinal (jugular vein &
brachiocephalics)
ant. cardinal (jugular vein &
brachiocephalics)
com. card. com. cardinal(s. vena cavas)
com. cardinal(s. vena cavas)
com. cardinal (s. vena cavas
-left s. v. c. lost in some)
post. card. l. lostr. azygous vein
l. lostr. azygous vein
l. lostr. azygous vein
hepatic l. hepatic vein
r. i. vena cava
l. hepatic vein
r. i. vena cava
l. hepatic vein
r. i. vena cava
hep. portal hepatic portal hepatic portal hepatic portal
renal port. renal portal renal portal lost
Page 72
gut
Vein from yolk sac to heart (vitelline vein) impinged on by hepatic diverticulum and forms hepatic capillaries.
Hepatic Portal Vein
heart
vitelline vein (from yolk sac)
liver (with hepatic veins)
hepatic portal vein
Page 73
Subphylum Vertebrata
hagfis
hes
lam
preys
Chondrichth
ys
Actin
optery
gii
coel
acan
ths
lungfis
hes
amphib
ians
Mam
mal
ia
Reptil
ia
renal portal; subclavians
jugular veins; rt. hepatic = posterior vena cava
*renal portal lost
*
Page 75
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)
Heart
Page 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.
Page 77
Human Heart Development
endocardium
myocardium
Page 78
Human Heart Development
Sinus Venosus
(ventral aorta)
Page 79
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)
Heart Chambers & Valves
Page 80
Human Heart Development
Page 81
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.
Human Heart Development
Page 82
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.
Human Heart Development
Page 83
Human Heart Blood Flow
Page 84
Human Heart Blood Flow
Page 85
Heart Chambers & Valves
Page 86
Heart Position/Stethoscope
Page 88
Blood Flow From Heart
low oxygen
high oxygen
Page 89
Heart Chambers & Valves
Teleost
Page 90
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
Heart Chambers
Page 91
Heart Chambers & Valves
Page 92
Heart Chambers & Valves
Page 93
bulb
us
arte
riosu
s
Subphylum Vertebrata
hagfis
hes
lam
preys
Chondrichth
ys
Actin
optery
gii
coel
acan
ths
lungfis
hes
amphib
ians
Mam
mal
ia
Reptil
ia
partial interatrialseptum
heart (sinus venosus, atrium, ventricle,
conus arteriosus)
completeinteratrialseptum
Page 94
Amniota
montre
mes
mar
supia
ls
euth
eria
ns
turtl
es
lizar
ds & s
nakes
croco
dilian
s
birds
conus arteriosus lost in adult;incomplete interventricular septum;sinus venosus lost (in rt. atrium)
completeinterventricularseptum
completeinterventricularseptum
Page 95
Gnathostome Heart
Chambers Chondrichthys Actinopterygii lungfishes
Sinus Venosus
sinus venosus sinus venosus sinus venosus
Atrium atrium atrium atrium (partially l.-r. divided)
Ventricle ventricle venticle ventricle
Conus Arteriosus
conus arteriosus
bulbus arteriosus (not
muscular)
conus arteriosus
Page 96
Gnathostome Heart
Chambers amphibians lizards turtles
Sinus Venosus
sinus venosus sinoatrial node (incorp. in rt. atrium)
sinoatrial node (incorp. in rt. atrium)
Atrium left atrium
right atrium
left atrium
right atrium
left atrium
right atrium
Ventricle ventricle ventricle (partial. left-right divided)
ventricle (partial. left-right divided)
Conus Arteriosus
conus arteriosus
lost lost
Page 97
Gnathostome Heart
Chambers crocodilians birds Mammalia
Sinus Venosus
sinoatrial node (incorp. in rt. atrium)
sinoatrial node (incorp. in rt. atrium)
sinoatrial node (incorp. in rt. atrium)
Atrium left atrium
right atrium
left atrium
right atrium
left atrium
right atrium
Ventricle left ventricle
right ventricle(connected by
foramen of Panizza)
left ventricle
right ventricle
left ventricle
right ventricle
Conus Arteriosus
lost lost lost
Page 99
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.
Lymphatic System
Page 100
Lymphatic SystemHIGH PRESSURE
heart
artery
vein
capillaries
LOW PRESSURE
LOW PRESSURE
Page 101
Lymphangitis = inflamation of a lymph vessel. (ROOT WORDS)
Lymphangitis of the vessel indicated by the arrow caused the edema in the middle finger.
Lymphatic System
Page 102
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.
Lymphatic System
Page 104
Lymph Node & Lg. Vessel(in mesentary proper)
Page 105
Human Cephalic Lymph System
Page 106
Human Lymphatic System
Page 107
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.
Lymphatic System
Page 108
Human Lymphatic System
Page 109
Subphylum Vertebrata
hagfis
hes
lam
preys
Chondrichth
ys
Actin
optery
gii
coel
acan
ths
lungfis
hes
amphib
ians
Mam
mal
ia
Reptil
ia
lacteals
lymphnodes &cisterns
Page 111
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
General Respiratory Systems
Page 112
Concurrent
Same Direction Current
to body
blood
water or air
from body (heart)
Page 113
Counter Current
Counter Current System
to body
blood
water or air
from body (heart)
Page 114
Human Trachea & Lung Development
Page 115
Human Respiratory System
nasal cavitypharynxlarynx
tracheabronchusbronchiolealveolus
inlung
Page 116
Human Respiratory System
Page 119
Human Ventilation
Page 121
Skin is a significant respiratory surface in many NON-amniotes.
Gills = aquatic pharyngeal respiratory surfaces. (Internal = within pharynx;
External = protrude from pharynx)
Aquatic Respiratory Structures
salamander (axolotl)
lungfishreedfish
Page 122
Internal GillsChondrichthys
Actinopterygii
Page 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.
Page 126
Gill Filament
lamella
efferent
afferent
Page 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.
Page 128
Lungs/Swimbladders Respiratory lungs/swimbladders are
often compartmentalized. Faveoli = non-mammal lung chambers. Alveoli = rounded mammal lung
chambers.
Page 129
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.)
Lungs/Swimbladders (Osteichthys)
Page 130
Lungs/Swimbladders
Actinopterygii
Polypterus
lungfish
salamanderbass
carp
Amia calva
Page 131
Craniate Respiration
hagfis
hes
lam
preys
Chondrichth
ys
Actin
optery
gii
coel
acan
ths
lungfis
hes
amphib
ians
Mam
mal
ia
Reptil
ia
lungs(swimbladder)
gillfilamentslost
respiratory gills with filaments
trachea(withcartilage“rings”)
alveoli
Page 132
sturg
eons
& pad
dlefis
h
gars bowfin
Amia
cal
va
TELEOSTS
reed
fishes
Class Actinopterygii
single dorsal lung withdorsal connection todigestive tract
Page 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)
- Negative pressure pulls air into lungs
- Liver pushes air out of lungs.
Page 134
Ventilation“swallow” air
posthepatic
prehepatic
Page 135
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.
Bird Respiration
Page 137
Avian Inhalation
Page 138
Avian Exhalation
Page 139
Avian Respiration
Page 140
Amniota
monotre
mes
mar
supia
ls
euth
eria
ns
turtl
es
lizar
ds & s
nakes
croco
dilian
s
birds
prehepaticdiaphragm
air sacs;parabronchi
* posthepatic diaphragm
*